import { Router } from 'express';
import db from '../db.js';
import { auth } from '../middleware.js';

const router = Router();

// 获取动态列表（含用户信息、是否已点赞）
router.get('/', auth, (req, res) => {
  const { category } = req.query;
  let sql = `
    SELECT p.*, u.nickname, u.avatar,
      (SELECT COUNT(*) FROM likes l WHERE l.post_id = p.id) as like_count,
      EXISTS(SELECT 1 FROM likes l WHERE l.post_id = p.id AND l.user_id = ?) as liked
    FROM posts p JOIN users u ON p.user_id = u.id
  `;
  const params = [req.user.id];
  if (category && category !== '全部') {
    sql += ' WHERE p.category = ?';
    params.push(category);
  }
  sql += ' ORDER BY p.created_at DESC';
  const posts = db.prepare(sql).all(...params);
  res.json(posts.map(p => ({ ...p, images: JSON.parse(p.images || '[]') })));
});

// 发布动态
router.post('/', auth, (req, res) => {
  const { content, images, category } = req.body;
  if (!content || !content.trim()) {
    return res.status(400).json({ message: '内容不能为空' });
  }
  const info = db
    .prepare('INSERT INTO posts (user_id, content, images, category) VALUES (?, ?, ?, ?)')
    .run(req.user.id, content, JSON.stringify(images || []), category || '动态');
  const post = db.prepare('SELECT * FROM posts WHERE id = ?').get(info.lastInsertRowid);
  res.json({ ...post, images: JSON.parse(post.images || '[]') });
});

// 删除动态
router.delete('/:id', auth, (req, res) => {
  const post = db.prepare('SELECT * FROM posts WHERE id = ?').get(req.params.id);
  if (!post) return res.status(404).json({ message: '动态不存在' });
  if (post.user_id !== req.user.id && req.user.role !== 'admin') {
    return res.status(403).json({ message: '无权删除' });
  }
  db.prepare('DELETE FROM comments WHERE post_id = ?').run(req.params.id);
  db.prepare('DELETE FROM likes WHERE post_id = ?').run(req.params.id);
  db.prepare('DELETE FROM posts WHERE id = ?').run(req.params.id);
  res.json({ message: '删除成功' });
});

// 点赞/取消点赞
router.post('/:id/like', auth, (req, res) => {
  const post = db.prepare('SELECT id FROM posts WHERE id = ?').get(req.params.id);
  if (!post) return res.status(404).json({ message: '动态不存在' });
  const existing = db
    .prepare('SELECT id FROM likes WHERE post_id = ? AND user_id = ?')
    .get(req.params.id, req.user.id);
  if (existing) {
    db.prepare('DELETE FROM likes WHERE id = ?').run(existing.id);
    res.json({ liked: false });
  } else {
    db.prepare('INSERT INTO likes (post_id, user_id) VALUES (?, ?)').run(req.params.id, req.user.id);
    res.json({ liked: true });
  }
});

// 获取评论
router.get('/:id/comments', auth, (req, res) => {
  const comments = db
    .prepare('SELECT c.*, u.nickname, u.avatar FROM comments c JOIN users u ON c.user_id = u.id WHERE c.post_id = ? ORDER BY c.created_at ASC')
    .all(req.params.id);
  res.json(comments);
});

// 发表评论
router.post('/:id/comments', auth, (req, res) => {
  const { content } = req.body;
  if (!content || !content.trim()) {
    return res.status(400).json({ message: '评论不能为空' });
  }
  db.prepare('INSERT INTO comments (post_id, user_id, content) VALUES (?, ?, ?)')
    .run(req.params.id, req.user.id, content);
  const list = db
    .prepare('SELECT c.*, u.nickname, u.avatar FROM comments c JOIN users u ON c.user_id = u.id WHERE c.post_id = ? ORDER BY c.created_at ASC')
    .all(req.params.id);
  res.json(list);
});

export default router;