// /app/static/js/bulk-select.js
// Multi-select mode controller for bulk tag operations
// Works with gallery-infinite.js and showcase.js

(function() {
  'use strict';

  // Use shared TagUtils module
  const { getTagIcon, getTagDisplayName, getTagDisplayNameForOverlay, escapeHtml, createTagChipHtml } = window.TagUtils || {};

  const state = {
    isSelectMode: false,
    selectedIds: new Set(),
    selectionOrder: []  // Array to track order of selection
  };

  // DOM elements (populated on init)
  const dom = {};

  // Autocomplete state
  let autocompleteItems = [];
  let autocompleteSelectedIndex = -1;
  let autocompleteDebounce = null;

  function init() {
    dom.selectBtn = document.getElementById('selectModeBtn');
    dom.panel = document.getElementById('bulkEditorPanel');
    dom.closeBtn = document.getElementById('closeBulkEditor');
    dom.countEl = document.getElementById('selectedCount');
    dom.clearBtn = document.getElementById('clearSelectionBtn');
    dom.addForm = document.getElementById('bulkAddTagForm');
    dom.tagInput = document.getElementById('bulkTagInput');
    dom.autocomplete = document.getElementById('bulkTagAutocomplete');
    dom.commonTags = document.getElementById('commonTagsList');

    if (!dom.selectBtn || !dom.panel) return;

    setupEventListeners();
  }

  function setupEventListeners() {
    // Toggle select mode
    dom.selectBtn.addEventListener('click', toggleSelectMode);
    dom.closeBtn?.addEventListener('click', exitSelectMode);
    dom.clearBtn?.addEventListener('click', clearSelection);

    // Image click handling (delegated) - use capture phase to intercept before modal
    document.addEventListener('click', handleImageClick, true);

    // Bulk add tag form
    dom.addForm?.addEventListener('submit', handleBulkAddTag);

    // Tag autocomplete
    setupAutocomplete();

    // Listen for gallery updates (new images loaded)
    document.addEventListener('galleryUpdated', updateSelectionUI);
    document.addEventListener('showcaseUpdated', updateSelectionUI);

    // Keyboard shortcut: Escape to exit select mode
    document.addEventListener('keydown', (e) => {
      if (e.key === 'Escape' && state.isSelectMode) {
        // Only exit if modal is not open
        const modal = document.getElementById('imageModal');
        if (!modal || !modal.classList.contains('active')) {
          exitSelectMode();
        }
      }
    });
  }

  function toggleSelectMode() {
    state.isSelectMode = !state.isSelectMode;
    document.body.classList.toggle('select-mode', state.isSelectMode);
    dom.selectBtn.textContent = state.isSelectMode ? 'Cancel' : 'Select';
    dom.selectBtn.classList.toggle('active', state.isSelectMode);

    if (state.isSelectMode) {
      dom.panel.classList.add('active');
      updateCommonTagsDisplay();
    } else {
      dom.panel.classList.remove('active');
      clearSelection();
    }
  }

  function exitSelectMode() {
    if (state.isSelectMode) {
      toggleSelectMode();
    }
  }

  function handleImageClick(e) {
    if (!state.isSelectMode) return;

    const item = e.target.closest('.img-clickable');
    if (!item) return;

    // Don't interfere with tag chip clicks
    if (e.target.closest('.tag-chip')) return;

    // Prevent modal from opening in select mode
    e.stopPropagation();
    e.preventDefault();

    const id = parseInt(item.dataset.id);
    if (isNaN(id)) return;

    if (state.selectedIds.has(id)) {
      state.selectedIds.delete(id);
      // Remove from order array without creating new array (preserves window.selectionOrder reference)
      const idx = state.selectionOrder.indexOf(id);
      if (idx !== -1) state.selectionOrder.splice(idx, 1);
      item.classList.remove('selected');
      removeOrderBadge(item);
    } else {
      state.selectedIds.add(id);
      state.selectionOrder.push(id);
      item.classList.add('selected');
      addOrderBadge(item, state.selectionOrder.length);
    }

    // Update all badges to reflect current order
    updateAllOrderBadges();
    updateCount();
    loadCommonTags();
    dispatchSelectionChanged();
  }

  function clearSelection() {
    state.selectedIds.clear();
    // Clear array without creating new one (preserves window.selectionOrder reference)
    state.selectionOrder.length = 0;
    document.querySelectorAll('.img-clickable.selected').forEach(el => {
      el.classList.remove('selected');
      removeOrderBadge(el);
    });
    updateCount();
    updateCommonTagsDisplay();
    dispatchSelectionChanged();
  }

  function updateCount() {
    if (dom.countEl) {
      dom.countEl.textContent = state.selectedIds.size;
    }
  }

  function dispatchSelectionChanged() {
    document.dispatchEvent(new CustomEvent('selectionChanged', {
      detail: {
        count: state.selectedIds.size,
        orderedIds: [...state.selectionOrder]
      }
    }));
  }

  // Enable select mode programmatically, optionally without opening the bulk panel
  function enableSelectMode(skipPanel = false) {
    if (state.isSelectMode) return;

    state.isSelectMode = true;
    document.body.classList.add('select-mode');
    dom.selectBtn.textContent = 'Cancel';
    dom.selectBtn.classList.add('active');

    if (!skipPanel) {
      dom.panel.classList.add('active');
      updateCommonTagsDisplay();
    }
  }

  // Disable select mode
  function disableSelectMode() {
    if (!state.isSelectMode) return;

    state.isSelectMode = false;
    document.body.classList.remove('select-mode');
    dom.selectBtn.textContent = 'Select';
    dom.selectBtn.classList.remove('active');
    dom.panel.classList.remove('active');
    clearSelection();
  }

  function updateSelectionUI() {
    // Re-apply selected class and order badges to any newly loaded images that are in selection
    document.querySelectorAll('.img-clickable').forEach(item => {
      const id = parseInt(item.dataset.id);
      if (state.selectedIds.has(id)) {
        item.classList.add('selected');
        const orderIndex = state.selectionOrder.indexOf(id);
        if (orderIndex !== -1) {
          addOrderBadge(item, orderIndex + 1);
        }
      }
    });
  }

  // ---------------------------
  // Order Badge Helpers
  // ---------------------------
  function addOrderBadge(item, orderNumber) {
    removeOrderBadge(item); // Remove existing badge first
    const badge = document.createElement('div');
    badge.className = 'selection-order-badge';
    badge.textContent = orderNumber;
    item.appendChild(badge);
  }

  function removeOrderBadge(item) {
    const existing = item.querySelector('.selection-order-badge');
    if (existing) existing.remove();
  }

  function updateAllOrderBadges() {
    document.querySelectorAll('.img-clickable').forEach(item => {
      const id = parseInt(item.dataset.id);
      const orderIndex = state.selectionOrder.indexOf(id);
      if (orderIndex !== -1) {
        addOrderBadge(item, orderIndex + 1);
      } else {
        removeOrderBadge(item);
      }
    });
  }

  function updateCommonTagsDisplay() {
    if (state.selectedIds.size === 0) {
      if (dom.commonTags) {
        dom.commonTags.innerHTML = '<span class="text-muted">No images selected</span>';
      }
    }
  }

  async function loadCommonTags() {
    if (state.selectedIds.size === 0) {
      updateCommonTagsDisplay();
      return;
    }

    const ids = Array.from(state.selectedIds);

    try {
      const response = await fetch('/api/images/common-tags', {
        method: 'POST',
        headers: { 'Content-Type': 'application/json' },
        body: JSON.stringify({ image_ids: ids })
      });
      const data = await response.json();

      if (data.ok) {
        renderCommonTags(data.tags);
      }
    } catch (err) {
      console.error('Failed to load common tags:', err);
    }
  }

  function renderCommonTags(tags) {
    if (!dom.commonTags) return;

    if (!tags || tags.length === 0) {
      dom.commonTags.innerHTML = '<span class="text-muted">No common tags</span>';
      return;
    }

    dom.commonTags.innerHTML = tags.map(t => {
      const icon = getTagIcon(t.kind);
      const display = getTagDisplayName(t.name, t.kind);
      const escapedName = escapeHtml(t.name);
      const escapedDisplay = escapeHtml(display);
      return `<span class="tag-chip removable" data-name="${escapedName}">
        ${icon} ${escapedDisplay}
        <button class="x" title="Remove from all selected">×</button>
      </span>`;
    }).join('');

    // Add remove handlers
    dom.commonTags.querySelectorAll('.tag-chip .x').forEach(btn => {
      btn.addEventListener('click', async (e) => {
        e.preventDefault();
        e.stopPropagation();
        const chip = e.target.closest('.tag-chip');
        const name = chip.dataset.name;
        chip.style.opacity = '0.5';
        await bulkRemoveTag(name);
      });
    });
  }

  async function handleBulkAddTag(e) {
    e.preventDefault();
    const name = dom.tagInput.value.trim();
    if (!name || state.selectedIds.size === 0) return;

    dom.tagInput.disabled = true;
    await bulkAddTag(name);
    dom.tagInput.value = '';
    dom.tagInput.disabled = false;
    dom.tagInput.focus();
    hideAutocomplete();
  }

  async function bulkAddTag(name) {
    const ids = Array.from(state.selectedIds);

    try {
      const response = await fetch('/api/images/bulk-add-tag', {
        method: 'POST',
        headers: { 'Content-Type': 'application/json' },
        body: JSON.stringify({ image_ids: ids, tag_name: name })
      });
      const data = await response.json();

      if (data.ok) {
        loadCommonTags(); // Refresh common tags
        refreshSelectedItemsTags(); // Update tag display on gallery items
      } else {
        console.error('Failed to add tag:', data.error);
      }
    } catch (err) {
      console.error('Failed to add tag:', err);
    }
  }

  async function bulkRemoveTag(name) {
    const ids = Array.from(state.selectedIds);

    try {
      const response = await fetch('/api/images/bulk-remove-tag', {
        method: 'POST',
        headers: { 'Content-Type': 'application/json' },
        body: JSON.stringify({ image_ids: ids, tag_name: name })
      });
      const data = await response.json();

      if (data.ok) {
        loadCommonTags(); // Refresh common tags
        refreshSelectedItemsTags(); // Update tag display on gallery items
      } else {
        console.error('Failed to remove tag:', data.error);
      }
    } catch (err) {
      console.error('Failed to remove tag:', err);
    }
  }

  // ---------------------------
  // Autocomplete
  // ---------------------------
  function setupAutocomplete() {
    if (!dom.tagInput) return;

    // Move autocomplete dropdown to body to escape transform containing block
    // (CSS transform on parent creates new stacking context that breaks fixed positioning)
    if (dom.autocomplete && dom.autocomplete.parentNode !== document.body) {
      document.body.appendChild(dom.autocomplete);
    }

    if (!dom.autocomplete) return;

    // Show autocomplete on focus
    dom.tagInput.addEventListener('focus', () => {
      const val = dom.tagInput.value.trim();
      fetchAutocomplete(val);
    });

    // Hide autocomplete on blur (with delay for click)
    dom.tagInput.addEventListener('blur', () => {
      setTimeout(hideAutocomplete, 200);
    });

    // Search as user types
    dom.tagInput.addEventListener('input', () => {
      clearTimeout(autocompleteDebounce);
      autocompleteDebounce = setTimeout(() => {
        fetchAutocomplete(dom.tagInput.value.trim());
      }, 150);
    });

    // Keyboard navigation
    dom.tagInput.addEventListener('keydown', (e) => {
      if (!dom.autocomplete.classList.contains('active')) return;

      if (e.key === 'ArrowDown') {
        e.preventDefault();
        const nextIndex = Math.min(autocompleteSelectedIndex + 1, autocompleteItems.length - 1);
        selectAutocompleteItem(nextIndex);
      } else if (e.key === 'ArrowUp') {
        e.preventDefault();
        const prevIndex = Math.max(autocompleteSelectedIndex - 1, 0);
        selectAutocompleteItem(prevIndex);
      } else if (e.key === 'Enter' && autocompleteSelectedIndex >= 0) {
        e.preventDefault();
        const selected = autocompleteItems[autocompleteSelectedIndex];
        if (selected) {
          dom.tagInput.value = selected.name;
          hideAutocomplete();
          // Submit the form
          dom.addForm.dispatchEvent(new Event('submit', { cancelable: true }));
        }
      } else if (e.key === 'Escape') {
        hideAutocomplete();
      }
    });

    // Click on autocomplete item
    dom.autocomplete.addEventListener('mousedown', (e) => {
      e.preventDefault();
      e.stopPropagation();
      const item = e.target.closest('.tag-autocomplete-item');
      if (!item) return;
      const name = item.dataset.name;
      if (name) {
        dom.tagInput.value = name;
        hideAutocomplete();
        dom.addForm.dispatchEvent(new Event('submit', { cancelable: true }));
      }
    });
  }

  function hideAutocomplete() {
    if (dom.autocomplete) {
      dom.autocomplete.classList.remove('active');
      dom.autocomplete.innerHTML = '';
    }
    autocompleteItems = [];
    autocompleteSelectedIndex = -1;
  }

  function positionAutocomplete() {
    if (!dom.autocomplete || !dom.tagInput) return;
    const rect = dom.tagInput.getBoundingClientRect();
    const viewportWidth = window.innerWidth;
    const dropdownWidth = rect.width;

    // Calculate left position, ensuring dropdown doesn't overflow right edge
    let leftPos = rect.left;
    if (leftPos + dropdownWidth > viewportWidth - 8) {
      leftPos = viewportWidth - dropdownWidth - 8;
    }

    dom.autocomplete.style.top = `${rect.bottom + 4}px`;
    dom.autocomplete.style.left = `${leftPos}px`;
    dom.autocomplete.style.width = `${dropdownWidth}px`;
  }

  async function fetchAutocomplete(query) {
    try {
      // Exclude system-managed tag kinds from autocomplete
      const excludeKinds = 'archive,post,source';
      const url = query
        ? `/api/tags/search?q=${encodeURIComponent(query)}&limit=8&exclude_kind=${excludeKinds}`
        : `/api/tags/search?limit=8&exclude_kind=${excludeKinds}`;
      const r = await fetch(url);
      const j = await r.json();
      renderAutocomplete(j.tags || []);
    } catch {
      hideAutocomplete();
    }
  }

  function renderAutocomplete(tags) {
    if (!dom.autocomplete) return;
    autocompleteItems = tags;
    autocompleteSelectedIndex = -1;

    if (tags.length === 0) {
      dom.autocomplete.innerHTML = '<div class="tag-autocomplete-empty">No matching tags</div>';
      positionAutocomplete();
      dom.autocomplete.classList.add('active');
      return;
    }

    dom.autocomplete.innerHTML = tags.map((t, i) => {
      const icon = getTagIcon(t.kind);
      const displayName = getTagDisplayName(t.name, t.kind);
      return `<div class="tag-autocomplete-item" data-index="${i}" data-name="${escapeHtml(t.name)}">
        <span>${icon} ${escapeHtml(displayName)}</span>
        <span class="tag-kind">${t.kind || 'user'}</span>
      </div>`;
    }).join('');

    positionAutocomplete();
    dom.autocomplete.classList.add('active');
  }

  function selectAutocompleteItem(index) {
    const items = dom.autocomplete?.querySelectorAll('.tag-autocomplete-item');
    if (!items) return;
    items.forEach((el, i) => {
      el.classList.toggle('selected', i === index);
    });
    autocompleteSelectedIndex = index;
  }

  // ---------------------------
  // Tag Refresh for Gallery Items
  // ---------------------------
  async function refreshItemTags(imageId) {
    // Only the gallery page renders tag overlays on thumbnails. Skip showcase items
    // (class .masonry-item) so closing the modal doesn't inject a .tag-overlay there.
    const item = document.querySelector(`.gallery-item[data-id="${imageId}"]`);
    if (!item) return;

    try {
      const r = await fetch(`/image/${imageId}/tags`);
      const data = await r.json();

      if (!data.ok) return;

      // Filter out archive and source tags (they're not shown in overlays)
      const visibleTags = (data.tags || []).filter(t => t.kind !== 'archive' && t.kind !== 'source');

      // Find or create tag overlay
      let overlay = item.querySelector('.tag-overlay');

      if (visibleTags.length === 0) {
        // No visible tags - remove overlay if exists
        if (overlay) overlay.remove();
        return;
      }

      if (!overlay) {
        overlay = document.createElement('div');
        overlay.className = 'tag-overlay';
        item.appendChild(overlay);
      }

      // Render tags with icons using shared utility
      overlay.innerHTML = visibleTags.map(t => createTagChipHtml(t)).join('');

    } catch (e) {
      console.error('Failed to refresh tags for image', imageId, e);
    }
  }

  async function refreshSelectedItemsTags() {
    // Refresh tags for all currently selected items
    const ids = Array.from(state.selectedIds);
    await Promise.all(ids.map(id => refreshItemTags(id)));
  }

  // Initialize on DOM ready
  if (document.readyState === 'loading') {
    document.addEventListener('DOMContentLoaded', init);
  } else {
    init();
  }

  // Expose global API for other scripts (like series editor, modal)
  window.selectedImages = state.selectedIds;
  window.selectionOrder = state.selectionOrder;  // Ordered array of selected IDs
  window.clearSelection = clearSelection;
  window.enableSelectMode = enableSelectMode;
  window.disableSelectMode = disableSelectMode;
  window.refreshItemTags = refreshItemTags;  // Refresh tags display on a single gallery item
})();