module Game exposing (..)

import Types exposing (..)

--| Initial game state with a simple adventure
init : Model
init =
    { currentScene = SceneId "start"
    , inventory = []
    , scenes =
        [ { id = SceneId "start"
          , title = "The Mysterious Mansion"
          , description = "You stand before an old mansion. The door is locked, but you notice a rusty key on the ground nearby."
          , choices =
              [ { text = "Pick up the key"
                , nextScene = SceneId "start"
                , requiredItem = Nothing
                , consumesItem = False
                }
              , { text = "Try the door"
                , nextScene = SceneId "inside"
                , requiredItem = Just (ItemId "rusty_key")
                , consumesItem = True
                }
              ]
          , items = [ { id = ItemId "rusty_key", name = "Rusty Key", description = "An old, rusty key that might fit the mansion's door." } ]
          }
        , { id = SceneId "inside"
          , title = "Inside the Mansion"
          , description = "You're inside the mansion. The air is musty and old. There's a dusty book on a table and a locked chest in the corner."
          , choices =
              [ { text = "Examine the book"
                , nextScene = SceneId "book"
                , requiredItem = Nothing
                , consumesItem = False
                }
              , { text = "Try to open the chest"
                , nextScene = SceneId "chest"
                , requiredItem = Nothing
                , consumesItem = False
                }
              ]
          , items = []
          }
        , { id = SceneId "book"
          , title = "The Dusty Book"
          , description = "The book contains a map of the mansion. You notice a small key drawn in the corner of one page."
          , choices =
              [ { text = "Take the key"
                , nextScene = SceneId "inside"
                , requiredItem = Nothing
                , consumesItem = False
                }
              , { text = "Return to the main room"
                , nextScene = SceneId "inside"
                , requiredItem = Nothing
                , consumesItem = False
                }
              ]
          , items = [ { id = ItemId "small_key", name = "Small Key", description = "A small key that might fit the chest." } ]
          }
        , { id = SceneId "chest"
          , title = "The Locked Chest"
          , description = "The chest is locked with a small lock. You need a key to open it."
          , choices =
              [ { text = "Use the small key"
                , nextScene = SceneId "treasure"
                , requiredItem = Just (ItemId "small_key")
                , consumesItem = True
                }
              , { text = "Return to the main room"
                , nextScene = SceneId "inside"
                , requiredItem = Nothing
                , consumesItem = False
                }
              ]
          , items = []
          }
        , { id = SceneId "treasure"
          , title = "The Treasure"
          , description = "Inside the chest, you find a valuable gem! Your adventure has been successful."
          , choices =
              [ { text = "Start a new adventure"
                , nextScene = SceneId "start"
                , requiredItem = Nothing
                , consumesItem = False
                }
              ]
          , items = [ { id = ItemId "gem", name = "Valuable Gem", description = "A beautiful gem that sparkles in the light." } ]
          }
        ]
    }

--| Find a scene by its ID
findScene : SceneId -> List Scene -> Maybe Scene
findScene targetId scenes =
    List.filter (\scene -> scene.id == targetId) scenes
        |> List.head

--| Find an item by its ID
findItem : ItemId -> List Item -> Maybe Item
findItem targetId items =
    List.filter (\item -> item.id == targetId) items
        |> List.head

--| Check if player has an item
hasItem : ItemId -> List Item -> Bool
hasItem itemId inventory =
    List.any (\item -> item.id == itemId) inventory

--| Update the game state based on messages
update : Msg -> Model -> Model
update msg model =
    case msg of
        ChooseChoice choice ->
            case choice.requiredItem of
                Just requiredItemId ->
                    if hasItem requiredItemId model.inventory then
                        let
                            newInventory =
                                if choice.consumesItem then
                                    List.filter (\item -> item.id /= requiredItemId) model.inventory
                                else
                                    model.inventory
                        in
                        { model
                            | currentScene = choice.nextScene
                            , inventory = newInventory
                        }
                    else
                        model

                Nothing ->
                    { model | currentScene = choice.nextScene }

        PickupItem item ->
            { model | inventory = item :: model.inventory }

        UseItem item _ ->
            if hasItem item.id model.inventory then
                { model
                    | inventory = List.filter (\i -> i.id /= item.id) model.inventory
                }
            else
                model