module Room (Room,buildRoom,buildEmptyRoom,mergeRoom,r_id,passage,contents,setSinglePassage,mergePassage,getPassAsStr,getPassageText,charDirToStr) where

import Data.List(nub,intersperse)

type Passage = [[Bool]]

--Contents key: 0 - bottomless pit, 1 - bats

data Room = Room {r_id :: Int, passage :: Passage, contents :: [Int]} deriving (Eq)

buildRoom :: Int -> Passage -> [Int] -> Room

buildRoom a b c = Room a (setPassage b) c

buildEmptyRoom :: Room

buildEmptyRoom = Room (-1) (setPassage [[False,False,False],[False,False,False],[False,False,False]]) []

setPassage :: Passage -> Passage

setPassage p

| length p /= 3 = error "Passage must have 3 rows."

| foldr (||) False (map ((/=3) . length) p) = error "Passage must have 3 columns in each row."

| otherwise = p

mergePassage :: (Bool->Bool->Bool) -> Passage -> Passage -> Passage

mergePassage c (a:as) (b:bs)

| null as || null bs = [mergeRow a b]

| otherwise = (mergeRow a b):(mergePassage c as bs)

where

mergeRow (x:xs) (y:ys) | null xs || null ys = [c x y]

| otherwise = (c x y):(mergeRow xs ys)

mergeRoom :: Room -> Room -> Maybe Room

mergeRoom r1 r2

| r_id r1 < 0 && r_id r2 < 0 = Nothing

| r_id r1 < 0 = Just $ buildRoom (r_id r2) (mergePassage (||) (passage r1) (passage r2)) (nub $ concat [contents r1, contents r2])

| otherwise = Just $ buildRoom (r_id r1) (mergePassage (||) (passage r1) (passage r2)) (nub $ concat [contents r1, contents r2])

setSinglePassage :: Char -> Passage

setSinglePassage c =

case c of

'n' -> setPassage [[False,True,False],[False,False,False],[False,False,False]]

'e' -> setPassage [[False,False,False],[False,False,True],[False,False,False]]

's' -> setPassage [[False,False,False],[False,False,False],[False,True,False]]

'w' -> setPassage [[False,False,False],[True,False,False],[False,False,False]]

_ -> setPassage [[False,False,False],[False,False,False],[False,False,False]]

unsetSinglePassage :: Char -> Passage

unsetSinglePassage c = map (map not) $ setSinglePassage c

-- returns a list of the full names of passages (North, South, East, West)

getFullPassList :: Room -> [String]

getFullPassList r = map charDirToStr $ getPassAsStr r

charDirToStr :: Char -> String

charDirToStr c =

case c of

'n' -> "North"

's' -> "South"

'e' -> "East"

'w' -> "West"

getPassageText :: Room -> String

getPassageText r

| numPass == 1 = ("There is a passage to the " ++ (head passages) ++ ".")

| numPass == 2 = ("There are passages to the " ++ (head passages) ++ " and " ++ (last passages) ++ ".")

| otherwise = ("There are passages to the " ++ (getPText passages) ++ ".")

where

passages = getFullPassList r

numPass = length passages

getPText (p:ps)

| null ps = ("and " ++ p)

| otherwise = (p ++ ", " ++ getPText ps)

getPText _ = ""

getPassAsStr :: Room -> String

getPassAsStr r = (concat $ map getPassAtIndex [(0,1),(1,0),(1,2),(2,1)])

where

p = passage r

getPassAtIndex iii | iii == (0,1) && ((!!) ((!!) p (fst iii)) (snd iii)) = "n"

| iii == (1,0) && ((!!) ((!!) p (fst iii)) (snd iii)) = "w"

| iii == (1,2) && ((!!) ((!!) p (fst iii)) (snd iii)) = "e"

| iii == (2,1) && ((!!) ((!!) p (fst iii)) (snd iii)) = "s"

| otherwise = ""

instance Show Room where

show a = "<id:" ++ (show $ r_id a) ++ "," ++ "pass:" ++ getPassAsStr a ++ ",[" ++ ( intersperse ','$ concat $ map show (contents a) ) ++ "]>"