// XCOM-like Game - Game Logic and Rendering
// Built using The Elm Architecture pattern

// ------------------------------------------------
// TYPE DEFINITIONS
// ------------------------------------------------

/**
 * @typedef {'floor' | 'wall' | 'obstacle'} TileType
 * @typedef {{ type: TileType, x: number, y: number, providesCover: boolean, health: number, damageFlash: number, color: string }} Tile
 * @typedef {'player' | 'enemy'} UnitOwner
 * @typedef {{ 
 *   id: number, 
 *   owner: UnitOwner, 
 *   x: number, 
 *   y: number, 
 *   maxMovement: number,
 *   movementRange: number,
 *   shootRange: number,
 *   damage: number,
 *   maxHp: number,
 *   currentHp: number,
 *   inCover: boolean,
 *   hasMoved: boolean,
 *   hasAttacked: boolean,
 *   isAnimating: boolean,
 *   animationType: 'none' | 'moving' | 'shooting' | 'dying',
 *   animationProgress: number,
 *   targetX: number,
 *   targetY: number,
 *   path: {x: number, y: number}[],
 *   projectileX: number,
 *   projectileY: number,
 *   projectileTargetX: number,
 *   projectileTargetY: number,
 *   deathParticles: DeathParticle[],
 *   isDead: boolean,
 *   pendingDamage: number,
 *   justCompletedShot: boolean,
 *   isVisible: boolean,
 *   lastSeen: number,
 *   lastKnownX: number,
 *   lastKnownY: number,
 *   aiBehavior: 'aggressive' | 'patrol' | 'stationary',
 *   turnOrder: number,
 *   patrolCenterX: number,
 *   patrolCenterY: number,
 *   patrolRadius: number,
 *   actionFeedbackTimer: number
 * }} Unit
 * @typedef {{ 
 *   x: number, 
 *   y: number, 
 *   velocityX: number, 
 *   velocityY: number, 
 *   size: number, 
 *   life: number, 
 *   maxLife: number,
 *   color: string
 * }} DeathParticle
 * @typedef {{ type: 'AwaitingSelection' } | { type: 'UnitSelected', unitId: number } | { type: 'AttackMode', unitId: number }} UIState
 * @typedef {{ grid: Tile[][], units: Unit[], selectedUnit: Unit | null, uiState: UIState, currentTurnIndex: number }} Model
 */

// ------------------------------------------------
// RENDER CONSTANTS
// ------------------------------------------------

const TILE_SIZE = 40;
const UNIT_RADIUS = 15;
const OBSTACLE_MAX_HEALTH = 20; 
const MAX_VISIBILITY_RANGE = 6; // Maximum distance units can see
const ENEMY_TURN_SPEED = 0.3; // Enemy turns are 3x faster than player turns
const ENEMY_ACTION_FEEDBACK_DURATION = 800; // How long to show enemy action feedback
const AI_BEHAVIORS = ['aggressive', 'patrol', 'stationary'];
const COLORS = {
    gridLine: '#444',
    floor: '#2a2a2a',
    wall: '#555',
    obstacle: '#2C3E50', // Dark blue-grey for obstacles
    player: '#00f',
    enemy: '#f00',
    unitBorder: '#fff',
    selectedBorder: '#0f0',
    moveHighlight: 'rgba(0, 150, 255, 0.4)',
    coverHighlight: 'rgba(255, 215, 0, 0.3)'
};

// ------------------------------------------------
// PROCEDURAL GENERATION CONSTANTS
// ------------------------------------------------

const GENERATION_TYPES = {
    SPARSE_WAREHOUSE: 'sparse_warehouse',
    HALLWAY_ROOMS: 'hallway_rooms',
    DRUNKARDS_WALK: 'drunkards_walk',
    CELLULAR_AUTOMATA: 'cellular_automata'
};

const WAREHOUSE_CONFIG = {
    obstacleChance: 0.15,
    minObstacles: 3,
    maxObstacles: 8
};

const HALLWAY_CONFIG = {
    minRoomSize: 3,
    maxRoomSize: 6,
    minRooms: 2,
    maxRooms: 5,
    corridorWidth: 2
};

const DRUNKARD_CONFIG = {
    steps: 0.4, // Percentage of grid to fill
    maxSteps: 1000,
    minPathLength: 0.3 // Minimum percentage of floor tiles
};

const CELLULAR_CONFIG = {
    iterations: 4,
    birthThreshold: 4,
    survivalThreshold: 3,
    minFloorPercentage: 0.4
};

// ------------------------------------------------
// UTILITY FUNCTIONS
// ------------------------------------------------

/**
 * Calculates the optimal grid size to fit the viewport
 * @returns {{ width: number, height: number }} Grid dimensions
 */
function calculateGridSize() {
    const viewportWidth = window.innerWidth;
    const viewportHeight = window.innerHeight;
    
    // Account for button space and borders
    const availableWidth = viewportWidth - 40;
    const availableHeight = viewportHeight - 40;
    
    const width = Math.floor(availableWidth / TILE_SIZE);
    const height = Math.floor(availableHeight / TILE_SIZE);
    
    // Ensure minimum grid size
    return {
        width: Math.max(width, 8),
        height: Math.max(height, 6)
    };
}

/**
 * Checks if a path between two points is blocked by obstacles
 * @param {number} startX 
 * @param {number} startY 
 * @param {number} endX 
 * @param {number} endY 
 * @param {Tile[][]} grid
 * @returns {boolean} True if path is blocked
 */
function isPathBlocked(startX, startY, endX, endY, grid) {
    console.log('isPathBlocked check from', startX, startY, 'to', endX, endY);
    
    const dx = Math.sign(endX - startX);
    const dy = Math.sign(endY - startY);
    
    let currentX = startX;
    let currentY = startY;
    
    while (currentX !== endX || currentY !== endY) {
        if (currentX !== endX) {
            currentX += dx;
            if (grid[currentY][currentX].type === 'obstacle') {
                console.log('Path blocked by obstacle at', currentX, currentY);
                return true;
            }
        }
        if (currentY !== endY) {
            currentY += dy;
            if (grid[currentY][currentX].type === 'obstacle') {
                console.log('Path blocked by obstacle at', currentX, currentY);
                return true;
            }
        }
    }
    
    console.log('Path is clear');
    return false;
}

/**
 * Checks if a unit is in cover based on adjacent obstacles
 * @param {Unit} unit 
 * @param {Tile[][]} grid
 * @returns {boolean} True if unit is in cover
 */
function checkCover(unit, grid) {
    const { x, y } = unit;
    const directions = [
        { dx: -1, dy: 0 }, { dx: 1, dy: 0 },
        { dx: 0, dy: -1 }, { dx: 0, dy: 1 }
    ];
    
    return directions.some(({ dx, dy }) => {
        const checkX = x + dx;
        const checkY = y + dy;
        return checkX >= 0 && checkX < grid[0].length &&
               checkY >= 0 && checkY < grid.length &&
               grid[checkY][checkX].type === 'obstacle';
    });
}

// ------------------------------------------------
// PATHFINDING AND ANIMATION
// ------------------------------------------------

/**
 * A* pathfinding algorithm to find optimal path between two points
 * @param {number} startX 
 * @param {number} startY 
 * @param {number} endX 
 * @param {number} endY 
 * @param {Tile[][]} grid
 * @returns {{x: number, y: number}[]} Path array
 */
function findPath(startX, startY, endX, endY, grid) {
    const width = grid[0].length;
    const height = grid.length;
    
    // Validate input coordinates
    if (startX < 0 || startX >= width || startY < 0 || startY >= height ||
        endX < 0 || endX >= width || endY < 0 || endY >= height) {
        console.error('findPath: Invalid coordinates:', { startX, startY, endX, endY, width, height });
        return [];
    }
    
    // If start and end are the same, no path needed
    if (startX === endX && startY === endY) {
        return [];
    }
    
    // Simple pathfinding for now - can be enhanced with A* later
    const path = [];
    let currentX = startX;
    let currentY = startY;
    
    // Move horizontally first, then vertically
    while (currentX !== endX) {
        const nextX = currentX + Math.sign(endX - currentX);
        if (grid[currentY][nextX].type !== 'obstacle') {
            currentX = nextX;
            path.push({ x: currentX, y: currentY });
        } else {
            // Try to go around obstacle
            if (currentY + 1 < height && grid[currentY + 1][currentX].type !== 'obstacle') {
                currentY++;
                path.push({ x: currentX, y: currentY });
            } else if (currentY - 1 >= 0 && grid[currentY - 1][currentX].type !== 'obstacle') {
                currentY--;
                path.push({ x: currentX, y: currentY });
            } else {
                // Can't find path
                console.warn('findPath: Cannot find path around obstacle');
                return [];
            }
        }
    }
    
    while (currentY !== endY) {
        const nextY = currentY + Math.sign(endY - currentY);
        if (grid[nextY][currentX].type !== 'obstacle') {
            currentY = nextY;
            path.push({ x: currentX, y: currentY });
        } else {
            // Try to go around obstacle
            if (currentX + 1 < width && grid[currentY][currentX + 1].type !== 'obstacle') {
                currentX++;
                path.push({ x: currentX, y: currentY });
            } else if (currentX - 1 >= 0 && grid[currentX - 1][currentY].type !== 'obstacle') {
                currentX--;
                path.push({ x: currentX, y: currentY });
            } else {
                // Can't find path
                console.warn('findPath: Cannot find path around obstacle');
                return [];
            }
        }
    }
    
    // Validate path before returning
    const validPath = path.filter(point => 
        point && typeof point.x === 'number' && typeof point.y === 'number' &&
        point.x >= 0 && point.x < width && point.y >= 0 && point.y < height
    );
    
    if (validPath.length !== path.length) {
        console.error('findPath: Invalid path points found:', path);
    }
    
    return validPath;
}

/**
 * Starts movement animation for a unit
 * @param {Unit} unit 
 * @param {number} targetX 
 * @param {number} targetY 
 * @param {Tile[][]} grid
 * @returns {Unit} Updated unit with animation state
 */
function startMovementAnimation(unit, targetX, targetY, grid) {
    console.log('startMovementAnimation called with:', { unit: unit.id, from: { x: unit.x, y: unit.y }, to: { x: targetX, y: targetY } });
    
    const path = findPath(unit.x, unit.y, targetX, targetY, grid);
    console.log('Path found:', path);
    
    if (path.length === 0) {
        console.warn('No path found for unit', unit.id);
        return unit; // No path found
    }
    
    const animatedUnit = {
        ...unit,
        isAnimating: true,
        animationType: 'moving',
        animationProgress: 0,
        targetX,
        targetY,
        path
    };
    
    console.log('Animated unit created:', animatedUnit);
    return animatedUnit;
}

/**
 * Updates animation progress for all units
 * @param {Unit[]} units 
 * @param {number} deltaTime 
 * @returns {Unit[]} Updated units
 */
function updateAnimations(units, deltaTime) {
    const ANIMATION_SPEED = 0.003; // Adjust for animation speed
    
    return units.map(unit => {
        if (!unit.isAnimating) return unit;
        
        const newProgress = unit.animationProgress + deltaTime * ANIMATION_SPEED;
        
        if (newProgress >= 1) {
            // Animation complete
            if (unit.animationType === 'moving') {
                return {
                    ...unit,
                    x: unit.targetX,
                    y: unit.targetY,
                    hasMoved: true,
                    isAnimating: false,
                    animationType: 'none',
                    animationProgress: 0,
                    targetX: -1,
                    targetY: -1,
                    path: []
                };
            } else if (unit.animationType === 'shooting') {
                return {
                    ...unit,
                    hasAttacked: true,
                    isAnimating: false,
                    animationType: 'none',
                    animationProgress: 0,
                    projectileX: -1,
                    projectileY: -1,
                    // Don't reset projectileTargetX/Y yet - keep them for damage processing
                    justCompletedShot: true // Flag to indicate shot just completed
                };
            } else if (unit.animationType === 'dying') {
                // Death animation is complete, remove the unit
                return null;
            }
        }
        
        // Update death particles if dying
        if (unit.animationType === 'dying') {
            const updatedParticles = updateDeathParticles(unit.deathParticles);
            if (updatedParticles.length === 0) {
                // All particles are gone, complete the death animation
                return null;
            }
            return {
                ...unit,
                deathParticles: updatedParticles,
                animationProgress: newProgress
            };
        }
        
        return {
            ...unit,
            animationProgress: newProgress
        };
    }).filter(unit => unit !== null); // Filter out units that completed their animation
}

/**
 * Gets the current position of a unit during animation
 * @param {Unit} unit 
 * @returns {{x: number, y: number}} Current position
 */
function getUnitPosition(unit) {
    // Safety checks
    if (!unit) {
        console.error('getUnitPosition: unit is undefined');
        return { x: 0, y: 0 };
    }
    
    if (typeof unit.x !== 'number' || typeof unit.y !== 'number') {
        console.error('getUnitPosition: unit coordinates are invalid:', unit);
        return { x: 0, y: 0 };
    }
    
    // If unit is not animating or not moving, return current position
    if (!unit.isAnimating || unit.animationType !== 'moving') {
        return { x: unit.x, y: unit.y };
    }
    
    // Safety check for path data
    if (!unit.path || !Array.isArray(unit.path) || unit.path.length === 0) {
        console.warn('getUnitPosition: unit has invalid path data, returning current position:', unit.id);
        return { x: unit.x, y: unit.y };
    }
    
    // Safety check for animation progress
    if (typeof unit.animationProgress !== 'number' || unit.animationProgress < 0 || unit.animationProgress > 1) {
        console.warn('getUnitPosition: unit has invalid animation progress, returning current position:', unit.id);
        return { x: unit.x, y: unit.y };
    }
    
    // Calculate position along path
    const totalDistance = unit.path.length;
    const currentStep = Math.floor(unit.animationProgress * totalDistance);
    
    if (currentStep >= unit.path.length) {
        if (typeof unit.targetX === 'number' && typeof unit.targetY === 'number') {
            return { x: unit.targetX, y: unit.targetY };
        } else {
            return { x: unit.x, y: unit.y };
        }
    }
    
    const pathPoint = unit.path[currentStep];
    if (pathPoint && typeof pathPoint.x === 'number' && typeof pathPoint.y === 'number') {
        return pathPoint;
    } else {
        console.warn('getUnitPosition: invalid path point at step', currentStep, 'for unit', unit.id, 'path:', unit.path);
        return { x: unit.x, y: unit.y };
    }
}

/**
 * Gets the current projectile position during shooting animation
 * @param {Unit} unit 
 * @returns {{x: number, y: number} | null} Current projectile position or null if not shooting
 */
function getProjectilePosition(unit) {
    if (!unit.isAnimating || unit.animationType !== 'shooting') {
        return null;
    }
    
    if (typeof unit.projectileX !== 'number' || typeof unit.projectileY !== 'number' ||
        typeof unit.projectileTargetX !== 'number' || typeof unit.projectileTargetY !== 'number') {
        return null;
    }
    
    // Calculate projectile position along the line from start to target
    const startX = unit.projectileX * TILE_SIZE + TILE_SIZE / 2;
    const startY = unit.projectileY * TILE_SIZE + TILE_SIZE / 2;
    const targetX = unit.projectileTargetX * TILE_SIZE + TILE_SIZE / 2;
    const targetY = unit.projectileTargetY * TILE_SIZE + TILE_SIZE / 2;
    
    const currentX = startX + (targetX - startX) * unit.animationProgress;
    const currentY = startY + (targetY - startY) * unit.animationProgress;
    
    return { x: currentX, y: currentY };
}

/**
 * Starts shooting animation for a unit
 * @param {Unit} unit 
 * @param {number} targetX 
 * @param {number} targetY 
 * @returns {Unit} Updated unit with shooting animation
 */
function startShootingAnimation(unit, targetX, targetY) {
    console.log('Starting shooting animation for unit:', unit.id, 'at target:', targetX, targetY);
    return {
        ...unit,
        isAnimating: true,
        animationType: 'shooting',
        animationProgress: 0,
        projectileX: unit.x,
        projectileY: unit.y,
        projectileTargetX: targetX,
        projectileTargetY: targetY
    };
}

/**
 * Creates death particles for a unit
 * @param {Unit} unit 
 * @returns {Unit} Updated unit with death particles
 */
function createDeathParticles(unit) {
    const DEATH_PARTICLE_COUNT = 30;
    const DEATH_PARTICLE_SPEED = 8;
    const DEATH_PARTICLE_SIZE = 3;
    const DEATH_PARTICLE_LIFETIME = 60;
    
    const centerX = unit.x * TILE_SIZE + TILE_SIZE / 2;
    const centerY = unit.y * TILE_SIZE + TILE_SIZE / 2;
    
    const deathParticles = [];
    for (let i = 0; i < DEATH_PARTICLE_COUNT; i++) {
        const angle = (Math.PI * 2 * i) / DEATH_PARTICLE_COUNT;
        const speed = DEATH_PARTICLE_SPEED * (0.5 + Math.random());
        
        // Choose color based on unit type
        let color;
        if (unit.owner === 'player') {
            color = ['#4CAF50', '#45a049', '#2E7D32'][Math.floor(Math.random() * 3)]; // Green variants
        } else {
            color = ['#F44336', '#D32F2F', '#B71C1C'][Math.floor(Math.random() * 3)]; // Red variants
        }
        
        deathParticles.push({
            x: centerX + (Math.random() - 0.5) * 10,
            y: centerY + (Math.random() - 0.5) * 10,
            velocityX: Math.cos(angle) * speed,
            velocityY: Math.sin(angle) * speed,
            size: DEATH_PARTICLE_SIZE + Math.random() * 2,
            life: DEATH_PARTICLE_LIFETIME,
            maxLife: DEATH_PARTICLE_LIFETIME,
            color: color
        });
    }
    
    return {
        ...unit,
        isAnimating: true,
        animationType: 'dying',
        animationProgress: 0,
        deathParticles,
        isDead: true
    };
}

/**
 * Updates death particle animations
 * @param {DeathParticle[]} particles 
 * @returns {DeathParticle[]} Updated particles
 */
function updateDeathParticles(particles) {
    return particles.map(particle => {
        // Apply gravity
        particle.velocityY += 0.3;
        
        // Update position
        particle.x += particle.velocityX;
        particle.y += particle.velocityY;
        
        // Reduce life
        particle.life--;
        
        // Add some randomness to movement
        particle.velocityX *= 0.98;
        particle.velocityY *= 0.98;
        
        return particle;
    }).filter(particle => particle.life > 0);
}

// ------------------------------------------------
// PROCEDURAL GENERATION ALGORITHMS
// ------------------------------------------------

/**
 * Generates a sparse warehouse-like environment
 * @param {number} width 
 * @param {number} height 
 * @returns {Tile[][]} Generated grid
 */
function generateSparseWarehouse(width, height) {
    const grid = Array.from({ length: height }, (_, y) =>
        Array.from({ length: width }, (_, x) => ({
            type: 'floor',
            x,
            y,
            providesCover: false,
            health: 0,
            damageFlash: 0,
            color: generateObstacleColor()
        }))
    );
    
    // Add random obstacles
    const numObstacles = Math.floor(
        Math.random() * (WAREHOUSE_CONFIG.maxObstacles - WAREHOUSE_CONFIG.minObstacles + 1) + 
        WAREHOUSE_CONFIG.minObstacles
    );
    
    let obstaclesPlaced = 0;
    const maxAttempts = width * height * 2;
    let attempts = 0;
    
    while (obstaclesPlaced < numObstacles && attempts < maxAttempts) {
        const x = Math.floor(Math.random() * width);
        const y = Math.floor(Math.random() * height);
        
        // Don't place on edges or if already occupied
        if (x > 0 && x < width - 1 && y > 0 && y < height - 1 && 
            grid[y][x].type === 'floor') {
            
            // Check if obstacle provides meaningful cover (not isolated)
            const hasAdjacentFloor = [
                { dx: -1, dy: 0 }, { dx: 1, dy: 0 },
                { dx: 0, dy: -1 }, { dx: 0, dy: 1 }
            ].some(({ dx, dy }) => {
                const checkX = x + dx;
                const checkY = y + dy;
                return checkX >= 0 && checkX < width && 
                       checkY >= 0 && checkY < height && 
                       grid[checkY][checkX].type === 'floor';
            });
            
            if (hasAdjacentFloor) {
                grid[y][x] = createObstacle(x, y);
                obstaclesPlaced++;
            }
        }
        attempts++;
    }
    
    return grid;
}

/**
 * Generates a structured hallway and room layout
 * @param {number} width 
 * @param {number} height 
 * @returns {Tile[][]} Generated grid
 */
function generateHallwayRooms(width, height) {
    const grid = Array.from({ length: height }, (_, y) =>
        Array.from({ length: width }, (_, x) => ({
            type: 'floor',
            x,
            y,
            providesCover: false,
            health: 0,
            damageFlash: 0,
            color: generateObstacleColor()
        }))
    );
    
    // Generate rooms
    const numRooms = Math.floor(
        Math.random() * (HALLWAY_CONFIG.maxRooms - HALLWAY_CONFIG.minRooms + 1) + 
        HALLWAY_CONFIG.minRooms
    );
    
    const rooms = [];
    
    for (let i = 0; i < numRooms; i++) {
        const roomWidth = Math.floor(
            Math.random() * (HALLWAY_CONFIG.maxRoomSize - HALLWAY_CONFIG.minRoomSize + 1) + 
            HALLWAY_CONFIG.minRoomSize
        );
        const roomHeight = Math.floor(
            Math.random() * (HALLWAY_CONFIG.maxRoomSize - HALLWAY_CONFIG.minRoomSize + 1) + 
            HALLWAY_CONFIG.minRoomSize
        );
        
        // Try to place room
        let roomPlaced = false;
        let attempts = 0;
        const maxAttempts = 50;
        
        while (!roomPlaced && attempts < maxAttempts) {
            const startX = Math.floor(Math.random() * (width - roomWidth - 2)) + 1;
            const startY = Math.floor(Math.random() * (height - roomHeight - 2)) + 1;
            
            // Check if room can fit
            let canFit = true;
            for (let y = startY - 1; y <= startY + roomHeight; y++) {
                for (let x = startX - 1; x <= startX + roomWidth; x++) {
                    if (y < 0 || y >= height || x < 0 || x >= width) {
                        canFit = false;
                        break;
                    }
                    if (grid[y][x].type === 'obstacle') {
                        canFit = false;
                        break;
                    }
                }
                if (!canFit) break;
            }
            
            if (canFit) {
                // Place room walls
                for (let y = startY; y < startY + roomHeight; y++) {
                    for (let x = startX; x < startX + roomWidth; x++) {
                        grid[y][x] = createObstacle(x, y);
                    }
                }
                
                // Add some interior obstacles for cover
                const interiorObstacles = Math.floor(Math.random() * 3) + 1;
                for (let j = 0; j < interiorObstacles; j++) {
                    const obstacleX = startX + 1 + Math.floor(Math.random() * (roomWidth - 2));
                    const obstacleY = startY + 1 + Math.floor(Math.random() * (roomHeight - 2));
                    
                    if (grid[obstacleY][obstacleX].type === 'obstacle') {
                        grid[obstacleY][obstacleX] = {
                            type: 'floor',
                            x: obstacleX,
                            y: obstacleY,
                            providesCover: false,
                            health: 0,
                            damageFlash: 0,
                            color: generateObstacleColor()
                        };
                    }
                }
                
                rooms.push({ startX, startY, width: roomWidth, height: roomHeight });
                roomPlaced = true;
            }
            attempts++;
        }
    }
    
    // Connect rooms with corridors
    if (rooms.length > 1) {
        for (let i = 0; i < rooms.length - 1; i++) {
            const room1 = rooms[i];
            const room2 = rooms[i + 1];
            
            // Create corridor between room centers
            const center1X = Math.floor(room1.startX + room1.width / 2);
            const center1Y = Math.floor(room1.startY + room1.height / 2);
            const center2X = Math.floor(room2.startX + room2.width / 2);
            const center2Y = Math.floor(room2.startY + room2.height / 2);
            
            // Horizontal corridor
            const corridorStartX = Math.min(center1X, center2X);
            const corridorEndX = Math.max(center1X, center2X);
            for (let x = corridorStartX; x <= corridorEndX; x++) {
                if (x >= 0 && x < width) {
                    for (let y = center1Y - 1; y <= center1Y + 1; y++) {
                        if (y >= 0 && y < height && grid[y][x].type === 'floor') {
                            grid[y][x] = {
                                type: 'obstacle',
                                x,
                                y,
                                providesCover: true,
                                health: OBSTACLE_MAX_HEALTH, // 6 shots to destroy
                                damageFlash: 0,
                                color: generateObstacleColor()
                            };
                        }
                    }
                }
            }
            
            // Vertical corridor
            const corridorStartY = Math.min(center1Y, center2Y);
            const corridorEndY = Math.max(center1Y, center2Y);
            for (let y = corridorStartY; y <= corridorEndY; y++) {
                if (y >= 0 && y < height) {
                    for (let x = center2X - 1; x <= center2X + 1; x++) {
                        if (x >= 0 && x < width && grid[y][x].type === 'floor') {
                            grid[y][x] = {
                                type: 'obstacle',
                                x,
                                y,
                                providesCover: true,
                                health: OBSTACLE_MAX_HEALTH, // 6 shots to destroy
                                damageFlash: 0,
                                color: generateObstacleColor()
                            };
                        }
                    }
                }
            }
        }
    }
    
    return grid;
}

/**
 * Generates a level using the Drunkard's Walk algorithm
 * @param {number} width 
 * @param {number} height 
 * @returns {Tile[][]} Generated grid
 */
function generateDrunkardsWalk(width, height) {
    const grid = Array.from({ length: height }, (_, y) =>
        Array.from({ length: width }, (_, x) => ({
            type: 'obstacle',
            x,
            y,
            providesCover: true,
            health: 0,
            damageFlash: 0,
            color: generateObstacleColor()
        }))
    );
    
    // Start from center
    let currentX = Math.floor(width / 2);
    let currentY = Math.floor(height / 2);
    
    const targetSteps = Math.floor(width * height * DRUNKARD_CONFIG.steps);
    let steps = 0;
    let maxAttempts = DRUNKARD_CONFIG.maxSteps;
    let attempts = 0;
    
    // Ensure starting position is floor
    grid[currentY][currentX] = {
        type: 'floor',
        x: currentX,
        y: currentY,
        providesCover: false,
        health: 0,
        damageFlash: 0,
        color: generateObstacleColor()
    };
    
    while (steps < targetSteps && attempts < maxAttempts) {
        // Random direction: 0=up, 1=right, 2=down, 3=left
        const direction = Math.floor(Math.random() * 4);
        let newX = currentX;
        let newY = currentY;
        
        switch (direction) {
            case 0: newY = Math.max(0, currentY - 1); break; // Up
            case 1: newX = Math.min(width - 1, currentX + 1); break; // Right
            case 2: newY = Math.min(height - 1, currentY + 1); break; // Down
            case 3: newX = Math.max(0, currentX - 1); break; // Left
        }
        
        // Carve path
        if (grid[newY][newX].type === 'obstacle') {
            grid[newY][newX] = {
                type: 'floor',
                x: newX,
                y: newY,
                providesCover: false,
                health: 0,
                damageFlash: 0,
                color: generateObstacleColor()
            };
            steps++;
        }
        
        currentX = newX;
        currentY = newY;
        attempts++;
    }
    
    // Add some random floor tiles to ensure connectivity
    const additionalFloorTiles = Math.floor(width * height * 0.1);
    for (let i = 0; i < additionalFloorTiles; i++) {
        const x = Math.floor(Math.random() * width);
        const y = Math.floor(Math.random() * height);
        
        if (grid[y][x].type === 'obstacle') {
            // Check if it's adjacent to existing floor
            const hasAdjacentFloor = [
                { dx: -1, dy: 0 }, { dx: 1, dy: 0 },
                { dx: 0, dy: -1 }, { dx: 0, dy: 1 }
            ].some(({ dx, dy }) => {
                const checkX = x + dx;
                const checkY = y + dy;
                return checkX >= 0 && checkX < width && 
                       checkY >= 0 && checkY < height && 
                       grid[checkY][checkX].type === 'floor';
            });
            
            if (hasAdjacentFloor) {
                grid[y][x] = {
                    type: 'floor',
                    x,
                    y,
                    providesCover: false,
                    health: 0,
                    damageFlash: 0,
                    color: generateObstacleColor()
                };
            }
        }
    }
    
    return grid;
}

/**
 * Generates a level using Cellular Automata
 * @param {number} width 
 * @param {number} height 
 * @returns {Tile[][]} Generated grid
 */
function generateCellularAutomata(width, height) {
    // Initialize with random noise
    let grid = Array.from({ length: height }, (_, y) =>
        Array.from({ length: width }, (_, x) => 
            Math.random() < 0.45 ? createObstacle(x, y) : {
                type: 'floor',
                x,
                y,
                providesCover: false,
                health: 0,
                damageFlash: 0,
                color: generateObstacleColor()
            }
        )
    );
    
    // Ensure edges are obstacles
    for (let y = 0; y < height; y++) {
        grid[y][0] = createObstacle(0, y);
        grid[y][width - 1] = createObstacle(width - 1, y);
    }
    for (let x = 0; x < width; x++) {
        grid[0][x] = createObstacle(x, 0);
        grid[height - 1][x] = createObstacle(x, height - 1);
    }
    
    // Run cellular automata iterations
    for (let iteration = 0; iteration < CELLULAR_CONFIG.iterations; iteration++) {
        const newGrid = Array.from({ length: height }, (_, y) =>
            Array.from({ length: width }, (_, x) => ({ ...grid[y][x] }))
        );
        
        for (let y = 1; y < height - 1; y++) {
            for (let x = 1; x < width - 1; x++) {
                // Count adjacent obstacles
                let adjacentObstacles = 0;
                for (let dy = -1; dy <= 1; dy++) {
                    for (let dx = -1; dx <= 1; dx++) {
                        if (dx === 0 && dy === 0) continue;
                        if (grid[y + dy][x + dx].type === 'obstacle') {
                            adjacentObstacles++;
                        }
                    }
                }
                
                // Apply rules
                if (grid[y][x].type === 'obstacle') {
                    // Survival rule
                    if (adjacentObstacles < CELLULAR_CONFIG.survivalThreshold) {
                        newGrid[y][x].type = 'floor';
                        newGrid[y][x].providesCover = false;
                    }
                } else {
                    // Birth rule
                    if (adjacentObstacles >= CELLULAR_CONFIG.birthThreshold) {
                        newGrid[y][x] = createObstacle(x, y);
                    }
                }
            }
        }
        
        grid = newGrid;
    }
    
    // Ensure minimum floor percentage
    const floorCount = grid.flat().filter(tile => tile.type === 'floor').length;
    const minFloorTiles = Math.floor(width * height * CELLULAR_CONFIG.minFloorPercentage);
    
    if (floorCount < minFloorTiles) {
        // Convert some obstacles to floor to meet minimum
        const obstaclesToConvert = minFloorTiles - floorCount;
        const obstacles = grid.flat().filter(tile => tile.type === 'obstacle' && 
            tile.x > 0 && tile.x < width - 1 && tile.y > 0 && tile.y < height - 1);
        
        for (let i = 0; i < Math.min(obstaclesToConvert, obstacles.length); i++) {
            const obstacle = obstacles[i];
            grid[obstacle.y][obstacle.x].type = 'floor';
            grid[obstacle.y][obstacle.x].providesCover = false;
        }
    }
    
    return grid;
}

/**
 * Checks if a grid is fully navigable using flood fill
 * @param {Tile[][]} grid 
 * @returns {boolean} True if grid is navigable
 */
function isGridNavigable(grid) {
    const width = grid[0].length;
    const height = grid.length;
    
    // Find a starting floor tile
    let startX = -1, startY = -1;
    for (let y = 0; y < height; y++) {
        for (let x = 0; x < width; x++) {
            if (grid[y][x].type === 'floor') {
                startX = x;
                startY = y;
                break;
            }
        }
        if (startX !== -1) break;
    }
    
    if (startX === -1) return false; // No floor tiles
    
    // Flood fill to count accessible floor tiles
    const visited = Array.from({ length: height }, () => new Array(width).fill(false));
    const queue = [{ x: startX, y: startY }];
    let accessibleCount = 0;
    
    while (queue.length > 0) {
        const { x, y } = queue.shift();
        
        if (visited[y][x] || grid[y][x].type !== 'floor') continue;
        
        visited[y][x] = true;
        accessibleCount++;
        
        // Add adjacent tiles to queue
        const directions = [
            { dx: -1, dy: 0 }, { dx: 1, dy: 0 },
            { dx: 0, dy: -1 }, { dx: 0, dy: 1 }
        ];
        
        for (const { dx, dy } of directions) {
            const newX = x + dx;
            const newY = y + dy;
            
            if (newX >= 0 && newX < width && newY >= 0 && newY < height &&
                !visited[newY][newX] && grid[newY][newX].type === 'floor') {
                queue.push({ x: newX, y: newY });
            }
        }
    }
    
    // Count total floor tiles
    const totalFloorTiles = grid.flat().filter(tile => tile.type === 'floor').length;
    
    // Grid is navigable if at least 90% of floor tiles are accessible
    return accessibleCount >= totalFloorTiles * 0.9;
}

/**
 * Ensures a grid is navigable by adding connecting paths if needed
 * @param {Tile[][]} grid 
 * @returns {Tile[][]} Navigable grid
 */
function ensureNavigability(grid) {
    if (isGridNavigable(grid)) {
        return grid;
    }
    
    const width = grid[0].length;
    const height = grid.length;
    
    // Find isolated floor regions and connect them
    const visited = Array.from({ length: height }, () => new Array(width).fill(false));
    const regions = [];
    
    for (let y = 0; y < height; y++) {
        for (let x = 0; x < width; x++) {
            if (grid[y][x].type === 'floor' && !visited[y][x]) {
                // Found new region, flood fill it
                const region = [];
                const queue = [{ x, y }];
                
                while (queue.length > 0) {
                    const { x: cx, y: cy } = queue.shift();
                    
                    if (visited[cy][cx] || grid[cy][cx].type !== 'floor') continue;
                    
                    visited[cy][cx] = true;
                    region.push({ x: cx, y: cy });
                    
                    const directions = [
                        { dx: -1, dy: 0 }, { dx: 1, dy: 0 },
                        { dx: 0, dy: -1 }, { dx: 0, dy: 1 }
                    ];
                    
                    for (const { dx, dy } of directions) {
                        const newX = cx + dx;
                        const newY = cy + dy;
                        
                        if (newX >= 0 && newX < width && newY >= 0 && newY < height &&
                            !visited[newY][newX] && grid[newY][newX].type === 'floor') {
                            queue.push({ x: newX, y: newY });
                        }
                    }
                }
                
                if (region.length > 0) {
                    regions.push(region);
                }
            }
        }
    }
    
    // Connect regions by creating paths between them
    for (let i = 0; i < regions.length - 1; i++) {
        const region1 = regions[i];
        const region2 = regions[i + 1];
        
        // Find closest points between regions
        let minDistance = Infinity;
        let point1 = null, point2 = null;
        
        for (const tile1 of region1) {
            for (const tile2 of region2) {
                const distance = Math.abs(tile1.x - tile2.x) + Math.abs(tile1.y - tile2.y);
                if (distance < minDistance) {
                    minDistance = distance;
                    point1 = tile1;
                    point2 = tile2;
                }
            }
        }
        
        if (point1 && point2) {
            // Create path between points
            let currentX = point1.x;
            let currentY = point1.y;
            
            while (currentX !== point2.x || currentY !== point2.y) {
                if (currentX !== point2.x) {
                    currentX += Math.sign(point2.x - currentX);
                    if (grid[currentY][currentX].type === 'obstacle') {
                        grid[currentY][currentX] = {
                            type: 'floor',
                            x: currentX,
                            y: currentY,
                            providesCover: false,
                            health: 0,
                            damageFlash: 0,
                            color: generateObstacleColor()
                        };
                    }
                }
                if (currentY !== point2.y) {
                    currentY += Math.sign(point2.y - currentY);
                    if (grid[currentY][currentX].type === 'obstacle') {
                        grid[currentY][currentX] = {
                            type: 'floor',
                            x: currentX,
                            y: currentY,
                            providesCover: false,
                            health: 0,
                            damageFlash: 0,
                            color: generateObstacleColor()
                        };
                    }
                }
            }
        }
    }
    
    return grid;
}

/**
 * Generates the game world using a randomly selected algorithm
 * @param {number} width 
 * @param {number} height 
 * @returns {Tile[][]} Generated grid
 */
function generateWorld(width, height) {
    const generationType = Math.random() < 0.25 ? 
        GENERATION_TYPES.SPARSE_WAREHOUSE : 
        Math.random() < 0.33 ? GENERATION_TYPES.HALLWAY_ROOMS :
        Math.random() < 0.5 ? GENERATION_TYPES.DRUNKARDS_WALK :
        GENERATION_TYPES.CELLULAR_AUTOMATA;
    
    console.log(`Generating ${generationType} layout...`);
    
    let grid;
    switch (generationType) {
        case GENERATION_TYPES.SPARSE_WAREHOUSE:
            grid = generateSparseWarehouse(width, height);
            break;
        case GENERATION_TYPES.HALLWAY_ROOMS:
            grid = generateHallwayRooms(width, height);
            break;
        case GENERATION_TYPES.DRUNKARDS_WALK:
            grid = generateDrunkardsWalk(width, height);
            break;
        case GENERATION_TYPES.CELLULAR_AUTOMATA:
            grid = generateCellularAutomata(width, height);
            break;
        default:
            grid = generateSparseWarehouse(width, height);
    }
    
    // Ensure navigability
    grid = ensureNavigability(grid);
    
    return grid;
}

// ------------------------------------------------
// SQUAD GENERATION
// ------------------------------------------------

/**
 * Generates a random stat within a given range
 * @param {number} min 
 * @param {number} max 
 * @returns {number} Random stat value
 */
function generateStat(min, max) {
    return Math.floor(Math.random() * (max - min + 1)) + min;
}

/**
 * Generates a player squad of 3 units
 * @param {Tile[][]} grid 
 * @returns {Unit[]} Array of player units
 */
function generatePlayerSquad(grid) {
    const units = [];
    const width = grid[0].length;
    const height = grid.length;
    
    // Find a good starting position for the squad
    let squadCenterX, squadCenterY;
    let attempts = 0;
    const maxAttempts = 100;
    
    do {
        squadCenterX = Math.floor(Math.random() * (width - 4)) + 2;
        squadCenterY = Math.floor(Math.random() * (height - 4)) + 2;
        attempts++;
    } while (
        attempts < maxAttempts && 
        (grid[squadCenterY][squadCenterX].type === 'obstacle' ||
         grid[squadCenterY][squadCenterX + 1].type === 'obstacle' ||
         grid[squadCenterY + 1][squadCenterX].type === 'obstacle')
    );
    
    // Place units in a triangle formation around the center
    const positions = [
        { x: squadCenterX, y: squadCenterY },
        { x: squadCenterX + 1, y: squadCenterY },
        { x: squadCenterX, y: squadCenterY + 1 }
    ];
    
    // Ensure all positions are valid
    const validPositions = positions.filter(pos => 
        pos.x >= 0 && pos.x < width && 
        pos.y >= 0 && pos.y < height && 
        grid[pos.y][pos.x].type !== 'obstacle'
    );
    
    // If we can't place all units in formation, place them randomly but close
    if (validPositions.length < 3) {
        for (let i = 0; i < 3; i++) {
            let x, y;
            do {
                x = squadCenterX + Math.floor(Math.random() * 3) - 1;
                y = squadCenterY + Math.floor(Math.random() * 3) - 1;
                x = Math.max(0, Math.min(width - 1, x));
                y = Math.max(0, Math.min(height - 1, y));
            } while (grid[y][x].type === 'obstacle' || 
                     units.some(unit => unit.x === x && unit.y === y));
            
            const unit = createPlayerUnit(i + 1, x, y);
            units.push(unit);
        }
    } else {
        // Place units in formation
        for (let i = 0; i < 3; i++) {
            const pos = validPositions[i];
            const unit = createPlayerUnit(i + 1, pos.x, pos.y);
            units.push(unit);
        }
    }
    
    return units;
}

/**
 * Creates a player unit with the given stats
 * @param {number} id 
 * @param {number} x 
 * @param {number} y 
 * @returns {Unit} Player unit
 */
function createPlayerUnit(id, x, y) {
    const unit = {
        id,
        owner: 'player',
        x,
        y,
        maxMovement: generateStat(2, 6), // Reduced from 2-10 to 2-6
        movementRange: 0, // Will be set to maxMovement
        shootRange: generateStat(3, 8), // Reduced from 4-15 to 3-8
        damage: generateStat(5, 20),
        maxHp: generateStat(30, 60),
        currentHp: 0, // Will be set to maxHp
        inCover: false,
        hasMoved: false,
        hasAttacked: false,
        isAnimating: false,
        animationType: 'none',
        animationProgress: 0,
        targetX: -1,
        targetY: -1,
        path: [],
        projectileX: -1,
        projectileY: -1,
        projectileTargetX: -1,
        projectileTargetY: -1,
        deathParticles: [],
        isDead: false,
        pendingDamage: 0,
        justCompletedShot: false,
        isVisible: true,
        lastSeen: 0,
        lastKnownX: x,
        lastKnownY: y,
        aiBehavior: 'aggressive',
        turnOrder: 0,
        patrolCenterX: 0,
        patrolCenterY: 0,
        patrolRadius: 0,
        actionFeedbackTimer: 0
    };
    
    // Set current values to max values
    unit.movementRange = unit.maxMovement;
    unit.currentHp = unit.maxHp;
    
    // Validate unit creation
    console.log('Player unit created:', unit);
    
    return unit;
}

/**
 * Generates an enemy squad of 2-7 units
 * @param {Tile[][]} grid 
 * @returns {Unit[]} Array of enemy units
 */
function generateEnemySquad(grid) {
    const units = [];
    const width = grid[0].length;
    const height = grid.length;
    const squadSize = generateStat(2, 7);
    
    for (let i = 0; i < squadSize; i++) {
        let x, y;
        do {
            x = Math.floor(Math.random() * width);
            y = Math.floor(Math.random() * height);
        } while (grid[y][x].type === 'obstacle' || 
                 units.some(unit => unit.x === x && unit.y === y));
        
        const unit = createEnemyUnit(100 + i + 1, x, y);
        units.push(unit);
    }
    
    return units;
}

/**
 * Creates an enemy unit with the given stats
 * @param {number} id 
 * @param {number} x 
 * @param {number} y 
 * @returns {Unit} Enemy unit
 */
function createEnemyUnit(id, x, y) {
    const aiBehavior = AI_BEHAVIORS[Math.floor(Math.random() * AI_BEHAVIORS.length)];
    
    const unit = {
        id,
        owner: 'enemy',
        x,
        y,
        maxMovement: generateStat(2, 6), // Reduced from 2-10 to 2-6
        movementRange: 0, // Will be set to maxMovement
        shootRange: generateStat(3, 8), // Reduced from 4-15 to 3-8
        damage: generateStat(5, 10),
        maxHp: generateStat(10, 20),
        currentHp: 0, // Will be set to maxHp
        inCover: false,
        hasMoved: false,
        hasAttacked: false,
        isAnimating: false,
        animationType: 'none',
        animationProgress: 0,
        targetX: -1,
        targetY: -1,
        path: [],
        projectileX: -1,
        projectileY: -1,
        projectileTargetX: -1,
        projectileTargetY: -1,
        deathParticles: [],
        isDead: false,
        pendingDamage: 0,
        justCompletedShot: false,
        isVisible: false, // Enemy units start hidden
        lastSeen: 0,
        lastKnownX: x,
        lastKnownY: y,
        aiBehavior,
        turnOrder: 0, // Will be set by generateTurnOrder
        patrolCenterX: x, // Starting position becomes patrol center
        patrolCenterY: y,
        patrolRadius: generateStat(3, 8), // Random patrol radius
        actionFeedbackTimer: 0
    };
    
    // Set current values to max values
    unit.movementRange = unit.maxMovement;
    unit.currentHp = unit.maxHp;
    
    // Validate unit creation
    console.log('Enemy unit created:', unit);
    
    return unit;
}

/**
 * Checks for completed shooting animations and applies damage to targets
 * @param {Unit[]} units 
 * @param {Tile[][]} grid
 * @returns {{units: Unit[], grid: Tile[][], updated: boolean}} Updated units and grid with damage applied
 */
function processCompletedShots(units, grid) {
    let unitsUpdated = false;
    let gridUpdated = false;
    let newGrid = grid;
    
    const updatedUnits = units.map(unit => {
        // Check if this unit just completed a shooting animation
        if (unit.justCompletedShot) {
            console.log('Processing completed shot for unit:', unit.id);
            console.log('Projectile target coordinates:', unit.projectileTargetX, unit.projectileTargetY);
            console.log('All units and their coordinates:');
            units.forEach(u => console.log(`Unit ${u.id} (${u.owner}): x=${u.x}, y=${u.y}`));
            
            // Check if we hit an obstacle
            if (grid[unit.projectileTargetY] && grid[unit.projectileTargetY][unit.projectileTargetX] && 
                grid[unit.projectileTargetY][unit.projectileTargetX].type === 'obstacle') {
                
                console.log('Shot hit obstacle, applying damage');
                if (!gridUpdated) {
                    newGrid = grid.map(row => [...row]);
                    gridUpdated = true;
                }
                
                // Get the current obstacle
                const currentObstacle = newGrid[unit.projectileTargetY][unit.projectileTargetX];
                
                // Apply damage
                currentObstacle.health -= 1;
                currentObstacle.damageFlash = 1.0; // Set flash effect
                
                if (currentObstacle.health <= 0) {
                    // Obstacle destroyed
                    newGrid[unit.projectileTargetY][unit.projectileTargetX] = {
                        type: 'floor',
                        x: unit.projectileTargetX,
                        y: unit.projectileTargetY,
                        providesCover: false,
                        health: 0,
                        damageFlash: 0,
                        color: generateObstacleColor()
                    };
                    console.log('Obstacle destroyed by shot!');
                }
                
                unitsUpdated = true;
            } else {
                // Find the target unit
                const targetUnit = units.find(u => 
                    u.x === unit.projectileTargetX && u.y === unit.projectileTargetY
                );
                
                console.log('Target unit found:', targetUnit);
                console.log('Target pending damage:', targetUnit?.pendingDamage);
                
                if (targetUnit && targetUnit.pendingDamage > 0) {
                    // Apply damage to target
                    const newHp = Math.max(0, targetUnit.currentHp - targetUnit.pendingDamage);
                    console.log('Applying damage:', targetUnit.pendingDamage, 'New HP:', newHp);
                    
                    if (newHp <= 0 && !targetUnit.isDead) {
                        // Target died - start death animation
                        console.log('Target died, starting death animation');
                        const deadUnit = createDeathParticles({
                            ...targetUnit,
                            currentHp: newHp,
                            pendingDamage: 0
                        });
                        
                        // Update the target unit in the array
                        const targetIndex = units.findIndex(u => u.id === targetUnit.id);
                        if (targetIndex !== -1) {
                            units[targetIndex] = deadUnit;
                        }
                        unitsUpdated = true;
                    } else {
                        // Target survived - just apply damage
                        console.log('Target survived with new HP:', newHp);
                        const updatedTarget = { ...targetUnit, currentHp: newHp, pendingDamage: 0 };
                        const targetIndex = units.findIndex(u => u.id === targetUnit.id);
                        units[targetIndex] = updatedTarget;
                        unitsUpdated = true;
                    }
                } else {
                    console.log('No target found or no pending damage');
                }
            }
            
            // Clear the flag and return updated shooting unit
            return {
                ...unit,
                justCompletedShot: false,
                projectileTargetX: -1,
                projectileTargetY: -1
            };
        }
        return unit;
    });
    
    return {
        units: unitsUpdated ? cleanupDeadUnits(units) : updatedUnits,
        grid: newGrid,
        updated: unitsUpdated || gridUpdated
    };
}

// ------------------------------------------------
// 1. STATE INITIALIZATION (MODEL)
// ------------------------------------------------

/**
 * Creates the initial state of the game.
 * @returns {Model} The initial model.
 */
function init() {
    const { width, height } = calculateGridSize();
    
    // Generate world using procedural generation
    const grid = generateWorld(width, height);

    // Generate squads
    const playerUnits = generatePlayerSquad(grid);
    const enemyUnits = generateEnemySquad(grid);
    let units = [...playerUnits, ...enemyUnits];
    
    // Generate turn order for all units
    const unitsWithTurnOrder = generateTurnOrder(units);
    
    // Update cover status for all units
    unitsWithTurnOrder.forEach(unit => {
        unit.inCover = checkCover(unit, grid);
    });
    
    // Set initial visibility - enemies start hidden unless they're in line of sight of player units
    const unitsWithVisibility = updateUnitVisibility(unitsWithTurnOrder, grid);
    
    // Debug: Show all obstacle health values
    console.log('=== GAME INITIALIZATION ===');
    let obstacleCount = 0;
    for (let y = 0; y < grid.length; y++) {
        for (let x = 0; x < grid[y].length; x++) {
            if (grid[y][x].type === 'obstacle') {
                obstacleCount++;
            }
        }
    }
    console.log(`Total obstacles created: ${obstacleCount}`);
    console.log('Initial currentTurnIndex:', 0);
    console.log('Initial turn order:', unitsWithVisibility.map(u => ({ id: u.id, owner: u.owner, turnOrder: u.turnOrder })));
    console.log('First unit in turn order:', unitsWithVisibility.find(u => u.turnOrder === 0));
    console.log('=== END INITIALIZATION ===');
    
    return {
        grid: grid,
        units: unitsWithVisibility,
        selectedUnit: null,
        uiState: { type: 'AwaitingSelection' },
        currentTurnIndex: 0
    };
}

// ------------------------------------------------
// 2. LOGIC (UPDATE)
// ------------------------------------------------

/**
 * Handles all state changes in the application.
 * @param {object} msg - The action message.
 * @param {Model} model - The current state.
 * @returns {Model} The new state.
 */
function update(msg, model) {
    // Check if it's a player unit's turn
    const currentUnit = model.units.find(u => u.turnOrder === model.currentTurnIndex);
    const isPlayerTurn = currentUnit && currentUnit.owner === 'player';
    
    if (!isPlayerTurn) {
        return model;
    }

    switch (msg.type) {
        case 'TILE_CLICKED': {
            const { x, y } = msg.payload;
            const unitAtTile = model.units.find(u => u.x === x && u.y === y);
            
            console.log('=== TILE CLICK ===');
            console.log('Clicked at:', x, y);
            console.log('Unit at tile:', unitAtTile ? `${unitAtTile.owner} ${unitAtTile.id}` : 'none');
            
            // Check if it's a player unit's turn
            const currentUnit = model.units.find(u => u.turnOrder === model.currentTurnIndex);
            console.log('Current unit in turn order:', currentUnit ? `${currentUnit.owner} ${currentUnit.id}` : 'none');
            console.log('Is player turn:', currentUnit && currentUnit.owner === 'player');
            
            if (!currentUnit || currentUnit.owner !== 'player') {
                console.log('Not a player unit\'s turn, returning');
                return model; // Not a player unit's turn
            }

            if (model.uiState.type === 'UnitSelected') {
                const selectedUnit = model.units.find(u => u.id === model.uiState.unitId);
                
                // Only allow actions if the selected unit is the current unit in turn order
                if (selectedUnit.id !== currentUnit.id) {
                    return model; // Can't act with a different unit
                }
                
                if (!selectedUnit.hasMoved) {
                    // Movement phase
                    const distance = Math.abs(selectedUnit.x - x) + Math.abs(selectedUnit.y - y);
                    const isMoveValid = distance > 0 && 
                                      distance <= selectedUnit.movementRange && 
                                      !unitAtTile &&
                                      model.grid[y][x].type !== 'obstacle' &&
                                      !isPathBlocked(selectedUnit.x, selectedUnit.y, x, y, model.grid) &&
                                      !selectedUnit.hasMoved;
                    
                    if (isMoveValid) {
                        const newUnits = model.units.map(unit =>
                            unit.id === selectedUnit.id
                                ? startMovementAnimation(unit, x, y, model.grid)
                                : unit
                        );
                        
                        // Update cover status for moved unit
                        newUnits.forEach(unit => {
                            unit.inCover = checkCover(unit, model.grid);
                        });
                        
                        // Update unit visibility after movement
                        const unitsWithVisibility = updateUnitVisibility(newUnits, model.grid);
                        
                        return { ...model, units: unitsWithVisibility, uiState: { type: 'AwaitingSelection' } };
                    }
                } else if (!selectedUnit.hasAttacked) {
                    // Attack phase - can attack any unit (including friendly fire)
                    if (unitAtTile) {
                        // Can't attack enemy units that are not visible
                        if (unitAtTile.owner === 'enemy' && !unitAtTile.isVisible) {
                            return model; // Invalid attack - enemy not visible
                        }
                        
                        // Can't attack units that are at their last known position (ghosts)
                        if (unitAtTile.owner === 'enemy' && 
                            unitAtTile.lastSeen && 
                            (unitAtTile.x !== unitAtTile.lastKnownX || unitAtTile.y !== unitAtTile.lastKnownY)) {
                            return model; // Invalid attack - attacking ghost position
                        }
                        
                        const distance = Math.abs(selectedUnit.x - unitAtTile.x) + Math.abs(selectedUnit.y - unitAtTile.y);
                        const isAttackValid = distance <= selectedUnit.shootRange && !selectedUnit.hasAttacked;
                        
                        if (isAttackValid) {
                            // Check line of sight
                            const los = checkLineOfSight(
                                selectedUnit.x, selectedUnit.y,
                                unitAtTile.x, unitAtTile.y,
                                model.grid, model.units
                            );
                            
                            if (los.blocked) {
                                // Line of sight is blocked - handle stray shot
                                let damage = selectedUnit.damage;
                                if (los.obstacleX !== null && los.obstacleY !== null) {
                                    // Hit an obstacle
                                    console.log('Stray shot hit obstacle at:', los.obstacleX, los.obstacleY);
                                    const newGrid = model.grid.map(row => [...row]);
                                    
                                    // Get the current obstacle
                                    const currentObstacle = newGrid[los.obstacleY][los.obstacleX];
                                    
                                    // Apply damage
                                    currentObstacle.health -= 1;
                                    currentObstacle.damageFlash = 1.0; // Set flash effect
                                    
                                    if (currentObstacle.health <= 0) {
                                        // Obstacle destroyed
                                        newGrid[los.obstacleY][los.obstacleX] = {
                                            type: 'floor',
                                            x: los.obstacleX,
                                            y: los.obstacleY,
                                            providesCover: false,
                                            health: 0,
                                            damageFlash: 0,
                                            color: generateObstacleColor()
                                        };
                                        console.log('Obstacle destroyed by stray shot!');
                                    }
                                    
                                    // Start shooting animation towards the obstacle
                                    const newUnits = model.units.map(unit =>
                                        unit.id === selectedUnit.id
                                            ? startShootingAnimation(unit, los.obstacleX, los.obstacleY)
                                            : unit
                                    );
                                    
                                    return { 
                                        ...model, 
                                        grid: newGrid, 
                                        units: newUnits, 
                                        uiState: { type: 'AwaitingSelection' } 
                                    };
                                } else if (los.blocker) {
                                    // Hit a blocking unit
                                    console.log('Stray shot hit blocking unit:', los.blocker.id);
                                    const newUnits = model.units.map(unit =>
                                        unit.id === los.blocker.id
                                            ? { ...unit, pendingDamage: damage }
                                            : unit.id === selectedUnit.id
                                            ? startShootingAnimation(unit, los.blocker.x, los.blocker.y)
                                            : unit
                                    );
                                    
                                    return { ...model, units: newUnits, uiState: { type: 'AwaitingSelection' } };
                                }
                            } else {
                                // Clear line of sight - proceed with normal attack
                                // Calculate damage (cover reduces damage by 50%)
                                let damage = selectedUnit.damage;
                                if (unitAtTile.inCover) {
                                    damage = Math.floor(damage * 0.5);
                                }
                                
                                // Start shooting animation and mark target for damage
                                const newUnits = model.units.map(unit =>
                                    unit.id === unitAtTile.id
                                        ? { ...unit, pendingDamage: damage } // Mark target for damage when projectile hits
                                        : unit.id === selectedUnit.id
                                        ? startShootingAnimation(unit, unitAtTile.x, unitAtTile.y)
                                        : unit
                                );
                                
                                return { ...model, units: newUnits, uiState: { type: 'AwaitingSelection' } };
                            }
                        }
                    }
                }
            }

            // Check if we can target an obstacle directly
            if (model.uiState.type === 'UnitSelected' && model.grid[y][x].type === 'obstacle') {
                const selectedUnit = model.units.find(u => u.id === model.uiState.unitId);
                
                if (selectedUnit && !selectedUnit.hasAttacked) {
                    const distance = Math.abs(selectedUnit.x - x) + Math.abs(selectedUnit.y - y);
                    const isAttackValid = distance <= selectedUnit.shootRange && !selectedUnit.hasAttacked;
                    
                    if (isAttackValid) {
                        console.log('Direct obstacle attack at:', x, y);
                        
                        // Start shooting animation towards the obstacle
                        const newUnits = model.units.map(unit =>
                            unit.id === selectedUnit.id
                                ? startShootingAnimation(unit, x, y)
                                : unit
                        );
                        
                        return { ...model, units: newUnits, uiState: { type: 'AwaitingSelection' } };
                    }
                }
            }

            if (unitAtTile && unitAtTile.owner === 'player' && 
                (!unitAtTile.hasMoved || !unitAtTile.hasAttacked)) {
                
                console.log('Attempting to select player unit:', unitAtTile.id);
                console.log('Unit state:', {
                    hasMoved: unitAtTile.hasMoved,
                    hasAttacked: unitAtTile.hasAttacked
                });
                
                // Only allow selecting the current unit in turn order
                if (unitAtTile.id !== currentUnit.id) {
                    console.log('Cannot select unit - not current unit in turn order');
                    return model; // Can't select a different unit
                }
                
                console.log('Successfully selecting unit:', unitAtTile.id);
                return { ...model, uiState: { type: 'UnitSelected', unitId: unitAtTile.id } };
            }

            // Can't select enemy units that are not visible
            if (unitAtTile && unitAtTile.owner === 'enemy' && !unitAtTile.isVisible) {
                return model; // Invalid selection - enemy not visible
            }

            return { ...model, uiState: { type: 'AwaitingSelection' } };
        }
        case 'SKIP_MOVEMENT': {
            if (model.uiState.type === 'UnitSelected') {
                const selectedUnit = model.units.find(u => u.id === model.uiState.unitId);
                const currentUnit = model.units.find(u => u.turnOrder === model.currentTurnIndex);
                
                // Only allow skipping if it's the current unit's turn
                if (!currentUnit || selectedUnit.id !== currentUnit.id) {
                    return model;
                }
                
                const newUnits = model.units.map(unit =>
                    unit.id === selectedUnit.id
                        ? { ...unit, hasMoved: true }
                        : unit
                );
                return { ...model, units: newUnits, uiState: { type: 'AwaitingSelection' } };
            }
            return model;
        }
        case 'SKIP_ATTACK': {
            if (model.uiState.type === 'UnitSelected') {
                const selectedUnit = model.units.find(u => u.id === model.uiState.unitId);
                const currentUnit = model.units.find(u => u.turnOrder === model.currentTurnIndex);
                
                // Only allow skipping if it's the current unit's turn
                if (!currentUnit || selectedUnit.id !== currentUnit.id) {
                    return model;
                }
                
                const newUnits = model.units.map(unit =>
                    unit.id === selectedUnit.id
                        ? { ...unit, hasAttacked: true }
                        : unit
                );
                return { ...model, units: newUnits, uiState: { type: 'AwaitingSelection' } };
            }
            return model;
        }
        case 'END_TURN_CLICKED': {
            // Advance to next turn in turn order
            return advanceTurn(model);
        }
        default:
            return model;
    }
}

// ------------------------------------------------
// 3. RENDERER (VIEW)
// ------------------------------------------------

/**
 * Draws the grid tiles and obstacles.
 * @param {Model} model
 * @param {CanvasRenderingContext2D} ctx
 */
function drawGrid(model, ctx) {
    const gridWidth = model.grid[0].length;
    const gridHeight = model.grid.length;

    // Draw tiles
    for (let y = 0; y < gridHeight; y++) {
        for (let x = 0; x < gridWidth; x++) {
            const tile = model.grid[y][x];
            const tileX = x * TILE_SIZE;
            const tileY = y * TILE_SIZE;
            
            // Fill tile
            ctx.fillStyle = tile.type === 'obstacle' ? tile.color : COLORS.floor;
            ctx.fillRect(tileX, tileY, TILE_SIZE, TILE_SIZE);
            
            // Draw obstacle health indicator
            if (tile.type === 'obstacle' && tile.health < OBSTACLE_MAX_HEALTH) {
                // Create a more gradual color fade based on health using grey/black/blue palette
                const healthRatio = tile.health / OBSTACLE_MAX_HEALTH;
                let damageColor;
                
                if (healthRatio > 0.83) {
                    // 5 HP - slight blue tint
                    damageColor = `rgba(52, 73, 94, ${0.2 + (1 - healthRatio) * 0.3})`;
                } else if (healthRatio > 0.66) {
                    // 4 HP - more blue-grey
                    damageColor = `rgba(44, 62, 80, ${0.3 + (1 - healthRatio) * 0.4})`;
                } else if (healthRatio > 0.5) {
                    // 3 HP - darker blue-grey
                    damageColor = `rgba(36, 51, 66, ${0.4 + (1 - healthRatio) * 0.4})`;
                } else if (healthRatio > 0.33) {
                    // 2 HP - very dark blue-grey
                    damageColor = `rgba(28, 40, 52, ${0.5 + (1 - healthRatio) * 0.4})`;
                } else {
                    // 1 HP - almost black with blue tint
                    damageColor = `rgba(20, 29, 38, ${0.6 + (1 - healthRatio) * 0.4})`;
                }
                
                ctx.fillStyle = damageColor;
                ctx.fillRect(tileX + 2, tileY + 2, TILE_SIZE - 4, TILE_SIZE - 4);
            }
            
            // Draw damage flash effect if obstacle was recently hit
            if (tile.type === 'obstacle' && tile.damageFlash && tile.damageFlash > 0) {
                ctx.fillStyle = `rgba(52, 152, 219, ${tile.damageFlash * 0.6})`; // Blue-white flash
                ctx.fillRect(tileX, tileY, TILE_SIZE, TILE_SIZE);
            }
            
            // Draw grid lines
            ctx.strokeStyle = COLORS.gridLine;
            ctx.lineWidth = 1;
            ctx.strokeRect(tileX, tileY, TILE_SIZE, TILE_SIZE);
        }
    }
}

/**
 * Draws highlights for valid moves and attacks.
 * @param {Model} model
 * @param {CanvasRenderingContext2D} ctx
 */
function drawHighlights(model, ctx) {
    if (model.uiState.type === 'AwaitingSelection') return;

    const selectedUnit = model.units.find(u => u.id === model.uiState.unitId);
    const currentUnit = model.units.find(u => u.turnOrder === model.currentTurnIndex);
    
    if (!selectedUnit || !currentUnit) return;
    
    // Only show highlights if the selected unit is the current unit in turn order
    if (selectedUnit.id !== currentUnit.id) return;

    if (model.uiState.type === 'UnitSelected' && !selectedUnit.hasMoved) {
        // Show movement range
        ctx.fillStyle = COLORS.moveHighlight;
        for (const row of model.grid) {
            for (const tile of row) {
                if (tile.type === 'obstacle') continue;
                
                const distance = Math.abs(selectedUnit.x - tile.x) + Math.abs(selectedUnit.y - tile.y);
                if (distance > 0 && distance <= selectedUnit.movementRange) {
                    // Check if path is not blocked
                    if (!isPathBlocked(selectedUnit.x, selectedUnit.y, tile.x, tile.y, model.grid)) {
                        ctx.fillRect(tile.x * TILE_SIZE, tile.y * TILE_SIZE, TILE_SIZE, TILE_SIZE);
                    }
                }
            }
        }
    }

    if (model.uiState.type === 'UnitSelected' && selectedUnit.hasMoved && !selectedUnit.hasAttacked) {
        // Show attack range
        ctx.fillStyle = 'rgba(255, 0, 0, 0.3)';
        for (const row of model.grid) {
            for (const tile of row) {
                const distance = Math.abs(selectedUnit.x - tile.x) + Math.abs(selectedUnit.y - tile.y);
                if (distance > 0 && distance <= selectedUnit.shootRange) {
                    ctx.fillRect(tile.x * TILE_SIZE, tile.y * TILE_SIZE, TILE_SIZE, TILE_SIZE);
                }
            }
        }
        
        // Highlight potential targets
        ctx.fillStyle = 'rgba(255, 0, 0, 0.6)';
        model.units.forEach(unit => {
            if (unit.id !== selectedUnit.id && 
                (unit.owner === 'player' || (unit.owner === 'enemy' && unit.isVisible && 
                 unit.x === unit.lastKnownX && unit.y === unit.lastKnownY))) {
                const distance = Math.abs(selectedUnit.x - unit.x) + Math.abs(selectedUnit.y - unit.y);
                if (distance <= selectedUnit.shootRange) {
                    ctx.beginPath();
                    ctx.arc(unit.x * TILE_SIZE + TILE_SIZE / 2, unit.y * TILE_SIZE + TILE_SIZE / 2, UNIT_RADIUS + 5, 0, Math.PI * 2);
                    ctx.fill();
                }
            }
        });
        
        // Highlight targetable obstacles
        ctx.fillStyle = 'rgba(52, 152, 219, 0.4)'; // Blue highlight for targetable obstacles
        for (const row of model.grid) {
            for (const tile of row) {
                if (tile.type === 'obstacle') {
                    const distance = Math.abs(selectedUnit.x - tile.x) + Math.abs(selectedUnit.y - tile.y);
                    if (distance > 0 && distance <= selectedUnit.shootRange) {
                        ctx.fillRect(tile.x * TILE_SIZE + 2, tile.y * TILE_SIZE + 2, TILE_SIZE - 4, TILE_SIZE - 4);
                    }
                }
            }
        }
    }
}

/**
 * Draws the units on the grid.
 * @param {Model} model
 * @param {CanvasRenderingContext2D} ctx
 */
function drawUnits(model, ctx) {
    model.units.forEach(unit => {
        if (unit.isDead) return;
        
        // Sanitize unit state to prevent crashes
        const sanitizedUnit = sanitizeUnitState(unit);
        
        let drawPosition;
        if (sanitizedUnit.owner === 'enemy' && !sanitizedUnit.isVisible && sanitizedUnit.lastSeen) {
            // Draw at last known position for invisible enemy units
            drawPosition = { x: sanitizedUnit.lastKnownX, y: sanitizedUnit.lastKnownY };
        } else {
            // Draw at current position for visible units
            try {
                drawPosition = getUnitPosition(sanitizedUnit);
            } catch (error) {
                console.warn('Error getting position for unit', sanitizedUnit.id, ':', error);
                drawPosition = { x: sanitizedUnit.x, y: sanitizedUnit.y };
            }
        }
        
        if (!drawPosition || typeof drawPosition.x !== 'number' || typeof drawPosition.y !== 'number') {
            console.warn('Invalid position for unit:', sanitizedUnit.id, drawPosition, 'skipping render');
            return; // Skip this unit
        }
        
        const { x, y } = drawPosition;
        const centerX = x * TILE_SIZE + TILE_SIZE / 2;
        const centerY = y * TILE_SIZE + TILE_SIZE / 2;

        // For invisible enemy units, draw as a ghost
        if (sanitizedUnit.owner === 'enemy' && !sanitizedUnit.isVisible) {
            ctx.globalAlpha = 0.3; // Make them semi-transparent
            ctx.fillStyle = '#666'; // Grey color for ghosts
        } else {
            ctx.globalAlpha = 1.0; // Full opacity for visible units
            ctx.fillStyle = sanitizedUnit.owner === 'player' ? COLORS.player : COLORS.enemy;
        }

    // Draw cover indicator
    if (sanitizedUnit.inCover) {
        ctx.fillStyle = COLORS.coverHighlight;
        ctx.beginPath();
        ctx.arc(centerX, centerY, UNIT_RADIUS + 5, 0, Math.PI * 2);
        ctx.fill();
    }

    // Draw shooting animation effect
    if (sanitizedUnit.isAnimating && sanitizedUnit.animationType === 'shooting') {
        const pulseSize = UNIT_RADIUS + 10 + Math.sin(sanitizedUnit.animationProgress * Math.PI * 4) * 5;
        ctx.fillStyle = 'rgba(255, 255, 0, 0.3)';
        ctx.beginPath();
        ctx.arc(centerX, centerY, pulseSize, 0, Math.PI * 2);
        ctx.fill();
        
        // Draw projectile
        const projectilePos = getProjectilePosition(sanitizedUnit);
        if (projectilePos) {
            // Draw projectile trail
            const trailLength = 15;
            const angle = Math.atan2(projectilePos.y - centerY, projectilePos.x - centerX);
            const trailStartX = projectilePos.x - Math.cos(angle) * trailLength;
            const trailStartY = projectilePos.y - Math.sin(angle) * trailLength;
            
            // Gradient for trail effect
            const gradient = ctx.createLinearGradient(trailStartX, trailStartY, projectilePos.x, projectilePos.y);
            gradient.addColorStop(0, 'rgba(255, 255, 0, 0)');
            gradient.addColorStop(0.5, 'rgba(255, 255, 0, 0.8)');
            gradient.addColorStop(1, 'rgba(255, 255, 0, 1)');
            
            ctx.strokeStyle = gradient;
            ctx.lineWidth = 3;
            ctx.lineCap = 'round';
            ctx.beginPath();
            ctx.moveTo(trailStartX, trailStartY);
            ctx.lineTo(projectilePos.x, projectilePos.y);
            ctx.stroke();
            
            // Draw projectile bolt
            ctx.fillStyle = '#FFFF00';
            ctx.beginPath();
            ctx.arc(projectilePos.x, projectilePos.y, 4, 0, Math.PI * 2);
            ctx.fill();
            
            // Add glow effect
            ctx.shadowColor = '#FFFF00';
            ctx.shadowBlur = 8;
            ctx.beginPath();
            ctx.arc(projectilePos.x, projectilePos.y, 2, 0, Math.PI * 2);
            ctx.fill();
            ctx.shadowBlur = 0;
            
            // Draw impact effect when projectile reaches target
            if (sanitizedUnit.animationProgress > 0.8) {
                const targetCenterX = sanitizedUnit.projectileTargetX * TILE_SIZE + TILE_SIZE / 2;
                const targetCenterY = sanitizedUnit.projectileTargetY * TILE_SIZE + TILE_SIZE / 2;
                
                // Impact explosion
                const explosionSize = (sanitizedUnit.animationProgress - 0.8) * 20;
                const alpha = 1 - (sanitizedUnit.animationProgress - 0.8) * 5;
                
                ctx.fillStyle = `rgba(255, 100, 0, ${alpha})`;
                ctx.beginPath();
                ctx.arc(targetCenterX, targetCenterY, explosionSize, 0, Math.PI * 2);
                ctx.fill();
                
                // Inner explosion
                ctx.fillStyle = `rgba(255, 255, 0, ${alpha * 0.8})`;
                ctx.beginPath();
                ctx.arc(targetCenterX, targetCenterY, explosionSize * 0.6, 0, Math.PI * 2);
                ctx.fill();
            }
        }
    }

    // Draw death particles
    if (sanitizedUnit.isAnimating && sanitizedUnit.animationType === 'dying' && sanitizedUnit.deathParticles) {
        sanitizedUnit.deathParticles.forEach(particle => {
            const alpha = particle.life / particle.maxLife;
            const size = particle.size * alpha;
            
            ctx.fillStyle = particle.color;
            ctx.globalAlpha = alpha;
            ctx.beginPath();
            ctx.arc(particle.x, particle.y, size, 0, Math.PI * 2);
            ctx.fill();
            
            // Add glow effect
            ctx.shadowColor = particle.color;
            ctx.shadowBlur = size * 2;
            ctx.beginPath();
            ctx.arc(particle.x, particle.y, size * 0.5, 0, Math.PI * 2);
            ctx.fill();
            ctx.shadowBlur = 0;
        });
        ctx.globalAlpha = 1; // Reset global alpha
    }

    // Draw targeting reticle for units in attack range
    if (model.uiState.type === 'UnitSelected' && 
        model.uiState.unitId !== sanitizedUnit.id &&
        sanitizedUnit.owner !== 'player') {
        const selectedUnit = model.units.find(u => u.id === model.uiState.unitId);
        if (selectedUnit && selectedUnit.hasMoved && !selectedUnit.hasAttacked) {
            const distance = Math.abs(selectedUnit.x - sanitizedUnit.x) + Math.abs(selectedUnit.y - sanitizedUnit.y);
            if (distance <= selectedUnit.shootRange) {
                // Draw targeting reticle
                ctx.strokeStyle = '#FF0000';
                ctx.lineWidth = 2;
                ctx.setLineDash([5, 5]);
                
                const reticleSize = UNIT_RADIUS + 8;
                ctx.beginPath();
                ctx.arc(centerX, centerY, reticleSize, 0, Math.PI * 2);
                ctx.stroke();
                
                // Draw crosshairs
                ctx.beginPath();
                ctx.moveTo(centerX - reticleSize - 5, centerY);
                ctx.lineTo(centerX - reticleSize + 5, centerY);
                ctx.moveTo(centerX + reticleSize - 5, centerY);
                ctx.lineTo(centerX + reticleSize + 5, centerY);
                ctx.moveTo(centerX, centerY - reticleSize - 5);
                ctx.lineTo(centerX, centerY - reticleSize + 5);
                ctx.moveTo(centerX, centerY + reticleSize - 5);
                ctx.lineTo(centerX, centerY + reticleSize + 5);
                ctx.stroke();
                
                ctx.setLineDash([]);
            }
        }
    }

    // Draw unit
    ctx.fillStyle = sanitizedUnit.owner === 'player' ? COLORS.player : COLORS.enemy;
    ctx.strokeStyle = (model.uiState.type === 'UnitSelected' && model.uiState.unitId === sanitizedUnit.id)
        ? COLORS.selectedBorder
        : COLORS.unitBorder;
    ctx.lineWidth = 2;

    // Add pending damage indicator
    if (sanitizedUnit.pendingDamage > 0) {
        ctx.strokeStyle = '#FF0000';
        ctx.lineWidth = 4;
    }

    ctx.beginPath();
    ctx.arc(centerX, centerY, UNIT_RADIUS, 0, Math.PI * 2);
    ctx.fill();
    ctx.stroke();

    // Draw HP bar
    const hpBarWidth = UNIT_RADIUS * 2;
    const hpBarHeight = 4;
    const hpBarX = centerX - hpBarWidth / 2;
    const hpBarY = centerY - UNIT_RADIUS - 10;
    
    // Background
    ctx.fillStyle = '#333';
    ctx.fillRect(hpBarX, hpBarY, hpBarWidth, hpBarHeight);
    
    // HP bar
    const hpPercentage = sanitizedUnit.currentHp / sanitizedUnit.maxHp;
    ctx.fillStyle = hpPercentage > 0.5 ? '#4CAF50' : hpPercentage > 0.25 ? '#FF9800' : '#F44336';
    ctx.fillRect(hpBarX, hpBarY, hpBarWidth * hpPercentage, hpBarHeight);
    
    // HP text
    ctx.fillStyle = '#fff';
    ctx.font = '10px Arial';
    ctx.textAlign = 'center';
    ctx.fillText(`${sanitizedUnit.currentHp}/${sanitizedUnit.maxHp}`, centerX, hpBarY - 2);
    
    // Draw action indicators
    if (sanitizedUnit.owner === 'player') {
        // Movement indicator
        if (!sanitizedUnit.hasMoved) {
            // ctx.fillStyle = '#4CAF50';
            // ctx.beginPath();
            // ctx.arc(centerX - 8, centerY + UNIT_RADIUS + 5, 3, 0, Math.PI * 2);
            // ctx.fill();
        }
        
        // Attack indicator
        if (!sanitizedUnit.hasAttacked) {
            ctx.fillStyle = sanitizedUnit.hasMoved ? '#FF0000' : '#FF9800'; // Red if ready to attack, orange if waiting
            ctx.beginPath();
            ctx.arc(centerX + 8, centerY + UNIT_RADIUS + 5, 3, 0, Math.PI * 2);
            ctx.fill();
        }
        
        // Phase indicator text
        if (model.uiState.type === 'UnitSelected' && model.uiState.unitId === sanitizedUnit.id) {
            ctx.fillStyle = '#fff';
            ctx.font = '12px Arial';
            ctx.textAlign = 'center';
            if (!sanitizedUnit.hasMoved) {
                // ctx.fillText('MOVE', centerX, centerY - UNIT_RADIUS - 15);
            } else if (!sanitizedUnit.hasAttacked) {
                // ctx.fillText('ATTACK', centerX, centerY - UNIT_RADIUS - 15);
            }
        }
    }
    
    // Draw turn indicator for current unit
    const currentUnit = model.units.find(u => u.turnOrder === model.currentTurnIndex);
    if (currentUnit && currentUnit.id === sanitizedUnit.id) {
        // Draw turn indicator ring
        ctx.strokeStyle = sanitizedUnit.owner === 'player' ? '#00FF00' : '#FF0000';
        ctx.lineWidth = 3;
        ctx.beginPath();
        ctx.arc(centerX, centerY, UNIT_RADIUS + 8, 0, Math.PI * 2);
        ctx.stroke();
        
        // Draw turn indicator text
        ctx.fillStyle = sanitizedUnit.owner === 'player' ? '#00FF00' : '#FF0000';
        ctx.font = '14px Arial';
        ctx.textAlign = 'center';
        // ctx.fillText(sanitizedUnit.owner === 'player' ? 'YOUR TURN' : 'ENEMY TURN', centerX, centerY + UNIT_RADIUS + 25);
        
        // For player units, add a subtle glow to show they're selectable
        if (sanitizedUnit.owner === 'player' && !sanitizedUnit.hasMoved && !sanitizedUnit.hasAttacked) {
            ctx.shadowColor = '#00FF00';
            ctx.shadowBlur = 15;
            ctx.beginPath();
            ctx.arc(centerX, centerY, UNIT_RADIUS + 2, 0, Math.PI * 2);
            ctx.stroke();
            ctx.shadowBlur = 0;
        }
        
        // For enemy units, show action feedback
        if (sanitizedUnit.owner === 'enemy' && sanitizedUnit.actionFeedbackTimer > 0) {
            // Draw action feedback ring
            const feedbackAlpha = sanitizedUnit.actionFeedbackTimer / ENEMY_ACTION_FEEDBACK_DURATION;
            ctx.strokeStyle = `rgba(255, 255, 0, ${feedbackAlpha})`;
            ctx.lineWidth = 4;
            ctx.beginPath();
            ctx.arc(centerX, centerY, UNIT_RADIUS + 15, 0, Math.PI * 2);
            ctx.stroke();
            
            // Draw action feedback text
            ctx.fillStyle = `rgba(255, 255, 0, ${feedbackAlpha})`;
            ctx.font = '12px Arial';
            ctx.textAlign = 'center';
            
            if (sanitizedUnit.isAnimating) {
                if (sanitizedUnit.animationType === 'moving') {
                    ctx.fillText('MOVING...', centerX, centerY + UNIT_RADIUS + 40);
                } else if (sanitizedUnit.animationType === 'shooting') {
                    ctx.fillText('ATTACKING...', centerX, centerY + UNIT_RADIUS + 40);
                }
            } else {
                ctx.fillText('THINKING...', centerX, centerY + UNIT_RADIUS + 40);
            }
        }
        
        // Show thinking indicator for current enemy unit even without action feedback
        if (sanitizedUnit.owner === 'enemy' && currentUnit && currentUnit.id === sanitizedUnit.id && 
            !sanitizedUnit.actionFeedbackTimer && !sanitizedUnit.isAnimating) {
            // Draw subtle thinking indicator
            ctx.strokeStyle = 'rgba(255, 255, 0, 0.3)';
            ctx.lineWidth = 2;
            ctx.beginPath();
            ctx.arc(centerX, centerY, UNIT_RADIUS + 12, 0, Math.PI * 2);
            ctx.stroke();
            
            // Draw thinking text
            ctx.fillStyle = 'rgba(255, 255, 0, 0.5)';
            ctx.font = '10px Arial';
            ctx.textAlign = 'center';
            ctx.fillText('THINKING...', centerX, centerY + UNIT_RADIUS + 35);
        }
    }
    
    // Draw movement path preview
    if (sanitizedUnit.isAnimating && sanitizedUnit.animationType === 'moving' && sanitizedUnit.path.length > 0) {
        ctx.strokeStyle = 'rgba(0, 255, 0, 0.5)';
        ctx.lineWidth = 2;
        ctx.setLineDash([5, 5]);
        
        ctx.beginPath();
        ctx.moveTo(sanitizedUnit.x * TILE_SIZE + TILE_SIZE / 2, sanitizedUnit.y * TILE_SIZE + TILE_SIZE / 2);
        
        for (const pathPoint of sanitizedUnit.path) {
            ctx.lineTo(pathPoint.x * TILE_SIZE + TILE_SIZE / 2, pathPoint.y * TILE_SIZE + TILE_SIZE / 2);
        }
        
                 ctx.stroke();
         ctx.setLineDash([]);
     }
 });
     
     // Reset global alpha to ensure proper rendering
     ctx.globalAlpha = 1.0;
 }

/**
 * Renders the entire game state to the canvas.
 * @param {Model} model - The current state to render.
 * @param {HTMLCanvasElement} canvas
 * @param {CanvasRenderingContext2D} ctx
 */
function view(model, canvas, ctx) {
    // Pre-condition: canvas and context are valid.
    ctx.clearRect(0, 0, canvas.width, canvas.height);
    
    drawGrid(model, ctx);
    drawHighlights(model, ctx);
    drawUnits(model, ctx);
    drawFogOfWar(model, ctx); // Add fog of war effect
    drawStatusMessage(model, ctx); // Add status message
    drawVisibilityRanges(model, ctx); // Add visibility ranges
    // Post-condition: canvas displays the current model state.
}

/**
 * Draws status messages at the top of the screen
 * @param {Model} model 
 * @param {HTMLCanvasElement} ctx 
 */
function drawStatusMessage(model, ctx) {
    const currentUnit = model.units.find(u => u.turnOrder === model.currentTurnIndex);
    if (!currentUnit) return;
    
    // Draw status message at top of screen
    ctx.fillStyle = 'rgba(0, 0, 0, 0.7)';
    ctx.fillRect(0, 0, ctx.canvas.width, 40);
    
    ctx.fillStyle = '#FFFFFF';
    ctx.font = '16px Arial';
    ctx.textAlign = 'center';
    
    if (currentUnit.owner === 'enemy') {
        if (currentUnit.isAnimating) {
            if (currentUnit.animationType === 'moving') {
                ctx.fillText(`Enemy ${currentUnit.id} is moving...`, ctx.canvas.width / 2, 25);
            } else if (currentUnit.animationType === 'shooting') {
                ctx.fillText(`Enemy ${currentUnit.id} is attacking...`, ctx.canvas.width / 2, 25);
            }
        } else {
            ctx.fillText(`Enemy ${currentUnit.id}'s turn`, ctx.canvas.width / 2, 25);
        }
    } else {
        ctx.fillText(`Player ${currentUnit.id}'s turn - Move and Attack`, ctx.canvas.width / 2, 25);
    }
}

/**
 * Draws visibility range indicators around player units
 * @param {Model} model 
 * @param {CanvasRenderingContext2D} ctx 
 */
function drawVisibilityRanges(model, ctx) {
    model.units.forEach(unit => {
        if (unit.owner === 'player' && !unit.isDead) {
            const centerX = unit.x * TILE_SIZE + TILE_SIZE / 2;
            const centerY = unit.y * TILE_SIZE + TILE_SIZE / 2;
            
            // Draw visibility range circle
            ctx.strokeStyle = 'rgba(0, 255, 255, 0.3)'; // Cyan with transparency
            ctx.lineWidth = 1;
            ctx.setLineDash([3, 3]); // Dashed line
            
            ctx.beginPath();
            ctx.arc(centerX, centerY, MAX_VISIBILITY_RANGE * TILE_SIZE, 0, Math.PI * 2);
            ctx.stroke();
            
            ctx.setLineDash([]); // Reset line dash
        }
    });
}

// ------------------------------------------------
// 4. MAIN APPLICATION LOOP
// ------------------------------------------------

/**
 * The main driver for the application.
 */
function App() {
    const canvas = document.getElementById('gameCanvas');
    const endTurnBtn = document.getElementById('endTurnBtn');
    const skipMovementBtn = document.getElementById('skipMovementBtn');
    const skipAttackBtn = document.getElementById('skipAttackBtn');
    
    if (!canvas || !endTurnBtn || !skipMovementBtn || !skipAttackBtn) return;
    
    const ctx = canvas.getContext('2d');
    let model = init();
    let lastTime = 0;
    let animationId;
    
    // Set canvas dimensions based on model
    canvas.width = model.grid[0].length * TILE_SIZE;
    canvas.height = model.grid.length * TILE_SIZE;

    /**
     * Updates button states based on current game state
     */
    function updateButtonStates() {
        const currentUnit = model.units.find(u => u.turnOrder === model.currentTurnIndex);
        const isPlayerTurn = currentUnit && currentUnit.owner === 'player';
        
        // Only enable end turn button if it's a player turn and they've completed their actions
        if (isPlayerTurn) {
            const hasUnfinishedActions = !currentUnit.hasMoved || !currentUnit.hasAttacked;
            const hasAnimatingUnits = model.units.some(u => u.isAnimating);
            endTurnBtn.disabled = hasUnfinishedActions || hasAnimatingUnits;
        } else {
            endTurnBtn.disabled = true; // Disable during enemy turns
        }
        
        // Only enable skip buttons if it's the current unit's turn and they're selected
        if (model.uiState.type === 'UnitSelected' && isPlayerTurn) {
            const selectedUnit = model.units.find(u => u.id === model.uiState.unitId);
            if (selectedUnit && selectedUnit.id === currentUnit.id) {
                skipMovementBtn.disabled = selectedUnit.hasMoved || selectedUnit.isAnimating;
                skipAttackBtn.disabled = selectedUnit.hasAttacked || selectedUnit.isAnimating;
            } else {
                skipMovementBtn.disabled = true;
                skipAttackBtn.disabled = true;
            }
        } else {
            skipMovementBtn.disabled = true;
            skipAttackBtn.disabled = true;
        }
    }

    /**
     * Game loop for animations
     */
    function gameLoop(currentTime) {
        const deltaTime = currentTime - lastTime;
        lastTime = currentTime;
        
        // Update animations
        model.units = updateAnimations(model.units, deltaTime);
        const shotResult = processCompletedShots(model.units, model.grid); // Process completed shots
        model.units = shotResult.units;
        if (shotResult.updated) {
            model.grid = shotResult.grid;
        }
        
        // Update obstacle flash effects
        model.grid = updateObstacleFlash(model.grid);
        
        // Update unit visibility based on line of sight - ONLY when player units move or when needed
        // model.units = updateUnitVisibility(model.units, model.grid);
        
        // Check if current unit has completed their turn and auto-advance
        const currentTurnUnit = model.units.find(u => u.turnOrder === model.currentTurnIndex);
        console.log('=== TURN CHECK ===');
        console.log('currentTurnIndex:', model.currentTurnIndex);
        console.log('currentTurnUnit:', currentTurnUnit ? `${currentTurnUnit.owner} ${currentTurnUnit.id}` : 'none');
        console.log('currentTurnUnit state:', currentTurnUnit ? {
            hasMoved: currentTurnUnit.hasMoved,
            hasAttacked: currentTurnUnit.hasAttacked,
            isAnimating: currentTurnUnit.isAnimating
        } : 'none');
        
        if (currentTurnUnit && currentTurnUnit.owner === 'player' && 
            currentTurnUnit.hasMoved && currentTurnUnit.hasAttacked) {
            // Player unit completed their turn, auto-advance
            console.log('Player unit completed turn, advancing...');
            model = advanceTurn(model);
            
            // Check if next unit is enemy and process their turn
            const nextUnit = model.units.find(u => u.turnOrder === model.currentTurnIndex);
            if (nextUnit && nextUnit.owner === 'enemy') {
                console.log('Next unit is enemy, processing their turn...');
                const result = executeEnemyTurn(model, nextUnit);
                model = advanceTurn(result);
                
                // Continue processing enemy turns until we reach a player unit
                while (true) {
                    const nextEnemyUnit = model.units.find(u => u.turnOrder === model.currentTurnIndex);
                    if (!nextEnemyUnit || nextEnemyUnit.owner === 'player') {
                        break; // Player turn or no more units
                    }
                    console.log('Processing next enemy turn for unit', nextEnemyUnit.id);
                    const enemyResult = executeEnemyTurn(model, nextEnemyUnit);
                    model = advanceTurn(enemyResult);
                }
            }
        }
        
        console.log('After turn advancement check - currentTurnIndex:', model.currentTurnIndex, 'currentUnit:', currentTurnUnit ? `${currentTurnUnit.owner} ${currentTurnUnit.id}` : 'none');
        console.log('=== END TURN CHECK ===');
        
        // Update action feedback timers
        model.units = updateActionFeedbackTimers(model.units);
        
        // Render
        view(model, canvas, ctx);
        updateButtonStates();
        
        // Check if we should continue the game loop
        const hasAnimations = model.units.some(u => u.isAnimating);
        const loopCurrentUnit = model.units.find(u => u.turnOrder === model.currentTurnIndex);
        
        console.log('Game loop continuation check:', {
            hasAnimations,
            currentTurnIndex: model.currentTurnIndex,
            currentUnit: loopCurrentUnit ? `${loopCurrentUnit.owner} ${loopCurrentUnit.id}` : 'none',
            unitState: loopCurrentUnit ? {
                hasMoved: loopCurrentUnit.hasMoved,
                hasAttacked: loopCurrentUnit.hasAttacked,
                isAnimating: loopCurrentUnit.isAnimating
            } : 'none'
        });
        
        if (hasAnimations) {
            console.log('Continuing game loop for animations...');
            requestAnimationFrame(gameLoop);
        } else {
            // If no animations, render once and stop
            console.log('Stopping game loop, rendering once...');
            view(model, canvas, ctx);
            updateButtonStates();
        }
    }

    /**
     * The dispatch function, linking events to the update logic.
     * @param {object} msg 
     */
    function dispatch(msg) {
        console.log('=== DISPATCH ===');
        console.log('Message type:', msg.type);
        
        model = update(msg, model);
        
        console.log('After update - currentTurnIndex:', model.currentTurnIndex);
        console.log('Current unit:', model.units.find(u => u.turnOrder === model.currentTurnIndex));
        console.log('Has animations:', model.units.some(u => u.isAnimating));
        
        // Start animation loop if needed
        if (model.units.some(u => u.isAnimating)) {
            console.log('Starting game loop for animations');
            if (animationId) {
                cancelAnimationFrame(animationId);
            }
            lastTime = performance.now();
            animationId = requestAnimationFrame(gameLoop);
        } else {
            console.log('No animations, just rendering once');
            // Just render once if no animations
            view(model, canvas, ctx);
            updateButtonStates();
        }
        
        // Check for game over
        const playerUnits = model.units.filter(u => u.owner === 'player' && !u.isDead);
        const enemyUnits = model.units.filter(u => u.owner === 'enemy' && !u.isDead);
        
        if (playerUnits.length === 0) {
            alert('Game Over! Enemy wins!');
            return;
        }
        if (enemyUnits.length === 0) {
            alert('Victory! Player wins!');
            return;
        }


    }
    
    // Setup Event Listeners
    canvas.addEventListener('click', (e) => {
        const rect = canvas.getBoundingClientRect();
        const x = e.clientX - rect.left;
        const y = e.clientY - rect.top;

        const tileX = Math.floor(x / TILE_SIZE);
        const tileY = Math.floor(y / TILE_SIZE);

        dispatch({ type: 'TILE_CLICKED', payload: { x: tileX, y: tileY } });
    });

    endTurnBtn.addEventListener('click', () => {
        dispatch({ type: 'END_TURN_CLICKED' });
    });

    skipMovementBtn.addEventListener('click', () => {
        dispatch({ type: 'SKIP_MOVEMENT' });
    });

    skipAttackBtn.addEventListener('click', () => {
        dispatch({ type: 'SKIP_ATTACK' });
    });

    // Handle window resize
    window.addEventListener('resize', () => {
        // Recalculate grid size and reinitialize if needed
        const newSize = calculateGridSize();
        if (newSize.width !== model.grid[0].length || newSize.height !== model.grid.length) {
            model = init();
            canvas.width = model.grid[0].length * TILE_SIZE;
            canvas.height = model.grid.length * TILE_SIZE;
            view(model, canvas, ctx);
            updateButtonStates();
        }
    });

    // Initial render
    dispatch({ type: 'INITIAL_RENDER' }); // Dispatch a dummy event to start
}

// Start the game when DOM is loaded
document.addEventListener('DOMContentLoaded', App);

/**
 * Checks if there's a clear line of sight between two points
 * @param {number} startX 
 * @param {number} startY 
 * @param {number} endX 
 * @param {number} endY 
 * @param {Tile[][]} grid 
 * @param {Unit[]} units 
 * @returns {{blocked: boolean, blocker: Unit | null, obstacleX: number | null, obstacleY: number | null}} Line of sight result
 */
function checkLineOfSight(startX, startY, endX, endY, grid, units) {
    const dx = endX - startX;
    const dy = endY - startY;
    const distance = Math.sqrt(dx * dx + dy * dy);
    
    // Add maximum visibility range - units can't see beyond this distance
    const MAX_VISIBILITY_RANGE = 6; // Reduced from unlimited to 6 tiles
    
    if (distance === 0) return { blocked: false, blocker: null, obstacleX: null, obstacleY: null };
    
    // If target is beyond visibility range, it's blocked
    if (distance > MAX_VISIBILITY_RANGE) {
        return { 
            blocked: true, 
            blocker: null, 
            obstacleX: null, 
            obstacleY: null,
            reason: 'beyond_visibility_range'
        };
    }
    
    // Use Bresenham's line algorithm to check each tile along the path
    const steps = Math.max(Math.abs(dx), Math.abs(dy));
    const xStep = dx / steps;
    const yStep = dy / steps;
    
    for (let i = 1; i <= steps; i++) {
        const checkX = Math.round(startX + xStep * i);
        const checkY = Math.round(startY + yStep * i);
        
        // Check if we've reached the target
        if (checkX === endX && checkY === endY) {
            break;
        }
        
        // Check for obstacles
        if (grid[checkY] && grid[checkY][checkX] && grid[checkY][checkX].type === 'obstacle') {
            return { 
                blocked: true, 
                blocker: null, 
                obstacleX: checkX, 
                obstacleY: checkY,
                reason: 'obstacle'
            };
        }
        
        // Check for units blocking the path
        const blockingUnit = units.find(unit => 
            unit.x === checkX && unit.y === checkY && !unit.isDead
        );
        
        if (blockingUnit) {
            return { 
                blocked: true, 
                blocker: blockingUnit, 
                obstacleX: null, 
                obstacleY: null,
                reason: 'unit'
            };
        }
    }
    
    return { blocked: false, blocker: null, obstacleX: null, obstacleY: null, reason: 'clear' };
}

/**
 * Updates obstacle damage flash effects
 * @param {Tile[][]} grid 
 * @returns {Tile[][]} Updated grid with reduced flash values
 */
function updateObstacleFlash(grid) {
    const FLASH_DECAY_RATE = 0.05; // How fast the flash fades
    
    return grid.map(row => 
        row.map(tile => {
            if (tile.type === 'obstacle' && tile.damageFlash > 0) {
                return {
                    ...tile,
                    damageFlash: Math.max(0, tile.damageFlash - FLASH_DECAY_RATE)
                };
            }
            return tile;
        })
    );
}

/**
 * Generates a varied obstacle color within the grey/black/blue palette
 * @returns {string} Hex color for the obstacle
 */
function generateObstacleColor() {
    const colors = [
        '#2C3E50', // Dark blue-grey (original)
        '#34495E', // Slightly lighter blue-grey
        '#2E4053', // Medium blue-grey
        '#283747', // Darker blue-grey
        '#1B2631', // Very dark blue-grey
        '#1F2937'  // Dark grey with blue tint
    ];
    return colors[Math.floor(Math.random() * colors.length)];
}

/**
 * Creates a standardized obstacle with consistent properties
 * @param {number} x 
 * @param {number} y 
 * @returns {Tile} Standardized obstacle tile
 */
function createObstacle(x, y) {
    return {
        type: 'obstacle',
        x,
        y,
        providesCover: true,
        health: OBSTACLE_MAX_HEALTH,
        damageFlash: 0,
        color: generateObstacleColor()
    };
}

/**
 * Updates unit visibility based on line of sight from player units
 * @param {Unit[]} units 
 * @param {Tile[][]} grid 
 * @returns {Unit[]} Updated units with visibility updated
 */
function updateUnitVisibility(units, grid) {
    const playerUnits = units.filter(unit => unit.owner === 'player' && !unit.isDead);
    const enemyUnits = units.filter(unit => unit.owner === 'enemy' && !unit.isDead);
    const currentTime = Date.now();
    
    // Update units with visibility and memory tracking
    const updatedUnits = units.map(unit => {
        if (unit.owner === 'enemy') {
            // Check if this enemy is currently visible to any player unit
            let isCurrentlyVisible = false;
            let lastSeenTime = unit.lastSeen || 0;
            
            // Check line of sight from each player unit
            for (const playerUnit of playerUnits) {
                const los = checkLineOfSight(
                    playerUnit.x, playerUnit.y,
                    unit.x, unit.y,
                    grid, units
                );
                
                if (!los.blocked) {
                    isCurrentlyVisible = true;
                    lastSeenTime = currentTime;
                    break;
                }
            }
            
            return { 
                ...unit, 
                isVisible: isCurrentlyVisible,
                lastSeen: lastSeenTime,
                lastKnownX: isCurrentlyVisible ? unit.x : (unit.lastKnownX || unit.x),
                lastKnownY: isCurrentlyVisible ? unit.y : (unit.lastKnownY || unit.y)
            };
        }
        return unit;
    });
    
    return updatedUnits;
}

/**
 * Draws fog of war effects for areas where enemy units might be hidden
 * @param {Model} model
 * @param {CanvasRenderingContext2D} ctx
 */
function drawFogOfWar(model, ctx) {
    // Create a subtle fog effect for areas outside player line of sight
    ctx.fillStyle = 'rgba(0, 0, 0, 0.1)';
    
    // Draw fog over the entire grid
    ctx.fillRect(0, 0, model.grid[0].length * TILE_SIZE, model.grid.length * TILE_SIZE);
    
    // Clear fog around player units (line of sight areas)
    const playerUnits = model.units.filter(unit => unit.owner === 'player' && !unit.isDead);
    
    playerUnits.forEach(playerUnit => {
        const centerX = playerUnit.x * TILE_SIZE + TILE_SIZE / 2;
        const centerY = playerUnit.y * TILE_SIZE + TILE_SIZE / 2;
        const sightRadius = Math.max(playerUnit.shootRange * TILE_SIZE, 100); // Minimum sight radius
        
        // Create radial gradient to clear fog around player units
        const gradient = ctx.createRadialGradient(centerX, centerY, 0, centerX, centerY, sightRadius);
        gradient.addColorStop(0, 'rgba(0, 0, 0, 0)');
        gradient.addColorStop(0.7, 'rgba(0, 0, 0, 0)');
        gradient.addColorStop(1, 'rgba(0, 0, 0, 0.1)');
        
        ctx.fillStyle = gradient;
        ctx.fillRect(0, 0, model.grid[0].length * TILE_SIZE, model.grid.length * TILE_SIZE);
    });
}

/**
 * Generates a random turn order for all units
 * @param {Unit[]} units 
 * @returns {Unit[]} Units with turn order assigned
 */
function generateTurnOrder(units) {
    // Separate player and enemy units
    const playerUnits = units.filter(u => u.owner === 'player');
    const enemyUnits = units.filter(u => u.owner === 'enemy');
    
    // Shuffle each group separately
    const shuffledPlayers = [...playerUnits].sort(() => Math.random() - 0.5);
    const shuffledEnemies = [...enemyUnits].sort(() => Math.random() - 0.5);
    
    // Combine: players first, then enemies
    const orderedUnits = [...shuffledPlayers, ...shuffledEnemies];
    
    // Assign turn order
    return orderedUnits.map((unit, index) => ({
        ...unit,
        turnOrder: index
    }));
}

/**
 * Finds the best cover position for a unit that allows them to attack while being protected
 * @param {Unit} unit 
 * @param {Tile[][]} grid 
 * @param {Unit[]} allUnits 
 * @returns {{x: number, y: number} | null} Best cover position or null if none found
 */
function findBestCoverPosition(unit, grid, allUnits) {
    const width = grid[0].length;
    const height = grid.length;
    const maxSearchDistance = 8; // Don't search too far
    
    let bestPosition = null;
    let bestScore = -1;
    
    // Search in expanding radius around unit
    for (let radius = 1; radius <= maxSearchDistance; radius++) {
        for (let dx = -radius; dx <= radius; dx++) {
            for (let dy = -radius; dy <= radius; dy++) {
                if (Math.abs(dx) + Math.abs(dy) !== radius) continue; // Only check perimeter
                
                const checkX = unit.x + dx;
                const checkY = unit.y + dy;
                
                // Check bounds
                if (checkX < 0 || checkX >= width || checkY < 0 || checkY >= height) continue;
                
                // Check if position is walkable
                if (grid[checkY][checkX].type === 'obstacle') continue;
                
                // Check if position is occupied
                if (allUnits.some(u => u.x === checkX && u.y === checkY && !u.isDead)) continue;
                
                // Check if position provides cover
                const hasCover = checkCover({ x: checkX, y: checkY }, grid);
                
                // Check if position allows attacking any visible enemies
                const canAttackFromHere = allUnits.some(target => 
                    target.owner === 'player' && 
                    !target.isDead &&
                    Math.abs(checkX - target.x) + Math.abs(checkY - target.y) <= unit.shootRange
                );
                
                // Calculate score: prioritize cover + attack capability
                let score = 0;
                if (hasCover) score += 10;
                if (canAttackFromHere) score += 5;
                score -= Math.abs(dx) + Math.abs(dy); // Prefer closer positions
                
                if (score > bestScore) {
                    bestScore = score;
                    bestPosition = { x: checkX, y: checkY };
                }
            }
        }
    }
    
    return bestPosition;
}

/**
 * Makes AI decisions for an enemy unit
 * @param {Unit} unit 
 * @param {Tile[][]} grid 
 * @param {Unit[]} allUnits 
 * @returns {{action: 'move' | 'attack' | 'skip', targetX?: number, targetY?: number, targetUnit?: Unit} | null} AI decision
 */
function makeAIDecision(unit, grid, allUnits) {
    console.log('makeAIDecision called for unit', unit.id, 'with behavior:', unit.aiBehavior);
    console.log('Unit state:', { hasMoved: unit.hasMoved, hasAttacked: unit.hasAttacked, isDead: unit.isDead });
    
    if (unit.isDead || unit.hasMoved && unit.hasAttacked) {
        console.log('Unit', unit.id, 'cannot act - dead or completed actions');
        return null; // Unit can't act
    }
    
    // Find visible player units
    const visiblePlayers = allUnits.filter(target => 
        target.owner === 'player' && 
        !target.isDead && 
        target.isVisible
    );
    
    console.log('Visible players for unit', unit.id, ':', visiblePlayers.length);
    
    // If no visible players, behavior depends on AI type
    if (visiblePlayers.length === 0) {
        console.log('No visible players for unit', unit.id, 'using behavior:', unit.aiBehavior);
        switch (unit.aiBehavior) {
            case 'aggressive':
                return { type: 'skip' }; // Wait for targets
            case 'patrol':
                return generatePatrolAction(unit, grid, allUnits);
            case 'stationary':
                return { type: 'skip' }; // Stay put
        }
    }
    
    // If we have visible players, behavior depends on AI type
    console.log('Visible players found for unit', unit.id, 'using behavior:', unit.aiBehavior);
    switch (unit.aiBehavior) {
        case 'aggressive':
            return generateAggressiveAction(unit, visiblePlayers, grid, allUnits);
        case 'patrol':
            return generatePatrolAction(unit, grid, allUnits, visiblePlayers);
        case 'stationary':
            return generateStationaryAction(unit, visiblePlayers, grid, allUnits);
    }
    
    return { type: 'skip' };
}

/**
 * Generates aggressive AI action - move toward and attack visible players
 * @param {Unit} unit 
 * @param {Unit[]} visiblePlayers 
 * @param {Tile[][]} grid 
 * @param {Unit[]} allUnits 
 * @returns {{action: string, targetX?: number, targetY?: number, targetUnit?: Unit}}
 */
function generateAggressiveAction(unit, visiblePlayers, grid, allUnits) {
    console.log('generateAggressiveAction for unit', unit.id, 'with', visiblePlayers.length, 'visible players');
    
    // Find closest visible player
    const closestPlayer = visiblePlayers.reduce((closest, player) => {
        const distance = Math.abs(unit.x - player.x) + Math.abs(unit.y - player.y);
        const closestDistance = Math.abs(unit.x - closest.x) + Math.abs(unit.y - closest.y);
        return distance < closestDistance ? player : closest;
    });
    
    const distance = Math.abs(unit.x - closestPlayer.x) + Math.abs(unit.y - closestPlayer.y);
    console.log('Distance to closest player for unit', unit.id, ':', distance, 'shoot range:', unit.shootRange);
    
    // If we can attack and haven't attacked yet, do it!
    if (!unit.hasAttacked && distance <= unit.shootRange) {
        console.log('Unit', unit.id, 'can attack player at', closestPlayer.x, closestPlayer.y);
        return { type: 'attack', targetX: closestPlayer.x, targetY: closestPlayer.y };
    }
    
    // If we can't attack but can move and haven't moved yet, move closer
    if (!unit.hasMoved && distance > unit.shootRange) {
        console.log('Unit', unit.id, 'needs to move closer to attack');
        const moveTarget = findMoveTowardTarget(unit, closestPlayer, grid, allUnits);
        if (moveTarget) {
            console.log('Move target found for unit', unit.id, ':', moveTarget);
            return { type: 'move', x: moveTarget.x, y: moveTarget.y };
        } else {
            console.log('No move target found for unit', unit.id);
        }
    }
    
    // If we've done what we can, skip the turn
    console.log('Unit', unit.id, 'skipping turn - no more actions possible');
    return { type: 'skip' };
}

/**
 * Generates patrol AI action - defend territory, engage if players enter
 * @param {Unit} unit 
 * @param {Tile[][]} grid 
 * @param {Unit[]} allUnits 
 * @param {Unit[]} visiblePlayers 
 * @returns {{action: string, targetX?: number, targetY?: number, targetUnit?: Unit}}
 */
function generatePatrolAction(unit, grid, allUnits, visiblePlayers = []) {
    // If players are visible, engage them
    if (visiblePlayers.length > 0) {
        return generateAggressiveAction(unit, visiblePlayers, grid, allUnits);
    }
    
    // Otherwise, patrol within territory
    if (!unit.hasMoved) {
        const patrolTarget = findPatrolPosition(unit, grid, allUnits);
        if (patrolTarget) {
            return { type: 'move', x: patrolTarget.x, y: patrolTarget.y };
        }
    }
    
    return { type: 'skip' };
}

/**
 * Generates stationary AI action - attack from cover, flee when attacked
 * @param {Unit} unit 
 * @param {Unit[]} visiblePlayers 
 * @param {Tile[][]} grid 
 * @param {Unit[]} allUnits 
 * @returns {{action: string, targetX?: number, targetY?: number, targetUnit?: Unit}}
 */
function generateStationaryAction(unit, visiblePlayers, grid, allUnits) {
    // If we can attack, do it
    if (!unit.hasAttacked) {
        const attackablePlayer = visiblePlayers.find(player => {
            const distance = Math.abs(unit.x - player.x) + Math.abs(unit.y - player.y);
            return distance <= unit.shootRange;
        });
        
        if (attackablePlayer) {
            return { type: 'attack', targetX: attackablePlayer.x, targetY: attackablePlayer.y };
        }
    }
    
    // If we're not in cover and can move, try to find cover
    if (!unit.hasMoved && !unit.inCover) {
        const coverPosition = findBestCoverPosition(unit, grid, allUnits);
        if (coverPosition) {
            return { type: 'move', x: coverPosition.x, y: coverPosition.y };
        }
    }
    
    return { type: 'skip' };
}

/**
 * Finds a movement target toward a specific target unit
 * @param {Unit} unit 
 * @param {Unit} target 
 * @param {Tile[][]} grid 
 * @param {Unit[]} allUnits 
 * @returns {{x: number, y: number} | null} Movement target or null if none found
 */
function findMoveTowardTarget(unit, target, grid, allUnits) {
    console.log('findMoveTowardTarget for unit', unit.id, 'toward target at', target.x, target.y);
    console.log('Unit position:', unit.x, unit.y, 'movement range:', unit.movementRange);
    
    const width = grid[0].length;
    const height = grid.length;
    const maxSearchDistance = Math.min(unit.movementRange, 8);
    
    console.log('Searching within distance:', maxSearchDistance);
    
    let bestPosition = null;
    let bestScore = -1;
    
    // Search for positions that get us closer to target
    for (let dx = -maxSearchDistance; dx <= maxSearchDistance; dx++) {
        for (let dy = -maxSearchDistance; dy <= maxSearchDistance; dy++) {
            if (Math.abs(dx) + Math.abs(dy) > unit.movementRange) continue;
            
            const checkX = unit.x + dx;
            const checkY = unit.y + dy;
            
            // Check bounds
            if (checkX < 0 || checkX >= width || checkY < 0 || checkY >= height) continue;
            
            // Check if position is walkable
            if (grid[checkY][checkX].type === 'obstacle') continue;
            
            // Check if position is occupied
            if (allUnits.some(u => u.x === checkX && u.y === checkY && !u.isDead)) continue;
            
            // Check if path is not blocked
            if (isPathBlocked(unit.x, unit.y, checkX, checkY, grid)) continue;
            
            // Calculate score: prefer positions closer to target
            const currentDistance = Math.abs(unit.x - target.x) + Math.abs(unit.y - target.y);
            const newDistance = Math.abs(checkX - target.x) + Math.abs(checkY - target.y);
            const distanceImprovement = currentDistance - newDistance;
            
            let score = distanceImprovement * 10; // Prioritize getting closer
            if (grid[checkY][checkX].providesCover) score += 5; // Bonus for cover
            
            if (score > bestScore) {
                bestScore = score;
                bestPosition = { x: checkX, y: checkY };
            }
        }
    }
    
    console.log('Best position found for unit', unit.id, ':', bestPosition, 'with score:', bestScore);
    return bestPosition;
}

/**
 * Finds a patrol position within the unit's territory
 * @param {Unit} unit 
 * @param {Tile[][]} grid 
 * @param {Unit[]} allUnits 
 * @returns {{x: number, y: number} | null} Patrol position or null if none found
 */
function findPatrolPosition(unit, grid, allUnits) {
    const width = grid[0].length;
    const height = grid.length;
    const maxSearchDistance = Math.min(unit.movementRange, unit.patrolRadius);
    
    let bestPosition = null;
    let bestScore = -1;
    
    // Search for positions within patrol radius
    for (let dx = -maxSearchDistance; dx <= maxSearchDistance; dx++) {
        for (let dy = -maxSearchDistance; dy <= maxSearchDistance; dy++) {
            if (Math.abs(dx) + Math.abs(dy) > unit.movementRange) continue;
            
            const checkX = unit.x + dx;
            const checkY = unit.y + dy;
            
            // Check bounds
            if (checkX < 0 || checkX >= width || checkY < 0 || checkY >= height) continue;
            
            // Check if position is within patrol radius
            const distanceFromCenter = Math.abs(checkX - unit.patrolCenterX) + Math.abs(checkY - unit.patrolCenterY);
            if (distanceFromCenter > unit.patrolRadius) continue;
            
            // Check if position is walkable
            if (grid[checkY][checkX].type === 'obstacle') continue;
            
            // Check if position is occupied
            if (allUnits.some(u => u.x === checkX && u.y === checkY && !u.isDead)) continue;
            
            // Check if path is not blocked
            if (isPathBlocked(unit.x, unit.y, checkX, checkY, grid)) continue;
            
            // Calculate score: prefer positions with good cover and visibility
            let score = 0;
            if (grid[checkY][checkX].providesCover) score += 8;
            
            // Bonus for positions that allow seeing outside patrol area
            const canSeeOutside = checkX === 0 || checkX === width - 1 || checkY === 0 || checkY === height - 1;
            if (canSeeOutside) score += 3;
            
            // Small random factor to avoid predictable patterns
            score += Math.random() * 2;
            
            if (score > bestScore) {
                bestScore = score;
                bestPosition = { x: checkX, y: checkY };
            }
        }
    }
    
    return bestPosition;
}

/**
 * Advances to the next turn in the turn order
 * @param {Model} model 
 * @returns {Model} Updated model with next turn
 */
function advanceTurn(model) {
    let nextTurnIndex = model.currentTurnIndex + 1;
    
    // Find next living unit
    while (nextTurnIndex < model.units.length) {
        const nextUnit = model.units.find(u => u.turnOrder === nextTurnIndex);
        if (nextUnit && !nextUnit.isDead) {
            break;
        }
        nextTurnIndex++;
    }
    
    // If we've gone through all units, start over
    if (nextTurnIndex >= model.units.length) {
        nextTurnIndex = 0;
        // Reset all units' actions
        const updatedUnits = model.units.map(unit => ({
            ...unit,
            hasMoved: false,
            hasAttacked: false
        }));
        
        return {
            ...model,
            units: updatedUnits,
            currentTurnIndex: nextTurnIndex,
            uiState: { type: 'AwaitingSelection' } // Reset UI state
        };
    }
    
    // Reset UI state when advancing to next turn
    return {
        ...model,
        currentTurnIndex: nextTurnIndex,
        uiState: { type: 'AwaitingSelection' }
    };
}

/**
 * Executes the current unit's turn (player or AI)
 * @param {Model} model 
 * @returns {Model} Updated model after turn execution
 */
function executeCurrentTurn(model) {
    const currentUnit = model.units.find(u => u.turnOrder === model.currentTurnIndex);
    
    if (!currentUnit || currentUnit.isDead) {
        console.log('No current unit or unit is dead, advancing turn');
        return advanceTurn(model);
    }
    
    // If it's a player unit, wait for player input
    if (currentUnit.owner === 'player') {
        console.log('Player turn, waiting for input');
        return model;
    }
    
    // If it's an enemy unit, execute AI turn immediately
    console.log('Enemy turn for unit', currentUnit.id, '- executing AI immediately');
    
    // Execute AI turn and advance immediately
    const result = executeEnemyTurn(model, currentUnit);
    console.log('AI turn completed for unit', currentUnit.id, 'advancing turn');
    
    // Always advance turn after enemy completes their actions
    return advanceTurn(result);
}



/**
 * Removes dead units from the turn order and adjusts turn indices
 * @param {Unit[]} units 
 * @returns {Unit[]} Updated units with dead units removed and turn order adjusted
 */
function cleanupDeadUnits(units) {
    const livingUnits = units.filter(unit => !unit.isDead);
    
    // Reassign turn order for remaining units
    return livingUnits.map((unit, index) => ({
        ...unit,
        turnOrder: index
    }));
}

/**
 * Updates action feedback timers for enemy units
 * @param {Unit[]} units 
 * @returns {Unit[]} Updated units
 */
function updateActionFeedbackTimers(units) {
    return units.map(unit => {
        if (unit.actionFeedbackTimer > 0) {
            return { ...unit, actionFeedbackTimer: Math.max(0, unit.actionFeedbackTimer - 16) }; // 16ms per frame at 60fps
        }
        return unit;
    });
}





/**
 * Pure function: Executes enemy turn with guaranteed termination
 * @param {Model} model 
 * @param {Unit} enemyUnit 
 * @returns {Model} Updated model with turn completed
 */
function executeEnemyTurn(model, enemyUnit) {
    // Pre-condition: enemyUnit is an enemy unit that needs to act
    if (enemyUnit.owner !== 'enemy') {
        throw new Error('executeEnemyTurn called with non-enemy unit');
    }
    
    console.log('Executing enemy turn for unit', enemyUnit.id);
    
    // Find visible player units
    const visiblePlayers = model.units.filter(target => 
        target.owner === 'player' && 
        !target.isDead && 
        target.isVisible
    );
    
    if (visiblePlayers.length === 0) {
        console.log('No visible players for unit', enemyUnit.id, 'skipping turn');
        // Mark both actions as complete and return
        const skippedUnit = { 
            ...enemyUnit, 
            hasMoved: true, 
            hasAttacked: true,
            isAnimating: false,
            animationType: 'none',
            animationProgress: 0,
            path: [],
            targetX: -1,
            targetY: -1
        };
        return {
            ...model,
            units: model.units.map(u => u.id === enemyUnit.id ? skippedUnit : u)
        };
    }
    
    // Find closest visible player
    const closestPlayer = visiblePlayers.reduce((closest, player) => {
        const distance = Math.abs(enemyUnit.x - player.x) + Math.abs(enemyUnit.y - player.y);
        const closestDistance = Math.abs(enemyUnit.x - closest.x) + Math.abs(enemyUnit.y - closest.y);
        return distance < closestDistance ? player : closest;
    });
    
    const distance = Math.abs(enemyUnit.x - closestPlayer.x) + Math.abs(enemyUnit.y - closestPlayer.y);
    console.log('Unit', enemyUnit.id, 'distance to player:', distance, 'shoot range:', enemyUnit.shootRange);
    
    let updatedModel = model;
    let updatedUnit = enemyUnit;
    
    // First action: Move if we can't attack yet
    if (!updatedUnit.hasMoved && distance > enemyUnit.shootRange) {
        console.log('Unit', enemyUnit.id, 'moving closer to attack');
        const moveTarget = findMoveTowardTarget(updatedUnit, closestPlayer, updatedModel.grid, updatedModel.units);
        if (moveTarget) {
            const moveResult = executeEnemyMove(updatedModel, updatedUnit, { type: 'move', x: moveTarget.x, y: moveTarget.y });
            updatedModel = moveResult;
            updatedUnit = moveResult.units.find(u => u.id === enemyUnit.id);
            console.log('Unit', enemyUnit.id, 'moved to', moveTarget.x, moveTarget.y);
        } else {
            // Can't move, mark as moved
            updatedUnit = { ...updatedUnit, hasMoved: true };
            updatedModel = {
                ...updatedModel,
                units: updatedModel.units.map(u => u.id === enemyUnit.id ? updatedUnit : u)
            };
        }
    } else if (!updatedUnit.hasMoved) {
        // No movement needed, mark as moved
        updatedUnit = { ...updatedUnit, hasMoved: true };
        updatedModel = {
            ...updatedModel,
            units: updatedModel.units.map(u => u.id === enemyUnit.id ? updatedUnit : u)
        };
    }
    
    // Second action: Attack if we can
    if (!updatedUnit.hasAttacked && distance <= enemyUnit.shootRange) {
        console.log('Unit', enemyUnit.id, 'attacking player at', closestPlayer.x, closestPlayer.y);
        const attackResult = executeEnemyAttack(updatedModel, updatedUnit, { type: 'attack', targetX: closestPlayer.x, targetY: closestPlayer.y });
        updatedModel = attackResult;
        updatedUnit = attackResult.units.find(u => u.id === enemyUnit.id);
        console.log('Unit', enemyUnit.id, 'attacked');
    } else if (!updatedUnit.hasAttacked) {
        // Can't attack, mark as attacked
        updatedUnit = { ...updatedUnit, hasAttacked: true };
        updatedModel = {
            ...updatedModel,
            units: updatedModel.units.map(u => u.id === enemyUnit.id ? updatedUnit : u)
        };
    }
    
    // Ensure both actions are marked as complete
    if (!updatedUnit.hasMoved) {
        updatedUnit = { 
            ...updatedUnit, 
            hasMoved: true,
            isAnimating: false,
            animationType: 'none',
            animationProgress: 0,
            path: [],
            targetX: -1,
            targetY: -1
        };
    }
    if (!updatedUnit.hasAttacked) {
        updatedUnit = { 
            ...updatedUnit, 
            hasAttacked: true,
            isAnimating: false,
            animationType: 'none',
            animationProgress: 0,
            projectileX: -1,
            projectileY: -1,
            projectileTargetX: -1,
            projectileTargetY: -1
        };
    }
    
    // Update the model with the final unit state
    const finalModel = {
        ...updatedModel,
        units: updatedModel.units.map(u => u.id === enemyUnit.id ? updatedUnit : u)
    };
    
    console.log('Enemy turn completed for unit', enemyUnit.id, 'final state:', {
        hasMoved: updatedUnit.hasMoved,
        hasAttacked: updatedUnit.hasAttacked
    });
    
    return finalModel;
}

/**
 * Pure function: Executes enemy movement
 * @param {Model} model 
 * @param {Unit} enemyUnit 
 * @param {Object} decision 
 * @returns {Model} Updated model
 */
function executeEnemyMove(model, enemyUnit, decision) {
    console.log('Executing enemy move for unit', enemyUnit.id, 'to', decision.x, decision.y);
    
    const path = findPath(enemyUnit.x, enemyUnit.y, decision.x, decision.y, model.grid);
    console.log('Path found:', path);
    
    if (path.length > 1) {
        // Start movement animation
        const animatedUnit = startMovementAnimation(enemyUnit, decision.x, decision.y, model.grid);
        animatedUnit.hasMoved = true;
        console.log('Enemy unit', enemyUnit.id, 'started movement animation');
        
        return {
            ...model,
            units: model.units.map(u => u.id === enemyUnit.id ? animatedUnit : u)
        };
    } else {
        // No movement needed, mark as moved
        console.log('Enemy unit', enemyUnit.id, 'no movement needed, marked as moved');
        return {
            ...model,
            units: model.units.map(u => 
                u.id === enemyUnit.id ? { ...u, hasMoved: true } : u
            )
        };
    }
}

/**
 * Pure function: Executes enemy attack
 * @param {Model} model 
 * @param {Unit} enemyUnit 
 * @param {Object} decision 
 * @returns {Model} Updated model
 */
function executeEnemyAttack(model, enemyUnit, decision) {
    console.log('Executing enemy attack for unit', enemyUnit.id, 'at target', decision.targetX, decision.targetY);
    
    const animatedUnit = startShootingAnimation(enemyUnit, decision.targetX, decision.targetY);
    animatedUnit.hasAttacked = true;
    console.log('Enemy unit', enemyUnit.id, 'started attack animation');
    
    return {
        ...model,
        units: model.units.map(u => u.id === enemyUnit.id ? animatedUnit : u)
    };
}

/**
 * Sanitizes unit animation state to prevent crashes
 * @param {Unit} unit 
 * @returns {Unit} Sanitized unit
 */
function sanitizeUnitState(unit) {
    // If unit is not animating, ensure all animation properties are reset
    if (!unit.isAnimating) {
        return {
            ...unit,
            animationType: 'none',
            animationProgress: 0,
            path: [],
            targetX: -1,
            targetY: -1,
            projectileX: -1,
            projectileY: -1,
            projectileTargetX: -1,
            projectileTargetY: -1
        };
    }
    
    // If unit is animating, validate animation properties
    const sanitizedUnit = { ...unit };
    
    // Validate path data
    if (sanitizedUnit.animationType === 'moving') {
        if (!sanitizedUnit.path || !Array.isArray(sanitizedUnit.path)) {
            sanitizedUnit.path = [];
        }
        if (typeof sanitizedUnit.targetX !== 'number' || typeof sanitizedUnit.targetY !== 'number') {
            sanitizedUnit.targetX = sanitizedUnit.x;
            sanitizedUnit.targetY = sanitizedUnit.y;
        }
    }
    
    // Validate projectile data
    if (sanitizedUnit.animationType === 'shooting') {
        if (typeof sanitizedUnit.projectileX !== 'number' || typeof sanitizedUnit.projectileY !== 'number') {
            sanitizedUnit.projectileX = sanitizedUnit.x;
            sanitizedUnit.projectileY = sanitizedUnit.y;
        }
        if (typeof sanitizedUnit.projectileTargetX !== 'number' || typeof sanitizedUnit.projectileTargetY !== 'number') {
            sanitizedUnit.projectileTargetX = sanitizedUnit.x;
            sanitizedUnit.projectileTargetY = sanitizedUnit.y;
        }
    }
    
    // Validate animation progress
    if (typeof sanitizedUnit.animationProgress !== 'number' || 
        sanitizedUnit.animationProgress < 0 || 
        sanitizedUnit.animationProgress > 1) {
        sanitizedUnit.animationProgress = 0;
    }
    
    return sanitizedUnit;
}