const api = require('../../utils/api');
const auth = require('../../utils/auth');

const STATUSES = ['正常', '迟到', '请假', '不参加讨论', '早退'];
const WEEKDAYS = ['周日', '周一', '周二', '周三', '周四', '周五', '周六'];
const STATUS_META = {
  正常: '#2E7D32',
  迟到: '#C67B30',
  请假: '#3A7BD5',
  早退: '#8B7A6A',
  '不参加讨论': '#C0392B'
};
const STATUS_ITEMS = STATUSES.map((label) => ({
  label,
  color: STATUS_META[label] || '#C67B30'
}));

function errMessage(err) {
  if (err && typeof err === 'object') {
    if (err.detail) return String(err.detail);
    if (err.error) return String(err.error);
    if (err.message) return err.message;
  }
  return '';
}

function pad2(n) {
  return n < 10 ? '0' + n : String(n);
}

function fmtTime(ts) {
  if (!ts) return '';
  const d = new Date(String(ts).replace(' ', 'T'));
  if (isNaN(d.getTime())) return String(ts);
  const now = new Date();
  const startOfDay = (x) => new Date(x.getFullYear(), x.getMonth(), x.getDate()).getTime();
  const diff = Math.round((startOfDay(now) - startOfDay(d)) / 86400000);
  const hm = pad2(d.getHours()) + ':' + pad2(d.getMinutes());
  if (diff === 0) return '今天 ' + hm;
  if (diff === 1) return '昨天 ' + hm;
  return pad2(d.getMonth() + 1) + '-' + pad2(d.getDate()) + ' ' + hm;
}

Page({
  data: {
    statusItems: STATUS_ITEMS,
    statusIndex: -1,
    loading: true,
    classDate: '',
    weekday: '',
    dayNum: '',
    checked: false,
    record: null,
    statusColor: '',
    // 视图模式：overview 总览 / detail 小组详情（仅老师）
    view: 'overview',
    // 当前选中的小组（详情页用）
    selectedGroupName: '',
    // 小组统计列表（老师总览用）
    groups: [],
    // 小组成员列表（详情页 & 学员小组 tab 用）
    members: [],
    checkedCount: 0,
    total: 0,
    // 用户角色
    isTeacher: false,
    myGroup: '',
    unassignedCount: 0,
    // 学员视图 tab：group / personal
    tab: 'group',
    // 个人历史
    history: [],
    historyPage: 1,
    historyTotal: 0,
    historyFinished: false,
    historyLoading: false,
    submitting: false,
    refreshing: false,
    loadError: '',
    // 周选择相关
    weekList: [],
    showWeekPicker: false,
  },

  onShow() {
    this.loadPage();
  },

  onPullDownRefresh() {
    this.loadPage().finally(() => wx.stopPullDownRefresh());
  },

  loadPage() {
    this.setData({ loadError: '' });
    return auth.ensureLogin()
      .then((token) => {
        if (!token) {
          wx.switchTab({ url: '/pages/profile/profile' });
          return;
        }
        // 先加载周列表，再加载当前周数据
        return this.loadWeeks();
      })
      .then(() => {
        return this.loadWeek();
      })
      .catch((err) => {
        const msg = (err && (err.error || err.detail || err.message)) || '加载失败，请重试';
        this.setData({ loading: false, loadError: msg });
        wx.showToast({ title: msg, icon: 'none' });
      });
  },

  onRetry() {
    this.loadPage();
  },

  /** 加载可用周列表 */
  loadWeeks() {
    return api.request({ url: '/api/v1/checkin/weeks' }).then((res) => {
      const weeks = res.weeks || [];
      const current = res.current_week || (weeks[0] || '');
      this.setData({
        weekList: weeks,
        classDate: this.data.classDate || current,
      });
    }).catch(() => {
      // 获取周列表失败不影响主流程
      console.warn('获取上课周列表失败');
    });
  },

  /** 打开周选择器 */
  openWeekPicker() {
    if (!this.data.weekList.length) {
      return;
    }
    this.setData({ showWeekPicker: true });
  },

  /** 关闭周选择器 */
  closeWeekPicker() {
    this.setData({ showWeekPicker: false });
  },

  /** 选择某一周 */
  onWeekSelect(e) {
    const classDate = e.currentTarget.dataset.date;
    if (!classDate || classDate === this.data.classDate) {
      this.setData({ showWeekPicker: false });
      return;
    }
    this.setData({
      classDate,
      showWeekPicker: false,
    });
    this.loadWeek();
  },

  /**
   * 加载当前周数据：
   * - 老师：加载小组统计总览
   * - 学员：加载小组统计 + 本组成员列表 + 个人历史（个人 tab 延迟加载）
   */
  loadWeek() {
    this.setData({ loading: true });
    const classDate = this.data.classDate;
    const params = classDate ? { class_date: classDate } : {};
    return api.request({ url: '/api/v1/checkin/groups', data: params }).then((res) => {
      const date = res.class_date || '';
      const weekday = WEEKDAYS[new Date(date + 'T00:00:00').getDay()] || '';
      const dayNum = date.split('-')[2] || '';
      const statusIndex = res.record && res.record.status
        ? Math.max(0, STATUSES.indexOf(res.record.status))
        : -1;
      const statusColor = res.record ? (STATUS_META[res.record.status] || '#C67B30') : '';
      const isTeacher = !!res.is_teacher;

      // 计算每个小组的百分比
      const groups = (res.groups || []).map((g) => ({
        ...g,
        percent: g.total ? Math.round(((g.checked_count || 0) / g.total) * 100) : 0
      }));

      const baseData = {
        classDate: date,
        weekday,
        dayNum,
        checked: !!res.checked,
        record: res.record || null,
        statusIndex,
        statusColor,
        isTeacher,
        myGroup: res.my_group || '',
        unassignedCount: res.unassigned_count || 0,
        groups,
      };

      // 如果当前在详情页（老师），重新加载该组详情
      if (isTeacher && this.data.view === 'detail' && this.data.selectedGroupName) {
        this.setData({ ...baseData, members: [], loading: true });
        return this.loadGroup(this.data.selectedGroupName).then(() => {
          this.setData({ loading: false });
        });
      }

      this.setData(baseData);

      if (!isTeacher) {
        // 学员：先设置兜底的小组名（避免/group失败时显示"暂无小组"）
        if (res.my_group) {
          this.setData({ groupName: res.my_group });
        }
        // 学员：加载本组成员列表
        return this.loadGroup(res.my_group || '').then(() => {
          this.setData({ loading: false });
        });
      }

      this.setData({ loading: false });
    }).catch(() => {
      this.setData({ loading: false });
    });
  },

  /** 加载指定小组的成员列表，不传则看自己小组 */
  loadGroup(groupName) {
    const data = { class_date: this.data.classDate };
    if (groupName) {
      data.group_name = groupName;
    }
    return api.request({ url: '/api/v1/checkin/group', data }).then((res) => {
      const members = (res.members || []).map((m) => ({
        ...m,
        shortName: (m.name || '?').charAt(0),
        timeText: m.checked && m.record ? fmtTime(m.record.checked_at) : ''
      }));
      const checkedCount = members.filter((m) => m.checked).length;
      this.setData({
        members,
        groupName: res.group_name || groupName || '',
        checkedCount,
        total: members.length
      });
    }).catch((err) => {
      console.warn('加载小组成员失败:', err);
      wx.showToast({ title: '加载小组成员失败', icon: 'none' });
    });
  },

  /** 老师：打开小组详情 */
  openGroup(e) {
    const groupName = e.currentTarget.dataset.group;
    if (!groupName) return;
    this.setData({ selectedGroupName: groupName, view: 'detail', members: [], loading: true });
    this.loadGroup(groupName).then(() => {
      this.setData({ loading: false });
    });
  },

  /** 老师：返回总览 */
  backToOverview() {
    this.setData({ view: 'overview', selectedGroupName: '', members: [] });
  },

  /** 加载个人历史（第一页） */
  loadHistory() {
    this.setData({ historyPage: 1, historyFinished: false, historyLoading: true });
    return this._loadHistoryPage(1, true).then(() => {
      this.setData({ historyLoading: false });
    }).catch(() => {
      this.setData({ historyLoading: false });
    });
  },

  /** 加载更多历史（翻页） */
  loadMoreHistory() {
    if (this.data.historyLoading || this.data.historyFinished) return;
    const nextPage = this.data.historyPage + 1;
    this.setData({ historyLoading: true });
    return this._loadHistoryPage(nextPage, false).then(() => {
      this.setData({ historyLoading: false, historyPage: nextPage });
    }).catch(() => {
      this.setData({ historyLoading: false });
    });
  },

  _loadHistoryPage(page, replace) {
    return api.request({ url: '/api/v1/checkin/list', data: { page, size: 20 } }).then((res) => {
      const list = (res.list || []).map((item) => {
        const color = STATUS_META[item.status] || '#C67B30';
        return {
          ...item,
          timeText: fmtTime(item.checked_at),
          color,
          bg: color + '1A'
        };
      });
      const total = res.total || 0;
      const history = replace ? list : this.data.history.concat(list);
      const finished = history.length >= total;
      this.setData({ history, historyTotal: total, historyFinished: finished });
    });
  },


  onStatusTap(e) {
    if (this.data.submitting) {
      return;
    }
    const statusIndex = Number(e.currentTarget.dataset.index);
    const status = STATUSES[statusIndex];
    if (!status) {
      return;
    }
    const prevIndex = this.data.statusIndex;
    this.setData({ statusIndex, submitting: true });
    api.request({
      url: '/api/v1/checkin',
      method: 'POST',
      data: {
        status,
        class_date: this.data.classDate,
      }
    }).then((res) => {
      const record = res.record || null;
      const statusColor = record ? (STATUS_META[record.status] || '#C67B30') : '';
      this.setData({ submitting: false, checked: true, record, statusColor });
      wx.showToast({ title: '打卡成功', icon: 'success' });
      // 学员：本地更新 members 中自己的记录，避免全量 reload
      if (!this.data.isTeacher && this.data.members.length > 0) {
        const myUserId = record && record.user_id;
        if (myUserId) {
          const members = this.data.members.map((m) => {
            if (m.user_id === myUserId) {
              return {
                ...m,
                checked: true,
                record: { status: record.status, checked_at: record.checked_at, note: record.note || '' },
                timeText: fmtTime(record.checked_at),
              };
            }
            return m;
          });
          const checkedCount = members.filter((m) => m.checked).length;
          this.setData({ members, checkedCount });
        }
      }
      // 老师视图：刷新小组统计（需要更新各小组计数）
      if (this.data.isTeacher) {
        this.loadWeek();
      }
      // 个人历史 tab：本地插入最新记录，避免全量 reload
      if (!this.data.isTeacher && this.data.tab === 'personal' && record && this.data.history.length > 0) {
        const color = STATUS_META[record.status] || '#C67B30';
        const newItem = {
          ...record,
          timeText: fmtTime(record.checked_at),
          color,
          bg: color + '1A',
        };
        // 检查是否已有同一天的记录（更新而非插入）
        const existingIdx = this.data.history.findIndex((h) => h.class_date === record.class_date);
        let history;
        if (existingIdx >= 0) {
          history = this.data.history.slice();
          history[existingIdx] = newItem;
        } else {
          history = [newItem].concat(this.data.history);
        }
        const historyTotal = Math.max(this.data.historyTotal, this.data.historyTotal + (existingIdx >= 0 ? 0 : 1));
        this.setData({ history, historyTotal });
      } else if (!this.data.isTeacher && this.data.tab === 'personal') {
        this.loadHistory();
      }
    }).catch((err) => {
      this.setData({ submitting: false, statusIndex: prevIndex });
      wx.showToast({ title: errMessage(err) || '打卡失败', icon: 'none' });
    });
  },

  /** 学员 tab 切换 */
  switchTab(e) {
    const tab = e.currentTarget.dataset.tab;
    if (tab !== 'group' && tab !== 'personal') {
      return;
    }
    this.setData({ tab });
    if (tab === 'personal') {
      // 每次切到个人 tab 都刷新历史数据
      this.loadHistory();
    } else if (tab === 'group' && this.data.myGroup) {
      // 每次切回小组 tab 都刷新小组成员数据
      this.loadGroup(this.data.myGroup);
    }
  },

  onRefresh() {
    this.setData({ refreshing: true });
    this.loadWeek().then(() => {
      // 学员个人 tab 也刷新一下
      if (!this.data.isTeacher && this.data.tab === 'personal') {
        return this.loadHistory();
      }
    }).then(() => {
      this.setData({ refreshing: false });
    });
  },

  // ---- 分享 ----
  onShareAppMessage() {
    const checked = this.data.checked;
    const status = this.data.record && this.data.record.status;
    const title = checked
      ? '我今天' + status + '啦，一起在明缘云道场打卡吧'
      : '明缘云道场 · 每日打卡，共同成长';
    return {
      title,
      path: '/pages/checkin/checkin'
    };
  },

  onShareTimeline() {
    return {
      title: '明缘云道场 · 每周打卡，共同进步',
      query: 'from=timeline'
    };
  },

  /** 上拉加载更多（个人历史 tab） */
  onReachBottom() {
    if (!this.data.isTeacher && this.data.tab === 'personal') {
      this.loadMoreHistory();
    }
  },
});