/** 虎牙浏览器兑换：与内置扩展（web/extension/huya-exchange-helper）的通信桥。 */

import type { HuyaBrowserExchangeKit } from '../api/modules';

/** 扩展注入回执 (huya-exchange-result) */
export interface ExchangeInjectResult {
  ok: boolean;
  written: number;
  failed: number;
  error: string;
}

/** 解析后端 Cookie 字符串为 [name, value] 数组，供兑换扩展注入 */
export function parseCookieString(cookieString: string): [string, string][] {
  return cookieString
    .split(';')
    .map((part) => part.trim())
    .filter((part) => part.includes('='))
    .map((part) => {
      const idx = part.indexOf('=');
      return [part.slice(0, idx), part.slice(idx + 1)];
    });
}

/** 内置扩展的内容脚本会在后台站点白名单页面（见 manifest matches）打上此标记 */
export function huyaExchangeHelperReady(): boolean {
  return document.documentElement.dataset.huyaExchangeHelper === '1';
}

function createRequestId(): string {
  return `hx-${Date.now().toString(36)}-${Math.random().toString(36).slice(2, 10)}`;
}

/**
 * 请求内置扩展自动注入登录态并打开目标页，等待扩展回执（4 秒超时）。
 * 同时留存到 window 供扩展图标点击兜底读取。
 * 注意：事件 detail 必须是 JSON 字符串（跨 world 传递限制），不要改成对象。
 */
export function requestExtensionInject(kit: HuyaBrowserExchangeKit): Promise<ExchangeInjectResult> {
  const requestId = createRequestId();
  const payload = JSON.stringify({
    request_id: requestId,
    target_url: kit.target_url,
    cookies: parseCookieString(kit.cookie_string),
  });
  (window as unknown as { __huyaExchangeKit?: string }).__huyaExchangeKit = payload;

  return new Promise<ExchangeInjectResult>((resolve) => {
    let timer = 0;
    let settled = false;

    function finish(result: ExchangeInjectResult): void {
      if (settled) return;
      settled = true;
      window.clearTimeout(timer);
      window.removeEventListener('huya-exchange-result', onResult);
      resolve(result);
    }

    function onResult(event: Event): void {
      const detail = (event as CustomEvent<unknown>).detail;
      if (typeof detail !== 'string') return;
      let parsed: { request_id?: string; ok?: boolean; written?: number; failed?: number; error?: string };
      try {
        parsed = JSON.parse(detail) as typeof parsed;
      } catch {
        return;
      }
      if (!parsed || parsed.request_id !== requestId) return;
      finish({
        ok: parsed.ok === true,
        written: typeof parsed.written === 'number' ? parsed.written : 0,
        failed: typeof parsed.failed === 'number' ? parsed.failed : 0,
        error: typeof parsed.error === 'string' ? parsed.error : '',
      });
    }

    timer = window.setTimeout(() => {
      finish({ ok: false, written: 0, failed: 0, error: '扩展未响应（未安装或安装后未刷新本页）' });
    }, 4000);

    window.addEventListener('huya-exchange-result', onResult);
    window.dispatchEvent(new CustomEvent('huya-exchange-kit', { detail: payload }));
  });
}

/** 在新标签页打开兑换页面（noopener 避免反向标签劫持） */
export function openExchangeTarget(targetUrl: string): void {
  window.open(targetUrl, '_blank', 'noopener,noreferrer');
}