import { jsPDF } from 'jspdf';
import html2canvas from 'html2canvas';

export const exportAsPdf = async (elementId: string, fileName: string, action: 'preview' | 'download'): Promise<void> => {
  const element = document.getElementById(elementId);
  
  if (!element) {
    console.error(`Element with id ${elementId} not found.`);
    return;
  }

  try {
    // We temporarily make the element visible to html2canvas if it's hidden by CSS
    // by cloning it or just capturing it directly (html2canvas can capture off-screen if it's positioned absolute)
    
    const canvas = await html2canvas(element, {
      scale: 2, // Higher resolution
      useCORS: true,
      logging: false,
      backgroundColor: '#ffffff' // Ensure white background
    });

    const imgData = canvas.toDataURL('image/jpeg', 0.95);
    
    // A4 dimensions in mm: 210 x 297
    const pdf = new jsPDF({
      orientation: 'portrait',
      unit: 'mm',
      format: 'a4',
    });

    const pdfWidth = pdf.internal.pageSize.getWidth();
    const pdfHeight = (canvas.height * pdfWidth) / canvas.width;

    pdf.addImage(imgData, 'JPEG', 0, 0, pdfWidth, pdfHeight);

    if (action === 'download') {
      pdf.save(`${fileName}.pdf`);
    } else {
      const pdfBlob = pdf.output('blob');
      const pdfUrl = URL.createObjectURL(pdfBlob);
      window.open(pdfUrl, '_blank');
      URL.revokeObjectURL(pdfUrl);
    }
  } catch (error) {
    console.error('Error generating PDF with html2canvas:', error);
  }
};