// Cocos Store 中的 Colyseus SDK 扩展提供此虚拟模块。
// @ts-ignore 扩展尚未导入时仍允许项目完成静态类型检查。
// import Colyseus from 'db://colyseus-sdk/colyseus.js';

import Colyseus from "db://assets/colyseus/colyseus-cocos-creator.js";


interface ColyseusRoom {
  send(type: string, message?: unknown): void;
  leave(consented?: boolean): Promise<unknown>;
  removeAllListeners(): void;
  onMessage(type: string, callback: (type: string, message: unknown) => void): void;
  onError(callback: (code: number, message?: string) => void): void;
  onLeave(callback: (code?: number) => void): void;
}

interface ColyseusClient {
  joinOrCreate(roomName: string, options?: Record<string, unknown>): Promise<ColyseusRoom>;
}

interface ColyseusEndpoint {
  hostname: string;
  port: number;
  secure: boolean;
  pathname: string;
}

export interface RoomClientCallbacks {
  onConnected?: () => void;
  onDisconnected?: (code?: number) => void;
  onTimeout?: () => void;
  onMessage?: (type: string, message: unknown) => void;
}

export interface RoomClientOptions {
  pingIntervalMs?: number;
  pingTimeoutMax?: number;
  retryDelayMs?: number;
  retryStepMs?: number;
  maxRetries?: number;
}

function parseColyseusEndpoint(rawUrl: string): ColyseusEndpoint {
  const value = rawUrl.trim();
  const match = value.match(
    /^(https?|wss?):\/\/([^/:?#]+)(?::(\d+))?(\/[^?#]*)?/i,
  );

  if (!match) {
    throw new Error(`[Colyseus] Invalid server URL: ${rawUrl}`);
  }

  const protocol = match[1].toLowerCase();
  const secure = protocol === 'https' || protocol === 'wss';

  return {
    hostname: match[2],
    port: match[3] ? Number(match[3]) : secure ? 443 : 80,
    secure,
    pathname: match[4] || '',
  };
}

/**
 * Colyseus room connection with the heartbeat and retry behaviour used by the
 * web hall client. One instance owns one logical room session.
 */
export class ColyseusRoomClient {
  private readonly client: ColyseusClient;
  private readonly pingIntervalMs: number;
  private readonly pingTimeoutMax: number;
  private readonly retryDelayMs: number;
  private readonly retryStepMs: number;
  private readonly maxRetries: number;

  private room: ColyseusRoom | null = null;
  private connecting: Promise<boolean> | null = null;
  private pingTimer: ReturnType<typeof setInterval> | null = null;
  private retryTimer: ReturnType<typeof setTimeout> | null = null;
  private retryResolve: (() => void) | null = null;
  private pendingPings = 0;
  private generation = 0;
  private shouldConnect = false;
  private kicked = false;

  constructor(
    private readonly roomName: string,
    serverUrl: string,
    private readonly callbacks: RoomClientCallbacks = {},
    options: RoomClientOptions = {},
  ) {
    const endpoint = parseColyseusEndpoint(serverUrl);
    this.client = new Colyseus.Client(endpoint) as ColyseusClient;
    this.pingIntervalMs = options.pingIntervalMs ?? 10_000;
    this.pingTimeoutMax = options.pingTimeoutMax ?? 3;
    this.retryDelayMs = options.retryDelayMs ?? 1_000;
    this.retryStepMs = options.retryStepMs ?? 2_000;
    this.maxRetries = options.maxRetries ?? 5;
  }

  get isConnected(): boolean {
    return this.room !== null;
  }

  async connect(joinOptions: Record<string, unknown> = {}): Promise<boolean> {
    if (this.room) return true;
    if (this.connecting) return this.connecting;

    this.shouldConnect = true;
    this.kicked = false;
    const generation = ++this.generation;
    const task = this.connectWithRetry(generation, joinOptions);
    this.connecting = task;
    try {
      return await task;
    } finally {
      if (this.connecting === task) this.connecting = null;
    }
  }

  async disconnect(): Promise<void> {
    this.shouldConnect = false;
    ++this.generation;
    this.clearTimers();

    const room = this.room;
    this.room = null;
    if (!room) return;

    room.removeAllListeners();
    try {
      await room.leave(true);
    } catch (error) {
      console.warn(`[ColyseusRoomClient] Failed to leave ${this.roomName}`, error);
    }
  }

  markKicked(): void {
    this.kicked = true;
    this.shouldConnect = false;
    this.clearTimers();
  }

  send(type: string, message: unknown = ''): boolean {
    if (!this.room) return false;
    //console.log('[Hall → Server]', type, message);
    this.room.send(type, message);
    return true;
  }

  private async connectWithRetry(
    generation: number,
    joinOptions: Record<string, unknown>,
  ): Promise<boolean> {
    for (let attempt = 0; attempt <= this.maxRetries; attempt += 1) {
      if (!this.isCurrent(generation)) return false;

      if (attempt > 0) {
        const delay = this.retryDelayMs + (attempt - 1) * this.retryStepMs;
        await this.waitForRetry(delay, generation);
        if (!this.isCurrent(generation)) return false;
      }

      try {
        const room = await this.client.joinOrCreate(this.roomName, joinOptions);
        if (!this.isCurrent(generation)) {
          room.removeAllListeners();
          await room.leave(true);
          return false;
        }
        this.attachRoom(room);
        return true;
      } catch (error) {
        console.warn(
          `[ColyseusRoomClient] Failed to join ${this.roomName} (${attempt + 1}/${this.maxRetries + 1})`,
          error,
        );
      }
    }

    if (this.isCurrent(generation)) {
      this.shouldConnect = false;
      this.callbacks.onTimeout?.();
    }
    return false;
  }

  private attachRoom(room: ColyseusRoom): void {
    this.room = room;
    this.pendingPings = 0;

    room.onMessage('*', (type: string, message: unknown) => {
      //console.log('[Hall ← Server]', type, message);
      if (type === 'PONG') {
        this.pendingPings = Math.max(0, this.pendingPings - 1);
        return;
      }

      if (this.isKickMessage(message)) this.markKicked();
      this.callbacks.onMessage?.(type, message);
    });

    room.onError((code: number, message?: string) => {
      console.warn(`[ColyseusRoomClient] ${this.roomName} error ${code}: ${message || ''}`);
    });

    room.onLeave((code?: number) => {
      if (this.room !== room) return;
      this.room = null;
      this.stopPing();
      this.callbacks.onDisconnected?.(code);
      if (this.shouldConnect && !this.kicked) void this.reconnect();
    });

    this.callbacks.onConnected?.();
    this.startPing();
  }

  private async reconnect(): Promise<void> {
    ++this.generation;
    this.connecting = null;
    await this.connect();
  }

  private startPing(): void {
    this.stopPing();
    this.pingTimer = setInterval(() => {
      if (this.pendingPings > this.pingTimeoutMax) {
        void this.restartAfterPingTimeout();
        return;
      }
      this.pendingPings += 1;
      this.send('PING', '');
    }, this.pingIntervalMs);
  }

  private async restartAfterPingTimeout(): Promise<void> {
    const room = this.room;
    this.room = null;
    this.stopPing();
    if (room) {
      room.removeAllListeners();
      try {
        await room.leave(true);
      } catch (error) {
        console.warn(`[ColyseusRoomClient] Failed to close timed-out ${this.roomName}`, error);
      }
    }
    if (this.shouldConnect && !this.kicked) await this.reconnect();
  }

  private waitForRetry(delay: number, generation: number): Promise<void> {
    return new Promise((resolve) => {
      this.retryResolve = resolve;
      this.retryTimer = setTimeout(() => {
        this.retryTimer = null;
        this.retryResolve = null;
        resolve();
      }, delay);

      if (!this.isCurrent(generation)) {
        clearTimeout(this.retryTimer);
        this.retryTimer = null;
        this.retryResolve = null;
        resolve();
      }
    });
  }

  private isCurrent(generation: number): boolean {
    return this.shouldConnect && generation === this.generation;
  }

  private isKickMessage(message: unknown): boolean {
    return Boolean(message && typeof message === 'object' && (message as { cmd?: string }).cmd === 'kick');
  }

  private clearTimers(): void {
    if (this.retryTimer) {
      clearTimeout(this.retryTimer);
      this.retryTimer = null;
      const resolve = this.retryResolve;
      this.retryResolve = null;
      resolve?.();
    }
    this.stopPing();
    this.pendingPings = 0;
  }

  private stopPing(): void {
    if (!this.pingTimer) return;
    clearInterval(this.pingTimer);
    this.pingTimer = null;
  }
}