Add 'users/glittershark/xanthous/' from commit '53b56744f4335c038724a1bcffc27a7eb8cf6a6d' r/978

git-subtree-dir: users/glittershark/xanthous
git-subtree-mainline: 91f53f02d8479303910abfd3f3690d3ef27e6c4b
git-subtree-split: 53b56744f4335c038724a1bcffc27a7eb8cf6a6d

13 files changed, 977 insertions, 0 deletions

diff --git a/users/glittershark/xanthous/src/Xanthous/Entities/Character.hs b/users/glittershark/xanthous/src/Xanthous/Entities/Character.hs
new file mode 100644
index 000000000000..c18d726a4bfd
--- /dev/null
+++ b/users/glittershark/xanthous/src/Xanthous/Entities/Character.hs
@@ -0,0 +1,276 @@
+{-# LANGUAGE TemplateHaskell #-}
+module Xanthous.Entities.Character
+  ( Character(..)
+  , characterName
+  , inventory
+  , characterDamage
+  , characterHitpoints'
+  , characterHitpoints
+  , hitpointRecoveryRate
+  , speed
+
+    -- * Inventory
+  , Inventory(..)
+  , backpack
+  , wielded
+  , items
+    -- ** Wielded items
+  , Wielded(..)
+  , hands
+  , leftHand
+  , rightHand
+  , inLeftHand
+  , inRightHand
+  , doubleHanded
+  , wieldedItems
+  , WieldedItem(..)
+  , wieldedItem
+  , wieldableItem
+  , asWieldedItem
+
+    -- *
+  , mkCharacter
+  , pickUpItem
+  , isDead
+  , damage
+  ) where
+--------------------------------------------------------------------------------
+import Xanthous.Prelude
+--------------------------------------------------------------------------------
+import           Brick
+import           Data.Aeson.Generic.DerivingVia
+import           Data.Aeson (ToJSON, FromJSON)
+import           Data.Coerce (coerce)
+import           Test.QuickCheck
+import           Test.QuickCheck.Instances.Vector ()
+import           Test.QuickCheck.Arbitrary.Generic
+--------------------------------------------------------------------------------
+import           Xanthous.Util.QuickCheck
+import           Xanthous.Game.State
+import           Xanthous.Entities.Item
+import           Xanthous.Data
+                 ( TicksPerTile, Hitpoints, Per, Ticks, (|*|), positioned
+                 , Positioned(..)
+                 )
+import           Xanthous.Entities.RawTypes (WieldableItem, wieldable)
+import qualified Xanthous.Entities.RawTypes as Raw
+--------------------------------------------------------------------------------
+
+data WieldedItem = WieldedItem
+  { _wieldedItem :: Item
+  , _wieldableItem :: WieldableItem
+    -- ^ Invariant: item ^. itemType . wieldable ≡ Just wieldableItem
+  }
+  deriving stock (Eq, Show, Ord, Generic)
+  deriving anyclass (NFData, CoArbitrary, Function)
+  deriving (ToJSON, FromJSON)
+       via WithOptions '[ FieldLabelModifier '[Drop 1] ]
+           WieldedItem
+makeFieldsNoPrefix ''WieldedItem
+
+asWieldedItem :: Prism' Item WieldedItem
+asWieldedItem = prism' hither yon
+ where
+   yon item = WieldedItem item <$> item ^. itemType . wieldable
+   hither (WieldedItem item _) = item
+
+instance Brain WieldedItem where
+  step ticks (Positioned p wi) =
+    over positioned (\i -> WieldedItem i $ wi ^. wieldableItem)
+    <$> step ticks (Positioned p $ wi ^. wieldedItem)
+
+instance Draw WieldedItem where
+  draw = draw . view wieldedItem
+
+instance Entity WieldedItem where
+  entityAttributes = entityAttributes . view wieldedItem
+  description = description . view wieldedItem
+  entityChar = entityChar . view wieldedItem
+
+instance Arbitrary WieldedItem where
+  arbitrary = genericArbitrary <&> \wi ->
+    wi & wieldedItem . itemType . wieldable ?~ wi ^. wieldableItem
+
+data Wielded
+  = DoubleHanded WieldedItem
+  | Hands { _leftHand :: !(Maybe WieldedItem)
+          , _rightHand :: !(Maybe WieldedItem)
+          }
+  deriving stock (Eq, Show, Ord, Generic)
+  deriving anyclass (NFData, CoArbitrary, Function)
+  deriving Arbitrary via GenericArbitrary Wielded
+  deriving (ToJSON, FromJSON)
+       via WithOptions '[ 'SumEnc 'ObjWithSingleField ]
+           Wielded
+
+hands :: Prism' Wielded (Maybe WieldedItem, Maybe WieldedItem)
+hands = prism' (uncurry Hands) $ \case
+  Hands l r -> Just (l, r)
+  _ -> Nothing
+
+leftHand :: Traversal' Wielded WieldedItem
+leftHand = hands . _1 . _Just
+
+inLeftHand :: WieldedItem -> Wielded
+inLeftHand wi = Hands (Just wi) Nothing
+
+rightHand :: Traversal' Wielded WieldedItem
+rightHand = hands . _2 . _Just
+
+inRightHand :: WieldedItem -> Wielded
+inRightHand wi = Hands Nothing (Just wi)
+
+doubleHanded :: Prism' Wielded WieldedItem
+doubleHanded = prism' DoubleHanded $ \case
+  DoubleHanded i -> Just i
+  _ -> Nothing
+
+wieldedItems :: Traversal' Wielded WieldedItem
+wieldedItems k (DoubleHanded wielded) = DoubleHanded <$> k wielded
+wieldedItems k (Hands l r) = Hands <$> _Just k l <*> _Just k r
+
+data Inventory = Inventory
+  { _backpack :: Vector Item
+  , _wielded :: Wielded
+  }
+  deriving stock (Eq, Show, Ord, Generic)
+  deriving anyclass (NFData, CoArbitrary, Function)
+  deriving Arbitrary via GenericArbitrary Inventory
+  deriving (ToJSON, FromJSON)
+       via WithOptions '[ FieldLabelModifier '[Drop 1] ]
+           Inventory
+makeFieldsNoPrefix ''Inventory
+
+items :: Traversal' Inventory Item
+items k (Inventory bp w) = Inventory
+  <$> traversed k bp
+  <*> (wieldedItems . wieldedItem) k w
+
+type instance Element Inventory = Item
+
+instance MonoFunctor Inventory where
+  omap = over items
+
+instance MonoFoldable Inventory where
+  ofoldMap = foldMapOf items
+  ofoldr = foldrOf items
+  ofoldl' = foldlOf' items
+  otoList = toListOf items
+  oall = allOf items
+  oany = anyOf items
+  onull = nullOf items
+  ofoldr1Ex = foldr1Of items
+  ofoldl1Ex' = foldl1Of' items
+  headEx = headEx . toListOf items
+  lastEx = lastEx . toListOf items
+
+instance MonoTraversable Inventory where
+  otraverse = traverseOf items
+
+instance Semigroup Inventory where
+  inv₁ <> inv₂ =
+    let backpack' = inv₁ ^. backpack <> inv₂ ^. backpack
+        (wielded', backpack'') = case (inv₁ ^. wielded, inv₂ ^. wielded) of
+          (wielded₁, wielded₂@(DoubleHanded _)) ->
+            (wielded₂, backpack' <> fromList (wielded₁ ^.. wieldedItems . wieldedItem))
+          (wielded₁, wielded₂@(Hands (Just _) (Just _))) ->
+            (wielded₂, backpack' <> fromList (wielded₁ ^.. wieldedItems . wieldedItem))
+          (wielded₁, Hands Nothing Nothing) -> (wielded₁, backpack')
+          (Hands Nothing Nothing, wielded₂) -> (wielded₂, backpack')
+          (Hands (Just l₁) Nothing, Hands Nothing (Just r₂)) ->
+            (Hands (Just l₁) (Just r₂), backpack')
+          (wielded₁@(DoubleHanded _), wielded₂) ->
+            (wielded₁, backpack' <> fromList (wielded₂ ^.. wieldedItems . wieldedItem))
+          (Hands Nothing (Just r₁), Hands Nothing (Just r₂)) ->
+            (Hands Nothing (Just r₂), r₁ ^. wieldedItem <| backpack')
+          (Hands Nothing r₁, Hands (Just l₂) Nothing) ->
+            (Hands (Just l₂) r₁, backpack')
+          (Hands (Just l₁) Nothing, Hands (Just l₂) Nothing) ->
+            (Hands (Just l₂) Nothing, l₁ ^. wieldedItem <| backpack')
+          (Hands (Just l₁) (Just r₁), Hands Nothing (Just r₂)) ->
+            (Hands (Just l₁) (Just r₂), r₁ ^. wieldedItem <| backpack')
+          (Hands (Just l₁) (Just r₁), Hands (Just l₂) Nothing) ->
+            (Hands (Just l₂) (Just r₁), l₁ ^. wieldedItem <| backpack')
+    in Inventory backpack'' wielded'
+
+instance Monoid Inventory where
+  mempty = Inventory mempty $ Hands Nothing Nothing
+
+--------------------------------------------------------------------------------
+
+data Character = Character
+  { _inventory :: !Inventory
+  , _characterName :: !(Maybe Text)
+  , _characterHitpoints' :: !Double
+  , _speed :: TicksPerTile
+  }
+  deriving stock (Show, Eq, Ord, Generic)
+  deriving anyclass (NFData, CoArbitrary, Function)
+  deriving (ToJSON, FromJSON)
+       via WithOptions '[ FieldLabelModifier '[Drop 1] ]
+           Character
+makeLenses ''Character
+
+characterHitpoints :: Character -> Hitpoints
+characterHitpoints = views characterHitpoints' floor
+
+scrollOffset :: Int
+scrollOffset = 5
+
+instance Draw Character where
+  draw _ = visibleRegion rloc rreg $ str "@"
+    where
+      rloc = Location (negate scrollOffset, negate scrollOffset)
+      rreg = (2 * scrollOffset, 2 * scrollOffset)
+  drawPriority = const maxBound -- Character should always be on top, for now
+
+instance Brain Character where
+  step ticks = (pure .) $ positioned . characterHitpoints' %~ \hp ->
+    if hp > fromIntegral initialHitpoints
+    then hp
+    else hp + hitpointRecoveryRate |*| ticks
+
+instance Entity Character where
+  description _ = "yourself"
+  entityChar _ = "@"
+
+instance Arbitrary Character where
+  arbitrary = genericArbitrary
+
+initialHitpoints :: Hitpoints
+initialHitpoints = 10
+
+hitpointRecoveryRate :: Double `Per` Ticks
+hitpointRecoveryRate = 1.0 / (15 * coerce defaultSpeed)
+
+defaultSpeed :: TicksPerTile
+defaultSpeed = 100
+
+mkCharacter :: Character
+mkCharacter = Character
+  { _inventory = mempty
+  , _characterName = Nothing
+  , _characterHitpoints' = fromIntegral initialHitpoints
+  , _speed = defaultSpeed
+  }
+
+defaultCharacterDamage :: Hitpoints
+defaultCharacterDamage = 1
+
+-- | Returns the damage that the character currently does with an attack
+-- TODO use double-handed/left-hand/right-hand here
+characterDamage :: Character -> Hitpoints
+characterDamage
+  = fromMaybe defaultCharacterDamage
+  . preview (inventory . wielded . wieldedItems . wieldableItem . Raw.damage)
+
+isDead :: Character -> Bool
+isDead = (== 0) . characterHitpoints
+
+pickUpItem :: Item -> Character -> Character
+pickUpItem it = inventory . backpack %~ (it <|)
+
+damage :: Hitpoints -> Character -> Character
+damage (fromIntegral -> amount) = characterHitpoints' %~ \case
+  n | n <= amount -> 0
+    | otherwise  -> n - amount
diff --git a/users/glittershark/xanthous/src/Xanthous/Entities/Creature.hs b/users/glittershark/xanthous/src/Xanthous/Entities/Creature.hs
new file mode 100644
index 000000000000..e95e9f0b985b
--- /dev/null
+++ b/users/glittershark/xanthous/src/Xanthous/Entities/Creature.hs
@@ -0,0 +1,92 @@
+{-# LANGUAGE RecordWildCards #-}
+{-# LANGUAGE TemplateHaskell #-}
+--------------------------------------------------------------------------------
+module Xanthous.Entities.Creature
+  ( -- * Creature
+    Creature(..)
+    -- ** Lenses
+  , creatureType
+  , hitpoints
+  , hippocampus
+
+    -- ** Creature functions
+  , newWithType
+  , damage
+  , isDead
+  , visionRadius
+
+    -- * Hippocampus
+  , Hippocampus(..)
+    -- ** Lenses
+  , destination
+    -- ** Destination
+  , Destination(..)
+  , destinationFromPos
+    -- *** Lenses
+  , destinationPosition
+  , destinationProgress
+  ) where
+--------------------------------------------------------------------------------
+import           Xanthous.Prelude
+--------------------------------------------------------------------------------
+import           Test.QuickCheck
+import           Test.QuickCheck.Arbitrary.Generic
+import           Data.Aeson.Generic.DerivingVia
+import           Data.Aeson (ToJSON, FromJSON)
+--------------------------------------------------------------------------------
+import           Xanthous.AI.Gormlak
+import           Xanthous.Entities.RawTypes hiding
+                 (Creature, description, damage)
+import qualified Xanthous.Entities.RawTypes as Raw
+import           Xanthous.Game.State
+import           Xanthous.Data
+import           Xanthous.Data.Entities
+import           Xanthous.Entities.Creature.Hippocampus
+--------------------------------------------------------------------------------
+
+data Creature = Creature
+  { _creatureType :: !CreatureType
+  , _hitpoints    :: !Hitpoints
+  , _hippocampus  :: !Hippocampus
+  }
+  deriving stock (Eq, Show, Ord, Generic)
+  deriving anyclass (NFData, CoArbitrary, Function)
+  deriving Draw via DrawRawCharPriority "_creatureType" 1000 Creature
+  deriving (ToJSON, FromJSON)
+       via WithOptions '[ FieldLabelModifier '[Drop 1] ]
+                       Creature
+instance Arbitrary Creature where arbitrary = genericArbitrary
+makeLenses ''Creature
+
+instance HasVisionRadius Creature where
+  visionRadius = const 50 -- TODO
+
+instance Brain Creature where
+  step = brainVia GormlakBrain
+  entityCanMove = const True
+
+instance Entity Creature where
+  entityAttributes _ = defaultEntityAttributes
+    & blocksObject .~ True
+  description = view $ creatureType . Raw.description
+  entityChar = view $ creatureType . char
+  entityCollision = const $ Just Combat
+
+--------------------------------------------------------------------------------
+
+newWithType :: CreatureType -> Creature
+newWithType _creatureType =
+  let _hitpoints = _creatureType ^. maxHitpoints
+      _hippocampus = initialHippocampus
+  in Creature {..}
+
+damage :: Hitpoints -> Creature -> Creature
+damage amount = hitpoints %~ \hp ->
+  if hp <= amount
+  then 0
+  else hp - amount
+
+isDead :: Creature -> Bool
+isDead = views hitpoints (== 0)
+
+{-# ANN module ("Hlint: ignore Use newtype instead of data" :: String) #-}
diff --git a/users/glittershark/xanthous/src/Xanthous/Entities/Creature/Hippocampus.hs b/users/glittershark/xanthous/src/Xanthous/Entities/Creature/Hippocampus.hs
new file mode 100644
index 000000000000..501a5b597221
--- /dev/null
+++ b/users/glittershark/xanthous/src/Xanthous/Entities/Creature/Hippocampus.hs
@@ -0,0 +1,64 @@
+{-# LANGUAGE RecordWildCards #-}
+{-# LANGUAGE TemplateHaskell #-}
+--------------------------------------------------------------------------------
+module Xanthous.Entities.Creature.Hippocampus
+  (-- * Hippocampus
+    Hippocampus(..)
+  , initialHippocampus
+    -- ** Lenses
+  , destination
+    -- ** Destination
+  , Destination(..)
+  , destinationFromPos
+    -- *** Lenses
+  , destinationPosition
+  , destinationProgress
+  )
+where
+--------------------------------------------------------------------------------
+import           Xanthous.Prelude
+--------------------------------------------------------------------------------
+import           Data.Aeson.Generic.DerivingVia
+import           Data.Aeson (ToJSON, FromJSON)
+import           Test.QuickCheck
+import           Test.QuickCheck.Arbitrary.Generic
+--------------------------------------------------------------------------------
+import           Xanthous.Data
+import           Xanthous.Util.QuickCheck
+--------------------------------------------------------------------------------
+
+
+data Destination = Destination
+  { _destinationPosition :: !Position
+    -- | The progress towards the destination, tracked as an offset from the
+    -- creature's original position.
+    --
+    -- When this value reaches >= 1, the creature has reached their destination
+  , _destinationProgress :: !Tiles
+  }
+  deriving stock (Eq, Show, Ord, Generic)
+  deriving anyclass (NFData, CoArbitrary, Function)
+  deriving (ToJSON, FromJSON)
+       via WithOptions '[ FieldLabelModifier '[Drop 1] ]
+                       Destination
+instance Arbitrary Destination where arbitrary = genericArbitrary
+makeLenses ''Destination
+
+destinationFromPos :: Position -> Destination
+destinationFromPos _destinationPosition =
+  let _destinationProgress = 0
+  in Destination{..}
+
+data Hippocampus = Hippocampus
+  { _destination :: !(Maybe Destination)
+  }
+  deriving stock (Eq, Show, Ord, Generic)
+  deriving anyclass (NFData, CoArbitrary, Function)
+  deriving Arbitrary via GenericArbitrary Hippocampus
+  deriving (ToJSON, FromJSON)
+       via WithOptions '[ FieldLabelModifier '[Drop 1] ]
+                       Hippocampus
+makeLenses ''Hippocampus
+
+initialHippocampus :: Hippocampus
+initialHippocampus = Hippocampus Nothing
diff --git a/users/glittershark/xanthous/src/Xanthous/Entities/Draw/Util.hs b/users/glittershark/xanthous/src/Xanthous/Entities/Draw/Util.hs
new file mode 100644
index 000000000000..aa6c5fa4fc47
--- /dev/null
+++ b/users/glittershark/xanthous/src/Xanthous/Entities/Draw/Util.hs
@@ -0,0 +1,31 @@
+module Xanthous.Entities.Draw.Util where
+--------------------------------------------------------------------------------
+import Xanthous.Prelude
+--------------------------------------------------------------------------------
+import Brick.Widgets.Border.Style
+import Brick.Types (Edges(..))
+--------------------------------------------------------------------------------
+
+borderFromEdges :: BorderStyle -> Edges Bool -> Char
+borderFromEdges bstyle edges = ($ bstyle) $ case edges of
+  Edges False False  False False -> const '☐'
+
+  Edges True  False  False False -> bsVertical
+  Edges False True   False False -> bsVertical
+  Edges False False  True  False -> bsHorizontal
+  Edges False False  False True  -> bsHorizontal
+
+  Edges True  True   False False -> bsVertical
+  Edges True  False  True  False -> bsCornerBR
+  Edges True  False  False True  -> bsCornerBL
+
+  Edges False True   True  False -> bsCornerTR
+  Edges False True   False True  -> bsCornerTL
+  Edges False False  True  True  -> bsHorizontal
+
+  Edges False True   True  True  -> bsIntersectT
+  Edges True  False  True  True  -> bsIntersectB
+  Edges True  True   False True  -> bsIntersectL
+  Edges True  True   True  False -> bsIntersectR
+
+  Edges True  True   True  True  -> bsIntersectFull
diff --git a/users/glittershark/xanthous/src/Xanthous/Entities/Entities.hs b/users/glittershark/xanthous/src/Xanthous/Entities/Entities.hs
new file mode 100644
index 000000000000..62e6e15c9853
--- /dev/null
+++ b/users/glittershark/xanthous/src/Xanthous/Entities/Entities.hs
@@ -0,0 +1,60 @@
+{-# LANGUAGE StandaloneDeriving #-}
+{-# OPTIONS_GHC -fno-warn-orphans #-}
+--------------------------------------------------------------------------------
+module Xanthous.Entities.Entities () where
+--------------------------------------------------------------------------------
+import           Xanthous.Prelude
+--------------------------------------------------------------------------------
+import           Test.QuickCheck
+import qualified Test.QuickCheck.Gen as Gen
+import           Data.Aeson
+--------------------------------------------------------------------------------
+import           Xanthous.Entities.Character
+import           Xanthous.Entities.Item
+import           Xanthous.Entities.Creature
+import           Xanthous.Entities.Environment
+import           Xanthous.Game.State
+import           Xanthous.Util.QuickCheck
+import           Data.Aeson.Generic.DerivingVia
+--------------------------------------------------------------------------------
+
+instance Arbitrary SomeEntity where
+  arbitrary = Gen.oneof
+    [ SomeEntity <$> arbitrary @Character
+    , SomeEntity <$> arbitrary @Item
+    , SomeEntity <$> arbitrary @Creature
+    , SomeEntity <$> arbitrary @Wall
+    , SomeEntity <$> arbitrary @Door
+    , SomeEntity <$> arbitrary @GroundMessage
+    , SomeEntity <$> arbitrary @Staircase
+    ]
+
+instance FromJSON SomeEntity where
+  parseJSON = withObject "Entity" $ \obj -> do
+    (entityType :: Text) <- obj .: "type"
+    case entityType of
+      "Character" -> SomeEntity @Character <$> obj .: "data"
+      "Item" -> SomeEntity @Item <$> obj .: "data"
+      "Creature" -> SomeEntity @Creature <$> obj .: "data"
+      "Wall" -> SomeEntity @Wall <$> obj .: "data"
+      "Door" -> SomeEntity @Door <$> obj .: "data"
+      "GroundMessage" -> SomeEntity @GroundMessage <$> obj .: "data"
+      "Staircase" -> SomeEntity @Staircase <$> obj .: "data"
+      _ -> fail . unpack $ "Invalid entity type \"" <> entityType <> "\""
+
+deriving via WithOptions '[ FieldLabelModifier '[Drop 1] ] GameLevel
+  instance FromJSON GameLevel
+deriving via WithOptions '[ FieldLabelModifier '[Drop 1] ] GameState
+  instance FromJSON GameState
+
+instance Entity SomeEntity where
+  entityAttributes (SomeEntity ent) = entityAttributes ent
+  description (SomeEntity ent) = description ent
+  entityChar (SomeEntity ent) = entityChar ent
+  entityCollision (SomeEntity ent) = entityCollision ent
+
+instance Function SomeEntity where
+  function = functionJSON
+
+instance CoArbitrary SomeEntity where
+  coarbitrary = coarbitrary . encode
diff --git a/users/glittershark/xanthous/src/Xanthous/Entities/Entities.hs-boot b/users/glittershark/xanthous/src/Xanthous/Entities/Entities.hs-boot
new file mode 100644
index 000000000000..519a862c6a5a
--- /dev/null
+++ b/users/glittershark/xanthous/src/Xanthous/Entities/Entities.hs-boot
@@ -0,0 +1,14 @@
+{-# OPTIONS_GHC -fno-warn-orphans #-}
+module Xanthous.Entities.Entities where
+
+import Test.QuickCheck
+import Data.Aeson
+import Xanthous.Game.State (SomeEntity, GameState, Entity)
+
+instance Arbitrary SomeEntity
+instance Function SomeEntity
+instance CoArbitrary SomeEntity
+instance FromJSON SomeEntity
+instance Entity SomeEntity
+
+instance FromJSON GameState
diff --git a/users/glittershark/xanthous/src/Xanthous/Entities/Environment.hs b/users/glittershark/xanthous/src/Xanthous/Entities/Environment.hs
new file mode 100644
index 000000000000..b45a91eabed2
--- /dev/null
+++ b/users/glittershark/xanthous/src/Xanthous/Entities/Environment.hs
@@ -0,0 +1,160 @@
+{-# LANGUAGE TemplateHaskell #-}
+module Xanthous.Entities.Environment
+  (
+    -- * Walls
+    Wall(..)
+
+    -- * Doors
+  , Door(..)
+  , open
+  , closed
+  , locked
+  , unlockedDoor
+
+    -- * Messages
+  , GroundMessage(..)
+
+    -- * Stairs
+  , Staircase(..)
+  ) where
+--------------------------------------------------------------------------------
+import Xanthous.Prelude
+--------------------------------------------------------------------------------
+import Test.QuickCheck
+import Brick (str)
+import Brick.Widgets.Border.Style (unicode)
+import Brick.Types (Edges(..))
+import Data.Aeson
+import Data.Aeson.Generic.DerivingVia
+--------------------------------------------------------------------------------
+import Xanthous.Entities.Draw.Util
+import Xanthous.Data
+import Xanthous.Data.Entities
+import Xanthous.Game.State
+import Xanthous.Util.QuickCheck
+--------------------------------------------------------------------------------
+
+data Wall = Wall
+  deriving stock (Show, Eq, Ord, Generic, Enum)
+  deriving anyclass (NFData, CoArbitrary, Function)
+
+instance ToJSON Wall where
+  toJSON = const $ String "Wall"
+
+instance FromJSON Wall where
+  parseJSON = withText "Wall" $ \case
+    "Wall" -> pure Wall
+    _      -> fail "Invalid Wall: expected Wall"
+
+instance Brain Wall where step = brainVia Brainless
+
+instance Entity Wall where
+  entityAttributes _ = defaultEntityAttributes
+    & blocksVision .~ True
+    & blocksObject .~ True
+  description _ = "a wall"
+  entityChar _ = "┼"
+
+instance Arbitrary Wall where
+  arbitrary = pure Wall
+
+wallEdges :: (MonoFoldable mono, Element mono ~ SomeEntity)
+          => Neighbors mono -> Edges Bool
+wallEdges neighs = any (entityIs @Wall) <$> edges neighs
+
+instance Draw Wall where
+  drawWithNeighbors neighs _wall =
+    str . pure . borderFromEdges unicode $ wallEdges neighs
+
+data Door = Door
+  { _open   :: Bool
+  , _locked :: Bool
+  }
+  deriving stock (Show, Eq, Ord, Generic)
+  deriving anyclass (NFData, CoArbitrary, Function, ToJSON, FromJSON)
+  deriving Arbitrary via GenericArbitrary Door
+makeLenses ''Door
+
+instance Draw Door where
+  drawWithNeighbors neighs door
+    = str . pure . ($ door ^. open) $ case wallEdges neighs of
+        Edges True  False  False False -> vertDoor
+        Edges False True   False False -> vertDoor
+        Edges True  True   False False -> vertDoor
+        Edges False False  True  False -> horizDoor
+        Edges False False  False True  -> horizDoor
+        Edges False False  True  True  -> horizDoor
+        _                              -> allsidesDoor
+    where
+      horizDoor True = '␣'
+      horizDoor False = 'ᚔ'
+      vertDoor True = '['
+      vertDoor False = 'ǂ'
+      allsidesDoor True = '+'
+      allsidesDoor False = '▥'
+
+instance Brain Door where step = brainVia Brainless
+
+instance Entity Door where
+  entityAttributes door = defaultEntityAttributes
+    & blocksVision .~ not (door ^. open)
+  description door | door ^. open = "an open door"
+                   | otherwise    = "a closed door"
+  entityChar _ = "d"
+  entityCollision door | door ^. open = Nothing
+                       | otherwise = Just Stop
+
+closed :: Lens' Door Bool
+closed = open . involuted not
+
+-- | A closed, unlocked door
+unlockedDoor :: Door
+unlockedDoor = Door
+  { _open = False
+  , _locked = False
+  }
+
+--------------------------------------------------------------------------------
+
+newtype GroundMessage = GroundMessage Text
+  deriving stock (Show, Eq, Ord, Generic)
+  deriving anyclass (NFData, CoArbitrary, Function)
+  deriving Arbitrary via GenericArbitrary GroundMessage
+  deriving (ToJSON, FromJSON)
+       via WithOptions '[ 'TagSingleConstructors 'True
+                        , 'SumEnc 'ObjWithSingleField
+                        ]
+           GroundMessage
+  deriving Draw
+       via DrawStyledCharacter ('Just 'Yellow) 'Nothing "≈"
+           GroundMessage
+instance Brain GroundMessage where step = brainVia Brainless
+
+instance Entity GroundMessage where
+  description = const "a message on the ground. Press r. to read it."
+  entityChar = const "≈"
+  entityCollision = const Nothing
+
+--------------------------------------------------------------------------------
+
+data Staircase = UpStaircase | DownStaircase
+  deriving stock (Show, Eq, Ord, Generic)
+  deriving anyclass (NFData, CoArbitrary, Function)
+  deriving Arbitrary via GenericArbitrary Staircase
+  deriving (ToJSON, FromJSON)
+       via WithOptions '[ 'TagSingleConstructors 'True
+                        , 'SumEnc 'ObjWithSingleField
+                        ]
+           Staircase
+instance Brain Staircase where step = brainVia Brainless
+
+instance Draw Staircase where
+  draw UpStaircase = str "<"
+  draw DownStaircase = str ">"
+
+instance Entity Staircase where
+  description UpStaircase = "a staircase leading upwards"
+  description DownStaircase = "a staircase leading downwards"
+  entityChar UpStaircase = "<"
+  entityChar DownStaircase = ">"
+  entityCollision = const Nothing
diff --git a/users/glittershark/xanthous/src/Xanthous/Entities/Item.hs b/users/glittershark/xanthous/src/Xanthous/Entities/Item.hs
new file mode 100644
index 000000000000..b50a5eab809d
--- /dev/null
+++ b/users/glittershark/xanthous/src/Xanthous/Entities/Item.hs
@@ -0,0 +1,49 @@
+{-# LANGUAGE TemplateHaskell #-}
+{-# LANGUAGE StandaloneDeriving #-}
+--------------------------------------------------------------------------------
+module Xanthous.Entities.Item
+  ( Item(..)
+  , itemType
+  , newWithType
+  , isEdible
+  ) where
+--------------------------------------------------------------------------------
+import           Xanthous.Prelude
+import           Test.QuickCheck
+import           Data.Aeson (ToJSON, FromJSON)
+import           Data.Aeson.Generic.DerivingVia
+--------------------------------------------------------------------------------
+import           Xanthous.Entities.RawTypes hiding (Item, description, isEdible)
+import qualified Xanthous.Entities.RawTypes as Raw
+import           Xanthous.Game.State
+--------------------------------------------------------------------------------
+
+data Item = Item
+  { _itemType :: ItemType
+  }
+  deriving stock (Eq, Show, Ord, Generic)
+  deriving anyclass (NFData, CoArbitrary, Function)
+  deriving Draw via DrawRawChar "_itemType" Item
+  deriving (ToJSON, FromJSON)
+       via WithOptions '[ FieldLabelModifier '[Drop 1] ]
+                       Item
+makeLenses ''Item
+
+{-# ANN Item ("HLint: ignore Use newtype instead of data" :: String )#-}
+
+-- deriving via (Brainless Item) instance Brain Item
+instance Brain Item where step = brainVia Brainless
+
+instance Arbitrary Item where
+  arbitrary = Item <$> arbitrary
+
+instance Entity Item where
+  description = view $ itemType . Raw.description
+  entityChar = view $ itemType . Raw.char
+  entityCollision = const Nothing
+
+newWithType :: ItemType -> Item
+newWithType = Item
+
+isEdible :: Item -> Bool
+isEdible = Raw.isEdible . view itemType
diff --git a/users/glittershark/xanthous/src/Xanthous/Entities/RawTypes.hs b/users/glittershark/xanthous/src/Xanthous/Entities/RawTypes.hs
new file mode 100644
index 000000000000..30039662f071
--- /dev/null
+++ b/users/glittershark/xanthous/src/Xanthous/Entities/RawTypes.hs
@@ -0,0 +1,133 @@
+{-# LANGUAGE TemplateHaskell       #-}
+{-# LANGUAGE DuplicateRecordFields #-}
+--------------------------------------------------------------------------------
+module Xanthous.Entities.RawTypes
+  (
+    EntityRaw(..)
+  , _Creature
+  , _Item
+
+    -- * Creatures
+  , CreatureType(..)
+  , hostile
+
+    -- * Items
+  , ItemType(..)
+    -- ** Item sub-types
+    -- *** Edible
+  , EdibleItem(..)
+  , isEdible
+    -- *** Wieldable
+  , WieldableItem(..)
+  , isWieldable
+
+    -- * Lens classes
+  , HasAttackMessage(..)
+  , HasChar(..)
+  , HasDamage(..)
+  , HasDescription(..)
+  , HasEatMessage(..)
+  , HasEdible(..)
+  , HasFriendly(..)
+  , HasHitpointsHealed(..)
+  , HasLongDescription(..)
+  , HasMaxHitpoints(..)
+  , HasName(..)
+  , HasSpeed(..)
+  , HasWieldable(..)
+  ) where
+--------------------------------------------------------------------------------
+import Xanthous.Prelude
+import Test.QuickCheck
+import Data.Aeson.Generic.DerivingVia
+import Data.Aeson (ToJSON, FromJSON)
+--------------------------------------------------------------------------------
+import Xanthous.Messages (Message(..))
+import Xanthous.Data (TicksPerTile, Hitpoints)
+import Xanthous.Data.EntityChar
+import Xanthous.Util.QuickCheck
+--------------------------------------------------------------------------------
+
+data CreatureType = CreatureType
+  { _name         :: !Text
+  , _description  :: !Text
+  , _char         :: !EntityChar
+  , _maxHitpoints :: !Hitpoints
+  , _friendly     :: !Bool
+  , _speed        :: !TicksPerTile
+  }
+  deriving stock (Show, Eq, Ord, Generic)
+  deriving anyclass (NFData, CoArbitrary, Function)
+  deriving Arbitrary via GenericArbitrary CreatureType
+  deriving (ToJSON, FromJSON)
+       via WithOptions '[ FieldLabelModifier '[Drop 1] ]
+                       CreatureType
+makeFieldsNoPrefix ''CreatureType
+
+hostile :: Lens' CreatureType Bool
+hostile = friendly . involuted not
+
+--------------------------------------------------------------------------------
+
+data EdibleItem = EdibleItem
+  { _hitpointsHealed :: Int
+  , _eatMessage :: Maybe Message
+  }
+  deriving stock (Show, Eq, Ord, Generic)
+  deriving anyclass (NFData, CoArbitrary, Function)
+  deriving Arbitrary via GenericArbitrary EdibleItem
+  deriving (ToJSON, FromJSON)
+       via WithOptions '[ FieldLabelModifier '[Drop 1] ]
+                       EdibleItem
+makeFieldsNoPrefix ''EdibleItem
+
+data WieldableItem = WieldableItem
+  { _damage :: !Hitpoints
+  , _attackMessage :: !(Maybe Message)
+  }
+  deriving stock (Show, Eq, Ord, Generic)
+  deriving anyclass (NFData, CoArbitrary, Function)
+  deriving Arbitrary via GenericArbitrary WieldableItem
+  deriving (ToJSON, FromJSON)
+       via WithOptions '[ FieldLabelModifier '[Drop 1] ]
+                       WieldableItem
+makeFieldsNoPrefix ''WieldableItem
+
+--------------------------------------------------------------------------------
+
+data ItemType = ItemType
+  { _name            :: Text
+  , _description     :: Text
+  , _longDescription :: Text
+  , _char            :: EntityChar
+  , _edible          :: Maybe EdibleItem
+  , _wieldable       :: Maybe WieldableItem
+  }
+  deriving stock (Show, Eq, Ord, Generic)
+  deriving anyclass (NFData, CoArbitrary, Function)
+  deriving Arbitrary via GenericArbitrary ItemType
+  deriving (ToJSON, FromJSON)
+       via WithOptions '[ FieldLabelModifier '[Drop 1] ]
+                       ItemType
+makeFieldsNoPrefix ''ItemType
+
+-- | Can this item be eaten?
+isEdible :: ItemType -> Bool
+isEdible = has $ edible . _Just
+
+-- | Can this item be used as a weapon?
+isWieldable :: ItemType -> Bool
+isWieldable = has $ wieldable . _Just
+
+--------------------------------------------------------------------------------
+
+data EntityRaw
+  = Creature CreatureType
+  | Item ItemType
+  deriving stock (Show, Eq, Generic)
+  deriving anyclass (NFData)
+  deriving Arbitrary via GenericArbitrary EntityRaw
+  deriving (FromJSON)
+       via WithOptions '[ SumEnc ObjWithSingleField ]
+                       EntityRaw
+makePrisms ''EntityRaw
diff --git a/users/glittershark/xanthous/src/Xanthous/Entities/Raws.hs b/users/glittershark/xanthous/src/Xanthous/Entities/Raws.hs
new file mode 100644
index 000000000000..d4cae7ccc299
--- /dev/null
+++ b/users/glittershark/xanthous/src/Xanthous/Entities/Raws.hs
@@ -0,0 +1,59 @@
+{-# LANGUAGE TemplateHaskell #-}
+--------------------------------------------------------------------------------
+module Xanthous.Entities.Raws
+  ( raws
+  , raw
+  , RawType(..)
+  , rawsWithType
+  , entityFromRaw
+  ) where
+--------------------------------------------------------------------------------
+import           Data.FileEmbed
+import qualified Data.Yaml as Yaml
+import           Xanthous.Prelude
+import           System.FilePath.Posix
+--------------------------------------------------------------------------------
+import           Xanthous.Entities.RawTypes
+import           Xanthous.Game.State
+import qualified Xanthous.Entities.Creature as Creature
+import qualified Xanthous.Entities.Item as Item
+import           Xanthous.AI.Gormlak ()
+--------------------------------------------------------------------------------
+rawRaws :: [(FilePath, ByteString)]
+rawRaws = $(embedDir "src/Xanthous/Entities/Raws")
+
+raws :: HashMap Text EntityRaw
+raws
+  = mapFromList
+  . map (bimap
+         (pack . takeBaseName)
+         (either (error . Yaml.prettyPrintParseException) id
+          . Yaml.decodeEither'))
+  $ rawRaws
+
+raw :: Text -> Maybe EntityRaw
+raw n = raws ^. at n
+
+class RawType (a :: Type) where
+  _RawType :: Prism' EntityRaw a
+
+instance RawType CreatureType where
+  _RawType = prism' Creature $ \case
+    Creature c -> Just c
+    _ -> Nothing
+
+instance RawType ItemType where
+  _RawType = prism' Item $ \case
+    Item i -> Just i
+    _ -> Nothing
+
+rawsWithType :: forall a. RawType a => HashMap Text a
+rawsWithType = mapFromList . itoListOf (ifolded . _RawType) $ raws
+
+--------------------------------------------------------------------------------
+
+entityFromRaw :: EntityRaw -> SomeEntity
+entityFromRaw (Creature creatureType)
+  = SomeEntity $ Creature.newWithType creatureType
+entityFromRaw (Item itemType)
+  = SomeEntity $ Item.newWithType itemType
diff --git a/users/glittershark/xanthous/src/Xanthous/Entities/Raws/gormlak.yaml b/users/glittershark/xanthous/src/Xanthous/Entities/Raws/gormlak.yaml
new file mode 100644
index 000000000000..2eac895190b3
--- /dev/null
+++ b/users/glittershark/xanthous/src/Xanthous/Entities/Raws/gormlak.yaml
@@ -0,0 +1,13 @@
+Creature:
+  name: gormlak
+  description: a gormlak
+  longDescription: |
+    A chittering imp-like creature with bright yellow horns. It adores shiny objects
+    and gathers in swarms.
+  char:
+    char: g
+    style:
+      foreground: red
+  maxHitpoints: 5
+  speed: 125
+  friendly: false
diff --git a/users/glittershark/xanthous/src/Xanthous/Entities/Raws/noodles.yaml b/users/glittershark/xanthous/src/Xanthous/Entities/Raws/noodles.yaml
new file mode 100644
index 000000000000..c3f19dce91d1
--- /dev/null
+++ b/users/glittershark/xanthous/src/Xanthous/Entities/Raws/noodles.yaml
@@ -0,0 +1,12 @@
+Item:
+  name: noodles
+  description: "a big bowl o' noodles"
+  longDescription: You know exactly what kind of noodles
+  char:
+    char: 'n'
+    style:
+      foreground: yellow
+  edible:
+    hitpointsHealed: 2
+    eatMessage:
+      - You slurp up the noodles. Yumm!
diff --git a/users/glittershark/xanthous/src/Xanthous/Entities/Raws/stick.yaml b/users/glittershark/xanthous/src/Xanthous/Entities/Raws/stick.yaml
new file mode 100644
index 000000000000..bc7fde4d8b02
--- /dev/null
+++ b/users/glittershark/xanthous/src/Xanthous/Entities/Raws/stick.yaml
@@ -0,0 +1,14 @@
+Item:
+  name: stick
+  description: a wooden stick
+  longDescription: A sturdy branch broken off from some sort of tree
+  char:
+    char: ∤
+    style:
+      foreground: yellow
+  wieldable:
+    damage: 2
+    attackMessage:
+      - You bonk the {{creature.creatureType.name}} over the head with your stick.
+      - You bash the {{creature.creatureType.name}} on the noggin with your stick.
+      - You whack the {{creature.creatureType.name}} with your stick.