// Data Loader - Handles loading JSON data files
class DataLoader {
  static async loadApps() {
    try {
      const response = await fetch('/data/apps/generated/apps.json', { cache: 'no-store' });
      if (!response.ok) {
        throw new Error(`Failed to load apps: ${response.status}`);
      }
      const data = await response.json();
      return data.apps;
    } catch (error) {
      console.error('Error loading apps data:', error);
      return [];
    }
  }

  static async loadCategories() {
    try {
      const response = await fetch('/data/apps/apps-categories.json');
      if (!response.ok) {
        throw new Error(`Failed to load categories: ${response.status}`);
      }
      const data = await response.json();
      return data.categories || [];
    } catch (error) {
      console.error('Error loading categories data:', error);
      return [];
    }
  }

  static async loadConfigCategories() {
    try {
      const response = await fetch('/data/apps/apps-config-categories.json');
      if (!response.ok) {
        throw new Error(`Failed to load config categories: ${response.status}`);
      }
      const data = await response.json();
      return data.categories || data;
    } catch (error) {
      console.error('Error loading config categories data:', error);
      return {};
    }
  }

  static async isAppInstalled(appName) {
    try {
      const apps = await this.loadApps();
      const app = apps.find(a => a.name === appName || a.id === appName);
      return app ? app.installed : false;
    } catch (error) {
      console.error(`Error checking if app ${appName} is installed:`, error);
      return false;
    }
  }

  static async getContainers() {
    try {
      // Local implementation - return empty array for now
      //console.log('Loading containers locally...');
      
      // TODO: Implement local container detection
      // This would require backend integration to query Docker
      
      // Return empty array for now
      return [];
      
    } catch (error) {
      console.error('Error loading containers:', error);
      return [];
    }
  }

  static async loadSystemConfigs() {
    try {
      //console.log('Loading system configs');
      
      // Load unified config
      try {
        const response = await fetch('/data/config/generated/configs.json');
        if (response.ok) {
          const data = await response.json();
          //console.log('✅ Loaded unified system config');
          return data;
        } else {
          console.warn('Failed to load unified config:', response.status);
          throw new Error(`Failed to load unified config: ${response.status}`);
        }
      } catch (error) {
        console.error('Error loading unified config:', error);
        throw error;
      }
    } catch (error) {
      console.error('Error loading system configs:', error);
      return [];
    }
  }

  static async loadConfig(configType) {
    try {
      //console.log(`Loading ${configType} config`);
      
      const response = await fetch(`data/config/generated/config_${configType}.json`);
      if (!response.ok) {
        throw new Error(`Failed to load ${configType} config: ${response.status}`);
      }
      
      const data = await response.json();
      return data;
    } catch (error) {
      console.error(`Error loading ${configType} data:`, error);
      return null;
    }
  }
}

// Category helper functions
let categories = [];

function getCategoryIcon(categoryId) {
  const category = categories.find(cat => cat.id === categoryId);
  return category ? category.icon : 'icons/categories/misc.svg';
}

function getCategoryName(categoryId) {
  const category = categories.find(cat => cat.id === categoryId);
  return category ? category.name : categoryId.charAt(0).toUpperCase() + categoryId.slice(1);
}

function getCategoryDescription(categoryId) {
  const category = categories.find(cat => cat.id === categoryId);
  return category ? category.description : '';
}

// Global apps variable for backward compatibility
let apps = [];

// Global system configs variable
let systemConfigs = [];

// Initialize apps and categories data
async function initializeData() {
  try {
    // Determine current page/route and load appropriate data
    const currentPath = window.location.pathname;
    const searchParams = new URLSearchParams(window.location.search);
    
    if (currentPath === '/dashboard' || currentPath === '/') {
      // Dashboard: Only installed apps + system info (no categories needed)
      await loadDashboardData();
    } else if (currentPath === '/apps' || currentPath === '/app' || searchParams.has('apps') || searchParams.has('app')) {
      // Apps page: All apps + categories (no system configs needed)
      await loadAppsPageData();
    } else if (currentPath.startsWith('/config') || searchParams.has('config')) {
      // Config pages: System configs + apps + categories
      await loadConfigDetailData();
    } else {
      // Default: Load all data for SPA
      await loadAppsPageData();
    }
    
  } catch (error) {
    console.error('Error initializing data:', error);
  }
}

// Dashboard update tracking
let lastDashboardUpdate = null;
let lastInstalledCount = 0;
let lastSystemDataHash = null;

// Dashboard-specific data loading
async function loadDashboardData() {
  // console.log('🔄 Loading dashboard data...');
  
  // Load all apps with installation status
  const allApps = await DataLoader.loadApps();
  apps = allApps; // All apps, not just installed
  categories = []; // Dashboard doesn't need categories
  systemConfigs = []; // Dashboard doesn't need system configs
  
  // Calculate installed apps count
  const installedCount = allApps.filter(app => app.installed === true || app.installed === 'true').length;
  
  // Check for updates
  const hasNewApps = installedCount !== lastInstalledCount;
  const currentTime = new Date();
  
  // Load system info for dashboard display (this waits for DOM elements)
  await loadSystemInfo();
  
  // Update installed count and show update indicator
  const installedCountEl = document.getElementById('installed-count');
  if (installedCountEl) {
    const oldValue = installedCountEl.textContent;
    installedCountEl.textContent = installedCount;
    
    // Don't show notification for automatic updates - only manual reloads
    // if (hasNewApps) {
    //   showUpdateIndicator(`New apps detected: ${installedCount - lastInstalledCount > 0 ? '+' + (installedCount - lastInstalledCount) : 'Updated'}`);
    // }
  } else {
    console.warn('⚠️ installed-count element not found');
  }
  
  // Update last update timestamp
  updateLastUpdateTime(currentTime);
  
  // Store current values for next comparison
  lastInstalledCount = installedCount;
  lastDashboardUpdate = currentTime;
  
  // Start countdown to next automatic update
  startUpdateCountdown();

  // Show/refresh the "out of date" banner on the dashboard.
  window.updateNotifier?.renderDashboardBanner();

  // console.log('✅ Dashboard data loaded successfully');
}

// Countdown timer for next automatic update
let updateCountdownInterval = null;

function startUpdateCountdown() {
  // Clear any existing countdown
  if (updateCountdownInterval) {
    clearInterval(updateCountdownInterval);
  }
  
  // Use existing countdown element from HTML
  const countdownEl = document.getElementById('update-countdown');
  if (!countdownEl) {
    console.warn('Update countdown element not found in HTML');
    return;
  }
  
  // Update countdown every second
  updateCountdownInterval = setInterval(() => {
    const now = new Date();
    const nextUpdate = new Date(lastDashboardUpdate.getTime() + 60000); // 60 seconds from last update
    const timeLeft = Math.max(0, Math.floor((nextUpdate - now) / 1000));
    
    if (timeLeft > 0) {
      countdownEl.textContent = `Next update: ${timeLeft}s`;
    } else {
      countdownEl.textContent = 'Updating...';
      // Actually update the dashboard data
      updateDashboardData().then(() => {
        // After update completes, reset the last update time and restart countdown
        lastDashboardUpdate = new Date();
        startUpdateCountdown(); // Restart the countdown
      });
    }
  }, 1000);
}

// Actually update dashboard data elements
async function updateDashboardData() {
  try {
    console.log('🔄 Auto-updating dashboard data...');
    
    // Directly update system info (simpler than full dashboard reload)
    await loadSystemInfo();
    
    // Reload apps to get updated installed count
    const allApps = await DataLoader.loadApps();
    apps = allApps;
    
    // Update installed count
    const installedCount = allApps.filter(app => app.installed === true || app.installed === 'true').length;
    const installedCountEl = document.getElementById('installed-count');
    if (installedCountEl) {
      installedCountEl.textContent = installedCount;
    }
    
    console.log('✅ Dashboard data updated successfully');
  } catch (error) {
    console.error('❌ Auto-update failed:', error);
  }
}

// Update last update timestamp display (simplified - just for tracking)
function updateLastUpdateTime(time) {
  // No timestamp display - just store the time for countdown
}

// Calculate time ago string
function getTimeAgo(date) {
  const now = new Date();
  const diff = Math.floor((now - date) / 1000); // seconds
  
  if (diff < 60) return 'just now';
  if (diff < 3600) return `${Math.floor(diff / 60)} min ago`;
  if (diff < 86400) return `${Math.floor(diff / 3600)} hours ago`;
  return `${Math.floor(diff / 86400)} days ago`;
}

// Apps page data loading
async function loadAppsPageData() {
  //console.log('Loading apps page data (all apps + categories)...');
  
  // Load apps and categories in parallel
  try {
    const [appsData, sidebarCategoriesData, configCategoriesData] = await Promise.all([
      DataLoader.loadApps(),
      DataLoader.loadCategories(),
      DataLoader.loadConfigCategories()
    ]);
    
    //console.log('🔍 DataLoader Results:');
    //console.log('  - appsData length:', appsData?.length || 0);
    //console.log('  - sidebarCategoriesData type:', typeof sidebarCategoriesData);
    //console.log('  - sidebarCategoriesData keys:', Object.keys(sidebarCategoriesData || {}));
    //console.log('  - configCategoriesData type:', typeof configCategoriesData);
    //console.log('  - configCategoriesData keys:', Object.keys(configCategoriesData || {}));
    
    apps = appsData;
    categories = sidebarCategoriesData; // For sidebar
    systemConfigs = []; // Apps page doesn't need system configs
    
    //console.log(`Apps page loaded: ${apps.length} apps, ${categories.length} categories`);
    ////console.log('Apps array:', apps);
    ////console.log('Categories array:', categories);
    
    // Trigger custom event for data loaded
    window.dispatchEvent(new CustomEvent('dataLoaded', { 
      detail: { 
        apps, 
        categories: categories, // For sidebar
        sidebarCategories: categories, // Explicit sidebar categories
        configCategories: configCategoriesData, // For config tabs
        systemConfigs 
      } 
    }));
  } catch (error) {
    console.error('❌ Promise.all failed:', error);
    // Fallback: try loading individually
    try {
      const appsData = await DataLoader.loadApps();
      const sidebarCategoriesData = await DataLoader.loadCategories();
      apps = appsData;
      categories = sidebarCategoriesData;
      systemConfigs = [];
      
      // Trigger custom event for data loaded (fallback)
      window.dispatchEvent(new CustomEvent('dataLoaded', { 
        detail: { 
          apps, 
          categories: categories, // For sidebar
          sidebarCategories: categories, // Explicit sidebar categories
          configCategories: {}, // Empty for fallback
          systemConfigs 
        } 
      }));
    } catch (individualError) {
      console.error('❌ Individual loading failed:', individualError);
      apps = [];
      categories = {};
      systemConfigs = [];
    }
  }
}

// Config detail page data loading
async function loadConfigDetailData() {
  
  // Load everything needed for config management
  const [appsData, categoriesData, systemConfigsData] = await Promise.all([
    DataLoader.loadApps(),
    DataLoader.loadCategories(),
    DataLoader.loadSystemConfigs()
  ]);
  
  apps = appsData;
  categories = categoriesData;
  systemConfigs = systemConfigsData;
  
  ////console.log(`Config detail loaded: ${apps.length} apps, ${categories.length} categories, ${systemConfigs.length} system configs`);
}

// Load system information for dashboard
async function loadSystemInfo() {
  try {
    //console.log('Loading system data');
    
    // Add timestamp to prevent browser caching
    const timestamp = Date.now();
    
    // Load system info from files generated by LibrePortal commands
    const systemResponse = await fetch(`/data/system/system_info.json?t=${timestamp}`);
    const diskResponse = await fetch(`/data/system/disk_usage.json?t=${timestamp}`);
    const memoryResponse = await fetch(`/data/system/memory_usage.json?t=${timestamp}`);
    
    if (!systemResponse.ok || !diskResponse.ok || !memoryResponse.ok) {
      throw new Error(`Failed to load system files: system=${systemResponse.status}, disk=${diskResponse.status}, memory=${memoryResponse.status}`);
    }
    
    const systemData = await systemResponse.json();
    const diskData = await diskResponse.json();
    const memoryData = await memoryResponse.json();
    
    //console.log('System data:', systemData);
    //console.log('Disk data:', diskData);
    //console.log('Memory data:', memoryData);
    
    // Prepare system data
    const osInfo = systemData.os || 'Unknown';
    const cleanOs = osInfo.includes('Ubuntu') ? 'Linux Ubuntu' : 
                   osInfo.includes('Debian') ? 'Linux Debian' :
                   osInfo.includes('CentOS') ? 'Linux CentOS' :
                   osInfo.split(' ')[0]; // Take first part like "Linux"
    
    const diskChartData = diskData.root || diskData;
    //console.log('Disk chart data:', diskChartData);
    
    // Wait for all dashboard elements to be available
    await waitForDashboardElements();
    
    // Now update all elements
    const systemInfoEl = document.getElementById('system-info');
    const uptimeEl = document.getElementById('uptime-info');
    const memoryEl = document.getElementById('memory-info');
    
    if (systemInfoEl) {
      systemInfoEl.textContent = cleanOs;
      // console.log('✅ Updated OS:', cleanOs);
    } else {
      console.warn('⚠️ system-info element not found');
    }
    
    if (uptimeEl) {
      uptimeEl.textContent = systemData.uptime || 'Unknown';
      // console.log('✅ Updated uptime:', systemData.uptime);
    } else {
      console.warn('⚠️ uptime-info element not found');
    }
    
    // Update memory info - use the text field which should be properly formatted
    if (memoryEl) {
      memoryEl.textContent = memoryData.text || 'Unknown';
      // console.log('✅ Updated memory:', memoryData.text);
    } else {
      console.warn('⚠️ memory-info element not found');
    }
    
    // Update disk usage chart
    updateDiskChart(diskChartData);
    
  } catch (error) {
    console.error('Error loading system info:', error);
    // Fallback values
    const systemInfoEl = document.getElementById('system-info');
    const uptimeEl = document.getElementById('uptime-info');
    const memoryEl = document.getElementById('memory-info');
    
    if (systemInfoEl) systemInfoEl.textContent = 'Linux';
    if (uptimeEl) uptimeEl.textContent = 'Unknown';
    if (memoryEl) memoryEl.textContent = 'Unknown';
    
    // Mock disk usage for demo - wait for DOM elements
    waitForDashboardElements().then(() => {
      updateDiskChart({ used: 50, total: 100 });
    });
  }
}

// Wait for dashboard elements to be available
function waitForDashboardElements() {
  return new Promise((resolve) => {
    const checkElements = () => {
      const circleFill = document.getElementById('disk-circle-fill');
      const percentText = document.getElementById('disk-percent');
      const systemInfoEl = document.getElementById('system-info');
      const uptimeEl = document.getElementById('uptime-info');
      const memoryEl = document.getElementById('memory-info');
      const installedCountEl = document.getElementById('installed-count');
      
      if (circleFill && percentText && systemInfoEl && uptimeEl && memoryEl && installedCountEl) {
        resolve();
      } else {
        // Check again after 100ms
        setTimeout(checkElements, 100);
      }
    };
    
    checkElements();
  });
}

// Update disk usage circle chart
function updateDiskChart(data) {
  //console.log('updateDiskChart called with:', data);
  
  const circleFill = document.getElementById('disk-circle-fill');
  const percentText = document.getElementById('disk-percent');
  
  if (!circleFill || !percentText) {
    // Silently fail if elements don't exist yet - they may load later
    return;
  }
  
  // Extract used and total from data structure
  let used, total;
  if (data.root) {
    used = data.root.used;
    total = data.root.total;
  } else {
    used = data.used;
    total = data.total;
  }
  
  // Calculate percentage
  const percentage = Math.round((used / total) * 100);
  //console.log(`Disk usage: ${used}/${total} = ${percentage}%`);
  
  // Update percentage text (only inside circle)
  if (percentText) percentText.textContent = `${percentage}%`;
  
  // Set circle fill height based on percentage (fills from bottom)
  circleFill.style.height = `${Math.max(percentage, 5)}%`; // Minimum 5% for visibility
  
  // Color based on usage
  let fillColor;
  if (percentage > 90) {
    fillColor = '#dc3545'; // Red
  } else if (percentage > 75) {
    fillColor = '#ffc107'; // Yellow
  } else {
    fillColor = '#28a745'; // Green
  }
  
  circleFill.style.background = `linear-gradient(to top, ${fillColor} 0%, ${fillColor} 100%)`;
}

// Minimal data loading (fallback)
async function loadMinimalData() {
  //console.log('Loading minimal data...');
  
  apps = [];
  categories = [];
  systemConfigs = [];
}

// Preload essential data for smooth navigation
async function preloadOtherPagesData(currentPage) {
  //console.log('Preloading essential data for navigation...');
  
  try {
    // No preloading needed - data loads fresh each page
    //console.log('Preloading complete (no caching)');
    
  } catch (error) {
    console.error('Error preloading navigation data:', error);
  }
}

// Data initialization is now handled by SystemLoader
// initializeData() will be called centrally