/**
 * Admin Calendar - Task Management
 *
 * Manages scheduled tasks with filtering, CRUD operations, and session-init integration
 */

(function() {
  'use strict';

  // State
  let currentView = 'list';
  let currentFilters = {
    status: '',
    category: '',
    priority: '',
    projectId: '',
    includeCompleted: false
  };
  let currentPage = 0;
  const pageSize = 50;
  let allTasks = [];

  // DOM Elements
  const tasksContainer = document.getElementById('tasks-container');
  const addTaskBtn = document.getElementById('add-task-btn');
  const taskModal = document.getElementById('task-modal');
  const taskDetailModal = document.getElementById('task-detail-modal');
  const taskForm = document.getElementById('task-form');
  const paginationContainer = document.getElementById('pagination-container');

  // Initialize
  document.addEventListener('DOMContentLoaded', init);

  function init() {
    setupEventListeners();
    loadStats();
    loadTasks();
  }

  function setupEventListeners() {
    // Add task button
    addTaskBtn.addEventListener('click', () => openTaskModal());

    // Modal controls
    document.getElementById('modal-close').addEventListener('click', closeTaskModal);
    document.getElementById('modal-cancel').addEventListener('click', closeTaskModal);
    document.getElementById('detail-modal-close').addEventListener('click', closeDetailModal);

    // Task form submission
    taskForm.addEventListener('submit', handleTaskSubmit);

    // Filters
    document.getElementById('filter-status').addEventListener('change', handleFilterChange);
    document.getElementById('filter-category').addEventListener('change', handleFilterChange);
    document.getElementById('filter-priority').addEventListener('change', handleFilterChange);
    document.getElementById('filter-project').addEventListener('change', handleFilterChange);
    document.getElementById('include-completed').addEventListener('change', handleFilterChange);
    document.getElementById('clear-filters-btn').addEventListener('click', clearFilters);

    // View toggle
    document.getElementById('view-list').addEventListener('click', () => setView('list'));
    document.getElementById('view-timeline').addEventListener('click', () => setView('timeline'));

    // Pagination
    document.getElementById('pagination-prev').addEventListener('click', () => changePage(-1));
    document.getElementById('pagination-next').addEventListener('click', () => changePage(1));

    // Event delegation for task actions
    tasksContainer.addEventListener('click', handleTaskAction);
    document.getElementById('task-detail-content').addEventListener('click', handleDetailAction);
  }

  function handleTaskAction(e) {
    const button = e.target.closest('button[data-action]');
    if (!button) return;

    const action = button.dataset.action;
    const taskId = button.dataset.taskId;

    if (action === 'view') viewTask(taskId);
    else if (action === 'complete') completeTask(taskId);
    else if (action === 'edit') editTask(taskId);
    else if (action === 'dismiss') dismissTask(taskId);
  }

  function handleDetailAction(e) {
    const button = e.target.closest('button[data-action]');
    if (!button) return;

    const action = button.dataset.action;
    const taskId = button.dataset.taskId;

    if (action === 'complete') completeTask(taskId);
    else if (action === 'edit') editTask(taskId);
    else if (action === 'dismiss') dismissTask(taskId);
    else if (action === 'delete') deleteTask(taskId);
  }

  async function loadStats() {
    try {
      const token = localStorage.getItem('admin_token');
      const response = await fetch('/api/calendar/stats', {
        cache: 'no-store',
        headers: { 'Authorization': `Bearer ${token}` }
      });

      if (!response.ok) {
        const errorText = await response.text();
        console.error('Stats API error:', response.status, errorText);
        throw new Error(`Failed to load stats: ${response.status}`);
      }

      const data = await response.json();
      const stats = data.stats;

      document.getElementById('stat-total').textContent = stats.total || 0;
      document.getElementById('stat-pending').textContent = stats.pending || 0;
      document.getElementById('stat-overdue').textContent = stats.overdue || 0;
      document.getElementById('stat-due-soon').textContent = stats.dueSoon || 0;
      document.getElementById('stat-completed').textContent = stats.completed || 0;

    } catch (error) {
      console.error('Error loading stats:', error);
      showError('Failed to load statistics: ' + error.message);
    }
  }

  async function loadTasks() {
    try {
      const token = localStorage.getItem('admin_token');

      // Build query parameters
      const params = new URLSearchParams({
        limit: pageSize,
        skip: currentPage * pageSize
      });

      if (currentFilters.status) params.append('status', currentFilters.status);
      if (currentFilters.category) params.append('category', currentFilters.category);
      if (currentFilters.priority) params.append('priority', currentFilters.priority);
      if (currentFilters.projectId) params.append('projectId', currentFilters.projectId);
      if (currentFilters.includeCompleted) params.append('includeCompleted', 'true');

      const response = await fetch(`/api/calendar/tasks?${params}`, {
        cache: 'no-store',
        headers: { 'Authorization': `Bearer ${token}` }
      });

      if (!response.ok) {
        const errorText = await response.text();
        console.error('Tasks API error:', response.status, errorText);
        throw new Error(`Failed to load tasks: ${response.status}`);
      }

      const data = await response.json();
      allTasks = data.tasks;

      renderTasks(allTasks);
      updatePagination(data.pagination);

    } catch (error) {
      console.error('Error loading tasks:', error);
      tasksContainer.innerHTML = `
        <div class="text-center py-12 text-red-600">
          <p>Failed to load tasks: ${error.message}</p>
          <p class="text-sm mt-2">Check console for details</p>
        </div>
      `;
    }
  }

  function renderTasks(tasks) {
    if (!tasks || tasks.length === 0) {
      tasksContainer.innerHTML = `
        <div class="text-center py-12 text-gray-500">
          <svg class="mx-auto h-12 w-12 text-gray-400" fill="none" stroke="currentColor" viewBox="0 0 24 24">
            <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>
          <p class="mt-2">No tasks found</p>
        </div>
      `;
      return;
    }

    if (currentView === 'list') {
      renderListView(tasks);
    } else {
      renderTimelineView(tasks);
    }
  }

  function renderListView(tasks) {
    const html = tasks.map(task => {
      const statusColor = getStatusColor(task.status);
      const priorityColor = getPriorityColor(task.priority);
      const dueDate = new Date(task.dueDate);
      const isOverdue = task.status === 'overdue' || (task.status === 'pending' && dueDate < new Date());

      return `
        <div class="bg-white rounded-lg shadow p-4 mb-3 hover:shadow-md transition-shadow">
          <div class="flex justify-between items-start">
            <div class="flex-1">
              <div class="flex items-center space-x-2 mb-2">
                <span class="px-2 py-1 text-xs rounded-full ${statusColor}">${task.status}</span>
                <span class="px-2 py-1 text-xs rounded-full ${priorityColor}">${task.priority}</span>
                <span class="px-2 py-1 text-xs rounded-full bg-gray-100 text-gray-700">${task.category}</span>
                ${task.recurrence !== 'once' ? `<span class="px-2 py-1 text-xs rounded-full bg-purple-100 text-purple-700">↻ ${task.recurrence}</span>` : ''}
              </div>

              <h3 class="text-lg font-semibold text-gray-900 mb-1">${escapeHtml(task.title)}</h3>
              <p class="text-sm text-gray-600 mb-2">${escapeHtml(task.description.substring(0, 150))}${task.description.length > 150 ? '...' : ''}</p>

              <div class="flex items-center space-x-4 text-xs text-gray-500">
                <div class="flex items-center">
                  <svg class="h-4 w-4 mr-1" fill="none" stroke="currentColor" viewBox="0 0 24 24">
                    <path stroke-linecap="round" stroke-linejoin="round" stroke-width="2" d="M8 7V3m8 4V3m-9 8h10M5 21h14a2 2 0 002-2V7a2 2 0 00-2-2H5a2 2 0 00-2 2v12a2 2 0 002 2z"/>
                  </svg>
                  <span class="${isOverdue ? 'text-red-600 font-semibold' : ''}">${formatDate(dueDate)}</span>
                </div>
                ${task.assignedTo ? `
                  <div class="flex items-center">
                    <svg class="h-4 w-4 mr-1" fill="none" stroke="currentColor" viewBox="0 0 24 24">
                      <path stroke-linecap="round" stroke-linejoin="round" stroke-width="2" d="M16 7a4 4 0 11-8 0 4 4 0 018 0zM12 14a7 7 0 00-7 7h14a7 7 0 00-7-7z"/>
                    </svg>
                    ${escapeHtml(task.assignedTo)}
                  </div>
                ` : ''}
                ${task.documentRef ? `
                  <div class="flex items-center">
                    <svg class="h-4 w-4 mr-1" fill="none" stroke="currentColor" viewBox="0 0 24 24">
                      <path stroke-linecap="round" stroke-linejoin="round" stroke-width="2" d="M9 12h6m-6 4h6m2 5H7a2 2 0 01-2-2V5a2 2 0 012-2h5.586a1 1 0 01.707.293l5.414 5.414a1 1 0 01.293.707V19a2 2 0 01-2 2z"/>
                    </svg>
                    <span class="text-blue-600">Document linked</span>
                  </div>
                ` : ''}
              </div>
            </div>

            <div class="ml-4 flex flex-col space-y-2">
              <button data-action="view" data-task-id="${task.id}" class="px-3 py-1 text-xs bg-blue-100 text-blue-700 rounded hover:bg-blue-200">
                View
              </button>
              ${task.status === 'pending' || task.status === 'overdue' ? `
                <button data-action="complete" data-task-id="${task.id}" class="px-3 py-1 text-xs bg-green-100 text-green-700 rounded hover:bg-green-200">
                  Complete
                </button>
              ` : ''}
              <button data-action="edit" data-task-id="${task.id}" class="px-3 py-1 text-xs bg-gray-100 text-gray-700 rounded hover:bg-gray-200">
                Edit
              </button>
              ${task.status === 'pending' ? `
                <button data-action="dismiss" data-task-id="${task.id}" class="px-3 py-1 text-xs bg-yellow-100 text-yellow-700 rounded hover:bg-yellow-200">
                  Dismiss
                </button>
              ` : ''}
            </div>
          </div>
        </div>
      `;
    }).join('');

    tasksContainer.innerHTML = html;
  }

  function renderTimelineView(tasks) {
    // Group tasks by due date
    const grouped = {};
    tasks.forEach(task => {
      const date = new Date(task.dueDate).toDateString();
      if (!grouped[date]) grouped[date] = [];
      grouped[date].push(task);
    });

    const html = Object.keys(grouped).sort((a, b) => new Date(a) - new Date(b)).map(date => {
      const dateTasks = grouped[date];
      return `
        <div class="mb-6">
          <h3 class="text-lg font-semibold text-gray-900 mb-3 border-b border-gray-200 pb-2">
            ${formatDateHeader(new Date(date))}
          </h3>
          <div class="space-y-2">
            ${dateTasks.map(task => `
              <div class="bg-white rounded-lg shadow p-3 hover:shadow-md transition-shadow flex justify-between items-center">
                <div class="flex-1">
                  <div class="flex items-center space-x-2 mb-1">
                    <span class="px-2 py-1 text-xs rounded-full ${getStatusColor(task.status)}">${task.status}</span>
                    <span class="px-2 py-1 text-xs rounded-full ${getPriorityColor(task.priority)}">${task.priority}</span>
                  </div>
                  <h4 class="font-medium text-gray-900">${escapeHtml(task.title)}</h4>
                  <p class="text-sm text-gray-600">${escapeHtml(task.category)}</p>
                </div>
                <div class="flex space-x-2">
                  <button data-action="view" data-task-id="${task.id}" class="px-3 py-1 text-xs bg-blue-100 text-blue-700 rounded hover:bg-blue-200">
                    View
                  </button>
                  ${task.status === 'pending' || task.status === 'overdue' ? `
                    <button data-action="complete" data-task-id="${task.id}" class="px-3 py-1 text-xs bg-green-100 text-green-700 rounded hover:bg-green-200">
                      Complete
                    </button>
                  ` : ''}
                </div>
              </div>
            `).join('')}
          </div>
        </div>
      `;
    }).join('');

    tasksContainer.innerHTML = html || '<div class="text-center py-12 text-gray-500">No tasks to display</div>';
  }

  function updatePagination(pagination) {
    if (!pagination) return;

    const showing = Math.min(pagination.skip + pagination.limit, pagination.total);
    document.getElementById('pagination-showing').textContent = showing;
    document.getElementById('pagination-total').textContent = pagination.total;

    document.getElementById('pagination-prev').disabled = pagination.skip === 0;
    document.getElementById('pagination-next').disabled = !pagination.hasMore;

    if (pagination.total > 0) {
      paginationContainer.classList.remove('hidden');
    } else {
      paginationContainer.classList.add('hidden');
    }
  }

  function changePage(delta) {
    currentPage += delta;
    if (currentPage < 0) currentPage = 0;
    loadTasks();
  }

  function setView(view) {
    currentView = view;

    // Update button styles
    document.getElementById('view-list').className = view === 'list'
      ? 'px-3 py-2 text-sm font-medium rounded-md bg-blue-100 text-blue-700'
      : 'px-3 py-2 text-sm font-medium rounded-md text-gray-600 hover:bg-gray-100';

    document.getElementById('view-timeline').className = view === 'timeline'
      ? 'px-3 py-2 text-sm font-medium rounded-md bg-blue-100 text-blue-700'
      : 'px-3 py-2 text-sm font-medium rounded-md text-gray-600 hover:bg-gray-100';

    renderTasks(allTasks);
  }

  function handleFilterChange(e) {
    const id = e.target.id;

    if (id === 'filter-status') currentFilters.status = e.target.value;
    else if (id === 'filter-category') currentFilters.category = e.target.value;
    else if (id === 'filter-priority') currentFilters.priority = e.target.value;
    else if (id === 'filter-project') currentFilters.projectId = e.target.value;
    else if (id === 'include-completed') currentFilters.includeCompleted = e.target.checked;

    currentPage = 0;
    loadTasks();
  }

  function clearFilters() {
    currentFilters = {
      status: '',
      category: '',
      priority: '',
      projectId: '',
      includeCompleted: false
    };

    document.getElementById('filter-status').value = '';
    document.getElementById('filter-category').value = '';
    document.getElementById('filter-priority').value = '';
    document.getElementById('filter-project').value = '';
    document.getElementById('include-completed').checked = false;

    currentPage = 0;
    loadTasks();
  }

  function openTaskModal(taskId = null) {
    document.getElementById('modal-title').textContent = taskId ? 'Edit Task' : 'Add Task';

    if (taskId) {
      loadTaskForEdit(taskId);
    } else {
      taskForm.reset();
      document.getElementById('task-id').value = '';
      document.getElementById('task-show-in-session-init').checked = true;
      document.getElementById('task-reminder-days').value = '7';
      document.getElementById('task-assigned-to').value = 'PM';
    }

    taskModal.classList.remove('hidden');
  }

  function closeTaskModal() {
    taskModal.classList.add('hidden');
    taskForm.reset();
  }

  function closeDetailModal() {
    taskDetailModal.classList.add('hidden');
  }

  async function loadTaskForEdit(taskId) {
    try {
      const token = localStorage.getItem('admin_token');
      const response = await fetch(`/api/calendar/tasks/${taskId}`, {
        headers: { 'Authorization': `Bearer ${token}` }
      });

      if (!response.ok) throw new Error('Failed to load task');

      const data = await response.json();
      const task = data.task;

      document.getElementById('task-id').value = task.id;
      document.getElementById('task-title').value = task.title;
      document.getElementById('task-description').value = task.description;
      document.getElementById('task-due-date').value = formatDateTimeLocal(new Date(task.dueDate));
      document.getElementById('task-priority').value = task.priority;
      document.getElementById('task-category').value = task.category;
      document.getElementById('task-recurrence').value = task.recurrence;
      document.getElementById('task-document-ref').value = task.documentRef || '';
      document.getElementById('task-assigned-to').value = task.assignedTo || 'PM';
      document.getElementById('task-show-in-session-init').checked = task.showInSessionInit;
      document.getElementById('task-reminder-days').value = task.reminderDaysBefore;

    } catch (error) {
      console.error('Error loading task:', error);
      showError('Failed to load task details');
      closeTaskModal();
    }
  }

  async function handleTaskSubmit(e) {
    e.preventDefault();

    const taskId = document.getElementById('task-id').value;
    const taskData = {
      title: document.getElementById('task-title').value,
      description: document.getElementById('task-description').value,
      dueDate: document.getElementById('task-due-date').value,
      priority: document.getElementById('task-priority').value,
      category: document.getElementById('task-category').value,
      recurrence: document.getElementById('task-recurrence').value,
      documentRef: document.getElementById('task-document-ref').value || null,
      assignedTo: document.getElementById('task-assigned-to').value,
      showInSessionInit: document.getElementById('task-show-in-session-init').checked,
      reminderDaysBefore: parseInt(document.getElementById('task-reminder-days').value)
    };

    try {
      const token = localStorage.getItem('admin_token');
      const url = taskId ? `/api/calendar/tasks/${taskId}` : '/api/calendar/tasks';
      const method = taskId ? 'PUT' : 'POST';

      const response = await fetch(url, {
        method,
        headers: {
          'Authorization': `Bearer ${token}`,
          'Content-Type': 'application/json'
        },
        body: JSON.stringify(taskData)
      });

      if (!response.ok) throw new Error('Failed to save task');

      closeTaskModal();
      loadTasks();
      loadStats();
      showSuccess(taskId ? 'Task updated successfully' : 'Task created successfully');

    } catch (error) {
      console.error('Error saving task:', error);
      showError('Failed to save task. Please try again.');
    }
  }

  async function viewTask(taskId) {
    try {
      const token = localStorage.getItem('admin_token');
      const response = await fetch(`/api/calendar/tasks/${taskId}`, {
        headers: { 'Authorization': `Bearer ${token}` }
      });

      if (!response.ok) throw new Error('Failed to load task');

      const data = await response.json();
      const task = data.task;

      const html = `
        <div class="space-y-4">
          <div class="flex items-center space-x-2">
            <span class="px-3 py-1 text-sm rounded-full ${getStatusColor(task.status)}">${task.status}</span>
            <span class="px-3 py-1 text-sm rounded-full ${getPriorityColor(task.priority)}">${task.priority}</span>
            <span class="px-3 py-1 text-sm rounded-full bg-gray-100 text-gray-700">${task.category}</span>
          </div>

          <h2 class="text-2xl font-bold text-gray-900">${escapeHtml(task.title)}</h2>

          <div class="bg-gray-50 rounded-lg p-4">
            <p class="text-gray-700">${escapeHtml(task.description)}</p>
          </div>

          <div class="grid grid-cols-2 gap-4 text-sm">
            <div>
              <span class="font-medium text-gray-700">Due Date:</span>
              <span class="text-gray-900 ml-2">${formatDateTime(new Date(task.dueDate))}</span>
            </div>
            <div>
              <span class="font-medium text-gray-700">Recurrence:</span>
              <span class="text-gray-900 ml-2">${task.recurrence}</span>
            </div>
            <div>
              <span class="font-medium text-gray-700">Assigned To:</span>
              <span class="text-gray-900 ml-2">${escapeHtml(task.assignedTo || 'Unassigned')}</span>
            </div>
            <div>
              <span class="font-medium text-gray-700">Session-Init:</span>
              <span class="text-gray-900 ml-2">${task.showInSessionInit ? 'Yes' : 'No'}</span>
            </div>
          </div>

          ${task.documentRef ? `
            <div class="bg-blue-50 border border-blue-200 rounded-lg p-4">
              <div class="flex items-start">
                <svg class="h-5 w-5 text-blue-600 mt-0.5" fill="none" stroke="currentColor" viewBox="0 0 24 24">
                  <path stroke-linecap="round" stroke-linejoin="round" stroke-width="2" d="M9 12h6m-6 4h6m2 5H7a2 2 0 01-2-2V5a2 2 0 012-2h5.586a1 1 0 01.707.293l5.414 5.414a1 1 0 01.293.707V19a2 2 0 01-2 2z"/>
                </svg>
                <div class="ml-3">
                  <p class="text-sm font-medium text-blue-900">Linked Document</p>
                  <p class="text-sm text-blue-700 mt-1">${escapeHtml(task.documentRef)}</p>
                </div>
              </div>
            </div>
          ` : ''}

          <div class="flex justify-end space-x-3 pt-4 border-t">
            ${task.status === 'pending' || task.status === 'overdue' ? `
              <button data-action="complete" data-task-id="${task.id}" class="px-4 py-2 bg-green-600 text-white rounded-md hover:bg-green-700">
                Mark Complete
              </button>
            ` : ''}
            <button data-action="edit" data-task-id="${task.id}" class="px-4 py-2 bg-blue-600 text-white rounded-md hover:bg-blue-700">
              Edit Task
            </button>
            ${task.status === 'pending' ? `
              <button data-action="dismiss" data-task-id="${task.id}" class="px-4 py-2 bg-yellow-600 text-white rounded-md hover:bg-yellow-700">
                Dismiss
              </button>
            ` : ''}
            <button data-action="delete" data-task-id="${task.id}" class="px-4 py-2 bg-red-600 text-white rounded-md hover:bg-red-700">
              Delete
            </button>
          </div>
        </div>
      `;

      document.getElementById('task-detail-content').innerHTML = html;
      taskDetailModal.classList.remove('hidden');

    } catch (error) {
      console.error('Error viewing task:', error);
      showError('Failed to load task details');
    }
  }

  async function completeTask(taskId) {
    if (!confirm('Mark this task as completed?')) return;

    try {
      const token = localStorage.getItem('admin_token');
      const response = await fetch(`/api/calendar/tasks/${taskId}/complete`, {
        method: 'POST',
        headers: { 'Authorization': `Bearer ${token}` }
      });

      if (!response.ok) throw new Error('Failed to complete task');

      closeDetailModal();
      loadTasks();
      loadStats();
      showSuccess('Task marked as completed');

    } catch (error) {
      console.error('Error completing task:', error);
      showError('Failed to complete task');
    }
  }

  async function dismissTask(taskId) {
    const reason = prompt('Reason for dismissing this task?');
    if (!reason) return;

    try {
      const token = localStorage.getItem('admin_token');
      const response = await fetch(`/api/calendar/tasks/${taskId}/dismiss`, {
        method: 'POST',
        headers: {
          'Authorization': `Bearer ${token}`,
          'Content-Type': 'application/json'
        },
        body: JSON.stringify({ reason })
      });

      if (!response.ok) throw new Error('Failed to dismiss task');

      closeDetailModal();
      loadTasks();
      loadStats();
      showSuccess('Task dismissed');

    } catch (error) {
      console.error('Error dismissing task:', error);
      showError('Failed to dismiss task');
    }
  }

  async function deleteTask(taskId) {
    if (!confirm('Are you sure you want to delete this task? This action cannot be undone.')) return;

    try {
      const token = localStorage.getItem('admin_token');
      const response = await fetch(`/api/calendar/tasks/${taskId}`, {
        method: 'DELETE',
        headers: { 'Authorization': `Bearer ${token}` }
      });

      if (!response.ok) throw new Error('Failed to delete task');

      closeDetailModal();
      loadTasks();
      loadStats();
      showSuccess('Task deleted successfully');

    } catch (error) {
      console.error('Error deleting task:', error);
      showError('Failed to delete task');
    }
  }

  function editTask(taskId) {
    closeDetailModal();
    openTaskModal(taskId);
  }

  // Utility functions
  function getStatusColor(status) {
    const colors = {
      pending: 'bg-yellow-100 text-yellow-800',
      in_progress: 'bg-blue-100 text-blue-800',
      completed: 'bg-green-100 text-green-800',
      dismissed: 'bg-gray-100 text-gray-800',
      overdue: 'bg-red-100 text-red-800'
    };
    return colors[status] || 'bg-gray-100 text-gray-800';
  }

  function getPriorityColor(priority) {
    const colors = {
      LOW: 'bg-gray-100 text-gray-700',
      MEDIUM: 'bg-blue-100 text-blue-700',
      HIGH: 'bg-orange-100 text-orange-700',
      CRITICAL: 'bg-red-100 text-red-700'
    };
    return colors[priority] || 'bg-gray-100 text-gray-700';
  }

  function formatDate(date) {
    const options = { year: 'numeric', month: 'short', day: 'numeric' };
    return date.toLocaleDateString('en-US', options);
  }

  function formatDateTime(date) {
    const options = { year: 'numeric', month: 'short', day: 'numeric', hour: '2-digit', minute: '2-digit' };
    return date.toLocaleDateString('en-US', options);
  }

  function formatDateHeader(date) {
    const today = new Date();
    const tomorrow = new Date(today);
    tomorrow.setDate(tomorrow.getDate() + 1);

    if (date.toDateString() === today.toDateString()) return 'Today';
    if (date.toDateString() === tomorrow.toDateString()) return 'Tomorrow';

    return formatDate(date);
  }

  function formatDateTimeLocal(date) {
    const year = date.getFullYear();
    const month = String(date.getMonth() + 1).padStart(2, '0');
    const day = String(date.getDate()).padStart(2, '0');
    const hours = String(date.getHours()).padStart(2, '0');
    const minutes = String(date.getMinutes()).padStart(2, '0');
    return `${year}-${month}-${day}T${hours}:${minutes}`;
  }

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

  function showSuccess(message) {
    alert(message);
  }

  function showError(message) {
    alert('Error: ' + message);
  }

})();