// Configuration
let config = {
  apiBaseUrl: '/api',
  businessId: parseInt(localStorage.getItem('payfrit_portal_business')) || 0,
  stationId: null,
  stationName: null,
  stationColor: null,
  refreshInterval: 5000,
};

// State
let orders = [];
let stations = [];
let refreshTimer = null;
let expandedOrders = new Set();

// Status ID mapping
const STATUS = { NEW: 1, PREPARING: 2, READY: 3, COMPLETED: 4 };
const STATUS_NAMES = { 1: 'New', 2: 'Preparing', 3: 'Ready', 4: 'Completed' };

// Initialize
document.addEventListener('DOMContentLoaded', () => {
  loadConfig();
  checkStationSelection();
  updateClock();
  setInterval(updateClock, 1000);

  // Monitor online/offline status
  window.addEventListener('online', () => {
    console.log('[KDS] Back online');
    updateStatus(true);
    loadOrders(); // Refresh immediately when back online
  });

  window.addEventListener('offline', () => {
    console.log('[KDS] Went offline');
    updateStatus(false);
  });

  // Initial connection check
  if (!navigator.onLine) {
    updateStatus(false);
  }
});

// Update clock display
function updateClock() {
  const now = new Date();
  const hours = String(now.getHours()).padStart(2, '0');
  const minutes = String(now.getMinutes()).padStart(2, '0');
  const seconds = String(now.getSeconds()).padStart(2, '0');
  document.getElementById('clock').textContent = `${hours}:${minutes}:${seconds}`;
}

// Load config from localStorage
function loadConfig() {
  // Load KDS-specific settings (station, refresh interval)
  const saved = localStorage.getItem('kds_config');
  if (saved) {
    try {
      const parsed = JSON.parse(saved);
      // Reset station selection if business changed since last KDS use
      if (parsed.businessId && parsed.businessId !== config.businessId) {
        config.stationId = null;
        config.stationName = null;
        config.stationColor = null;
        saveConfigToStorage();
      } else {
        config.stationId = parsed.stationId !== undefined ? parsed.stationId : null;
        config.stationName = parsed.stationName || null;
        config.stationColor = parsed.stationColor || null;
      }
      config.refreshInterval = (parsed.refreshInterval || 5) * 1000;
    } catch (e) {
      console.error('[KDS] Failed to load config:', e);
    }
  }

  console.log('[KDS] Config loaded:', config);
}

function saveConfigToStorage() {
  localStorage.setItem('kds_config', JSON.stringify({
    businessId: config.businessId,
    stationId: config.stationId,
    stationName: config.stationName,
    stationColor: config.stationColor,
    refreshInterval: config.refreshInterval / 1000
  }));
}

// Check if station selection is needed
async function checkStationSelection() {
  if (!config.businessId) {
    console.log('[KDS] No businessId - please log in via Portal first');
    updateStatus(false, 'No business selected - log in via Portal');
    return;
  }

  console.log('[KDS] Starting with businessId:', config.businessId, 'stationId:', config.stationId);

  // Load business name
  await loadName();

  // If station already selected (including 0 for "all"), start KDS
  if (config.stationId !== null && config.stationId !== undefined) {
    updateStationBadge();
    startAutoRefresh();
    return;
  }

  // Load stations to see if we need to show picker
  await loadStations();
  if (stations.length > 0) {
    showStationSelection();
  } else {
    // No stations configured, default to all orders
    config.stationId = 0;
    updateStationBadge();
    startAutoRefresh();
  }
}

// Load business name from API
async function loadName() {
  if (!config.businessId) return;

  try {
    const response = await fetch(`${config.apiBaseUrl}/businesses/get.cfm`, {
      method: 'POST',
      headers: { 'Content-Type': 'application/json' },
      body: JSON.stringify({ BusinessID: config.businessId })
    });
    const data = await response.json();
    if (data.OK && data.BUSINESS && data.BUSINESS.Name) {
      document.getElementById('businessName').textContent = ' - ' + data.BUSINESS.Name;
    }
  } catch (e) {
    console.error('[KDS] Failed to load business name:', e);
  }
}

// Load stations from API
async function loadStations() {
  if (!config.businessId) return;

  try {
    const response = await fetch(`${config.apiBaseUrl}/stations/list.cfm`, {
      method: 'POST',
      headers: { 'Content-Type': 'application/json' },
      body: JSON.stringify({ BusinessID: config.businessId })
    });
    const data = await response.json();
    if (data.OK) {
      stations = data.STATIONS || [];
    }
  } catch (e) {
    console.error('Failed to load stations:', e);
  }
}

// Show station selection overlay
async function showStationSelection() {
  if (stations.length === 0) {
    await loadStations();
  }

  const overlay = document.getElementById('stationOverlay');
  const buttons = document.getElementById('stationButtons');

  let html = `
    <button class="station-btn all-stations" onclick="selectStation(0, 'All Stations', null)">
      <svg xmlns="http://www.w3.org/2000/svg" fill="none" viewBox="0 0 24 24" stroke="currentColor">
        <path stroke-linecap="round" stroke-linejoin="round" stroke-width="2" d="M4 6h16M4 10h16M4 14h16M4 18h16" />
      </svg>
      All Stations
    </button>
  `;

  stations.forEach(s => {
    const color = s.Color || '#666';
    html += `
      <button class="station-btn" style="background: ${color}; color: #fff;" onclick="selectStation(${s.StationID}, '${escapeHtml(s.Name)}', '${color}')">
        ${escapeHtml(s.Name)}
      </button>
    `;
  });

  buttons.innerHTML = html;
  overlay.classList.remove('hidden');
}

// Select a station
function selectStation(stationId, stationName, stationColor) {
  config.stationId = stationId;
  config.stationName = stationName;
  config.stationColor = stationColor;

  // Save to localStorage
  saveConfigToStorage();

  // Hide overlay and start
  document.getElementById('stationOverlay').classList.add('hidden');
  updateStationBadge();
  startAutoRefresh();
}

// Update station badge in header
function updateStationBadge() {
  const badge = document.getElementById('stationBadge');
  const name = config.stationId && config.stationName ? config.stationName : 'All';
  badge.innerHTML = `<span class="station-name-display">/ ${escapeHtml(name)}</span>`;
}

// Start auto-refresh
function startAutoRefresh() {
  if (!config.businessId) return;
  loadOrders();
  if (refreshTimer) clearInterval(refreshTimer);
  refreshTimer = setInterval(loadOrders, config.refreshInterval);
}

// Load orders from API
async function loadOrders() {
  if (!config.businessId) return;

  // Check if online before attempting fetch
  if (!navigator.onLine) {
    updateStatus(false);
    return;
  }

  try {
    const url = `${config.apiBaseUrl}/orders/listForKDS.cfm`;
    const response = await fetch(url, {
      method: 'POST',
      headers: { 'Content-Type': 'application/json' },
      body: JSON.stringify({
        BusinessID: config.businessId,
        StationID: config.stationId || 0
      })
    });

    const data = await response.json();

    if (data.OK) {
      orders = data.ORDERS || [];
      renderOrders();
      updateStatus(true, `${orders.length} active orders`);
    } else {
      updateStatus(false, `Error: ${data.MESSAGE || data.ERROR}`);
    }
  } catch (error) {
    console.error('Failed to load orders:', error);
    updateStatus(false, 'Connection error');
  }
}

// Update status indicator
function updateStatus(isConnected, message) {
  const indicator = document.getElementById('statusIndicator');
  if (isConnected) {
    indicator.classList.remove('disconnected');
  } else {
    indicator.classList.add('disconnected');
  }
}

// Render orders to DOM
function renderOrders() {
  const grid = document.getElementById('ordersGrid');
  console.log('renderOrders called, orders count:', orders.length);
  if (orders.length === 0) {
    grid.innerHTML = `
      <div class="empty-state">
        <svg xmlns="http://www.w3.org/2000/svg" fill="none" viewBox="0 0 24 24" stroke="currentColor">
          <path stroke-linecap="round" stroke-linejoin="round" stroke-width="2" d="M9 5H7a2 2 0 00-2 2v12a2 2 0 002 2h10a2 2 0 002-2V7a2 2 0 00-2-2h-2M9 5a2 2 0 002 2h2a2 2 0 002-2M9 5a2 2 0 012-2h2a2 2 0 012 2" />
        </svg>
        <h2>No Active Orders</h2>
        <p>New orders will appear here automatically</p>
      </div>
    `;
    return;
  }
  orders.forEach((order, i) => {
    console.log(`Order ${i}: ID=${order.OrderID}, LineItems count=${order.LineItems?.length || 0}`);
    if (order.LineItems) {
      order.LineItems.forEach(li => {
        console.log(`  LineItem: ${li.Name} (ID=${li.OrderLineItemID}, ParentID=${li.ParentOrderLineItemID})`);
      });
    }
  });
  grid.innerHTML = orders.map(order => renderOrder(order)).join('');
}

// Check if a root item belongs to the current station
function isStationItem(item) {
  if (!config.stationId || config.stationId === 0) return true;
  const sid = parseInt(item.StationID) || 0;
  return sid === config.stationId || sid === 0;
}

// Toggle expand/collapse for an order
function toggleExpand(orderId) {
  if (expandedOrders.has(orderId)) {
    expandedOrders.delete(orderId);
  } else {
    expandedOrders.add(orderId);
  }
  renderOrders();
}

// Render single order card
function renderOrder(order) {
  const statusClass = getStatusClass(order.StatusID);
  const elapsedTime = getElapsedTime(order.SubmittedOn);
  const timeClass = getTimeClass(elapsedTime);
  const allRootItems = order.LineItems.filter(item => item.ParentOrderLineItemID === 0);
  const isFiltering = config.stationId && config.stationId > 0;
  const isExpanded = expandedOrders.has(order.OrderID);

  // Split into station items and other-station items
  const stationItems = isFiltering ? allRootItems.filter(i => isStationItem(i)) : allRootItems;
  const otherItems = isFiltering ? allRootItems.filter(i => !isStationItem(i)) : [];
  const hasOtherItems = otherItems.length > 0;

  // Build expand toggle button
  let expandToggle = '';
  if (isFiltering && hasOtherItems) {
    if (isExpanded) {
      expandToggle = `<button class="expand-toggle" onclick="toggleExpand(${order.OrderID})">Hide ${otherItems.length} other item${otherItems.length > 1 ? 's' : ''}</button>`;
    } else {
      expandToggle = `<button class="expand-toggle" onclick="toggleExpand(${order.OrderID})">Show ${otherItems.length} other item${otherItems.length > 1 ? 's' : ''}</button>`;
    }
  }

  // Render line items: station items always, other items only when expanded
  let lineItemsHtml = stationItems.map(item => renderLineItem(item, order.LineItems, false)).join('');
  if (isExpanded && hasOtherItems) {
    lineItemsHtml += otherItems.map(item => renderLineItem(item, order.LineItems, true)).join('');
  }

  return `
    <div class="order-card ${statusClass}">
      <div class="order-header">
        <div class="order-number">#${order.OrderID}${order.OrderTypeID === 2 ? ' <span class="badge-pickup">PICKUP</span>' : ''}${order.OrderTypeID === 3 ? ' <span class="badge-delivery">DELIVERY</span>' : ''}</div>
        <div class="order-time">
          <div class="elapsed-time ${timeClass}">${formatElapsedTime(elapsedTime)}</div>
          <div class="submit-time">${formatSubmitTime(order.SubmittedOn)}</div>
        </div>
      </div>

      <div class="order-info">
        <div><strong>${getLocationLabel(order)}:</strong> ${getLocationValue(order)}</div>
        <div><strong>Customer:</strong> ${order.FirstName || ''} ${order.LastName || ''}</div>
        <div><strong>Status:</strong> ${STATUS_NAMES[order.StatusID] || 'Unknown'}</div>
      </div>

      ${order.Remarks ? `<div class="order-remarks">Note: ${escapeHtml(order.Remarks)}</div>` : ''}

      <div class="line-items">
        ${lineItemsHtml}
      </div>
      ${expandToggle}

      <div class="action-buttons">
        ${renderActionButtons(order)}
      </div>
    </div>
  `;
}

// Render line item with modifiers
function renderLineItem(item, allItems, isOtherStation = false) {
  const modifiers = allItems.filter(mod => mod.ParentOrderLineItemID === item.OrderLineItemID);
  console.log(`Item: ${item.Name} (ID: ${item.OrderLineItemID}) has ${modifiers.length} direct modifiers:`, modifiers.map(m => m.Name));
  const otherClass = isOtherStation ? ' other-station' : '';
  const doneClass = (item.StatusID === 1) ? ' line-item-done' : '';
  return `
    <div class="line-item${otherClass}${doneClass}">
      <div class="line-item-main">
        <div class="item-name">${escapeHtml(item.Name)}</div>
        <div class="item-qty">x${item.Quantity}</div>
      </div>
      ${modifiers.length > 0 ? renderAllModifiers(modifiers, allItems) : ''}
      ${item.Remark ? `<div class="item-remark">Note: ${escapeHtml(item.Remark)}</div>` : ''}
    </div>
  `;
}

// Render all modifiers
function renderAllModifiers(modifiers, allItems) {
  let html = '<div class="modifiers">';

  function getModifierPath(mod) {
    const path = [];
    let current = mod;
    while (current) {
      path.unshift(current.Name);
      const parentId = current.ParentOrderLineItemID;
      if (parentId === 0) break;
      current = allItems.find(item => item.OrderLineItemID === parentId);
    }
    return path;
  }

  const leafModifiers = [];
  function collectLeafModifiers(mods, depth = 0) {
    mods.forEach(mod => {
      // Inverted groups: show removed defaults with "NO" prefix instead of listing all selected defaults
      if (mod.IsInvertedGroup || mod.ISINVERTEDGROUP) {
        const removed = mod.RemovedDefaults || mod.REMOVEDDEFAULTS || [];
        if (removed.length > 0) {
          removed.forEach(name => {
            leafModifiers.push({ mod: { Name: 'NO ' + name, ItemParentName: mod.Name }, path: [] });
          });
        }
        return;
      }

      // Skip default modifiers - only show customizations
      if (mod.IsCheckedByDefault) return;

      const children = allItems.filter(item => item.ParentOrderLineItemID === mod.OrderLineItemID);
      if (children.length === 0) {
        const path = getModifierPath(mod);
        leafModifiers.push({ mod, path });
      } else {
        collectLeafModifiers(children, depth + 1);
      }
    });
  }
  collectLeafModifiers(modifiers);

  leafModifiers.forEach(({ mod }) => {
    const displayText = mod.ItemParentName
      ? `${mod.ItemParentName}: ${mod.Name}`
      : mod.Name;
    html += `<div class="modifier">+ ${escapeHtml(displayText)}</div>`;
  });

  html += '</div>';
  return html;
}

// Check if this station's items are all done for an order
function isStationDoneForOrder(order) {
  if (!config.stationId || config.stationId === 0) return false;
  const stationRootItems = order.LineItems.filter(li =>
    li.ParentOrderLineItemID === 0 && (parseInt(li.StationID) || 0) === config.stationId
  );
  if (stationRootItems.length === 0) return true; // no items for this station
  return stationRootItems.every(li => li.StatusID === 1);
}

// Render action buttons based on order status
function renderActionButtons(order) {
  const isFiltering = config.stationId && config.stationId > 0;

  if (isFiltering) {
    // Station worker view: acknowledge new orders, then mark station done
    if (order.StatusID === STATUS.NEW) {
      return `<button class="btn btn-start" onclick="updateOrderStatus(${order.OrderID}, ${STATUS.PREPARING})">Start Preparing</button>`;
    }
    if (order.StatusID === STATUS.PREPARING) {
      if (isStationDoneForOrder(order)) {
        return `<button class="btn btn-station-done" disabled>Station Done</button>`;
      } else {
        return `<button class="btn btn-station-done" onclick="markStationDone(${order.OrderID})">Mark Station Done</button>`;
      }
    }
    if (order.StatusID === STATUS.READY) {
      return `<button class="btn btn-complete" onclick="updateOrderStatus(${order.OrderID}, ${STATUS.COMPLETED})">Complete</button>`;
    }
    return '';
  }

  // Manager view (no station selected): whole-order buttons
  switch (order.StatusID) {
    case STATUS.NEW:
      return `<button class="btn btn-start" onclick="updateOrderStatus(${order.OrderID}, ${STATUS.PREPARING})">Start Preparing</button>`;
    case STATUS.PREPARING:
      return `<button class="btn btn-ready" onclick="updateOrderStatus(${order.OrderID}, ${STATUS.READY})">Mark as Ready</button>`;
    case STATUS.READY:
      return `<button class="btn btn-complete" onclick="updateOrderStatus(${order.OrderID}, ${STATUS.COMPLETED})">Complete</button>`;
    default:
      return '';
  }
}

// Update order status
async function updateOrderStatus(orderId, newStatusId) {
  try {
    const response = await fetch(`${config.apiBaseUrl}/orders/updateStatus.cfm`, {
      method: 'POST',
      headers: { 'Content-Type': 'application/json' },
      body: JSON.stringify({ OrderID: orderId, StatusID: newStatusId })
    });
    const data = await response.json();
    if (data.OK) {
      await loadOrders();
    } else {
      alert(`Failed to update order: ${data.MESSAGE || data.ERROR}`);
    }
  } catch (error) {
    console.error('Failed to update order status:', error);
    alert('Failed to update order status. Please try again.');
  }
}

// Mark station's items as done for an order
async function markStationDone(orderId) {
  try {
    const response = await fetch(`${config.apiBaseUrl}/orders/markStationDone.cfm`, {
      method: 'POST',
      headers: { 'Content-Type': 'application/json' },
      body: JSON.stringify({ OrderID: orderId, StationID: config.stationId })
    });
    const data = await response.json();
    if (data.OK) {
      await loadOrders();
    } else {
      alert(`Failed to mark station done: ${data.MESSAGE || data.ERROR}`);
    }
  } catch (error) {
    console.error('Failed to mark station done:', error);
    alert('Failed to mark station done. Please try again.');
  }
}

// Helper functions

// Get location label based on order type (Table vs Type)
function getLocationLabel(order) {
  // OrderTypeID: 1=Dine-In, 2=Takeaway, 3=Delivery
  if (order.OrderTypeID === 2 || order.OrderTypeID === 3) {
    return 'Type';
  }
  return 'Table';
}

// Get location value based on order type
function getLocationValue(order) {
  // OrderTypeID: 1=Dine-In, 2=Takeaway, 3=Delivery
  if (order.OrderTypeID === 2) {
    return 'Takeaway';
  }
  if (order.OrderTypeID === 3) {
    return 'Delivery';
  }
  // Dine-in: show service point name
  return order.Name || 'N/A';
}

function getStatusClass(statusId) {
  switch (statusId) {
    case STATUS.NEW: return 'new';
    case STATUS.PREPARING: return 'preparing';
    case STATUS.READY: return 'ready';
    default: return '';
  }
}

function getElapsedTime(submittedOn) {
  if (!submittedOn) return 0;
  return Math.floor((new Date() - new Date(submittedOn)) / 1000);
}

function getTimeClass(seconds) {
  if (seconds > 900) return 'critical';
  if (seconds > 600) return 'warning';
  return '';
}

function formatElapsedTime(seconds) {
  const minutes = Math.floor(seconds / 60);
  const secs = seconds % 60;
  return `${minutes}:${secs.toString().padStart(2, '0')}`;
}

function formatSubmitTime(dateString) {
  if (!dateString) return '';
  return new Date(dateString).toLocaleTimeString([], { hour: '2-digit', minute: '2-digit' });
}

function escapeHtml(text) {
  if (!text) return '';
  const div = document.createElement('div');
  div.textContent = text;
  return div.innerHTML;
}