#4 Pick up items

lib/RPGEngine/Data/Level.hs

@@ -37,6 +37,15 @@ hasAt pos level = match firstItem firstEntity
           firstItem   = find ((== pos) . getICoord) $ items level
           getICoord i = (itemX i, itemY i)
 
+getWithId :: String -> Level -> Maybe (Either Item Entity)
+getWithId id level = match firstItem firstEntity
+    where match :: Maybe Item -> Maybe Entity -> Maybe (Either Item Entity)
+          match (Just a) _ = Just $ Left a
+          match _ (Just a) = Just $ Right a
+          match _ _        = Nothing
+          firstEntity      = find ((== id) . entityId) $ entities level
+          firstItem        = find ((== id) . itemId) $ items level
+
 directionOffsets :: Direction -> (X, Y)
 directionOffsets North  = ( 0,  1)
 directionOffsets East   = ( 1,  0)

lib/RPGEngine/Input/ActionSelection.hs

@@ -4,10 +4,11 @@ module RPGEngine.Input.ActionSelection
 
 import RPGEngine.Input.Core (InputHandler, handleKey, composeInputHandlers, ListSelector (selection))
 
-import RPGEngine.Data (Game (..), State (..), Direction (..), Action (..), ItemId, EntityId)
+import RPGEngine.Data (Game (..), State (..), Direction (..), Action (..), ItemId, EntityId, Level (..), Player (inventory))
 import Graphics.Gloss.Interface.IO.Game (Key(SpecialKey), SpecialKey (KeyUp, KeyDown))
 import Graphics.Gloss.Interface.IO.Interact
     ( SpecialKey(..), KeyState(..) )
+import RPGEngine.Data.Level (getWithId)
 
 ------------------------------ Exported ------------------------------
 
@@ -22,9 +23,10 @@ handleInputActionSelection = composeInputHandlers [
 ----------------------------------------------------------------------
 
 selectAction :: Game -> Game
-selectAction game@Game{ state = ActionSelection list selection continue } = newGame
+selectAction game@Game{ state = ActionSelection list selector continue } = newGame
     where newGame = game{ state = execute selectedAction continue }
-          selectedAction = Leave
+          selectedAction = list !! index
+          index = selection selector
 selectAction g = g
 
 -- TODO Lift this code from LevelSelection
@@ -52,8 +54,16 @@ execute (IncreasePlayerHp iid) s = increasePlayerHp iid s
 execute _ s = s
 
 -- Pick up the item with itemId and put it in the players inventory
+-- Should receive a Playing state
 pickUpItem :: ItemId -> State -> State
-pickUpItem _ s = s -- TODO
+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 }
+          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
 useItem :: ItemId -> State -> State -- TODO