'use server';

import * as React from 'react';
import { renderToBuffer } from '@react-pdf/renderer';
import { getAllProducts } from '@/lib/products';
import { getExcelTechnicalDataForProduct } from '@/lib/excel-products';
import { PDFBrochure } from '@/lib/pdf-brochure';
import { ProductData as PDFProductData } from '@/lib/pdf-datasheet';

/**
 * Server action to generate a PDF brochure.
 * Fetches products from Payload CMS and technical data from Excel.
 * Returns the PDF as a base64 string.
 */
export async function generateBrochureAction(params: {
  locale: 'en' | 'de';
  productSlugs?: string[];
  title?: string;
  subtitle?: string;
}) {
  try {
    const { locale, productSlugs, title, subtitle } = params;

    // 1. Fetch products from Payload
    let products = await getAllProducts(locale);

    // 2. Filter by slugs if provided
    if (productSlugs && productSlugs.length > 0) {
      products = products.filter((p) => productSlugs.includes(p.slug));
    }

    // 3. Map Payload products to PDF internal model and attach Excel data
    const pdfProducts: PDFProductData[] = products.map((p, index) => {
      // Get technical data from Excel
      const excelData = getExcelTechnicalDataForProduct({
        slug: p.slug,
        sku: p.frontmatter.sku,
        name: p.frontmatter.title,
      });

      return {
        id: index + 1,
        name: p.frontmatter.title,
        sku: p.frontmatter.sku,
        shortDescriptionHtml: p.frontmatter.description,
        descriptionHtml: p.frontmatter.description,
        // Application text is usually part of description in Payload v3
        applicationHtml: '', 
        featuredImage: p.frontmatter.images[0] || null,
        images: p.frontmatter.images,
        categories: p.frontmatter.categories.map((name) => ({ name })),
        attributes: excelData?.attributes || [],
      };
    });

    if (pdfProducts.length === 0) {
      throw new Error('No products found for brochure generation.');
    }

    // 4. Render to PDF buffer
    // Note: React 19 / Next 15+ might need specific handling for renderToBuffer in actions
    const buffer = await renderToBuffer(
      React.createElement(PDFBrochure, {
        products: pdfProducts,
        locale,
        title,
        subtitle,
      })
    );

    // 5. Convert to Base64 for returning to client
    return {
      success: true,
      data: buffer.toString('base64'),
      fileName: `KLZ_Cables_Brochure_${locale.toUpperCase()}.pdf`,
    };
  } catch (error) {
    console.error('[Action] Brochure generation failed:', error);
    return {
      success: false,
      error: error instanceof Error ? error.message : 'Unknown error occurred',
    };
  }
}