import { Router, Request, Response } from 'express';
import { getDb } from '../db';
import { authMiddleware, AuthRequest } from '../middleware/auth';

const router = Router();

router.get('/', (req: Request, res: Response) => {
  const db = getDb();
  const list = db.prepareCompat(`
    SELECT a.*,
           GROUP_CONCAT(g.name) AS groups_name,
           GROUP_CONCAT(g.id) AS groups_id
    FROM activities a
    LEFT JOIN activity_groups ag ON a.id = ag.activity_id
    LEFT JOIN work_groups g ON ag.group_id = g.id
    GROUP BY a.id
    ORDER BY a.start_time DESC
  `).all().map((item: any) => ({
    ...item,
    groups: (item.groups_id ? String(item.groups_id).split(',').map(Number) : []),
    groups_name_list: (item.groups_name ? String(item.groups_name).split(',') : []),
  }));
  res.json(list);
});

router.get('/:id', (req: Request, res: Response) => {
  const id = Number(req.params.id);
  const db = getDb();
  const act = db.prepareCompat('SELECT * FROM activities WHERE id = ?').get(id) as any;
  if (!act) return res.status(404).json({ error: '活动不存在' });
  const groups = db.prepareCompat(`
    SELECT g.id, g.name FROM activity_groups ag
    JOIN work_groups g ON ag.group_id = g.id
    WHERE ag.activity_id = ?
  `).all(id);
  res.json({ ...act, groups: groups.map((g: any) => g.id), groups_name_list: groups.map((g: any) => g.name) });
});

router.post('/', authMiddleware, (req: AuthRequest, res: Response) => {
  const { title, content, start_time, end_time, groups } = req.body || {};
  if (!title || !String(title).trim()) return res.status(400).json({ error: '活动标题不能为空' });
  if (!start_time || !end_time) return res.status(400).json({ error: '活动时间不能为空' });

  const db = getDb();
  try {
    db.execCompat('BEGIN');
    const info = db.prepareCompat('INSERT INTO activities (title, content, start_time, end_time) VALUES (?,?,?,?)')
      .run(String(title).trim(), content || '', start_time, end_time);
    const activityId = Number(info.lastInsertRowid);
    const insertAG = db.prepareCompat('INSERT OR IGNORE INTO activity_groups (activity_id, group_id) VALUES (?,?)');
    if (Array.isArray(groups)) {
      for (const gid of groups) insertAG.run(activityId, Number(gid));
    }
    db.execCompat('COMMIT');
    db.save();
    res.json({ id: activityId });
  } catch (e: any) {
    try { db.execCompat('ROLLBACK'); } catch {}
    res.status(500).json({ error: e.message });
  }
});

router.put('/:id', authMiddleware, (req: AuthRequest, res: Response) => {
  const id = Number(req.params.id);
  const { title, content, start_time, end_time, groups } = req.body || {};
  if (!title || !String(title).trim()) return res.status(400).json({ error: '活动标题不能为空' });
  if (!start_time || !end_time) return res.status(400).json({ error: '活动时间不能为空' });

  const db = getDb();
  try {
    db.execCompat('BEGIN');
    db.prepareCompat('UPDATE activities SET title=?, content=?, start_time=?, end_time=? WHERE id=?')
      .run(String(title).trim(), content || '', start_time, end_time, id);
    db.prepareCompat('DELETE FROM activity_groups WHERE activity_id = ?').run(id);
    const insertAG = db.prepareCompat('INSERT OR IGNORE INTO activity_groups (activity_id, group_id) VALUES (?,?)');
    if (Array.isArray(groups)) {
      for (const gid of groups) insertAG.run(id, Number(gid));
    }
    db.execCompat('COMMIT');
    db.save();
    res.json({ ok: true });
  } catch (e: any) {
    try { db.execCompat('ROLLBACK'); } catch {}
    res.status(500).json({ error: e.message });
  }
});

router.delete('/:id', authMiddleware, (req: AuthRequest, res: Response) => {
  const id = Number(req.params.id);
  const db = getDb();
  db.prepareCompat('DELETE FROM activities WHERE id = ?').run(id);
  db.save();
  res.json({ ok: true });
});

router.get('/:id/participants', (req: Request, res: Response) => {
  const id = Number(req.params.id);
  const db = getDb();
  const act = db.prepareCompat('SELECT * FROM activities WHERE id = ?').get(id);
  if (!act) return res.status(404).json({ error: '活动不存在' });

  const groupIds = db.prepareCompat('SELECT group_id FROM activity_groups WHERE activity_id = ?').all(id).map((r: any) => r.group_id);
  let users: any[];
  if (groupIds.length === 0) {
    users = db.prepareCompat(`
      SELECT u.id, u.class, u.name, u.volunteer_no, g.name AS group_name
      FROM users u LEFT JOIN work_groups g ON u.group_id = g.id
      ORDER BY u.class, u.name
    `).all();
  } else {
    const ph = groupIds.map(() => '?').join(',');
    users = db.prepareCompat(`
      SELECT u.id, u.class, u.name, u.volunteer_no, g.name AS group_name
      FROM users u
      LEFT JOIN work_groups g ON u.group_id = g.id
      WHERE u.group_id IN (${ph}) OR u.group_id IS NULL
      ORDER BY u.class, u.name
    `).all(...groupIds);
  }

  const hoursRows = db.prepareCompat('SELECT * FROM hours WHERE activity_id = ?').all(id);
  const hoursMap: Record<number, any> = {};
  for (const h of hoursRows) hoursMap[(h as any).user_id] = h;

  const list = users.map((u: any) => ({
    ...u,
    hours: hoursMap[u.id]?.hours ?? 0,
    remark: hoursMap[u.id]?.remark ?? '',
    hours_id: hoursMap[u.id]?.id ?? null,
  }));
  res.json({ activity: act, list });
});

export default router;