package connect4

import (
	"encoding/json"

	"github.com/ryanhamamura/games/player"
)

// NATS subject helpers.
const SubjectPrefix = "connect4"

func GameSubject(gameID string) string { return SubjectPrefix + "." + gameID }
func ChatSubject(gameID string) string { return SubjectPrefix + ".chat." + gameID }

type Player struct {
	ID       player.ID
	UserID   *string // UUID for authenticated users, nil for guests
	Nickname string
	Color    int // 1 = Red, 2 = Yellow
}

type Status int

const (
	StatusWaitingForPlayer Status = iota
	StatusInProgress
	StatusWon
	StatusDraw
)

type Game struct {
	ID            string
	Board         [6][7]int  // 6 rows, 7 columns; 0=empty, 1=red, 2=yellow
	Players       [2]*Player // Index 0 = creator (Red), Index 1 = joiner (Yellow)
	CurrentTurn   int        // 1 or 2 (matches player color)
	Status        Status
	Winner        *Player
	WinningCells  [][2]int // Coordinates of winning 4 cells for highlighting
	RematchGameID *string  // ID of the rematch game, if one was created
}

func NewGame(id string) *Game {
	return &Game{
		ID:          id,
		Board:       [6][7]int{},
		CurrentTurn: 1, // Red goes first
		Status:      StatusWaitingForPlayer,
	}
}

func (g *Game) IsFinished() bool {
	return g.Status == StatusWon || g.Status == StatusDraw
}

func (g *Game) BoardToJSON() string {
	data, _ := json.Marshal(g.Board)
	return string(data)
}

func (g *Game) BoardFromJSON(data string) error {
	return json.Unmarshal([]byte(data), &g.Board)
}

func (g *Game) WinningCellsToJSON() string {
	if g.WinningCells == nil {
		return ""
	}
	data, _ := json.Marshal(g.WinningCells)
	return string(data)
}

func (g *Game) WinningCellsFromJSON(data string) error {
	if data == "" {
		return nil
	}
	return json.Unmarshal([]byte(data), &g.WinningCells)
}