const { sleep } = require('../helpers/automator');

class CourseListPage {
  /**
   * @param {object} miniProgram - miniprogram-automator 实例
   */
  constructor(miniProgram) {
    this.mp = miniProgram;
  }

  /**
   * 等待课程列表页加载完成
   */
  async waitForLoad() {
    const page = await this.mp.currentPage();
    await page.waitFor('.course-list-page', { timeout: 10000 });
    await sleep(1500); // 等待数据加载
    return page;
  }

  /**
   * 获取课程列表
   * @returns {Promise<Array<{name: string, status: string, location: string}>>}
   */
  async getCourseList() {
    const page = await this.mp.currentPage();
    const cards = await page.$$('.course-card');
    const courses = [];

    for (const card of cards) {
      try {
        const nameEl = await card.$('.course-name');
        const statusEl = await card.$('.status-tag text');
        const name = nameEl ? (await nameEl.text()).trim() : '';
        const status = statusEl ? (await statusEl.text()).trim() : '';
        courses.push({ name, status });
      } catch (e) {
        // 跳过无法解析的卡片
      }
    }

    return courses;
  }

  /**
   * 获取课程卡片数量
   */
  async getCourseCount() {
    const page = await this.mp.currentPage();
    try {
      const cards = await page.$$('.course-card');
      return cards.length;
    } catch (e) {
      return 0;
    }
  }

  /**
   * 按状态筛选课程
   * @param {string} status - 'all' | 'pending' | 'in_progress' | 'ended'
   */
  async filterByStatus(status) {
    const page = await this.mp.currentPage();

    const tabValueMap = {
      all: 0,
      pending: 1,
      in_progress: 2,
      ended: 3
    };

    const tabIndex = tabValueMap[status];
    if (tabIndex === undefined) {
      throw new Error(`未知的筛选状态: ${status}`);
    }

    const tabs = await page.$$('.tab-item');
    if (tabs.length > tabIndex) {
      await tabs[tabIndex].tap();
      await sleep(1500); // 等待筛选结果渲染
    }
  }

  /**
   * 点击指定索引的课程卡片
   * @param {number} index - 课程卡片索引（从0开始）
   */
  async clickCourse(index = 0) {
    const page = await this.mp.currentPage();
    const cards = await page.$$('.course-card');
    if (cards.length <= index) {
      throw new Error(`课程索引 ${index} 超出范围，当前共 ${cards.length} 个课程`);
    }
    await cards[index].tap();
    await sleep(2000); // 等待课程详情页加载
    return this.mp.currentPage();
  }

  /**
   * 验证某个课程是否有学员（人数 > 0）
   * @param {number} index - 课程卡片索引
   */
  async verifyCourseHasStudents(index = 0) {
    const page = await this.mp.currentPage();
    const cards = await page.$$('.course-card');
    if (cards.length <= index) {
      return false;
    }

    try {
      const infoRows = await cards[index].$$('.info-row');
      // 最后一行为 "人数 X / Y" 信息
      if (infoRows.length > 0) {
        const lastRow = infoRows[infoRows.length - 1];
        const valueEl = await lastRow.$('.info-value');
        if (valueEl) {
          const text = (await valueEl.text()).trim();
          const match = text.match(/^(\d+)\s*\/\s*\d+$/);
          if (match) {
            return parseInt(match[1], 10) > 0;
          }
        }
      }
    } catch (e) {
      // 忽略
    }

    return false;
  }

  /**
   * 检查是否显示"暂无课程"的空状态
   */
  async isEmpty() {
    const page = await this.mp.currentPage();
    try {
      const emptyEl = await page.$('.empty-wrap');
      return !!emptyEl;
    } catch (e) {
      return false;
    }
  }

  /**
   * 检查是否仍在加载中
   */
  async isLoading() {
    const page = await this.mp.currentPage();
    try {
      const loadingEl = await page.$('.loading-wrap');
      return !!loadingEl;
    } catch (e) {
      return false;
    }
  }
}

module.exports = CourseListPage;