/**
 * Baba Yaga Language Mode for CodeMirror
 * Provides syntax highlighting for the Baba Yaga functional programming language
 */

// Global function to initialize the Baba Yaga language mode
window.initBabaYagaMode = function() {
    // Check if CodeMirror is available
    if (typeof CodeMirror === 'undefined') {
        console.log('CodeMirror not available yet, will retry...');
        setTimeout(window.initBabaYagaMode, 100);
        return;
    }

    console.log('Initializing Baba Yaga language mode...');

    // Baba Yaga language keywords
    const keywords = [
        'when', 'is', 'then', 'else', 'with', 'rec', 'in',
        'Ok', 'Err', 'true', 'false', 'PI', 'INFINITY',
        'and', 'or', 'xor', 'not', 'if'
    ];

    // Baba Yaga type system
    const types = [
        'Int', 'String', 'Result', 'Float', 'Number', 
        'List', 'Table', 'Bool', 'Unit', 'Maybe'
    ];

    // Function names that are commonly used
    const builtins = [
        'map', 'filter', 'reduce', 'fold', 'head', 'tail',
        'length', 'append', 'concat', 'reverse', 'sort'
    ];

    // Main tokenizer function
    function tokenize(stream, state) {
        // Handle comments
        if (stream.match(/\/\/.*/)) {
            return 'comment';
        }

        // Handle multi-line comments
        if (stream.match(/\/\*/)) {
            state.inComment = true;
            return 'comment';
        }

        if (state.inComment) {
            if (stream.match(/\*\//)) {
                state.inComment = false;
            } else {
                stream.next();
            }
            return 'comment';
        }

        // Handle whitespace
        if (stream.eatSpace()) {
            return null;
        }

        // Handle numbers (integers and floats)
        if (stream.match(/^-?\d+\.\d+/)) {
            return 'number';
        }
        if (stream.match(/^-?\d+/)) {
            return 'number';
        }

        // Handle strings
        if (stream.match(/^"[^"]*"/)) {
            return 'string';
        }

        // Handle identifiers and keywords
        if (stream.match(/^[a-zA-Z_][a-zA-Z0-9_]*/)) {
            const word = stream.current();
            
            if (keywords.includes(word)) {
                return 'keyword';
            }
            
            if (types.includes(word)) {
                return 'type';
            }
            
            if (builtins.includes(word)) {
                return 'builtin';
            }
            
            // Check if it's a function declaration (followed by :)
            const nextChar = stream.peek();
            if (nextChar === ':') {
                return 'function';
            }
            
            return 'variable';
        }

        // Handle operators and symbols
        if (stream.match(/^->/)) {
            return 'operator';
        }
        
        if (stream.match(/^[=!<>]=/)) {
            return 'operator';
        }
        
        if (stream.match(/^[+\-*/%=<>!&|^,;:()[\]{}]/)) {
            return 'operator';
        }
        
        // Handle dots for member access
        if (stream.match(/^\./)) {
            return 'operator';
        }

        // Handle unknown characters
        stream.next();
        return null;
    }

    // Define the Baba Yaga language mode
    CodeMirror.defineMode("baba-yaga", function() {
        return {
            startState: function() {
                return {
                    inComment: false,
                    inString: false,
                    indentLevel: 0
                };
            },

            token: function(stream, state) {
                return tokenize(stream, state);
            },

            // Indentation rules
            indent: function(state, textAfter) {
                const baseIndent = state.indentLevel * 2;
                
                // Increase indent after certain patterns
                if (textAfter.match(/^[a-zA-Z_][a-zA-Z0-9_]*\s*:/)) {
                    return baseIndent + 2;
                }
                
                if (textAfter.match(/^->/)) {
                    return baseIndent + 2;
                }
                
                if (textAfter.match(/^when/)) {
                    return baseIndent + 2;
                }
                
                if (textAfter.match(/^with/)) {
                    return baseIndent + 2;
                }
                
                return baseIndent;
            },

            // Line comment character
            lineComment: "//",

            // Auto-indent on certain characters
            electricChars: "{}:->",

            // Fold code blocks
            fold: "indent"
        };
    });

    // Note: CodeMirror 5 doesn't have defineTheme, we use CSS instead
    // The theme is defined in the CSS with .cm-s-baba-yaga classes
    
    // Also register MIME types
    CodeMirror.defineMIME("text/x-baba-yaga", "baba-yaga");
    CodeMirror.defineMIME("text/baba-yaga", "baba-yaga");
    CodeMirror.defineMIME("application/x-baba-yaga", "baba-yaga");

    console.log('Baba Yaga language mode loaded successfully!');
    console.log('Available modes:', Object.keys(CodeMirror.modes));
    
    // Dispatch a custom event to notify that the mode is ready
    window.dispatchEvent(new CustomEvent('baba-yaga-mode-ready'));
};

// Start initialization
console.log('Baba Yaga mode script loaded, waiting for CodeMirror...');
window.initBabaYagaMode();