-- Represents an item in the game.

module RPGEngine.Internals.Data.Internals
( Action(..)
, Condition(..)
, Object(..)
, EntityId
, ItemId
) where

----------------------------- Constants ------------------------------

type EntityId = String
type ItemId = String

data Object = 
    Item { -- All fields are required
        -- Easy way to identify items
        id          :: ItemId,
        -- Horizontal coördinate in the level
        x           :: Int,
        -- Vertical coördinate in the level
        y           :: Int,
        name        :: String,
        -- Short description of the object
        description :: String,
        -- Counts how often the object can be used by the player. Either 
        -- infinite or a natural number
        useTimes    :: Maybe Int,
        -- List of conditional actions when the player is standing on this object
        actions     :: [([Condition], Action)],
        -- Interpretation depends on action with this object.
        value       :: Maybe Int
    }
    | Entity {
    -- Required fields
        -- Easy way to identify items
        id          :: EntityId,
        -- Horizontal coördinate in the level
        x           :: Int,
        -- Vertical coördinate in the level
        y           :: Int,
        name        :: String,
        -- Short description of the object
        description :: String,
        -- List of conditional actions when the player is standing on this object
        actions     :: [([Condition], Action)],
    -- Optional fields
        -- The direction of the item. e.g. a door has a direction.
        direction   :: Maybe Direction,
        -- Some entities have health points.
        hp          :: Maybe Int,
        -- Interpretation depends on action with this object.
        value       :: Maybe Int
    }

data Direction = North 
               | East 
               | South 
               | West
               deriving (Show)

data Action = Leave
            | RetrieveItem ItemId
            | UseItem ItemId
            | DecreaseHp EntityId ItemId
            | IncreasePlayerHp ItemId
            | Nothing
            deriving (Show, Eq)

data Condition = InventoryFull
               | InventoryContains ItemId
               | Not Condition
               | AlwaysFalse
               deriving (Show, Eq)

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