Validate attempted shed against prev card

2 files changed, 40 insertions, 31 deletions

diff --git a/Game.hs b/Game.hs
index 871d188..e6d8270 100644
--- a/Game.hs
+++ b/Game.hs
@@ -12,6 +12,7 @@ data Game = Game { players :: [Player]
                  , playerIdx :: Int
                  , attack :: Int
                  , direction :: Int      -- ^ 1 when CCW, -1 when CW
+                 , prevCard :: Card
                  , stockPile :: [Card]
                  , discardPile :: [Card]
                  }
@@ -27,35 +28,38 @@ beginRounds n game = do
 
 -- | Let current player take their turn.
 beginTurn :: Game -> IO Game
-beginTurn game@(Game plyrs pidx att dir stock disc) = do
+beginTurn game@(Game plyrs pidx att dir prev stock disc) = do
+    let player = plyrs !! pidx
+
     putStrLn $ replicate 80 '-'
+    putStrLn $ P.name player ++ "'s turn (input 0 to skip turn and draw card)"
+    putStrLn $ P.showCards player
     putStrLn $ "Current attack: " ++ show att
-    decision <- prompt game
+    putStrLn $ "Prev card: " ++ C.showCard prev
 
-    let player = plyrs !! pidx
-    game'@(Game _ pidx' _ _ _ _)
-        <- case decision of
-             Nothing -> drawAndSkip game
-             Just card -> shedAndContinue card game
+    decision <- prompt game
+    game' <- case decision of
+               Nothing -> drawAndSkip game
+               Just card -> shedAndContinue card game
 
-    if pidx' == pidx  -- shedAndContinue does this when player wins
+    if playerIdx game' == pidx  -- shedAndContinue does this when player wins
        then return game'
        else beginTurn game'
 
 -- | Game state after player draws card(s) and skips turn.
 drawAndSkip :: Game -> IO Game
-drawAndSkip game@(Game plyrs pidx att dir stock disc) = do
+drawAndSkip game@(Game plyrs pidx att dir prev stock disc) = do
     let player = plyrs !! pidx
     let player' = player `draw` (take att stock)
     let plyrs' = P.update plyrs pidx player'
     let pidx' = (pidx + dir) `mod` length plyrs
     let stock' = drop att stock
     putStrLn $ (P.name player) ++ " draws " ++ (C.showCards $ take att stock)
-    return $ Game plyrs' pidx' 1 dir stock' disc
+    return $ Game plyrs' pidx' 1 dir prev stock' disc
 
 -- | Game state after player sheds card.
 shedAndContinue :: Card -> Game -> IO Game
-shedAndContinue card game@(Game plyrs pidx att dir stock disc) = do
+shedAndContinue card game@(Game plyrs pidx att dir prev stock disc) = do
     let player = plyrs !! pidx
     let player' = player `shed` card
     let disc' = card:disc
@@ -73,35 +77,39 @@ shedAndContinue card game@(Game plyrs pidx att dir stock disc) = do
                  Card _ C.Three -> if att == 1 then 3 else att + 3
                  _ -> 1
     putStrLn $ (P.name player) ++ " plays " ++ (C.showCard card)
-    return $ Game plyrs' pidx' att' dir' stock disc'
+    return $ Game plyrs' pidx' att' dir' card stock disc'
 
 -- | Prompt player to play a card (or draw card and skip turn).
 prompt :: Game -> IO (Maybe Card)
-prompt game@(Game plyrs pidx att _ _ _) = do
+prompt game@(Game plyrs pidx att _ prev _ _) = do
     let player = plyrs !! pidx
     let cards = P.cards player
-    putStrLn $ P.name player ++ "'s turn (input 0 to skip turn and draw card)"
-    putStrLn $ P.showCards player
     cardIdxStr <- getLine
     if any (== False) $ map isDigit cardIdxStr
-        then do
-            putStrLn "Please input card #"
-            prompt game
-        else do
-            let cardIdx = read cardIdxStr - 1
-            if cardIdx == -1
-                then do
-                   return Nothing
-                else do
-                    if cardIdx < 0 || cardIdx >= length cards
-                        then do
-                            putStrLn "This card does not exist, try again"
-                            prompt game
-                        else return $ Just (cards !! cardIdx)
+       then do
+           putStrLn "Please input card #"
+           prompt game
+       else do
+           let cardIdx = read cardIdxStr - 1
+           if cardIdx == -1
+              then do
+                 return Nothing
+              else do
+                  if cardIdx < 0 || cardIdx >= length cards
+                     then do
+                         putStrLn "This card does not exist, try again"
+                         prompt game
+                     else do
+                         let card = cards !! cardIdx
+                         if C.isValid prev card
+                            then return $ Just card
+                            else do
+                                putStrLn "You cannot play this card, try again"
+                                prompt game
 
 -- | Deal c cards to each player in game.
 dealCards :: Int -> Game -> Game
-dealCards c game@(Game plyrs _ _ _ stock disc)
+dealCards c game@(Game plyrs _ _ _ _ stock disc)
   | (length $ P.cards $ head plyrs) < c =
       dealCards c game { players = newPlyrs, stockPile = newStock }
   | otherwise = game
diff --git a/Main.hs b/Main.hs
index 7e66efa..aaae87c 100644
--- a/Main.hs
+++ b/Main.hs
@@ -29,7 +29,8 @@ main = do
                     , playerIdx   = 0
                     , attack      = 1
                     , direction   = 1
-                    , stockPile   = stock
+                    , prevCard    = head stock
+                    , stockPile   = tail stock
                     , discardPile = discard
                     }