{-# LANGUAGE OverloadedStrings #-}
{-# LANGUAGE RecordWildCards   #-}

module Worldcup.Squads (Squad(..), buildSquads) where

import           Data.Aeson
import           Data.ByteString.Lazy.Char8 as BL8
import           Prelude                    as P
import           Worldcup.Countries
import           Worldcup.Games
import           Worldcup.Teams

data Squad = Squad {
    squadTeamId            :: Int,
    squadCountryId         :: Int,
    squadGoalsFor          :: Int,
    squadGoalsAgainst      :: Int,
    squadCountryPopulation :: Int
} deriving (Show)

instance ToJSON Squad where
    toJSON Squad{..} =
        object [ "tId" .= squadTeamId,
            "cId" .= squadCountryId,
            "gf" .= squadGoalsFor,
            "ga" .= squadGoalsAgainst,
            "p" .= squadCountryPopulation ]

parseInt :: Value -> Int
parseInt Null = 0
parseInt x    = read $ BL8.unpack $ encode x :: Int

goalsForTeamId :: Int -> [Game] -> Int
goalsForTeamId _id = P.foldl reducer 0 where
    reducer acc x
        | gameTeam1Id x == _id = acc + parseInt (gameScore1 x) + parseInt (gameScore1et x) + parseInt (gameScore1p x)
        | gameTeam2Id x == _id = acc + parseInt (gameScore2 x) + parseInt (gameScore2et x) + parseInt (gameScore2p x)
        | otherwise = acc

goalsAgainstTeamId :: Int -> [Game] -> Int
goalsAgainstTeamId _id = P.foldl reducer 0 where
    reducer acc x
        | gameTeam1Id x == _id = acc + parseInt (gameScore2 x) + parseInt (gameScore2et x) + parseInt (gameScore2p x)
        | gameTeam2Id x == _id = acc + parseInt (gameScore1 x) + parseInt (gameScore1et x) + parseInt (gameScore1p x)
        | otherwise = acc

buildSquads :: Countries -> [Game] -> Teams -> [Int] -> [Squad]
buildSquads cs gs ts = P.foldl reducer [] where
    reducer acc x = Squad x (getCountry x) (getGoalsFor x) (getGoalsAgainst x) (getPopulation x) : acc
    getCountry x = teamCountryId (lookupTeam x ts)
    getGoalsFor x = goalsForTeamId x gs
    getGoalsAgainst x = goalsAgainstTeamId x gs
    getPopulation x = countryPop (lookupCountry (teamCountryId $ lookupTeam x ts) cs)