/**
 * Image Scraper Module
 */

let currentJobId = null;
let currentImages = [];
let imageStepIndicator = null;

function initImageScraper() {
  const elements = {
    grid: document.getElementById('imgGrid'),
    counter: document.getElementById('img_counter'),
    toolbar: document.getElementById('imageToolbar'),
    skeleton: document.getElementById('imageSkeleton'),
    btnScrape: document.getElementById('btnScrape'),
    btnSelectAll: document.getElementById('btnSelectAll'),
    btnSelectNone: document.getElementById('btnSelectNone'),
    btnZip: document.getElementById('btnZip'),
    btnPdf: document.getElementById('btnPdf'),
    zipName: document.getElementById('zip_name'),
    pdfName: document.getElementById('pdf_name'),
    pageUrl: document.getElementById('page_url'),
    progress: document.getElementById('imgProgress')
  };

  // Initialize step indicator
  imageStepIndicator = new StepIndicator('imageStepIndicator', [
    'Enter URL',
    'Fetch Images',
    'Select',
    'Download'
  ]);

  // Show empty state initially
  showImageGridEmpty(elements.grid);

  // Event listeners
  elements.btnScrape.addEventListener('click', () => handleScrapeImages(elements));
  elements.btnSelectAll.addEventListener('click', () => selectAllImages(elements));
  elements.btnSelectNone.addEventListener('click', () => clearImageSelection(elements));

  elements.btnZip.addEventListener('click', () => {
    let name = elements.zipName.value.trim() || 'images.zip';
    if (!name.toLowerCase().endsWith('.zip')) name += '.zip';
    handleDownload('/api/download-zip', 'zip_name', name, elements);
  });

  elements.btnPdf.addEventListener('click', () => {
    let name = elements.pdfName.value.trim() || 'images.pdf';
    if (!name.toLowerCase().endsWith('.pdf')) name += '.pdf';
    handleDownload('/api/download-pdf', 'pdf_name', name, elements);
  });

  // URL input - update step
  elements.pageUrl.addEventListener('input', () => {
    if (elements.pageUrl.value.trim()) {
      imageStepIndicator.setStep(1);
    }
    clearFieldError(elements.pageUrl.closest('.form-group'));
  });

  // URL validation
  elements.pageUrl.addEventListener('blur', () => {
    const value = elements.pageUrl.value.trim();
    if (value) validateUrl(elements.pageUrl);
  });

  // Enter to scrape
  elements.pageUrl.addEventListener('keydown', (e) => {
    if (e.key === 'Enter') {
      e.preventDefault();
      elements.btnScrape.click();
    }
  });

  // Keyboard shortcuts
  registerShortcut('ctrl+a', () => {
    if (document.getElementById('page-images').classList.contains('active') && currentImages.length > 0) {
      selectAllImages(elements);
    }
  });

  registerShortcut('ctrl+d', () => {
    if (document.getElementById('page-images').classList.contains('active') && currentImages.length > 0) {
      clearImageSelection(elements);
    }
  });
}

function getSelectedIds(grid) {
  const ids = [];
  grid.querySelectorAll('input[type="checkbox"]').forEach(cb => {
    if (cb.checked) ids.push(cb.dataset.id);
  });
  return ids;
}

function updateCounter(elements) {
  const total = currentImages.length;
  const selected = getSelectedIds(elements.grid).length;
  elements.counter.textContent = `${total} images • ${selected} selected`;
  
  // Update step indicator based on selection
  if (selected > 0 && imageStepIndicator) {
    imageStepIndicator.setStep(3); // Ready to download
  }
}

function setImageButtonsEnabled(elements, enabled) {
  elements.btnSelectAll.disabled = !enabled;
  elements.btnSelectNone.disabled = !enabled;
  elements.btnZip.disabled = !enabled;
  elements.btnPdf.disabled = !enabled;
}

function renderImages(images, elements) {
  elements.grid.innerHTML = '';

  images.forEach(img => {
    const card = createImageCard(img, elements);
    elements.grid.appendChild(card);
  });

  updateCounter(elements);
}

function createImageCard(img, elements) {
  const card = document.createElement('div');
  card.className = 'image-card';

  // Preview button
  const previewBtn = document.createElement('button');
  previewBtn.className = 'image-preview-btn';
  previewBtn.innerHTML = `<svg fill="none" stroke="currentColor" viewBox="0 0 24 24"><path stroke-linecap="round" stroke-linejoin="round" stroke-width="2" d="M21 21l-6-6m2-5a7 7 0 11-14 0 7 7 0 0114 0zM10 7v3m0 0v3m0-3h3m-3 0H7"/></svg>`;
  previewBtn.addEventListener('click', (e) => {
    e.stopPropagation();
    const dims = (img.width && img.height) ? `${img.width}×${img.height}` : null;
    const size = img.bytes ? formatFileSize(img.bytes) : null;
    showImageModal(img.url, img.filename, dims, size);
  });

  // Thumbnail
  const thumb = document.createElement('img');
  thumb.className = 'image-thumb';
  thumb.src = img.url;
  thumb.loading = 'lazy';
  thumb.referrerPolicy = 'no-referrer';
  thumb.alt = img.filename;

  // Meta
  const meta = document.createElement('div');
  meta.className = 'image-meta';

  const filename = document.createElement('div');
  filename.className = 'image-filename';
  filename.title = img.filename;
  filename.textContent = img.filename;

  const info = document.createElement('div');
  info.className = 'image-info';

  const sizeBadge = document.createElement('span');
  sizeBadge.className = 'image-badge';
  sizeBadge.textContent = (img.width && img.height) ? `${img.width}×${img.height}` : '?';

  const checkboxContainer = document.createElement('div');
  checkboxContainer.className = 'image-checkbox';

  const checkbox = document.createElement('input');
  checkbox.type = 'checkbox';
  checkbox.dataset.id = img.id;
  checkbox.addEventListener('click', e => e.stopPropagation());
  checkbox.addEventListener('change', () => {
    card.classList.toggle('selected', checkbox.checked);
    updateCounter(elements);
  });

  checkboxContainer.appendChild(checkbox);
  checkboxContainer.appendChild(document.createTextNode('Select'));

  info.appendChild(sizeBadge);
  info.appendChild(checkboxContainer);
  meta.appendChild(filename);
  meta.appendChild(info);

  card.appendChild(previewBtn);
  card.appendChild(thumb);
  card.appendChild(meta);

  card.addEventListener('click', () => {
    checkbox.checked = !checkbox.checked;
    card.classList.toggle('selected', checkbox.checked);
    updateCounter(elements);
  });

  return card;
}

async function handleScrapeImages(elements) {
  const pageUrl = elements.pageUrl.value.trim();
  
  if (!pageUrl) {
    setFieldError(elements.pageUrl.closest('.form-group'), 'URL required');
    showToast('URL Required', 'Enter a webpage URL', 'error');
    return;
  }
  
  if (!validateUrl(elements.pageUrl)) {
    showToast('Invalid URL', 'Enter a valid URL', 'error');
    return;
  }

  setButtonLoading(elements.btnScrape, true, 'Scraping...');
  setImageButtonsEnabled(elements, false);
  elements.toolbar.style.display = 'none';
  elements.skeleton.style.display = 'grid';
  elements.grid.innerHTML = '';
  currentJobId = null;
  currentImages = [];
  showProgress(elements.progress, true, true);
  imageStepIndicator.setStep(1); // Fetching

  try {
    const fd = new FormData();
    fd.append('page_url', pageUrl);
    
    const res = await fetch('/api/scrape-images', { method: 'POST', body: fd });
    
    if (!res.ok) {
      let err = { detail: 'Request failed' };
      try { err = await res.json(); } catch {}
      throw new Error(err.detail || 'Request failed');
    }
    
    const data = await res.json();
    currentJobId = data.job_id;
    currentImages = data.images || [];

    elements.skeleton.style.display = 'none';
    
    if (currentImages.length > 0) {
      renderImages(currentImages, elements);
      elements.toolbar.style.display = 'flex';
      setImageButtonsEnabled(elements, true);
      showToast('Scrape Complete', `Found ${currentImages.length} images`, 'success');
      imageStepIndicator.setStep(2); // Select step
    } else {
      showImageGridEmpty(elements.grid);
      showToast('No Images', 'No suitable images found on this page', 'info');
      imageStepIndicator.setStep(0);
    }
  } catch (e) {
    elements.skeleton.style.display = 'none';
    
    // Show error state with retry action
    showErrorState(elements.grid, 
      'Scraping Failed', 
      e.message || 'Could not fetch images from this URL. The page might be blocking requests or require authentication.',
      [
        { id: 'retry', label: 'Try Again', primary: true, handler: () => handleScrapeImages(elements) },
        { id: 'clear', label: 'Clear', handler: () => {
          elements.pageUrl.value = '';
          showImageGridEmpty(elements.grid);
          imageStepIndicator.reset();
        }}
      ]
    );
    
    imageStepIndicator.setStep(0);
  } finally {
    setButtonLoading(elements.btnScrape, false);
    showProgress(elements.progress, false);
  }
}

function selectAllImages(elements) {
  elements.grid.querySelectorAll('input[type="checkbox"]').forEach(cb => {
    cb.checked = true;
    cb.closest('.image-card').classList.add('selected');
  });
  updateCounter(elements);
  showToast('Selected All', `${currentImages.length} images`, 'success');
  imageStepIndicator.setStep(3); // Ready to download
}

function clearImageSelection(elements) {
  elements.grid.querySelectorAll('input[type="checkbox"]').forEach(cb => {
    cb.checked = false;
    cb.closest('.image-card').classList.remove('selected');
  });
  updateCounter(elements);
  showToast('Cleared', 'Selection cleared', 'info');
  imageStepIndicator.setStep(2); // Back to select
}

async function handleDownload(endpoint, nameField, nameValue, elements) {
  if (!currentJobId) {
    showToast('No Images', 'Fetch images first', 'error');
    return;
  }
  
  const ids = getSelectedIds(elements.grid);
  
  if (ids.length === 0) {
    showToast('No Selection', 'Select at least one image', 'error');
    return;
  }

  const isZip = nameField === 'zip_name';
  const btn = isZip ? elements.btnZip : elements.btnPdf;
  
  setButtonLoading(btn, true, 'Preparing...');
  showProgress(elements.progress, true, true);

  try {
    const fd = new FormData();
    fd.append('job_id', currentJobId);
    fd.append('image_ids', ids.join(','));
    fd.append(nameField, nameValue);

    const res = await fetch(endpoint, { method: 'POST', body: fd });
    
    if (!res.ok) {
      let err = { detail: 'Request failed' };
      try { err = await res.json(); } catch {}
      throw new Error(err.detail || 'Request failed');
    }
    
    const blob = await res.blob();

    const url = URL.createObjectURL(blob);
    const a = document.createElement('a');
    a.href = url;
    a.download = nameValue;
    document.body.appendChild(a);
    a.click();
    a.remove();
    URL.revokeObjectURL(url);

    showToast('Downloaded', `${ids.length} images as ${nameValue}`, 'success');
    imageStepIndicator.complete();
    
    // Show success animation
    showSuccessAnimation('Download Complete!', `${ids.length} images saved as ${nameValue}`);
  } catch (e) {
    showToast('Download Failed', e.message, 'error');
    imageStepIndicator.setStep(2);
  } finally {
    setButtonLoading(btn, false);
    showProgress(elements.progress, false);
    updateCounter(elements);
  }
}