#12 Add zone move constraints

lib/PatienceBoard.hs

@@ -3,6 +3,9 @@ module PatienceBoard
 , Board (..)
 , amountOfGameStacks
 , amountOfEndingStacks
+, gameStacksCoord
+, endingStacksCoord
+, pileCoord
 
 , handleInputs
 , initGame
@@ -39,6 +42,20 @@ amountOfGameStacks = 7
 amountOfEndingStacks :: Int
 amountOfEndingStacks = 4
 
+-- Coordinate of the GameStacks
+gameStacksCoord :: Coordinate
+gameStacksCoord = (0, 0)
+
+-- Coordinate of the EndingStacks
+endingStacksCoord :: Coordinate
+endingStacksCoord = (x, 1)
+    where x = amountOfGameStacks - amountOfEndingStacks
+
+-- Coordinate of the Pile
+pileCoord :: Coordinate
+pileCoord = (0, 1)
+
+-- Step size to rotate the pile of the game
 rotateStep :: Int
 rotateStep = 3
 
@@ -86,7 +103,7 @@ canPlayOn :: Card -> Stack -> Bool
 canPlayOn (_,King,_) []             = True
 canPlayOn (t1,v1,_)  ((t2,v2,_):cs) = differentColor && predValue
     where differentColor = t1 /= t2 && fromEnum t1 + fromEnum t2 `elem` [1,2,4,5]
-          predValue      = fromEnum v1 + 1 == fromEnum v2
+          predValue      = succ v1 == v2
 canPlayOn _          _   = False
 
 -- Check if a card can be played ontop of an EndingStack.
@@ -94,7 +111,7 @@ canFinishOn :: Card -> Stack -> Bool
 canFinishOn (_,Ace,_) []             = True
 canFinishOn (t1,v1,_) ((t2,v2,_):cs) = sameType && succValue
     where sameType  = t1 == t2
-          succValue = fromEnum v1 == fromEnum v2 + 1
+          succValue = v1 == succ v2
 canFinishOn _         _              = False
 
 -- Move a card to a GameStack. Move all the cards below the given card
@@ -116,9 +133,37 @@ moveToES from to
 
 ------------------------------ Input ---------------------------------
 
+-- Check if a coordinate is in the pile.
+isInPile :: Coordinate -> Bool
+isInPile = (pileCoord == )
+
+-- Check if a coordinate is in an endingStack.
+isInEnding :: Coordinate -> Bool
+isInEnding (x, y) = leftBound && rightBound && yCheck
+    where leftBound  = fst endingStacksCoord <= x
+          rightBound = x < amountOfGameStacks
+          yCheck     = y == snd endingStacksCoord
+
+-- Check if a coordinate is in a GameStack.
+isInGame :: Coordinate -> Game -> Bool
+isInGame (x, y) g = horizontalCheck && verticalCheck
+    where horizontalCheck = leftBound && rightBound
+          verticalCheck   = upBound && downBound
+          leftBound       = fst gameStacksCoord <= x
+          rightBound      = x < amountOfGameStacks
+          upBound         = y <= snd gameStacksCoord
+          downBound       = negate y < length (gameStacks (board g) !! x)
+
+-- Check if moving in a direction is legal.
+isLegalMove :: Direction -> Game -> Bool
+isLegalMove dir g = isInPile coord || isInEnding coord || isInGame coord g
+    where coord   = position $ move dir $ selector g
+
 -- Move the selector of the game. (Wrapper)
 moveSelector :: Direction -> Game -> Game
-moveSelector dir g@Game{ selector = s } = g{ selector = move dir s }
+moveSelector dir g@Game{ selector = s }
+    | isLegalMove dir g = g{ selector = move dir s }
+    | otherwise         = g
 
 -- Toggle selector. (Wrapper)
 toggleSelector :: Game -> Game