import type { Transport } from '../../YouleNexus/assets/framework/net/transport.ts';

/** 内存 Transport：模拟服务器。用 microtask 队列异步触发回调，贴近真实 WS 时序。 */
export class FakeTransport implements Transport {
  sent: string[] = [];
  url = '';
  connectCalls = 0;
  closeCalls = 0;
  private openCb?: () => void;
  private msgCb?: (f: string) => void;
  private closeCb?: () => void;
  private pending: Array<() => void> = [];
  private closed = false;
  private hasConnectFailure = false;
  private connectFailure: unknown;

  connect(url: string): void {
    this.connectCalls++;
    this.url = url;
    if (this.hasConnectFailure) {
      const error = this.connectFailure;
      this.hasConnectFailure = false;
      this.connectFailure = undefined;
      throw error;
    }
    this.pending.push(() => this.openCb?.());
  }
  send(frame: string): void { if (!this.closed) this.sent.push(frame); }
  close(): void {
    this.closeCalls++;
    if (this.closed) return;
    this.closed = true;
    this.pending.push(() => this.closeCb?.());
  }
  onOpen(cb: () => void): void { this.openCb = cb; }
  onMessage(cb: (f: string) => void): void { this.msgCb = cb; }
  onClose(cb: () => void): void { this.closeCb = cb; }

  /** 测试侧：令下一次 connect 同步失败。 */
  failNextConnect(error: unknown): void {
    this.hasConnectFailure = true;
    this.connectFailure = error;
  }

  /** 测试侧：模拟服务器推一帧给客户端。 */
  serverPush(frame: string): void { this.pending.push(() => this.msgCb?.(frame)); }

  /** 测试侧：模拟远端 close；允许重复信号以验证连接代际去重。 */
  serverClose(): void {
    this.closed = true;
    this.pending.push(() => this.closeCb?.());
  }

  /** 测试侧：生产 adapter 的 error 最终收敛到 close 生命周期。 */
  serverError(): void {
    this.closed = true;
    this.pending.push(() => this.closeCb?.());
  }

  /** 冲刷所有挂起回调（解析微任务）。 */
  async flush(): Promise<void> {
    while (this.pending.length) { const fn = this.pending.shift()!; fn(); await Promise.resolve(); }
  }
}