/**
 * 浏览器管理模块
 * 负责：启动浏览器、创建上下文、加载/保存登录状态
 */

const { chromium } = require('playwright');
const fs = require('fs');
const path = require('path');
const config = require('../config');
const logger = require('./logger');

/**
 * 启动浏览器实例
 * @returns {Promise<import('playwright').Browser>}
 */
async function launchBrowser() {
  const headless = config.browser.headless;
  logger.info(`启动浏览器... (headless: ${headless})`);
  logger.info('  → 调用 chromium.launch()...');
  const browser = await chromium.launch({
    headless,
  });
  logger.info('✅ 浏览器启动成功');
  return browser;
}

/**
 * 创建浏览器上下文
 * - 如果 state.json 存在且有效，加载登录状态
 * - 否则创建干净的上下文
 * @param {import('playwright').Browser} browser
 * @returns {Promise<{context: import('playwright').BrowserContext, stateLoaded: boolean}>}
 */
async function createContext(browser) {
  let stateLoaded = false;
  const statePath = path.resolve(config.statePath);

  logger.info('检查 state.json...');
  logger.info(`  → 路径: ${statePath}`);

  if (fs.existsSync(statePath)) {
    logger.info('  → state.json 文件存在，开始验证内容...');
    try {
      const raw = fs.readFileSync(statePath, 'utf-8');
      logger.info(`  → 文件大小: ${raw.length} 字节`);
      const state = JSON.parse(raw);
      const hasCookies = Array.isArray(state.cookies) && state.cookies.length > 0;
      const hasOrigins = Array.isArray(state.origins) && state.origins.length > 0;
      logger.info(`  → cookies: ${hasCookies ? state.cookies.length + '条' : '空'}`);
      logger.info(`  → origins: ${hasOrigins ? state.origins.length + '条' : '空'}`);

      if (!hasCookies && !hasOrigins) {
        logger.warn('  → state.json 内容无效（空 cookies 和 origins），将重新登录');
        stateLoaded = false;
      } else {
        logger.info('  → state.json 有效，将加载登录状态');
        stateLoaded = true;
      }
    } catch (err) {
      logger.warn(`  → state.json 解析失败: ${err.message}，将重新登录`);
      stateLoaded = false;
    }
  } else {
    logger.info('  → state.json 不存在，将创建新上下文');
    stateLoaded = false;
  }

  const contextOptions = {
    locale: config.browser.locale,
  };

  if (stateLoaded) {
    contextOptions.storageState = statePath;
  }

  logger.info('正在创建浏览器上下文...');
  const context = await browser.newContext(contextOptions);
  logger.info(stateLoaded ? '✅ 上下文已创建（已加载登录状态）' : '✅ 上下文已创建（未登录）');

  return { context, stateLoaded };
}

/**
 * 保存登录状态到 state.json
 * @param {import('playwright').BrowserContext} context
 */
async function saveState(context) {
  const statePath = path.resolve(config.statePath);
  logger.info('  → 正在保存 state.json...');
  await context.storageState({ path: statePath });
  logger.info(`  → state.json 已保存到 ${statePath}`);
}

module.exports = {
  launchBrowser,
  createContext,
  saveState,
};