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

module Worldcup.Games (Game(..), parseGames) where

import           Data.Aeson
import           Data.Aeson.Types

data Game = Game {
    roundId  :: Int,
    playAt   :: String,
    team1Id  :: Int,
    team2Id  :: Int,
    score1   :: Value,
    score2   :: Value,
    score1et :: Value,
    score2et :: Value,
    score1p  :: Value,
    score2p  :: Value } deriving (Show)

instance FromJSON Game where
    parseJSON = withObject "game" $ \o -> do
        roundId <- o .: "round_id"
        team1Id <- o .: "team1_id"
        team2Id <- o .: "team2_id"
        playAt <- o .: "play_at"
        score1 <- o .: "score1"
        score2 <- o .: "score2"
        score1et <- o .: "score1et"
        score2et <- o .: "score2et"
        score1p <- o .: "score1p"
        score2p <- o .: "score2p"
        return Game{..}

parseGames :: Either String [Value] -> [Game]
parseGames (Left x)   = error x
parseGames (Right xs) = foldl reduce [] xs where
    reduce acc x = case (parseEither parseJSON x :: Either String Game) of
        (Left s)  -> error s
        (Right v) -> v : acc