package server

import (
	"log"
	"math/rand"
)

type chessGame struct {
	id                int
	players           [2]Player
	currentTurnPlayer Player
}

const (
	PlayerToMove      = 0
	CheckPlayerChange = 1
)

func NewChessGame(gameId int, players [2]Player) *chessGame {
	var game chessGame = chessGame{
		players: players,
		id:      gameId,
	}

	return &game
}

func (game *chessGame) handle() {

	defer log.Println("Game ", game.id, ": handle() ended")

	gameState := PlayerToMove
	game.currentTurnPlayer = game.players[0]
	var move *chessMove
	var messageType int
	var receivedMessage []byte

	WriteMessageToPlayer(&game.players[0], []byte("bd init"), 1)
	WriteMessageToPlayer(&game.players[1], []byte("bd init"), 1)

	WriteMessageToPlayer(&game.players[0], []byte("cl white"), 1)
	WriteMessageToPlayer(&game.players[1], []byte("cl black"), 1)

	for {

		switch gameState {
		case PlayerToMove:
			var err error
			messageType, receivedMessage, err = ReadMessageFromPlayer(&game.currentTurnPlayer)
			if err != nil {
				log.Println("Error while reading message:", err)
				// At the moment, we return when there is an error while reading a message.
				// This means, the game just ends uncontrolled
				return
			}
			move, err = parseMove(string(receivedMessage))
			log.Println("Player ", game.currentTurnPlayer, " moved: ", move)

			if err != nil {
				log.Println("Game: ", game.id, err)
				continue
			}
			gameState = CheckPlayerChange

		case CheckPlayerChange:

			if move.realMove {
				if game.currentTurnPlayer.id == game.players[0].id {
					game.currentTurnPlayer = game.players[1]
				} else {
					game.currentTurnPlayer = game.players[0]
				}

				err := WriteMessageToPlayer(&game.players[0], receivedMessage, messageType)
				if err != nil {
					log.Println("Error during message writing:", err)
					continue
				}
				err = WriteMessageToPlayer(&game.players[1], receivedMessage, messageType)
				if err != nil {
					log.Println("Error during message writing:", err)
					continue
				}
				gameState = PlayerToMove
			} else {
				// Nothing to do if move was not real
			}

		}

		log.Println("GameState = ", gameState)
		if gameState == PlayerToMove {
			log.Println("with player ", game.currentTurnPlayer, " to move")
		}
	}

}

func addPlayersToGame(players [2]Player) {
	log.Printf("Adding players %d and %d to new game", players[0].id, players[1].id)
	game := NewChessGame(rand.Int(), players)

	go game.handle()
}