import { Router, Response } from 'express';
import multer from 'multer';
import path from 'path';
import fs from 'fs';
import { fileURLToPath } from 'url';
import sharp from 'sharp';
import { queryOne, queryAll, execute } from '../db';
import { authMiddleware, AuthRequest } from '../middleware/auth.js';

const __dirname = path.dirname(fileURLToPath(import.meta.url));
const uploadsDir = path.join(__dirname, '..', '..', 'uploads');

if (!fs.existsSync(uploadsDir)) {
  fs.mkdirSync(uploadsDir, { recursive: true });
}

const ALLOWED_EXTENSIONS = new Set(['.jpg', '.jpeg', '.png', '.gif', '.webp', '.heic', '.heif', '.avif']);
const ALLOWED_MIMES = new Set([
  'image/jpeg', 'image/png', 'image/gif', 'image/webp',
  'image/heic', 'image/heif', 'image/avif',
]);

const storage = multer.diskStorage({
  destination: (_req, _file, cb) => cb(null, uploadsDir),
  filename: (_req, file, cb) => {
    const ext = path.extname(file.originalname).toLowerCase() || '.jpg';
    cb(null, `${Date.now()}-${Math.random().toString(36).slice(2, 8)}${ext}`);
  },
});

const upload = multer({
  storage,
  limits: { fileSize: 20 * 1024 * 1024 },
  fileFilter: (_req, file, cb) => {
    const ext = path.extname(file.originalname).toLowerCase();
    if (!ALLOWED_EXTENSIONS.has(ext) || !ALLOWED_MIMES.has(file.mimetype)) {
      cb(new Error('Неподдерживаемый формат файла'));
      return;
    }
    cb(null, true);
  },
});

const router = Router();

router.get('/', (req: AuthRequest, res: Response) => {
  const page = Math.max(1, parseInt(req.query.page as string) || 1);
  const limit = 12;
  const offset = (page - 1) * limit;

  const cats = queryAll(
    `SELECT c.id, c.image_url, c.caption, c.created_at, c.user_id,
            u.username, u.points AS user_points, u.avatar_url AS user_avatar_url,
            (SELECT COUNT(*) FROM likes WHERE cat_id = c.id) AS likes_count,
            (SELECT COUNT(*) FROM comments WHERE cat_id = c.id) AS comments_count
     FROM cats c
     JOIN users u ON u.id = c.user_id
     ORDER BY c.created_at DESC
     LIMIT ? OFFSET ?`,
    [limit, offset]
  );

  const countResult = queryOne('SELECT COUNT(*) as count FROM cats');
  const total = countResult?.count || 0;

  res.json({ cats, total, page, totalPages: Math.ceil(total / limit) });
});

router.get('/user/:userId', (req: AuthRequest, res: Response) => {
  const userId = parseInt(req.params.userId);
  const cats = queryAll(
    `SELECT c.id, c.image_url, c.caption, c.created_at, c.user_id,
            u.username, u.points AS user_points, u.avatar_url AS user_avatar_url,
            (SELECT COUNT(*) FROM likes WHERE cat_id = c.id) AS likes_count,
            (SELECT COUNT(*) FROM comments WHERE cat_id = c.id) AS comments_count
     FROM cats c
     JOIN users u ON u.id = c.user_id
     WHERE c.user_id = ?
     ORDER BY c.created_at DESC`,
    [userId]
  );

  res.json({ cats });
});

router.get('/:id', (req: AuthRequest, res: Response) => {
  const cat = queryOne(
    `SELECT c.id, c.image_url, c.caption, c.created_at, c.user_id,
            u.username, u.points AS user_points, u.avatar_url AS user_avatar_url,
            (SELECT COUNT(*) FROM likes WHERE cat_id = c.id) AS likes_count,
            (SELECT COUNT(*) FROM comments WHERE cat_id = c.id) AS comments_count
     FROM cats c
     JOIN users u ON u.id = c.user_id
     WHERE c.id = ?`,
    [req.params.id]
  );

  if (!cat) {
    res.status(404).json({ error: 'Cat not found' });
    return;
  }

  res.json({ cat });
});

router.post('/', authMiddleware, upload.single('image'), async (req: AuthRequest, res: Response) => {
  if (!req.file) {
    res.status(400).json({ error: 'Нужно выбрать изображение (jpg, png, gif, webp, heic, avif, до 20MB)' });
    return;
  }

  const caption = (req.body.caption || '').trim();
  if (caption.length > 500) {
    fs.unlinkSync(req.file.path);
    res.status(400).json({ error: 'Подпись не может быть длиннее 500 символов' });
    return;
  }

  const origPath = req.file.path;
  const origExt = path.extname(req.file.filename).toLowerCase();
  const isGif = origExt === '.gif';

  let finalFilename = req.file.filename;
  let finalPath = origPath;

  if (!isGif) {
    finalFilename = req.file.filename.replace(/\.[^.]+$/, '.jpg');
    finalPath = path.join(uploadsDir, finalFilename);
    try {
      await sharp(origPath).jpeg({ quality: 85 }).toFile(finalPath);
      if (origPath !== finalPath) fs.unlinkSync(origPath);
    } catch {
      try { fs.unlinkSync(origPath); } catch {}
      res.status(400).json({ error: 'Не удалось обработать изображение. Попробуйте другой формат.' });
      return;
    }
  }

  const image_url = `/uploads/${finalFilename}`;

  execute(
    'INSERT INTO cats (user_id, image_url, caption) VALUES (?, ?, ?)',
    [req.userId, image_url, caption]
  );

  execute('UPDATE users SET points = points + 1 WHERE id = ?', [req.userId]);

  const cat = queryOne(
    `SELECT c.id, c.image_url, c.caption, c.created_at, c.user_id,
            u.username, u.points AS user_points, u.avatar_url AS user_avatar_url,
            0 AS likes_count,
            0 AS comments_count
     FROM cats c
     JOIN users u ON u.id = c.user_id
     WHERE c.id = (SELECT MAX(id) FROM cats WHERE user_id = ?)`,
    [req.userId]
  );

  res.status(201).json({ cat });
});

router.delete('/:id', authMiddleware, (req: AuthRequest, res: Response) => {
  const cat = queryOne('SELECT user_id, image_url FROM cats WHERE id = ?', [req.params.id]);
  if (!cat) {
    res.status(404).json({ error: 'Cat not found' });
    return;
  }
  if (cat.user_id !== req.userId && !req.isAdmin) {
    res.status(403).json({ error: 'Not your cat' });
    return;
  }

  execute('DELETE FROM comments WHERE cat_id = ?', [req.params.id]);
  execute('DELETE FROM likes WHERE cat_id = ?', [req.params.id]);
  execute('DELETE FROM cats WHERE id = ?', [req.params.id]);

  if (cat.image_url) {
    const filePath = path.join(uploadsDir, path.basename(cat.image_url));
    try { fs.unlinkSync(filePath); } catch {}
  }

  res.json({ ok: true });
});

export default router;