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

module Worldcup.Tourneys (Tourneys, Tourney(..), buildTourneys) where

import           Data.Aeson
import           Data.HashMap.Strict  as HM
import           Prelude              as P
import           Worldcup.Events
import           Worldcup.EventsTeams
import           Worldcup.Games
import           Worldcup.Rounds

type Tourneys = HashMap String Tourney

data Tourney = Tourney {
    tourneyGames :: [Game],
    tourneyTeams :: [Int] } deriving (Show)

instance ToJSON Tourney where
    toJSON Tourney{..} = object [ "games" .= tourneyGames, "teams" .= tourneyTeams ]

roundIsInEvent :: Int -> Int -> Rounds -> Bool
roundIsInEvent eid rid rs = roundEventId getRound == eid where
    getRound = lookupRound rid rs

teamIdsFromEventId :: Int -> [EventTeam] -> [Int]
teamIdsFromEventId eid = foldl reducer [] where
    reducer acc x
        | eventsTeamsEventId x == eid = eventsTeamsTeamId x : acc
        | otherwise = acc

gamesFromEventId :: Int -> Rounds -> [Game] -> [Game]
gamesFromEventId eid rs = foldl reducer [] where
    reducer acc x
        | roundIsInEvent eid (gameRoundId x) rs = x : acc
        | otherwise = acc

buildTourneys :: Rounds -> [EventTeam] -> [Game] -> [Event] -> Tourneys
buildTourneys rs ets gs = foldl reducer HM.empty where
    reducer acc x = HM.insert (getEvent x) (Tourney (getGames x) (getTeams x)) acc
    getGames x = gamesFromEventId (eventId x) rs gs
    getTeams x = teamIdsFromEventId (eventId x) ets
    getEvent x = drop 6 (eventName x)