import Data.List (sort, group, sortBy, groupBy)
import Data.List.Split
import Control.Arrow ((&&&))

file = ["You know i'm getting real sick of frustation frustation frustation frustation frustation frustation all this SHIT!!! Haskell irritates me"]


simpleMapReduce :: (a -> b) -> ([b] -> c) -> [a] -> c
simpleMapReduce mapFunction reduceFunction input = reduceFunction (map mapFunction input)

stringSplitter str = splitOn " " str

mapFunc :: String -> [(String,Int)]
mapFunc str= getCountOFWords (splitOn " " str)

getCountOFWords :: [String] -> [(String,Int)]
getCountOFWords = map (head &&& length) . group . sort

sortTuple (a1,b1) (a2,b2) = compare a1 a2
groupTuple (a1,b1) (a2,b2) = a1 == a2

combining :: [(String,Int)] -> (String,Int)
combining ((word,value):xs) = (word, (value + summation xs))

summation :: [(String,Int)] -> Int
summation [] = 0
summation ((word,value):xs) = value + summation xs

reducer :: [[(String,Int)]] -> [(String,Int)]
reducer list = map combining (groupBy groupTuple (sortBy sortTuple (concat list)))

run = simpleMapReduce mapFunc reducer file