import fs from 'node:fs';
import path from 'node:path';
import puppeteer from 'puppeteer';
import { get_app_config } from '../config/app_config.js';

let browser_singleton = null;

function get_action_timeout_ms() {
  const cfg = get_app_config();
  return cfg.crawler.action_timeout_ms;
}

function get_crx_src_path() {
  const cfg = get_app_config();
  return cfg.crawler.crx_src_path;
}

function get_extension_id_from_targets(targets) {
  for (const target of targets) {
    const url = target.url();
    if (!url) continue;
    if (url.startsWith('chrome-extension://')) {
      const match = url.match(/^chrome-extension:\/\/([^/]+)\//);
      if (match && match[1]) return match[1];
    }
  }
  return null;
}

async function wait_for_extension_id(browser, timeout_ms) {
  const existing = get_extension_id_from_targets(browser.targets());
  if (existing) {
    return existing;
  }

  const target = await browser
    .waitForTarget((t) => {
      const url = t.url();
      return typeof url === 'string' && url.startsWith('chrome-extension://');
    }, { timeout: timeout_ms })
    .catch(() => null);

  if (!target) {
    return null;
  }

  return get_extension_id_from_targets([target]);
}

function get_chrome_executable_path() {
  const cfg = get_app_config();
  return path.resolve(cfg.crawler.chrome_executable_path);
}

export async function get_or_create_browser() {
  if (browser_singleton) {
    return browser_singleton;
  }

  const chrome_executable_path = get_chrome_executable_path();
  if (!fs.existsSync(chrome_executable_path)) {
    throw new Error(`Chrome 不存在: ${chrome_executable_path}`);
  }

  const raw_extension_path = path.resolve(get_crx_src_path());
  const manifest_path = path.resolve(raw_extension_path, 'manifest.json');
  if (!fs.existsSync(manifest_path)) {
    throw new Error(`扩展 manifest.json 不存在: ${manifest_path}`);
  }

  const cfg = get_app_config();
  const extension_path = raw_extension_path.replace(/\\/g, '/');
  const headless = cfg.crawler.puppeteer_headless;
  const user_data_dir = path.resolve(process.cwd(), 'puppeteer_profile');

  browser_singleton = await puppeteer.launch({
    executablePath: chrome_executable_path,
    headless,
    args: [
      `--user-data-dir=${user_data_dir}`,
      '--enable-extensions',
      `--disable-extensions-except=${extension_path}`,
      `--load-extension=${extension_path}`,
      '--no-default-browser-check',
      '--disable-popup-blocking',
      '--disable-dev-shm-usage'
    ]
  });

  return browser_singleton;
}

export async function invoke_extension_action(action_name, action_payload) {
  const browser = await get_or_create_browser();

  const page = await browser.newPage();
  await page.goto('about:blank');

  // 尝试先打开 chrome://extensions 触发扩展初始化（某些环境下扩展 target 不会立刻出现）
  try {
    await page.goto('chrome://extensions/', { waitUntil: 'domcontentloaded' });
  } catch (err) {
    // ignore
  }

  const extension_id = await wait_for_extension_id(browser, 15000);
  if (!extension_id) {
    await page.close();
    throw new Error(
      '未找到扩展 extension_id：Chrome 未加载扩展（常见原因：MV2 被禁用/企业策略未生效/CRX_SRC_PATH 不正确/使用了 headless）'
    );
  }

  const bridge_url = `chrome-extension://${extension_id}/bridge/bridge.html`;
  await page.goto(bridge_url, { waitUntil: 'domcontentloaded' });

  const timeout_ms = get_action_timeout_ms();
  const action_res = await page.evaluate(
    async (action, payload, timeout) => {
      function with_timeout(promise, timeout_ms_inner) {
        return new Promise((resolve, reject) => {
          const timer = setTimeout(() => reject(new Error('action_timeout')), timeout_ms_inner);
          promise
            .then((v) => {
              clearTimeout(timer);
              resolve(v);
            })
            .catch((e) => {
              clearTimeout(timer);
              reject(e);
            });
        });
      }

      if (!window.server_bridge_invoke) {
        throw new Error('bridge 未注入 window.server_bridge_invoke');
      }

      return await with_timeout(window.server_bridge_invoke(action, payload), timeout);
    },
    action_name,
    action_payload || {},
    timeout_ms
  );

  await page.close();
  return action_res;
}