import { NextResponse } from 'next/server';
import { productService } from '../../../lib/services/productService';
import { PRODUCTS } from '../../../lib/data/products';

export const dynamic = 'force-dynamic';
export const revalidate = 3600; // Revalidate every hour

export async function GET() {
  const baseUrl = process.env.NEXT_PUBLIC_SITE_URL || 'https://canina.ir';

  let productsList: any[] = [];
  try {
    const res = await productService.getProducts({ limit: 999 });
    productsList = res.data && res.data.length > 0 ? res.data : PRODUCTS;
  } catch {
    productsList = PRODUCTS;
  }

  // Only active, indexable products
  const indexableProducts = productsList.filter(p => !p.noIndex && p.stockStatus !== 'DISCONTINUED');

  const itemsXml = indexableProducts.map(product => {
    const slug = product.slug || product.artNo || product.id;
    const link = `${baseUrl}/shop/${slug}`;
    const id = product.artNo || product.id;
    const title = product.nameEn ? `${product.nameFa || product.name} (${product.nameEn})` : (product.nameFa || product.name);
    const description = product.metaDescription || product.shortDescription || product.description || 'مکمل درمانی اصل کنینا آلمان';
    
    const primaryImg = product.ogImage || product.image;
    const imageLink = primaryImg ? (primaryImg.startsWith('http') ? primaryImg : `${baseUrl}${primaryImg}`) : '';

    let availability = 'in_stock';
    if (product.stockStatus === 'OUT_OF_STOCK') availability = 'out_of_stock';
    if (product.stockStatus === 'PRE_ORDER') availability = 'preorder';

    const price = product.priceValue ? `${product.priceValue * 10} IRR` : '0 IRR';
    const gtinTag = product.barcode ? `<g:gtin>${product.barcode}</g:gtin>` : '';
    const additionalImages = (product.images || [])
      .filter((img: string) => img && img !== primaryImg)
      .slice(0, 5)
      .map((img: string) => `<g:additional_image_link>${img.startsWith('http') ? img : `${baseUrl}${img}`}</g:additional_image_link>`)
      .join('\n        ');

    return `    <item>
      <g:id>${id}</g:id>
      <title><![CDATA[${title}]]></title>
      <description><![CDATA[${description}]]></description>
      <link>${link}</link>
      <g:image_link>${imageLink}</g:image_link>
      ${additionalImages}
      <g:availability>${availability}</g:availability>
      <g:price>${price}</g:price>
      <g:brand>Canina pharma GmbH</g:brand>
      <g:mpn>${product.artNo}</g:mpn>
      ${gtinTag}
      <g:condition>new</g:condition>
      <g:product_type><![CDATA[${product.category || 'مکمل حیوانات'}]]></g:product_type>
    </item>`;
  }).join('\n');

  const xmlContent = `<?xml version="1.0" encoding="UTF-8"?>
<rss version="2.0" xmlns:g="http://base.google.com/ns/1.0">
  <channel>
    <title>فید محصولات و مکمل‌های تخصصی کنینا ایران</title>
    <link>${baseUrl}/shop</link>
    <description>فید رسمی محصولات و مکمل‌های دارویی سگ و گربه برند Canina آلمان</description>
    <lastBuildDate>${new Date().toUTCString()}</lastBuildDate>
${itemsXml}
  </channel>
</rss>`;

  return new NextResponse(xmlContent, {
    status: 200,
    headers: {
      'Content-Type': 'application/xml; charset=utf-8',
      'Cache-Control': 'public, max-age=3600, s-maxage=3600, stale-while-revalidate=86400',
    },
  });
}