// ═══════════════════════════════════════════════════════
// QR Code Reader (using jsQR library)
// ═══════════════════════════════════════════════════════
let qrCameraStream = null;
let qrScanInterval = null;
let qrScanHistoryList = [];

function startQrCamera() {
  if (!navigator.mediaDevices || !navigator.mediaDevices.getUserMedia) {
    return setStatus('qrReaderStatus', 'error', 'Camera API not supported in this browser.');
  }

  navigator.mediaDevices.getUserMedia({ video: { facingMode: 'environment' } })
    .then(stream => {
      qrCameraStream = stream;
      const video = document.getElementById('qrVideo');
      video.srcObject = stream;
      video.play();

      document.getElementById('qrCameraContainer').style.display = 'block';
      document.getElementById('qrCameraBtn').style.display = 'none';
      document.getElementById('qrStopBtn').style.display = '';
      document.getElementById('qrImagePreview').style.display = 'none';

      setStatus('qrReaderStatus', 'info', 'Camera active — scanning for QR codes...');

      // Start scanning frames
      const canvas = document.getElementById('qrScanCanvas');
      const ctx = canvas.getContext('2d', { willReadFrequently: true });

      qrScanInterval = setInterval(() => {
        if (video.readyState === video.HAVE_ENOUGH_DATA) {
          canvas.width = video.videoWidth;
          canvas.height = video.videoHeight;
          ctx.drawImage(video, 0, 0, canvas.width, canvas.height);
          const imageData = ctx.getImageData(0, 0, canvas.width, canvas.height);

          if (typeof jsQR !== 'undefined') {
            const code = jsQR(imageData.data, imageData.width, imageData.height, { inversionAttempts: 'dontInvert' });
            if (code) {
              showQrResult(code.data);
              setStatus('qrReaderStatus', 'success', 'QR code detected ✓');
            }
          }
        }
      }, 250);
    })
    .catch(err => {
      setStatus('qrReaderStatus', 'error', 'Camera access denied: ' + err.message);
    });
}

function stopQrCamera() {
  if (qrScanInterval) { clearInterval(qrScanInterval); qrScanInterval = null; }
  if (qrCameraStream) {
    qrCameraStream.getTracks().forEach(t => t.stop());
    qrCameraStream = null;
  }
  const video = document.getElementById('qrVideo');
  video.srcObject = null;

  document.getElementById('qrCameraContainer').style.display = 'none';
  document.getElementById('qrCameraBtn').style.display = '';
  document.getElementById('qrStopBtn').style.display = 'none';
  setStatus('qrReaderStatus', 'info', 'Camera stopped.');
}

function scanQrFromFile(event) {
  const file = event.target.files[0];
  if (!file) return;

  // Stop camera if running
  stopQrCamera();

  const img = document.getElementById('qrPreviewImg');
  const reader = new FileReader();
  reader.onload = function (e) {
    img.src = e.target.result;
    document.getElementById('qrImagePreview').style.display = 'block';

    const tempImg = new Image();
    tempImg.onload = function () {
      const canvas = document.getElementById('qrImgCanvas');
      const ctx = canvas.getContext('2d', { willReadFrequently: true });
      canvas.width = tempImg.width;
      canvas.height = tempImg.height;
      ctx.drawImage(tempImg, 0, 0);
      const imageData = ctx.getImageData(0, 0, canvas.width, canvas.height);

      if (typeof jsQR !== 'undefined') {
        const code = jsQR(imageData.data, imageData.width, imageData.height, { inversionAttempts: 'attemptBoth' });
        if (code) {
          showQrResult(code.data);
          setStatus('qrReaderStatus', 'success', 'QR code detected in image ✓');
        } else {
          setStatus('qrReaderStatus', 'error', 'No QR code found in this image.');
        }
      } else {
        setStatus('qrReaderStatus', 'error', 'QR scanning library not loaded.');
      }
    };
    tempImg.src = e.target.result;
  };
  reader.readAsDataURL(file);

  // Reset file input so same file can be re-selected
  event.target.value = '';
}

function showQrResult(data) {
  document.getElementById('qrReaderPlaceholder').style.display = 'none';
  document.getElementById('qrReaderResult').style.display = 'block';
  document.getElementById('qrDecodedText').textContent = data;

  // Detect type
  let type = 'Plain Text';
  const openBtn = document.getElementById('qrOpenLinkBtn');
  openBtn.style.display = 'none';

  if (/^https?:\/\//i.test(data)) {
    type = '🔗 URL';
    openBtn.style.display = '';
  } else if (/^mailto:/i.test(data)) {
    type = '📧 Email';
    openBtn.style.display = '';
  } else if (/^tel:/i.test(data)) {
    type = '📞 Phone Number';
  } else if (/^BEGIN:VCARD/i.test(data)) {
    type = '👤 vCard Contact';
  } else if (/^BEGIN:VEVENT/i.test(data)) {
    type = '📅 Calendar Event';
  } else if (/^WIFI:/i.test(data)) {
    type = '📶 Wi-Fi Network';
  } else if (/^smsto:/i.test(data)) {
    type = '💬 SMS';
  } else if (/^geo:/i.test(data)) {
    type = '📍 Geolocation';
  }

  document.getElementById('qrDecodedType').textContent = type;

  // Add to history (keep last 10)
  const now = new Date().toLocaleTimeString();
  qrScanHistoryList.unshift({ data: data.length > 80 ? data.slice(0, 80) + '...' : data, time: now, full: data });
  if (qrScanHistoryList.length > 10) qrScanHistoryList.pop();

  document.getElementById('qrScanHistory').innerHTML = qrScanHistoryList.map(h =>
    `<div class="result-row" style="cursor:pointer;" onclick="copyText('${h.full.replace(/'/g, "\\'")}')">
      <div class="label">${h.time}</div>
      <div class="value" style="font-size:0.78rem;">${h.data.replace(/</g, '&lt;')}</div>
    </div>`
  ).join('');
}

// Stop camera when navigating away
const origShowPage = window.showPage;
if (origShowPage) {
  window.showPage = function (name) {
    if (name !== 'qrreader' && qrCameraStream) stopQrCamera();
    origShowPage(name);
  };
}