import { NextResponse } from 'next/server';
import * as XLSX from 'xlsx';

export async function POST(request: Request) {
  try {
    const { data } = await request.json();

    // Create a new workbook
    const wb = XLSX.utils.book_new();

    // Process each document's data
    data.forEach((doc: any, index: number) => {
      // Create worksheet for the main data
      const mainData = {
        Company: doc.company,
        Address: doc.address,
        'Total Sum': doc.total_sum,
      };
      const mainWS = XLSX.utils.json_to_sheet([mainData]);

      // Create worksheet for items
      const itemsWS = XLSX.utils.json_to_sheet(doc.items);

      // Add worksheets to workbook
      XLSX.utils.book_append_sheet(wb, mainWS, `Doc${index + 1} Summary`);
      XLSX.utils.book_append_sheet(wb, itemsWS, `Doc${index + 1} Items`);
    });

    // Generate Excel file buffer
    const excelBuffer = XLSX.write(wb, { type: 'buffer', bookType: 'xlsx' });

    // Return the Excel file as a response
    return new NextResponse(excelBuffer, {
      headers: {
        'Content-Type': 'application/vnd.openxmlformats-officedocument.spreadsheetml.sheet',
        'Content-Disposition': 'attachment; filename="extracted_data.xlsx"',
      },
    });
  } catch (error) {
    console.error('Error generating Excel file:', error);
    return NextResponse.json(
      { error: 'Failed to generate Excel file' },
      { status: 500 }
    );
  }
}