module Main (main) where

ordinals :: [ String ]
ordinals = [
    "second",
    "third",
    "fourth",
    "fifth",
    "sixth",
    "seventh",
    "eighth",
    "ninth",
    "tenth",
    "eleventh",
    "twelfth"
    ]

signatures :: [ ( Int, Int, Int, Int) ]
signatures = [
    ( 3, 6, 5, 0 ),
    ( 5, 6, 4, 1 ),
    ( 4, 7, 5, 1 ),
    ( 4, 4, 5, 5 ),
    ( 3, 5, 8, 8 ),
    ( 5, 5, 10, 5 ),
    ( 5, 5, 9, 20 ),
    ( 4, 6, 7, 10 ),
    ( 3, 5, 9, 23 ),
    ( 6, 6, 6, 3 ),
    ( 6, 8, 8, 3 )
    ]

cardinals :: [ String ]
cardinals = [
    "Two",
    "Three",
    "Four",
    "Five",
    "Six",
    "Seven",
    "Eight",
    "Nine",
    "Ten",
    "Eleven",
    "Twelve"
    ]


gifta :: [ String ]
gifta = [
    "turtle",
    "French",
    "calling",
    "gold",
    "geese",
    "swans",
    "maids",
    "ladies",
    "lords",
    "pipers",
    "drummers"
    ]

giftb :: [ String ]
giftb = [
    "doves",
    "hens",
    "birds",
    "rings",
    "a-laying",
    "a-swimming",
    "a-milking",
    "dancing",
    "a-leaping",
    "piping",
    "drumming"
    ]

gifts :: [ ( String, String, String ) ]
gifts = [ ( c, a, b ) | c <- cardinals, a <- gifta, b <- giftb ]

matchGifts :: ( Int, Int, Int ) -> [ ( String, String, String ) ]
matchGifts ( i, j, k ) = filter match gifts
    where
        match ( c, a, b ) = (length c == i) && (length a == j) && (length b == k)

giftStr :: ( String, String, String ) -> String
giftStr (c, a, b) = c ++ " " ++ a ++ " " ++ b

wrapGift :: ( Int, Int, Int, Int ) -> String
wrapGift (i, j, k, l) = gs !! l
    where
        gs = map giftStr $ matchGifts (i, j, k)

concatLines :: [ String ] -> String
concatLines ls = foldr (\a b -> a ++ "\n" ++ b) "" ls

opening :: String -> String
opening o = "On the " ++ o ++ " day of Christmas my true love gave to me\n"

partridge :: String
partridge = "partridge in a pear tree"

makeVerse :: String -> [ String ] -> String
makeVerse o [] = (opening o) ++ "A " ++ partridge
makeVerse o gs = (opening o) ++ (concatLines gs) ++ "And a " ++ partridge

allGifts :: [ String ]
allGifts = map wrapGift $ reverse signatures

recurseVerse :: [ ( String, String ) ] -> [ String ]
recurseVerse [] = [ makeVerse "first" [] ]
recurseVerse (t:ts) = [ (makeVerse ord gs) ] ++ (recurseVerse ts)
    where
        ord = fst t
        gs = [(snd t)] ++ (map snd ts)

tuples :: [ ( String, String ) ]
tuples = zip (reverse ordinals) allGifts


main :: IO ()
main = putStrLn $ foldr (\a b -> a ++ "\n\n" ++ b) "" $ reverse $ recurseVerse tuples