#4 Increase playerhp

lib/RPGEngine/Input/ActionSelection.hs

@@ -4,11 +4,12 @@ module RPGEngine.Input.ActionSelection
 
 import RPGEngine.Input.Core (InputHandler, handleKey, composeInputHandlers, ListSelector (selection))
 
-import RPGEngine.Data (Game (..), State (..), Direction (..), Action (..), ItemId, EntityId, Level (..), Player (inventory))
+import RPGEngine.Data (Game (..), State (..), Direction (..), Action (..), ItemId, EntityId, Level (..), Player (inventory, playerHp, Player), Item (..), HP)
 import Graphics.Gloss.Interface.IO.Game (Key(SpecialKey), SpecialKey (KeyUp, KeyDown))
 import Graphics.Gloss.Interface.IO.Interact
     ( SpecialKey(..), KeyState(..) )
 import RPGEngine.Data.Level (getWithId)
+import Data.Foldable (find)
 
 ------------------------------ Exported ------------------------------
 
@@ -50,7 +51,8 @@ execute :: Action -> State -> State
 execute (RetrieveItem id     ) s = pickUpItem id s
 execute (UseItem      id     ) s = useItem id s
 execute (DecreaseHp   eid iid) s = decreaseHp eid iid s
-execute (IncreasePlayerHp iid) s = increasePlayerHp iid s
+execute (IncreasePlayerHp iid) s = healedPlayer
+    where healedPlayer = s{ player = increasePlayerHp iid (player s)}
 execute _ s = s
 
 -- Pick up the item with itemId and put it in the players inventory
@@ -58,14 +60,14 @@ execute _ s = s
 pickUpItem :: ItemId -> State -> State
 pickUpItem id s@Playing{ level = level, player = player } = newState
     where (Just (Left pickedUpItem)) = getWithId id level
-          newState     = s{ level = newLevel, player = newPlayer }
-          newLevel     = level{ items = filteredItems }
+          newState      = s{ level = newLevel, player = newPlayer }
+          newLevel      = level{ items = filteredItems }
           filteredItems = filter (/= pickedUpItem) $ items level
           newPlayer     = player{ inventory = newInventory }
           newInventory  = pickedUpItem:inventory player
 pickUpItem _ _ = Error "Something went wrong while picking up an item"
 
--- Use an item on the player
+-- Use an item
 useItem :: ItemId -> State -> State -- TODO
 useItem _ s = s -- TODO
 
@@ -79,8 +81,23 @@ decreaseHp _ _ s = s
 -- TODO Break item if durability below zero
 
 -- Heal a bit
-increasePlayerHp :: ItemId -> State -> State
-increasePlayerHp _ s = s
--- TODO Increase playerHp
--- TODO Decrease durability of item
--- TODO Remove item if durability below zero
+-- Should receive a Player
+increasePlayerHp :: ItemId -> Player -> Player
+increasePlayerHp id p@Player{ playerHp = hp, inventory = inventory} = newPlayer
+    where newPlayer = p{ playerHp = newHp, inventory = newInventory newItem }
+          (Just usedItem) = find ((== id) . itemId) inventory
+          newItem  = decreaseDurability usedItem
+          newInventory (Just item) = item:filteredInventory
+          newInventory _           = filteredInventory
+          filteredInventory =filter (/= usedItem) inventory
+          newHp = changeHealth hp (itemValue usedItem)
+
+decreaseDurability :: Item -> Maybe Item
+decreaseDurability item@Item{ useTimes = Nothing  } = Just item -- Infinite uses, never breaks
+decreaseDurability item@Item{ useTimes = Just val } | 0 < val - 1 = Just item{ useTimes = Just (val - 1) }
+                                                    | otherwise = Nothing -- Broken
+
+-- Change given health by a given amount
+changeHealth :: HP -> HP -> HP
+changeHealth (Just health) (Just difference) = Just (health + difference)
+changeHealth health        _                 = health