/**
 * Fridger Frontend Application
 * Tablet-optimized UI: Main -> Scan -> Manage navigation and 3-button product management.
 */

const state = {
  currentTab: 'main', // 'main' or 'manage'
  items: [],
  meta: {
    categories: [],
    locations: [],
    units: []
  },
  filters: {
    search: '',
    category: 'All',
    status: 'all'
  },
  activeGramsItem: null,
  activeGramsValue: 0,
  html5QrCode: null,
  isScanning: false
};

// Initialize Application
document.addEventListener('DOMContentLoaded', async () => {
  await loadMetadata();
  await loadStats();
  await loadItems();
  initLucide();
});

function initLucide() {
  if (window.lucide) {
    window.lucide.createIcons();
  }
}

// ----------------------------------------------------
// API Calls
// ----------------------------------------------------

async function loadMetadata() {
  try {
    const res = await fetch('/api/meta');
    if (res.ok) {
      state.meta = await res.json();
      renderCategoryFilters();
      populateModalSelects();
    }
  } catch (err) {
    console.error('Failed to load metadata:', err);
  }
}

async function loadStats() {
  try {
    const res = await fetch('/api/stats');
    if (res.ok) {
      const stats = await res.json();
      document.getElementById('stat-total').textContent = stats.total || 0;
      document.getElementById('stat-fresh').textContent = stats.fresh || 0;
      document.getElementById('stat-expiring').textContent = stats.expiringSoon || 0;
      document.getElementById('stat-opened').textContent = stats.opened || 0;
    }
  } catch (err) {
    console.error('Failed to load stats:', err);
  }
}

async function loadItems() {
  try {
    const params = new URLSearchParams();
    if (state.filters.search) params.append('search', state.filters.search);
    if (state.filters.category && state.filters.category !== 'All') params.append('category', state.filters.category);
    if (state.filters.status && state.filters.status !== 'all') params.append('status', state.filters.status);

    const res = await fetch(`/api/items?${params.toString()}`);
    if (res.ok) {
      state.items = await res.json();
      renderApp();
    }
  } catch (err) {
    console.error('Failed to load items:', err);
    showToast('Failed to load fridge items', 'error');
  }
}

// ----------------------------------------------------
// Navigation Tab Switching (Main -> Scan -> Manage)
// ----------------------------------------------------

function switchTab(tab) {
  state.currentTab = tab;
  
  const mainBtn = document.getElementById('nav-main-btn');
  const manageBtn = document.getElementById('nav-manage-btn');
  const viewContainer = document.getElementById('view-tab-container');
  const manageContainer = document.getElementById('manage-tab-container');

  const activeClasses = 'flex items-center justify-center gap-2 px-3 sm:px-6 py-2.5 sm:py-3 rounded-xl text-xs sm:text-sm font-bold transition-all bg-teal-500 text-white shadow-md active:scale-95 touch-manipulation min-h-[44px]';
  const inactiveClasses = 'flex items-center justify-center gap-2 px-3 sm:px-6 py-2.5 sm:py-3 rounded-xl text-xs sm:text-sm font-bold transition-all text-slate-300 hover:text-white hover:bg-slate-800/80 active:scale-95 touch-manipulation min-h-[44px]';

  if (tab === 'main') {
    mainBtn.className = activeClasses;
    manageBtn.className = inactiveClasses;
    viewContainer.classList.remove('hidden');
    manageContainer.classList.add('hidden');
  } else if (tab === 'manage') {
    manageBtn.className = activeClasses;
    mainBtn.className = inactiveClasses;
    manageContainer.classList.remove('hidden');
    viewContainer.classList.add('hidden');
  }

  renderApp();
}

let searchDebounceTimer = null;
function handleSearch(val) {
  state.filters.search = val.trim();
  const clearBtn = document.getElementById('clear-search');
  if (state.filters.search) {
    clearBtn.classList.remove('hidden');
  } else {
    clearBtn.classList.add('hidden');
  }

  clearTimeout(searchDebounceTimer);
  searchDebounceTimer = setTimeout(() => {
    loadItems();
  }, 200);
}

function clearSearch() {
  document.getElementById('search-input').value = '';
  document.getElementById('clear-search').classList.add('hidden');
  state.filters.search = '';
  loadItems();
}

function setStatusFilter(status) {
  state.filters.status = status;
  document.querySelectorAll('[data-status-btn]').forEach(btn => {
    if (btn.getAttribute('data-status-btn') === status) {
      btn.className = 'status-chip active px-3.5 py-2 rounded-xl bg-slate-800 border border-slate-700 text-white font-bold min-h-[38px] touch-manipulation';
    } else {
      btn.className = 'status-chip px-3.5 py-2 rounded-xl bg-slate-900 border border-slate-800 text-slate-400 hover:text-slate-200 min-h-[38px] touch-manipulation';
    }
  });
  loadItems();
}

function setCategoryFilter(category) {
  state.filters.category = category;
  renderCategoryFilters();
  loadItems();
}

function renderCategoryFilters() {
  const container = document.getElementById('category-filter-bar');
  if (!container) return;

  let html = `
    <button onclick="setCategoryFilter('All')" class="px-3.5 py-2 rounded-xl border whitespace-nowrap transition text-xs sm:text-sm min-h-[38px] touch-manipulation ${
      state.filters.category === 'All' 
        ? 'bg-teal-500/20 text-teal-300 border-teal-500/50 font-bold' 
        : 'bg-slate-900 text-slate-400 border-slate-800 hover:text-slate-200'
    }">
      All Categories
    </button>
  `;

  state.meta.categories.forEach(cat => {
    const isSelected = state.filters.category === cat.id;
    html += `
      <button onclick="setCategoryFilter('${escapeHtml(cat.id)}')" class="px-3.5 py-2 rounded-xl border whitespace-nowrap transition text-xs sm:text-sm min-h-[38px] touch-manipulation ${
        isSelected 
          ? 'bg-teal-500/20 text-teal-300 border-teal-500/50 font-bold' 
          : 'bg-slate-900 text-slate-400 border-slate-800 hover:text-slate-200'
      }">
        ${escapeHtml(cat.name)}
      </button>
    `;
  });

  container.innerHTML = html;
}

function populateModalSelects() {
  const catSelect = document.getElementById('modal-category');
  if (catSelect && state.meta.categories) {
    catSelect.innerHTML = state.meta.categories.map(c => `
      <option value="${escapeHtml(c.id)}">${escapeHtml(c.name)}</option>
    `).join('');
  }
}

// ----------------------------------------------------
// UI Rendering
// ----------------------------------------------------

function renderApp() {
  const emptyState = document.getElementById('empty-state');

  if (state.items.length === 0) {
    emptyState.classList.remove('hidden');
    document.getElementById('fridge-view-content').innerHTML = '';
    document.getElementById('manage-items-list').innerHTML = '';
    return;
  }

  emptyState.classList.add('hidden');

  if (state.currentTab === 'main') {
    renderFridgeView();
  } else {
    renderManageView();
  }

  initLucide();
}

// MAIN TAB: Fridge View (Tablet-optimized cards)
function renderFridgeView() {
  const container = document.getElementById('fridge-view-content');
  if (!container) return;

  container.innerHTML = state.items.map(item => {
    const expiryInfo = getExpiryStatus(item.expiry_date);
    const percent = item.initial_quantity > 0 
      ? Math.min(100, Math.max(0, Math.round((item.quantity / item.initial_quantity) * 100))) 
      : 100;

    let progressBarColor = 'bg-teal-500';
    if (percent <= 20) progressBarColor = 'bg-rose-500';
    else if (percent <= 50) progressBarColor = 'bg-amber-500';

    return `
      <div class="shelf-card rounded-2xl sm:rounded-3xl p-4 sm:p-5 flex flex-col justify-between transition hover:border-teal-500/40 space-y-3.5">
        
        <div>
          <!-- Header: Brand & Expiry -->
          <div class="flex items-center justify-between gap-2 mb-2">
            <span class="text-xs font-bold text-teal-400 bg-teal-500/10 px-2.5 py-1 rounded-lg truncate max-w-[140px]">
              ${escapeHtml(item.brand || item.category)}
            </span>
            <span class="text-xs font-bold px-2.5 py-1 rounded-lg flex items-center gap-1.5 shrink-0 ${expiryInfo.badgeClass}">
              <i data-lucide="${expiryInfo.icon}" class="w-3.5 h-3.5"></i>
              <span>${expiryInfo.label}</span>
            </span>
          </div>

          <!-- Product Details & Image -->
          <div class="flex items-center gap-3.5 my-2">
            ${item.image_url ? `
              <img src="${escapeHtml(item.image_url)}" alt="${escapeHtml(item.name)}" class="w-14 h-14 object-contain rounded-2xl bg-white/5 p-1 border border-slate-700/60 shrink-0">
            ` : `
              <div class="w-14 h-14 rounded-2xl bg-slate-800/80 border border-slate-700 text-teal-400 flex items-center justify-center shrink-0">
                <i data-lucide="${getCategoryIcon(item.category)}" class="w-7 h-7"></i>
              </div>
            `}
            
            <div class="min-w-0 flex-1">
              <h4 class="font-bold text-white text-base leading-snug line-clamp-2">${escapeHtml(item.name)}</h4>
              ${item.notes ? `<p class="text-xs text-slate-400 italic mt-0.5 truncate">${escapeHtml(item.notes)}</p>` : ''}
            </div>
          </div>

          <!-- Grams / Quantity Progress -->
          <div class="mt-3 bg-slate-950/80 rounded-2xl p-3 border border-slate-800/80">
            <div class="flex items-center justify-between text-xs sm:text-sm mb-1.5">
              <span class="font-bold text-white flex items-center gap-1">
                <span class="text-lg font-black text-teal-300">${item.quantity}</span>
                <span class="text-slate-400 font-normal">${item.unit}</span>
              </span>
              <span class="text-xs text-slate-400">
                Pack: ${item.initial_quantity} ${item.unit} (${percent}%)
              </span>
            </div>
            <div class="w-full bg-slate-800 h-2 rounded-full overflow-hidden">
              <div class="${progressBarColor} h-full rounded-full transition-all duration-300" style="width: ${percent}%;"></div>
            </div>
          </div>
        </div>

        <!-- 3 Quick Tablet Action Buttons -->
        <div class="grid grid-cols-3 gap-2 pt-2 border-t border-slate-800/80">
          <button onclick="addWholePacket(${item.id})" class="flex items-center justify-center gap-1.5 py-2.5 px-2 rounded-xl bg-emerald-500/15 hover:bg-emerald-500/25 text-emerald-300 border border-emerald-500/30 text-xs sm:text-sm font-bold transition active:scale-95 touch-manipulation min-h-[42px]" title="Add 1 whole packet">
            <i data-lucide="plus" class="w-4 h-4"></i>
            <span>Add</span>
          </button>
          <button onclick="removeWholePacket(${item.id})" class="flex items-center justify-center gap-1.5 py-2.5 px-2 rounded-xl bg-rose-500/15 hover:bg-rose-500/25 text-rose-300 border border-rose-500/30 text-xs sm:text-sm font-bold transition active:scale-95 touch-manipulation min-h-[42px]" title="Remove 1 whole packet">
            <i data-lucide="minus" class="w-4 h-4"></i>
            <span>Remove</span>
          </button>
          <button onclick="openGramsModal(${item.id})" class="flex items-center justify-center gap-1.5 py-2.5 px-2 rounded-xl bg-teal-500/20 hover:bg-teal-500/30 text-teal-300 border border-teal-500/40 text-xs sm:text-sm font-bold transition active:scale-95 touch-manipulation min-h-[42px]" title="Manage grams remaining">
            <i data-lucide="sliders" class="w-4 h-4"></i>
            <span>Manage</span>
          </button>
        </div>

      </div>
    `;
  }).join('');
}

// MANAGE TAB: Manage Products Interface (Optimized for Tablet with Large Controls)
function renderManageView() {
  const container = document.getElementById('manage-items-list');
  if (!container) return;

  container.innerHTML = state.items.map(item => {
    const expiryInfo = getExpiryStatus(item.expiry_date);
    const percent = item.initial_quantity > 0 
      ? Math.min(100, Math.max(0, Math.round((item.quantity / item.initial_quantity) * 100))) 
      : 100;

    return `
      <div class="bg-slate-900 border border-slate-800 rounded-2xl sm:rounded-3xl p-4 sm:p-5 shadow-lg transition hover:border-slate-700 space-y-4">
        
        <div class="flex flex-col tablet:flex-row items-start tablet:items-center justify-between gap-4">
          
          <!-- Product info -->
          <div class="flex items-center gap-3.5 min-w-0 flex-1">
            ${item.image_url ? `
              <img src="${escapeHtml(item.image_url)}" alt="${escapeHtml(item.name)}" class="w-14 h-14 object-contain rounded-2xl bg-white/5 p-1 border border-slate-800 shrink-0">
            ` : `
              <div class="w-14 h-14 rounded-2xl bg-slate-800 border border-slate-700 text-teal-400 flex items-center justify-center shrink-0">
                <i data-lucide="${getCategoryIcon(item.category)}" class="w-7 h-7"></i>
              </div>
            `}

            <div class="min-w-0 flex-1">
              <div class="flex items-center gap-2 flex-wrap">
                <h4 class="font-extrabold text-white text-base sm:text-lg truncate">${escapeHtml(item.name)}</h4>
                ${item.brand ? `<span class="text-xs px-2 py-0.5 rounded-lg bg-slate-800 text-slate-300 font-medium">${escapeHtml(item.brand)}</span>` : ''}
              </div>
              <div class="text-xs sm:text-sm text-slate-400 flex items-center gap-2.5 mt-1 flex-wrap">
                <span class="font-black text-teal-300 text-sm sm:text-base">${item.quantity} ${item.unit}</span>
                <span>(Pack size: ${item.initial_quantity} ${item.unit})</span>
                <span>&bull;</span>
                <span class="${expiryInfo.badgeClass} px-2 py-0.5 rounded-lg font-bold text-xs">${expiryInfo.label}</span>
              </div>
            </div>
          </div>

          <!-- The 3 Core Tablet Action Buttons: Add, Remove, Manage Product Grams -->
          <div class="flex items-center gap-2 w-full tablet:w-auto justify-end flex-wrap">
            
            <!-- 1. Add Whole Packet -->
            <button 
              onclick="addWholePacket(${item.id})" 
              class="flex-1 tablet:flex-initial px-4 py-3 rounded-2xl bg-emerald-500/15 hover:bg-emerald-500/25 text-emerald-300 border border-emerald-500/30 text-xs sm:text-sm font-bold flex items-center justify-center gap-1.5 transition active:scale-95 touch-manipulation min-h-[46px]" 
              title="Add 1 Whole Packet"
            >
              <i data-lucide="plus" class="w-4 h-4"></i>
              <span>Add</span>
            </button>

            <!-- 2. Remove Whole Packet -->
            <button 
              onclick="removeWholePacket(${item.id})" 
              class="flex-1 tablet:flex-initial px-4 py-3 rounded-2xl bg-rose-500/15 hover:bg-rose-500/25 text-rose-300 border border-rose-500/30 text-xs sm:text-sm font-bold flex items-center justify-center gap-1.5 transition active:scale-95 touch-manipulation min-h-[46px]" 
              title="Remove 1 Whole Packet"
            >
              <i data-lucide="minus" class="w-4 h-4"></i>
              <span>Remove</span>
            </button>

            <!-- 3. Manage Grams / Partial -->
            <button 
              onclick="openGramsModal(${item.id})" 
              class="flex-1 tablet:flex-initial px-5 py-3 rounded-2xl bg-teal-500 hover:bg-teal-400 text-white text-xs sm:text-sm font-bold flex items-center justify-center gap-1.5 shadow-md shadow-teal-500/20 transition active:scale-95 touch-manipulation min-h-[46px]" 
              title="Manage product grams"
            >
              <i data-lucide="sliders" class="w-4 h-4"></i>
              <span>Manage</span>
            </button>

            <!-- Secondary: Edit / Delete -->
            <button onclick="openItemModal(${item.id})" class="p-3 rounded-2xl bg-slate-800 hover:bg-slate-700 text-slate-300 hover:text-white border border-slate-700 min-h-[46px] min-w-[46px] flex items-center justify-center touch-manipulation" title="Edit details">
              <i data-lucide="pencil" class="w-4 h-4"></i>
            </button>
            <button onclick="confirmDeleteItem(${item.id}, '${escapeHtml(item.name)}')" class="p-3 rounded-2xl bg-slate-800 hover:bg-rose-900/40 text-slate-400 hover:text-rose-300 border border-slate-700 min-h-[46px] min-w-[46px] flex items-center justify-center touch-manipulation" title="Delete">
              <i data-lucide="trash-2" class="w-4 h-4"></i>
            </button>

          </div>

        </div>

      </div>
    `;
  }).join('');
}

// ----------------------------------------------------
// 3 Primary Action Handlers
// ----------------------------------------------------

async function addWholePacket(itemId) {
  try {
    const res = await fetch(`/api/items/${itemId}/add-packet`, {
      method: 'POST',
      headers: { 'Content-Type': 'application/json' },
      body: JSON.stringify({ count: 1 })
    });

    if (res.ok) {
      const updated = await res.json();
      showToast(`+1 Pack of ${updated.name} (Total: ${updated.quantity} ${updated.unit})`, 'success');
      await loadStats();
      await loadItems();
    } else {
      showToast('Failed to add packet', 'error');
    }
  } catch (err) {
    console.error(err);
    showToast('Network error', 'error');
  }
}

async function removeWholePacket(itemId) {
  try {
    const res = await fetch(`/api/items/${itemId}/remove-packet`, {
      method: 'POST',
      headers: { 'Content-Type': 'application/json' },
      body: JSON.stringify({ count: 1 })
    });

    if (res.ok) {
      const updated = await res.json();
      showToast(`-1 Pack of ${updated.name} (Remaining: ${updated.quantity} ${updated.unit})`, 'info');
      await loadStats();
      await loadItems();
    } else {
      showToast('Failed to remove packet', 'error');
    }
  } catch (err) {
    console.error(err);
    showToast('Network error', 'error');
  }
}

// ----------------------------------------------------
// Manage Grams Modal Logic
// ----------------------------------------------------

function openGramsModal(itemId) {
  const item = state.items.find(i => i.id === itemId);
  if (!item) return;

  state.activeGramsItem = item;
  state.activeGramsValue = item.quantity;

  document.getElementById('grams-modal-title').textContent = item.name;
  document.getElementById('grams-modal-sub').textContent = `1 Full Packet = ${item.initial_quantity} ${item.unit}`;
  document.getElementById('grams-modal-unit').textContent = item.unit;
  document.getElementById('grams-current-val').textContent = item.quantity;
  document.getElementById('grams-exact-input').value = item.quantity;

  const slider = document.getElementById('grams-slider');
  slider.max = Math.max(item.initial_quantity * 2, item.quantity, 100);
  slider.step = (item.unit === 'g' || item.unit === 'ml') ? '5' : '1';
  slider.value = item.quantity;

  updateGramsGauge();
  document.getElementById('grams-modal').classList.remove('hidden');
  initLucide();
}

function closeGramsModal() {
  document.getElementById('grams-modal').classList.add('hidden');
  state.activeGramsItem = null;
}

function onGramsSliderChange(val) {
  state.activeGramsValue = parseFloat(val);
  document.getElementById('grams-exact-input').value = state.activeGramsValue;
  updateGramsGauge();
}

function onGramsExactInput(val) {
  const num = parseFloat(val);
  if (!isNaN(num) && num >= 0) {
    state.activeGramsValue = num;
    document.getElementById('grams-slider').value = num;
    updateGramsGauge();
  }
}

function applyGramsDelta(delta) {
  state.activeGramsValue = Math.max(0, state.activeGramsValue + delta);
  document.getElementById('grams-slider').value = state.activeGramsValue;
  document.getElementById('grams-exact-input').value = state.activeGramsValue;
  updateGramsGauge();
}

function setGramsPercent(ratio) {
  if (!state.activeGramsItem) return;
  state.activeGramsValue = Math.round(state.activeGramsItem.initial_quantity * ratio);
  document.getElementById('grams-slider').value = state.activeGramsValue;
  document.getElementById('grams-exact-input').value = state.activeGramsValue;
  updateGramsGauge();
}

function updateGramsGauge() {
  document.getElementById('grams-current-val').textContent = state.activeGramsValue;
  if (state.activeGramsItem && state.activeGramsItem.initial_quantity > 0) {
    const pct = Math.round((state.activeGramsValue / state.activeGramsItem.initial_quantity) * 100);
    document.getElementById('grams-percent-text').textContent = `${pct}% remaining of a full ${state.activeGramsItem.initial_quantity}${state.activeGramsItem.unit} packet`;
  }
}

async function saveGramsAdjustment() {
  if (!state.activeGramsItem) return;
  const itemId = state.activeGramsItem.id;
  const newQty = state.activeGramsValue;

  try {
    const res = await fetch(`/api/items/${itemId}/quantity`, {
      method: 'PATCH',
      headers: { 'Content-Type': 'application/json' },
      body: JSON.stringify({ newQuantity: newQty, markOpened: true })
    });

    if (res.ok) {
      showToast(`Updated to ${newQty} ${state.activeGramsItem.unit}`, 'success');
      closeGramsModal();
      await loadStats();
      await loadItems();
    } else {
      showToast('Failed to update quantity', 'error');
    }
  } catch (err) {
    console.error('Save grams error:', err);
    showToast('Network error while updating quantity', 'error');
  }
}

async function consumeAllAndRemove() {
  if (!state.activeGramsItem) return;
  const itemId = state.activeGramsItem.id;

  if (confirm(`Remove "${state.activeGramsItem.name}" from fridge?`)) {
    try {
      const res = await fetch(`/api/items/${itemId}`, { method: 'DELETE' });
      if (res.ok) {
        showToast('Item removed', 'info');
        closeGramsModal();
        await loadStats();
        await loadItems();
      }
    } catch (err) {
      console.error(err);
    }
  }
}

// ----------------------------------------------------
// Item Add / Edit Modal
// ----------------------------------------------------

function openItemModal(itemId = null) {
  const form = document.getElementById('item-form');
  form.reset();
  document.getElementById('modal-image-container').classList.add('hidden');
  document.getElementById('modal-image-url').value = '';

  if (itemId) {
    const item = state.items.find(i => i.id === itemId);
    if (!item) return;

    document.getElementById('modal-item-id').value = item.id;
    document.getElementById('item-modal-title').textContent = 'Edit Product';
    document.getElementById('modal-barcode').value = item.barcode || '';
    document.getElementById('modal-name').value = item.name || '';
    document.getElementById('modal-brand').value = item.brand || '';
    document.getElementById('modal-quantity').value = item.quantity;
    document.getElementById('modal-initial-quantity').value = item.initial_quantity || item.quantity;
    document.getElementById('modal-unit').value = item.unit || 'g';
    document.getElementById('modal-category').value = item.category || 'General';
    document.getElementById('modal-expiry').value = item.expiry_date || '';
    document.getElementById('modal-notes').value = item.notes || '';

    if (item.image_url) {
      document.getElementById('modal-image-url').value = item.image_url;
      document.getElementById('modal-image-preview').src = item.image_url;
      document.getElementById('modal-image-label').textContent = item.name;
      document.getElementById('modal-image-container').classList.remove('hidden');
    }
  } else {
    document.getElementById('modal-item-id').value = '';
    document.getElementById('item-modal-title').textContent = 'Add Product';
    document.getElementById('modal-unit').value = 'g';
    document.getElementById('modal-quantity').value = '';
    document.getElementById('modal-initial-quantity').value = '';
  }

  document.getElementById('item-modal').classList.remove('hidden');
  initLucide();
}

function closeItemModal() {
  document.getElementById('item-modal').classList.add('hidden');
}

async function lookupCurrentBarcode() {
  const code = document.getElementById('modal-barcode').value.trim();
  if (!code) {
    showToast('Please enter a barcode number first', 'error');
    return;
  }

  const btn = document.getElementById('modal-barcode-lookup-btn');
  btn.textContent = 'Searching...';
  btn.disabled = true;

  try {
    const res = await fetch(`/api/barcode/${encodeURIComponent(code)}`);
    if (res.ok) {
      const data = await res.json();
      applyProductDataToForm(data);
      showToast(`Found: ${data.name}`, 'success');
    } else {
      showToast('Product not found in Open Food Facts', 'info');
    }
  } catch (err) {
    console.error(err);
    showToast('Barcode lookup failed', 'error');
  } finally {
    btn.textContent = 'Lookup';
    btn.disabled = false;
  }
}

function applyProductDataToForm(data) {
  if (data.name) document.getElementById('modal-name').value = data.name;
  if (data.brand) document.getElementById('modal-brand').value = data.brand;
  if (data.quantity) {
    document.getElementById('modal-quantity').value = data.quantity;
    document.getElementById('modal-initial-quantity').value = data.quantity;
  }
  if (data.unit) document.getElementById('modal-unit').value = data.unit;
  if (data.category) document.getElementById('modal-category').value = data.category;
  if (data.barcode) document.getElementById('modal-barcode').value = data.barcode;

  if (data.image_url) {
    document.getElementById('modal-image-url').value = data.image_url;
    document.getElementById('modal-image-preview').src = data.image_url;
    document.getElementById('modal-image-label').textContent = data.name;
    document.getElementById('modal-image-container').classList.remove('hidden');
  }
}

function setModalExpiryDays(days) {
  const date = new Date(Date.now() + days * 24 * 60 * 60 * 1000);
  document.getElementById('modal-expiry').value = date.toISOString().slice(0, 10);
}

async function handleItemFormSubmit(event) {
  event.preventDefault();

  const itemId = document.getElementById('modal-item-id').value;
  const qty = parseFloat(document.getElementById('modal-quantity').value);
  const initQty = parseFloat(document.getElementById('modal-initial-quantity').value) || qty;

  const payload = {
    name: document.getElementById('modal-name').value.trim(),
    brand: document.getElementById('modal-brand').value.trim(),
    barcode: document.getElementById('modal-barcode').value.trim(),
    quantity: qty,
    initial_quantity: initQty,
    unit: document.getElementById('modal-unit').value,
    category: document.getElementById('modal-category').value,
    expiry_date: document.getElementById('modal-expiry').value || null,
    notes: document.getElementById('modal-notes').value.trim(),
    image_url: document.getElementById('modal-image-url').value || null
  };

  try {
    const url = itemId ? `/api/items/${itemId}` : '/api/items';
    const method = itemId ? 'PUT' : 'POST';

    const res = await fetch(url, {
      method: method,
      headers: { 'Content-Type': 'application/json' },
      body: JSON.stringify(payload)
    });

    if (res.ok) {
      showToast(itemId ? 'Product updated' : 'Product added to fridge', 'success');
      closeItemModal();
      await loadStats();
      await loadItems();
    } else {
      const err = await res.json();
      showToast(err.error || 'Failed to save product', 'error');
    }
  } catch (err) {
    console.error(err);
    showToast('Network error while saving product', 'error');
  }
}

async function confirmDeleteItem(itemId, name) {
  if (confirm(`Remove "${name}" from fridge?`)) {
    try {
      const res = await fetch(`/api/items/${itemId}`, { method: 'DELETE' });
      if (res.ok) {
        showToast(`Removed "${name}"`, 'info');
        await loadStats();
        await loadItems();
      }
    } catch (err) {
      console.error(err);
      showToast('Failed to delete product', 'error');
    }
  }
}

// ----------------------------------------------------
// Tablet Live Camera Barcode Scanner
// ----------------------------------------------------

function openScannerModal() {
  document.getElementById('scanner-modal').classList.remove('hidden');
  document.getElementById('scanner-manual-input').value = '';
  document.getElementById('scanner-status').textContent = 'Initializing camera...';

  startCameraScanner();
  initLucide();
}

function closeScannerModal() {
  stopCameraScanner();
  document.getElementById('scanner-modal').classList.add('hidden');
}

async function startCameraScanner() {
  if (!window.Html5Qrcode) {
    document.getElementById('scanner-status').textContent = 'Scanner library loading...';
    return;
  }

  try {
    if (state.html5QrCode) {
      await state.html5QrCode.stop().catch(() => {});
    }

    state.html5QrCode = new Html5Qrcode("barcode-reader");
    const config = {
      fps: 10,
      qrbox: { width: 260, height: 160 },
      aspectRatio: 1.333
    };

    await state.html5QrCode.start(
      { facingMode: "environment" },
      config,
      onBarcodeScannedSuccess,
      onBarcodeScanError
    );

    state.isScanning = true;
    document.getElementById('scanner-status').textContent = 'Point tablet camera at barcode.';
  } catch (err) {
    console.warn('Camera start error:', err);
    document.getElementById('scanner-status').textContent = 'Camera unavailable. Please enter barcode number below.';
  }
}

async function stopCameraScanner() {
  if (state.html5QrCode && state.isScanning) {
    try {
      await state.html5QrCode.stop();
      state.isScanning = false;
    } catch (e) {
      console.warn(e);
    }
  }
}

async function onBarcodeScannedSuccess(decodedText) {
  playBeepSound();
  stopCameraScanner();
  document.getElementById('scanner-status').textContent = `Scanned ${decodedText}!`;

  try {
    const res = await fetch(`/api/barcode/${encodeURIComponent(decodedText)}`);
    closeScannerModal();

    if (res.ok) {
      const data = await res.json();
      openItemModal();
      applyProductDataToForm(data);
      showToast(`Scanned: ${data.name}`, 'success');
    } else {
      openItemModal();
      document.getElementById('modal-barcode').value = decodedText;
      showToast(`Scanned barcode: ${decodedText}. Enter details.`, 'info');
    }
  } catch (err) {
    console.error(err);
    closeScannerModal();
    openItemModal();
    document.getElementById('modal-barcode').value = decodedText;
  }
}

function onBarcodeScanError() {}

function handleManualBarcodeSubmit() {
  const code = document.getElementById('scanner-manual-input').value.trim();
  if (!code) return;
  onBarcodeScannedSuccess(code);
}

function playBeepSound() {
  try {
    const ctx = new (window.AudioContext || window.webkitAudioContext)();
    const osc = ctx.createOscillator();
    const gain = ctx.createGain();
    osc.type = 'sine';
    osc.frequency.setValueAtTime(880, ctx.currentTime);
    gain.gain.setValueAtTime(0.15, ctx.currentTime);
    gain.gain.exponentialRampToValueAtTime(0.01, ctx.currentTime + 0.15);
    osc.connect(gain);
    gain.connect(ctx.destination);
    osc.start();
    osc.stop(ctx.currentTime + 0.15);
  } catch (e) {}
}

// ----------------------------------------------------
// Helpers
// ----------------------------------------------------

function getExpiryStatus(expiryDateStr) {
  if (!expiryDateStr) {
    return { label: 'No Expiry', badgeClass: 'bg-slate-800 text-slate-400', icon: 'calendar' };
  }

  const today = new Date();
  today.setHours(0, 0, 0, 0);

  const expDate = new Date(expiryDateStr);
  expDate.setHours(0, 0, 0, 0);

  const diffDays = Math.round((expDate - today) / (1000 * 60 * 60 * 24));

  if (diffDays < 0) {
    return {
      label: `Expired ${Math.abs(diffDays)}d ago`,
      badgeClass: 'bg-rose-500/20 text-rose-300 border border-rose-500/30',
      icon: 'alert-triangle'
    };
  }
  if (diffDays === 0) {
    return {
      label: 'Expires Today!',
      badgeClass: 'bg-rose-500/20 text-rose-300 border border-rose-500/30 font-bold',
      icon: 'alert-circle'
    };
  }
  if (diffDays === 1) {
    return {
      label: 'Expires Tomorrow',
      badgeClass: 'bg-amber-500/20 text-amber-300 border border-amber-500/30',
      icon: 'clock'
    };
  }
  if (diffDays <= 3) {
    return {
      label: `${diffDays} days left`,
      badgeClass: 'bg-amber-500/20 text-amber-300 border border-amber-500/30',
      icon: 'clock'
    };
  }
  return {
    label: `${diffDays} days left`,
    badgeClass: 'bg-emerald-500/10 text-emerald-400 border border-emerald-500/20',
    icon: 'calendar-check'
  };
}

function getCategoryIcon(category) {
  const cat = state.meta.categories.find(c => c.id === category);
  return cat ? cat.icon : 'package';
}

function escapeHtml(str) {
  if (!str) return '';
  return String(str)
    .replace(/&/g, '&amp;')
    .replace(/</g, '&lt;')
    .replace(/>/g, '&gt;')
    .replace(/"/g, '&quot;')
    .replace(/'/g, '&#39;');
}

function showToast(message, type = 'info') {
  const container = document.getElementById('toast-container');
  if (!container) return;

  const toast = document.createElement('div');
  const colors = {
    success: 'bg-teal-600 text-white border-teal-500',
    error: 'bg-rose-600 text-white border-rose-500',
    info: 'bg-slate-800 text-slate-100 border-slate-700'
  };

  toast.className = `p-3.5 rounded-2xl border shadow-2xl text-xs sm:text-sm font-semibold flex items-center gap-2 transform transition-all duration-300 translate-y-2 opacity-0 pointer-events-auto ${colors[type] || colors.info}`;
  toast.innerHTML = `<span>${escapeHtml(message)}</span>`;

  container.appendChild(toast);

  requestAnimationFrame(() => {
    toast.classList.remove('translate-y-2', 'opacity-0');
  });

  setTimeout(() => {
    toast.classList.add('translate-y-2', 'opacity-0');
    setTimeout(() => toast.remove(), 300);
  }, 3000);
}

async function seedDemoData() {
  try {
    const res = await fetch('/api/seed?force=true', { method: 'POST' });
    if (res.ok) {
      showToast('Loaded sample items!', 'success');
      await loadStats();
      await loadItems();
    }
  } catch (err) {
    console.error(err);
  }
}