/**
 * Export dashboard as PDF by capturing a screenshot of #dashboard-content
 * and assembling it into a multi-page PDF (html2canvas + jsPDF).
 */
function exportDashboardToPdf() {
  var el = document.getElementById('dashboard-content');
  if (!el) {
    if (typeof console !== 'undefined' && console.warn) {
      console.warn('export-pdf: #dashboard-content not found');
    }
    return;
  }

  var btn = document.getElementById('pdf-export-btn');
  var originalText = btn ? btn.innerHTML : '';
  if (btn) {
    btn.disabled = true;
    btn.innerHTML = 'Generating PDF…';
  }

  var regionEl = document.getElementById('regionBadge');
  var region = regionEl ? (regionEl.textContent || '').trim() : '';

  if (typeof html2canvas === 'undefined' || typeof jspdf === 'undefined') {
    if (btn) {
      btn.disabled = false;
      btn.innerHTML = originalText;
    }
    alert('PDF export requires html2canvas and jsPDF. Please refresh the page.');
    return;
  }

  var JsPDFConstructor = (typeof jspdf !== 'undefined' && jspdf.jsPDF) ? jspdf.jsPDF : jspdf;

  var auditSection = el.querySelector('section[aria-label="Audit analysis"]');
  var auditSectionDisplay = '';
  if (auditSection) {
    auditSectionDisplay = auditSection.style.display;
    auditSection.style.display = 'none';
  }

  function restoreAuditSection() {
    if (auditSection) {
      auditSection.style.display = auditSectionDisplay;
    }
  }

  html2canvas(el, {
    scale: 2,
    useCORS: true,
    allowTaint: true,
    logging: false
  }).then(function(canvas) {
    var imgW = canvas.width;
    var imgH = canvas.height;
    var dataUrl = canvas.toDataURL('image/png');

    var doc = new JsPDFConstructor({ orientation: 'portrait', unit: 'mm', format: 'a4' });
    var pageW = 210;
    var pageH = 297;
    var margin = 10;
    var contentW = pageW - 2 * margin;
    var headerH = 14;
    var firstPageImgTop = margin + headerH;
    var firstPageImgH = pageH - firstPageImgTop - margin;
    var otherPageImgH = pageH - 2 * margin;

    var imgWmm = contentW;
    var imgHmm = contentW * (imgH / imgW);

    doc.setFontSize(14);
    doc.text('Dashboard report', margin, margin + 6);
    doc.setFontSize(10);
    doc.text(region ? 'Region: ' + region : '', margin, margin + 12);

    var shown = 0;
    var totalH = imgHmm;
    var pageNum = 0;
    var imgYmm = firstPageImgTop;

    while (shown < totalH) {
      if (pageNum > 0) {
        doc.addPage();
        imgYmm = margin;
      }
      var sliceH = pageNum === 0 ? firstPageImgH : otherPageImgH;
      var yOffset = -shown;
      doc.addImage(dataUrl, 'PNG', margin, imgYmm + yOffset, imgWmm, imgHmm);
      shown += sliceH;
      pageNum += 1;
    }

    doc.save('dashboard-report.pdf');

    restoreAuditSection();
    if (btn) {
      btn.disabled = false;
      btn.innerHTML = originalText;
    }
  }).catch(function (err) {
    if (typeof console !== 'undefined' && console.error) {
      console.error('export-pdf:', err);
    }
    restoreAuditSection();
    if (btn) {
      btn.disabled = false;
      btn.innerHTML = originalText;
    }
    alert('Failed to generate PDF. Please try again.');
  });
}