const express = require('express');
const { v4: uuidv4 } = require('uuid');
const fs = require('fs');
const path = require('path');

function createProductRoutes(db) {
  const router = express.Router();

  // List products (optional filter by shop_id)
  router.get('/', (req, res) => {
    const { shop_id } = req.query;
    let products;
    if (shop_id) {
      products = db.prepare('SELECT * FROM products WHERE shop_id = ? ORDER BY created_at DESC').all(shop_id);
    } else {
      products = db.prepare('SELECT * FROM products ORDER BY created_at DESC').all();
    }
    // Parse shop info
    const shopStmt = db.prepare('SELECT shop_name FROM shops WHERE id = ?');
    products = products.map(p => ({
      ...p,
      shop_name: shopStmt.get(p.shop_id)?.shop_name || 'Unknown'
    }));
    res.json(products);
  });

  // Export products (optional filter by shop_id)
  router.get('/export', (req, res) => {
    const { shop_id } = req.query;
    let products;
    if (shop_id) {
      products = db.prepare('SELECT p.*, s.shop_name FROM products p LEFT JOIN shops s ON p.shop_id = s.id WHERE p.shop_id = ? ORDER BY p.created_at DESC').all(shop_id);
    } else {
      products = db.prepare('SELECT p.*, s.shop_name FROM products p LEFT JOIN shops s ON p.shop_id = s.id ORDER BY p.created_at DESC').all();
    }
    res.setHeader('Content-Disposition', 'attachment; filename=products.json');
    res.json(products);
  });

  // Upload reference image for a product
  router.post('/:id/image', (req, res) => {
    const product = db.prepare('SELECT * FROM products WHERE id = ?').get(req.params.id);
    if (!product) return res.status(404).json({ error: 'Product not found' });
    const { image } = req.body;
    if (!image) return res.status(400).json({ error: 'image (base64) required' });

    let imagesRoot = path.join(__dirname, '..', 'images');
    try {
      const savePathRow = db.prepare("SELECT value FROM configs WHERE key = 'image_save_path'").get();
      if (savePathRow?.value?.trim()) imagesRoot = savePathRow.value.trim();
    } catch (_) {}

    const imagesDir = path.join(imagesRoot, product.id);
    if (!fs.existsSync(imagesDir)) fs.mkdirSync(imagesDir, { recursive: true });

    const filename = 'ref.png';
    const filePath = path.join(imagesDir, filename);
    const base64Data = image.replace(/^data:image\/\w+;base64,/, '');
    fs.writeFileSync(filePath, Buffer.from(base64Data, 'base64'));

    const publicPath = `/api/images/${product.id}/${filename}`;
    db.prepare("UPDATE products SET reference_image = ?, updated_at = CURRENT_TIMESTAMP WHERE id = ?")
      .run(publicPath, req.params.id);
    res.json({ reference_image: publicPath });
  });

  // Delete reference image for a product
  router.delete('/:id/image', (req, res) => {
    const product = db.prepare('SELECT * FROM products WHERE id = ?').get(req.params.id);
    if (!product) return res.status(404).json({ error: 'Product not found' });
    if (!product.reference_image) return res.json({ success: true });

    let imagesRoot = path.join(__dirname, '..', 'images');
    try {
      const savePathRow = db.prepare("SELECT value FROM configs WHERE key = 'image_save_path'").get();
      if (savePathRow?.value?.trim()) imagesRoot = savePathRow.value.trim();
    } catch (_) {}

    const filePath = path.join(imagesRoot, product.id, 'ref.png');
    if (fs.existsSync(filePath)) fs.unlinkSync(filePath);

    db.prepare("UPDATE products SET reference_image = '', updated_at = CURRENT_TIMESTAMP WHERE id = ?")
      .run(req.params.id);
    res.json({ success: true });
  });

  // Get product by id
  router.get('/:id', (req, res) => {
    const product = db.prepare('SELECT * FROM products WHERE id = ?').get(req.params.id);
    if (!product) return res.status(404).json({ error: 'Product not found' });
    const shop = db.prepare('SELECT shop_name FROM shops WHERE id = ?').get(product.shop_id);
    res.json({ ...product, shop_name: shop?.shop_name || 'Unknown' });
  });

  // Create product
  router.post('/', (req, res) => {
    const { shop_id, title } = req.body;
    if (!shop_id || !title) {
      return res.status(400).json({ error: 'shop_id and title are required' });
    }
    const shop = db.prepare('SELECT * FROM shops WHERE id = ?').get(shop_id);
    if (!shop) return res.status(404).json({ error: 'Shop not found' });
    
    const id = uuidv4();
    db.prepare('INSERT INTO products (id, shop_id, title) VALUES (?, ?, ?)').run(id, shop_id, title);
    res.status(201).json(db.prepare('SELECT * FROM products WHERE id = ?').get(id));
  });

  // Batch create products
  router.post('/batch', (req, res) => {
    const { shop_id, titles } = req.body;
    if (!shop_id || !Array.isArray(titles) || titles.length === 0) {
      return res.status(400).json({ error: 'shop_id and titles array are required' });
    }
    const shop = db.prepare('SELECT * FROM shops WHERE id = ?').get(shop_id);
    if (!shop) return res.status(404).json({ error: 'Shop not found' });
    
    const insert = db.prepare('INSERT INTO products (id, shop_id, title) VALUES (?, ?, ?)');
    const products = [];
    const batchInsert = db.transaction((titles) => {
      for (const title of titles) {
        const id = uuidv4();
        insert.run(id, shop_id, title);
        products.push(id);
      }
    });
    batchInsert(titles);
    
    const created = db.prepare('SELECT * FROM products WHERE id IN (' + products.map(() => '?').join(',') + ')').all(...products);
    res.status(201).json(created);
  });

  // Update product
  router.put('/:id', (req, res) => {
    const { title, status } = req.body;
    const product = db.prepare('SELECT * FROM products WHERE id = ?').get(req.params.id);
    if (!product) return res.status(404).json({ error: 'Product not found' });
    
    db.prepare('UPDATE products SET title = ?, status = ?, updated_at = CURRENT_TIMESTAMP WHERE id = ?')
      .run(title || product.title, status || product.status, req.params.id);
    
    res.json(db.prepare('SELECT * FROM products WHERE id = ?').get(req.params.id));
  });

  // Batch delete products (POST because DELETE with body is not reliable)
  router.post('/batch-delete', (req, res) => {
    const { ids } = req.body;
    if (!Array.isArray(ids) || ids.length === 0) {
      return res.status(400).json({ error: 'ids array required' });
    }
    const placeholders = ids.map(() => '?').join(',');
    const result = db.prepare('DELETE FROM products WHERE id IN (' + placeholders + ')').run(...ids);
    res.json({ deleted: result.changes });
  });

  // Batch delete products (legacy DELETE route)
  router.delete('/batch', (req, res) => {
    const { ids } = req.body;
    if (!Array.isArray(ids) || ids.length === 0) {
      return res.status(400).json({ error: 'ids array required' });
    }
    const placeholders = ids.map(() => '?').join(',');
    const result = db.prepare('DELETE FROM products WHERE id IN (' + placeholders + ')').run(...ids);
    res.json({ deleted: result.changes });
  });

  // Delete product
  router.delete('/:id', (req, res) => {
    const result = db.prepare('DELETE FROM products WHERE id = ?').run(req.params.id);
    if (result.changes === 0) return res.status(404).json({ error: 'Product not found' });
    res.json({ success: true });
  });

  // Import products from array
  router.post('/import', (req, res) => {
    const { shop_id, products: importProducts } = req.body;
    if (!shop_id || !Array.isArray(importProducts) || importProducts.length === 0) {
      return res.status(400).json({ error: 'shop_id and products array required' });
    }
    const shop = db.prepare('SELECT * FROM shops WHERE id = ?').get(shop_id);
    if (!shop) return res.status(404).json({ error: 'Shop not found' });

    const insert = db.prepare('INSERT OR IGNORE INTO products (id, shop_id, title) VALUES (?, ?, ?)');
    let imported = 0;
    const batch = db.transaction(() => {
      for (const p of importProducts) {
        const title = typeof p === 'string' ? p : p.title;
        if (!title) continue;
        const id = uuidv4();
        const info = insert.run(id, shop_id, title);
        if (info.changes > 0) imported++;
      }
    });
    batch();
    res.json({ total: importProducts.length, imported });
  });






  return router;
}

module.exports = createProductRoutes;