import { NextRequest, NextResponse } from 'next/server';
import { getPayload } from 'payload';
import configPromise from '@payload-config';
import { renderToStream } from '@react-pdf/renderer';
import React from 'react';
import { PDFPage } from '@/lib/pdf-page';

export async function GET(req: NextRequest, { params }: { params: Promise<{ slug: string }> }) {
  try {
    const { slug } = await params;

    // Get Payload App
    const payload = await getPayload({ config: configPromise });

    // Fetch the page
    const pages = await payload.find({
      collection: 'pages',
      where: {
        slug: { equals: slug },
        _status: { equals: 'published' },
      },
      limit: 1,
    });

    if (pages.totalDocs === 0) {
      return new NextResponse('Page not found', { status: 404 });
    }

    const page = pages.docs[0];

    // Determine locale from searchParams or default to 'de'
    const searchParams = req.nextUrl.searchParams;
    const locale = (searchParams.get('locale') as 'en' | 'de') || 'de';

    // Render the React-PDF document into a stream
    const stream = await renderToStream(<PDFPage page={page} locale={locale} />);

    // Pipe the Node.js Readable stream into a valid fetch/Web Response stream
    const body = new ReadableStream({
      start(controller) {
        stream.on('data', (chunk) => controller.enqueue(chunk));
        stream.on('end', () => controller.close());
        stream.on('error', (err) => controller.error(err));
      },
      cancel() {
        (stream as any).destroy?.();
      },
    });

    const filename = `${slug}.pdf`;

    return new NextResponse(body, {
      status: 200,
      headers: {
        'Content-Type': 'application/pdf',
        'Content-Disposition': `attachment; filename="${filename}"`,
        // Cache control if needed, skip for now.
      },
    });
  } catch (error) {
    console.error('Error generating PDF:', error);
    return new NextResponse('Internal Server Error', { status: 500 });
  }
}