Allow eating edible items

Add menu support to the prompt system, and an "Eat" command that prompts
for an item to eat and eats the item the character specifies, restoring
an amount of hitpoints configurable via the item raw type.

src/Xanthous/App.hs

@@ -13,6 +13,7 @@ import           Control.Monad.Random (MonadRandom)
 import           Control.Monad.State.Class (modify)
 import           Data.Aeson (object, ToJSON)
 import qualified Data.Aeson as A
+import qualified Data.Vector as V
 import           System.Exit
 --------------------------------------------------------------------------------
 import           Xanthous.Command
@@ -29,16 +30,18 @@ import           Xanthous.Game.Draw (drawGame)
 import           Xanthous.Game.Prompt
 import           Xanthous.Monad
 import           Xanthous.Resource (Name)
-import           Xanthous.Messages (message)
+import qualified Xanthous.Messages as Messages
 import           Xanthous.Util.Inflection (toSentence)
 --------------------------------------------------------------------------------
 import qualified Xanthous.Entities.Character as Character
 import           Xanthous.Entities.Character
 import           Xanthous.Entities
 import           Xanthous.Entities.Item (Item)
+import qualified Xanthous.Entities.Item as Item
 import           Xanthous.Entities.Creature (Creature)
 import qualified Xanthous.Entities.Creature as Creature
 import           Xanthous.Entities.Environment (Door, open, locked)
+import           Xanthous.Entities.RawTypes (edible, eatMessage, hitpointsHealed)
 import           Xanthous.Generators
 import qualified Xanthous.Generators.CaveAutomata as CaveAutomata
 --------------------------------------------------------------------------------
@@ -155,6 +158,26 @@ handleCommand Open = do
 
 handleCommand Wait = stepGame >> continue
 
+handleCommand Eat = do
+  uses (character . inventory)
+       (V.mapMaybe (\item -> (item,) <$> item ^. Item.itemType . edible))
+    >>= \case
+      Empty -> say_ ["eat", "noFood"]
+      food ->
+        let foodMenuItem idx (item, edibleItem)
+              = ( item ^. Item.itemType . char . char
+                , MenuOption (description item) (idx, item, edibleItem))
+            menuItems = mkMenuItems $ imap foodMenuItem food
+        in menu_ ["eat", "menuPrompt"] Cancellable menuItems
+          $ \(MenuResult (idx, item, edibleItem)) -> do
+            character . inventory %= \inv ->
+              let (before, after) = V.splitAt idx inv
+              in before <> fromMaybe Empty (tailMay after)
+            let msg = fromMaybe (Messages.lookup ["eat", "eat"])
+                      $ edibleItem ^. eatMessage
+            message msg $ object ["item" A..= item]
+  continue
+
 handleCommand ToggleRevealAll = do
   val <- debugState . allRevealed <%= not
   say ["debug", "toggleRevealAll"] $ object [ "revealAll" A..= val ]
@@ -168,39 +191,43 @@ handlePromptEvent
   -> BrickEvent Name ()
   -> AppM (Next GameState)
 
-handlePromptEvent _ (Prompt Cancellable _ _ _) (VtyEvent (EvKey KEsc [])) = do
-  promptState .= NoPrompt
-  continue
-handlePromptEvent _ pr (VtyEvent (EvKey KEnter [])) = do
-  submitPrompt pr
+handlePromptEvent _ (Prompt Cancellable _ _ _ _) (VtyEvent (EvKey KEsc [])) = do
   promptState .= NoPrompt
   continue
+handlePromptEvent _ pr (VtyEvent (EvKey KEnter [])) =
+  submitPrompt pr >> clearPrompt
 
 handlePromptEvent
   msg
-  (Prompt c SStringPrompt (StringPromptState edit) cb)
+  (Prompt c SStringPrompt (StringPromptState edit) pi cb)
   (VtyEvent ev)
   = do
     edit' <- lift $ handleEditorEvent ev edit
-    let prompt' = Prompt c SStringPrompt (StringPromptState edit') cb
+    let prompt' = Prompt c SStringPrompt (StringPromptState edit') pi cb
     promptState .= WaitingPrompt msg prompt'
     continue
 
-handlePromptEvent _ (Prompt _ SDirectionPrompt _ cb)
+handlePromptEvent _ (Prompt _ SDirectionPrompt _ _ cb)
   (VtyEvent (EvKey (KChar (directionFromChar -> Just dir)) []))
-  = do
-    cb $ DirectionResult dir
-    promptState .= NoPrompt
-    continue
-handlePromptEvent _ (Prompt _ SDirectionPrompt _ _) _ = continue
+  = cb (DirectionResult dir) >> clearPrompt
+handlePromptEvent _ (Prompt _ SDirectionPrompt _ _ _) _ = continue
 
-handlePromptEvent _ (Prompt _ SContinue _ _) _ = continue
+handlePromptEvent _ (Prompt _ SContinue _ _ _) _ = continue
+
+handlePromptEvent _ (Prompt _ SMenu _ items cb) (VtyEvent (EvKey (KChar chr) []))
+  | Just (MenuOption _ res) <- items ^. at chr
+  = cb (MenuResult res) >> clearPrompt
+  | otherwise
+  = continue
 
 handlePromptEvent _ _ _ = undefined
 
+clearPrompt :: AppM (Next GameState)
+clearPrompt = promptState .= NoPrompt >> continue
+
 prompt
   :: forall (pt :: PromptType) (params :: Type).
-    (ToJSON params, SingPromptType pt)
+    (ToJSON params, SingPromptType pt, PromptInput pt ~ ())
   => [Text]                     -- ^ Message key
   -> params                     -- ^ Message params
   -> PromptCancellable
@@ -208,19 +235,40 @@ prompt
   -> AppM ()
 prompt msgPath params cancellable cb = do
   let pt = singPromptType @pt
-  msg <- message msgPath params
+  msg <- Messages.message msgPath params
   let p = mkPrompt cancellable pt cb
   promptState .= WaitingPrompt msg p
 
 prompt_
   :: forall (pt :: PromptType) .
-    (SingPromptType pt)
+    (SingPromptType pt, PromptInput pt ~ ())
   => [Text] -- ^ Message key
   -> PromptCancellable
   -> (PromptResult pt -> AppM ()) -- ^ Prompt promise handler
   -> AppM ()
 prompt_ msg = prompt msg $ object []
 
+menu :: forall (a :: Type) (params :: Type).
+       (ToJSON params)
+     => [Text]                            -- ^ Message key
+     -> params                            -- ^ Message params
+     -> PromptCancellable
+     -> Map Char (MenuOption a)           -- ^ Menu items
+     -> (PromptResult ('Menu a) -> AppM ()) -- ^ Menu promise handler
+     -> AppM ()
+menu msgPath params cancellable items cb = do
+  msg <- Messages.message msgPath params
+  let p = mkMenu cancellable items cb
+  promptState .= WaitingPrompt msg p
+
+menu_ :: forall (a :: Type).
+        [Text]                            -- ^ Message key
+      -> PromptCancellable
+      -> Map Char (MenuOption a)           -- ^ Menu items
+      -> (PromptResult ('Menu a) -> AppM ()) -- ^ Menu promise handler
+      -> AppM ()
+menu_ msgPath = menu msgPath $ object []
+
 --------------------------------------------------------------------------------
 
 entitiesAtPositionWithType