import {
  WebSocketGateway,
  WebSocketServer,
  SubscribeMessage,
  OnGatewayConnection,
  OnGatewayDisconnect,
  OnGatewayInit,
} from '@nestjs/websockets';
import { Server, Socket } from 'socket.io';
import { RoomsService } from '../rooms/rooms.service';
import { RoomEventsService } from './room-events.service';
import { PrismaService } from '../prisma/prisma.service';
import { RoomPackService } from '../room-pack/room-pack.service';

@WebSocketGateway({
  cors: {
    // Примечание: декоратор выполняется на этапе инициализации,
    // ConfigModule.forRoot() уже загружает переменные в process.env
    origin: process.env.CORS_ORIGIN || 'http://localhost:5173',
    credentials: true,
  },
})
export class GameGateway implements OnGatewayConnection, OnGatewayDisconnect, OnGatewayInit {
  @WebSocketServer()
  server: Server;

  constructor(
    private roomsService: RoomsService,
    private roomEventsService: RoomEventsService,
    private prisma: PrismaService,
    private roomPackService: RoomPackService,
  ) {}

  afterInit(server: Server) {
    this.roomEventsService.setServer(server);
  }

  handleConnection(client: Socket) {
    console.log(`Client connected: ${client.id}`);
  }

  handleDisconnect(client: Socket) {
    console.log(`Client disconnected: ${client.id}`);
  }

  private async isHost(roomId: string, userId: string): Promise<boolean> {
    const room = await this.prisma.room.findUnique({
      where: { id: roomId },
      select: { hostId: true },
    });
    return room?.hostId === userId;
  }

  @SubscribeMessage('joinRoom')
  async handleJoinRoom(client: Socket, payload: { roomCode: string; userId: string }) {
    client.join(payload.roomCode);
    const room = await this.roomsService.getRoomByCode(payload.roomCode);
    this.server.to(payload.roomCode).emit('roomUpdate', room);
  }

  @SubscribeMessage('startGame')
  async handleStartGame(client: Socket, payload: { roomId: string; roomCode: string; userId: string }) {
    const isHost = await this.isHost(payload.roomId, payload.userId);
    if (!isHost) {
      client.emit('error', { message: 'Only the host can start the game' });
      return;
    }

    await this.roomsService.updateRoomStatus(payload.roomId, 'PLAYING');
    const room = await this.roomsService.getRoomByCode(payload.roomCode);
    if (room) {
      this.server.to(room.code).emit('gameStarted', room);
    }
  }

  @SubscribeMessage('revealAnswer')
  async handleRevealAnswer(client: Socket, payload: { roomCode: string; answerIndex: number; userId: string; roomId: string }) {
    const isHost = await this.isHost(payload.roomId, payload.userId);
    if (!isHost) {
      client.emit('error', { message: 'Only the host can reveal answers' });
      return;
    }

    this.server.to(payload.roomCode).emit('answerRevealed', payload);
  }

  @SubscribeMessage('updateScore')
  async handleUpdateScore(client: Socket, payload: { participantId: string; score: number; roomCode: string; userId: string; roomId: string }) {
    const isHost = await this.isHost(payload.roomId, payload.userId);
    if (!isHost) {
      client.emit('error', { message: 'Only the host can update scores' });
      return;
    }

    await this.roomsService.updateParticipantScore(payload.participantId, payload.score);
    this.server.to(payload.roomCode).emit('scoreUpdated', payload);
  }

  @SubscribeMessage('nextQuestion')
  async handleNextQuestion(client: Socket, payload: { roomCode: string; userId: string; roomId: string }) {
    const isHost = await this.isHost(payload.roomId, payload.userId);
    if (!isHost) {
      client.emit('error', { message: 'Only the host can change questions' });
      return;
    }

    this.server.to(payload.roomCode).emit('questionChanged', payload);
  }

  @SubscribeMessage('endGame')
  async handleEndGame(client: Socket, payload: { roomId: string; roomCode: string; userId: string }) {
    const isHost = await this.isHost(payload.roomId, payload.userId);
    if (!isHost) {
      client.emit('error', { message: 'Only the host can end the game' });
      return;
    }

    await this.roomsService.updateRoomStatus(payload.roomId, 'FINISHED');
    this.server.to(payload.roomCode).emit('gameEnded', payload);
  }

  @SubscribeMessage('setCurrentPlayer')
  async handleSetCurrentPlayer(client: Socket, payload: { roomId: string; roomCode: string; userId: string; playerId: string }) {
    const isHost = await this.isHost(payload.roomId, payload.userId);
    if (!isHost) {
      client.emit('error', { message: 'Only the host can select the current player' });
      return;
    }

    await this.prisma.room.update({
      where: { id: payload.roomId },
      data: { currentPlayerId: payload.playerId },
    });

    this.server.to(payload.roomCode).emit('currentPlayerChanged', { playerId: payload.playerId });
  }

  @SubscribeMessage('updateRoomSettings')
  async handleUpdateRoomSettings(client: Socket, payload: { roomId: string; roomCode: string; userId: string; settings: any }) {
    const isHost = await this.isHost(payload.roomId, payload.userId);
    if (!isHost) {
      client.emit('error', { message: 'Only the host can update room settings' });
      return;
    }

    await this.prisma.room.update({
      where: { id: payload.roomId },
      data: payload.settings,
    });

    const room = await this.roomsService.getRoomByCode(payload.roomCode);
    this.server.to(payload.roomCode).emit('roomUpdate', room);
  }

  @SubscribeMessage('restartGame')
  async handleRestartGame(client: Socket, payload: { roomId: string; roomCode: string; userId: string }) {
    const isHost = await this.isHost(payload.roomId, payload.userId);
    if (!isHost) {
      client.emit('error', { message: 'Only the host can restart the game' });
      return;
    }

    await this.prisma.room.update({
      where: { id: payload.roomId },
      data: {
        status: 'WAITING',
        currentQuestionIndex: 0,
        revealedAnswers: {},
        currentPlayerId: null,
        isGameOver: false,
        answeredQuestions: 0,
      },
    });

    await this.prisma.participant.updateMany({
      where: { roomId: payload.roomId },
      data: { score: 0 },
    });

    const room = await this.roomsService.getRoomByCode(payload.roomCode);
    this.server.to(payload.roomCode).emit('gameRestarted', room);
  }

  @SubscribeMessage('updateCustomQuestions')
  async handleUpdateCustomQuestions(client: Socket, payload: { roomId: string; roomCode: string; userId: string; questions: any }) {
    // DEPRECATED: Use updateRoomPack instead
    return this.handleUpdateRoomPack(client, payload);
  }

  @SubscribeMessage('updateRoomPack')
  async handleUpdateRoomPack(client: Socket, payload: { roomId: string; roomCode: string; userId: string; questions: any[] }) {
    const isHost = await this.isHost(payload.roomId, payload.userId);
    if (!isHost) {
      client.emit('error', { message: 'Only the host can update questions' });
      return;
    }

    const room = await this.roomsService.updateRoomPack(payload.roomId, payload.questions);
    this.server.to(payload.roomCode).emit('roomPackUpdated', room);
  }

  @SubscribeMessage('importQuestions')
  async handleImportQuestions(client: Socket, payload: {
    roomId: string;
    roomCode: string;
    userId: string;
    sourcePackId: string;
    questionIndices: number[];
  }) {
    const isHost = await this.isHost(payload.roomId, payload.userId);
    if (!isHost) {
      client.emit('error', { message: 'Only the host can import questions' });
      return;
    }

    await this.roomPackService.importQuestions(payload.roomId, payload.sourcePackId, payload.questionIndices);

    const room = await this.roomsService.getRoomByCode(payload.roomCode);
    this.server.to(payload.roomCode).emit('roomPackUpdated', room);
  }

  @SubscribeMessage('kickPlayer')
  async handleKickPlayer(client: Socket, payload: { roomId: string; roomCode: string; userId: string; participantId: string }) {
    const isHost = await this.isHost(payload.roomId, payload.userId);
    if (!isHost) {
      client.emit('error', { message: 'Only the host can kick players' });
      return;
    }

    await this.prisma.participant.update({
      where: { id: payload.participantId },
      data: { isActive: false },
    });

    const room = await this.roomsService.getRoomByCode(payload.roomCode);
    this.server.to(payload.roomCode).emit('playerKicked', { participantId: payload.participantId, room });
  }
}