Allow specifying seed on startup

Allow specifying the seed for the game's global RNG on startup, and
print the seed when the game exits. This'll allow us to more reliably
reproduce bugs - yay!

4 files changed, 68 insertions, 25 deletions

diff --git a/src/Main.hs b/src/Main.hs
index 547dc92f4023..61640c364654 100644
--- a/src/Main.hs
+++ b/src/Main.hs
@@ -1,25 +1,50 @@
 module Main ( main ) where
 --------------------------------------------------------------------------------
-import           Xanthous.Prelude
+import           Xanthous.Prelude hiding (finally)
 import           Brick
 import qualified Options.Applicative as Opt
 import           System.Random
+import           Control.Monad.Random (getRandom)
+import           Control.Exception (finally)
 --------------------------------------------------------------------------------
-import           Xanthous.Game (getInitialState)
+import qualified Xanthous.Game as Game
 import           Xanthous.App (makeApp)
 import           Xanthous.Generators
-  ( GeneratorInput
-  , parseGeneratorInput
-  , generateFromInput
-  , showCells
-  )
+                 ( GeneratorInput
+                 , parseGeneratorInput
+                 , generateFromInput
+                 , showCells
+                 )
+import qualified Xanthous.Entities.Character as Character
 import           Xanthous.Generators.Util (regions)
 import           Xanthous.Generators.LevelContents
 import           Xanthous.Data (Dimensions, Dimensions'(Dimensions))
 import           Data.Array.IArray ( amap )
 --------------------------------------------------------------------------------
+
+data RunParams = RunParams
+  { seed :: Maybe Int
+  , characterName :: Maybe Text
+  }
+  deriving stock (Show, Eq)
+
+parseRunParams :: Opt.Parser RunParams
+parseRunParams = RunParams
+  <$> optional (Opt.option Opt.auto
+      ( Opt.long "seed"
+      <> Opt.help "Random seed for the game."
+      ))
+  <*> optional (Opt.strOption
+      ( Opt.short 'n'
+      <> Opt.long "name"
+      <> Opt.help
+        ( "Name for the character. If not set on the command line, "
+        <> "will be prompted for at runtime"
+        )
+      ))
+
 data Command
-  = Run
+  = Run RunParams
   | Generate GeneratorInput Dimensions
 
 parseDimensions :: Opt.Parser Dimensions
@@ -34,10 +59,10 @@ parseDimensions = Dimensions
        )
 
 parseCommand :: Opt.Parser Command
-parseCommand = (<|> pure Run) $ Opt.subparser
+parseCommand = (<|> Run <$> parseRunParams) $ Opt.subparser
   $ Opt.command "run"
       (Opt.info
-       (pure Run)
+       (Run <$> parseRunParams)
        (Opt.progDesc "Run the game"))
   <> Opt.command "generate"
       (Opt.info
@@ -53,11 +78,20 @@ optParser = Opt.info
   (parseCommand <**> Opt.helper)
   (Opt.header "Xanthous: a WIP TUI RPG")
 
-runGame :: IO ()
-runGame =  do
+runGame :: RunParams -> IO ()
+runGame rparams = do
   app <- makeApp
-  initialState <- getInitialState
-  _ <- defaultMain app initialState
+  gameSeed <- maybe getRandom pure $ seed rparams
+  let initialState = Game.initialStateFromSeed gameSeed &~ do
+        for_ (characterName rparams) $ \cn ->
+          Game.character . Character.characterName ?= cn
+  _game' <- defaultMain app initialState `finally` do
+    putStr "\n\n"
+    putStrLn "Thanks for playing Xanthous!"
+    when (isNothing $ seed rparams)
+      . putStrLn
+      $ "Seed: " <> tshow gameSeed
+    putStr "\n\n"
   pure ()
 
 runGenerate :: GeneratorInput -> Dimensions -> IO ()
@@ -74,7 +108,7 @@ runGenerate input dims = do
   putStrLn $ showCells res
 
 runCommand :: Command -> IO ()
-runCommand Run = runGame
+runCommand (Run runParams) = runGame runParams
 runCommand (Generate input dims) = runGenerate input dims
 
 main :: IO ()
diff --git a/src/Xanthous/App.hs b/src/Xanthous/App.hs
index ac0a213f08a1..7ba4bc673ace 100644
--- a/src/Xanthous/App.hs
+++ b/src/Xanthous/App.hs
@@ -64,10 +64,12 @@ startEvent :: AppM ()
 startEvent = do
   initLevel
   modify updateCharacterVision
-  prompt_ @'StringPrompt ["character", "namePrompt"] Uncancellable
-    $ \(StringResult s) -> do
-      character . characterName ?= s
-      say ["welcome"] =<< use character
+  use (character . characterName) >>= \case
+    Nothing -> prompt_ @'StringPrompt ["character", "namePrompt"] Uncancellable
+      $ \(StringResult s) -> do
+        character . characterName ?= s
+        say ["welcome"] =<< use character
+    Just n -> say ["welcome"] $ object [ "characterName" A..= n ]
 
 initLevel :: AppM ()
 initLevel = do
@@ -178,6 +180,7 @@ handleCommand Eat = do
             character . characterHitpoints +=
               edibleItem ^. hitpointsHealed . to fromIntegral
             message msg $ object ["item" A..= item]
+  stepGame
   continue
 
 handleCommand ToggleRevealAll = do
@@ -201,11 +204,11 @@ handlePromptEvent _ pr (VtyEvent (EvKey KEnter [])) =
 
 handlePromptEvent
   msg
-  (Prompt c SStringPrompt (StringPromptState edit) pi cb)
+  (Prompt c SStringPrompt (StringPromptState edit) pri cb)
   (VtyEvent ev)
   = do
     edit' <- lift $ handleEditorEvent ev edit
-    let prompt' = Prompt c SStringPrompt (StringPromptState edit') pi cb
+    let prompt' = Prompt c SStringPrompt (StringPromptState edit') pri cb
     promptState .= WaitingPrompt msg prompt'
     continue
 
diff --git a/src/Xanthous/Game.hs b/src/Xanthous/Game.hs
index 0ab5425a04f4..bbcf19ede4af 100644
--- a/src/Xanthous/Game.hs
+++ b/src/Xanthous/Game.hs
@@ -8,6 +8,7 @@ module Xanthous.Game
   , GamePromptState(..)
 
   , getInitialState
+  , initialStateFromSeed
 
   , positionedCharacter
   , character
diff --git a/src/Xanthous/Game/Lenses.hs b/src/Xanthous/Game/Lenses.hs
index 101de3021c48..f49477a2db23 100644
--- a/src/Xanthous/Game/Lenses.hs
+++ b/src/Xanthous/Game/Lenses.hs
@@ -6,6 +6,7 @@ module Xanthous.Game.Lenses
   , characterPosition
   , updateCharacterVision
   , getInitialState
+  , initialStateFromSeed
 
     -- * Collisions
   , Collision(..)
@@ -16,6 +17,7 @@ import           Xanthous.Prelude
 --------------------------------------------------------------------------------
 import           System.Random
 import           Control.Monad.State
+import           Control.Monad.Random (getRandom)
 --------------------------------------------------------------------------------
 import           Xanthous.Game.State
 import           Xanthous.Data
@@ -28,9 +30,12 @@ import           Xanthous.Entities.Creature (Creature)
 --------------------------------------------------------------------------------
 
 getInitialState :: IO GameState
-getInitialState = do
-  _randomGen <- getStdGen
-  let char = mkCharacter
+getInitialState = initialStateFromSeed <$> getRandom
+
+initialStateFromSeed :: Int -> GameState
+initialStateFromSeed seed =
+  let _randomGen = mkStdGen seed
+      char = mkCharacter
       (_characterEntityID, _entities)
         = EntityMap.insertAtReturningID
           (Position 0 0)
@@ -42,7 +47,7 @@ getInitialState = do
       _debugState = DebugState
         { _allRevealed = False
         }
-  pure GameState {..}
+  in GameState {..}
 
 
 positionedCharacter :: Lens' GameState (Positioned Character)