module Counter(
    SenateCounter,
    Criteria,

    createSenateCounter,
    doCount,
    getBallot,
    getTotal,

    matchID,
    matchList
    ) where




--  This source is licensed under Creative Commons CC0 v1.0.

--  To read the full text, see license.txt in the main directory of this repository
--  or go to https://creativecommons.org/publicdomain/zero/1.0/legalcode.txt

--  For a human readable summary, go to https://creativecommons.org/publicdomain/zero/1.0/




import qualified Candidate as Typ
import qualified Preferences as Pref
import qualified CSV as CSV
import qualified Storage as Vec
import qualified System.IO as IO
import qualified File as File
import qualified Control.Monad as Con
import qualified Data.Either.Unwrap as Either
import qualified Data.Maybe as Maybe
import qualified Data.List as List
import Data.Array ( (!) )
import qualified Data.Array as Arr




data SenateCounter = SenateCounter
    { prefData   :: Vec.Store
    , ballotMap  :: Typ.BelowLineBallot
    , numBallots :: Int }




type Criteria = [Either Typ.CandidateID [Typ.CandidateID]]




createSenateCounter :: FilePath -> Typ.AboveLineBallot -> Typ.BelowLineBallot -> IO SenateCounter
createSenateCounter f a b = do
    numLines <- File.countLines f
    prefStore <- Vec.createStore numLines (length b)

    h <- IO.openFile f IO.ReadMode
    let readFunc n p = if (n > numLines) then return p else do
            t0 <- IO.hGetLine h
            let prefs = parseRawLine a b t0
                result = Maybe.fromJust prefs
            if (Maybe.isJust prefs)
                then Vec.setPrefs prefStore (p + 1) result >> readFunc (n + 1) (p + 1)
                else readFunc (n + 1) p
    p <- readFunc 1 0
    IO.hClose h

    return (SenateCounter
        { prefData = prefStore
        , ballotMap = b
        , numBallots = p })




parseRawLine :: Typ.AboveLineBallot -> Typ.BelowLineBallot -> String -> Maybe [Pref.Preference]
parseRawLine a b input =
    let t1 = CSV.parseRecord CSV.defaultSettings (input ++ "\n")
        t2 = Maybe.listToMaybe . reverse . Either.fromRight $ t1
        t3 = Pref.parsePreferences (length a) (length b) (Maybe.fromJust t2)
        t4 = Pref.normalise a b (Either.fromRight t3)
    in if (Either.isRight t1 && Maybe.isJust t2 && Either.isRight t3)
        then t4
        else Nothing




doCount :: SenateCounter -> Criteria -> IO Int
doCount sen criteria = do
    let checkList = map (toInternal (ballotMap sen)) criteria
        upperBound = length checkList
        checkArray = Arr.listArray (1,upperBound) checkList

        testFunc bal check rank = if (check > upperBound) then return True else do
            case (checkArray ! check) of
                Left x -> do
                    r <- Vec.checkPref (prefData sen) bal (x,rank)
                    if r
                        then testFunc bal (check + 1) (rank + 1)
                        else return False
                Right xs -> do
                    rs <- mapM (\p -> Vec.checkPref (prefData sen) bal (p,rank)) xs
                    if (or rs)
                        then testFunc bal check (rank + 1)
                        else testFunc bal (check + 1) rank

        tailFunc n p = if (n > numBallots sen) then return p else do
            r <- testFunc n 1 1
            if r then tailFunc (n + 1) (p + 1) else tailFunc (n + 1) p

    if (all (isValid (ballotMap sen)) criteria)
        then tailFunc 1 0
        else return 0




toInternal :: Typ.BelowLineBallot -> Either Typ.CandidateID [Typ.CandidateID] -> Either Typ.Position (Arr.Array Int Typ.Position)
toInternal ballot (Left c) =
    let r = Maybe.fromJust (List.elemIndex c ballot)
    in Left (r + 1)
toInternal ballot (Right cs) =
    let f x = Maybe.fromJust (List.elemIndex x ballot)
        r = map ((+ 1) . f) cs
    in Right (Arr.listArray (1,length r) r)




isValid :: Typ.BelowLineBallot -> Either Typ.CandidateID [Typ.CandidateID] -> Bool
isValid ballot (Left x) = x `elem` ballot
isValid ballot (Right xs) = all (`elem` ballot) xs




getBallot :: SenateCounter -> Typ.BelowLineBallot
getBallot = ballotMap




getTotal :: SenateCounter -> Int
getTotal = numBallots




matchID :: Typ.CandidateID -> Either Typ.CandidateID [Typ.CandidateID]
matchID = Left




matchList :: [Typ.CandidateID] -> Either Typ.CandidateID [Typ.CandidateID]
matchList = Right