class AppConstants {
  // App Info
  static const String appName = 'AI Study Assistant';
  static const String appVersion = '1.0.0';
  
  // Firebase Configuration
  static const String firebaseProjectId = 'teachit-dev-12345';
  
  // API Configuration
  static const String apiBaseUrl = 'http://localhost:5001';
  static const String apiVersion = 'v1';
  
  // Storage Keys
  static const String userTokenKey = 'user_token';
  static const String userPreferencesKey = 'user_preferences';
  static const String themeKey = 'theme_mode';
  
  // Animation Durations
  static const Duration shortAnimation = Duration(milliseconds: 200);
  static const Duration mediumAnimation = Duration(milliseconds: 300);
  static const Duration longAnimation = Duration(milliseconds: 500);
  
  // Spacing
  static const double spacingXS = 4.0;
  static const double spacingS = 8.0;
  static const double spacingM = 16.0;
  static const double spacingL = 24.0;
  static const double spacingXL = 32.0;
  
  // Border Radius
  static const double radiusXS = 4.0;
  static const double radiusS = 8.0;
  static const double radiusM = 12.0;
  static const double radiusL = 16.0;
  static const double radiusXL = 20.0;
  
  // Screen Breakpoints
  static const double mobileBreakpoint = 600.0;
  static const double tabletBreakpoint = 1024.0;
  static const double desktopBreakpoint = 1440.0;
  
  // Pagination
  static const int defaultPageSize = 20;
  static const int maxPageSize = 100;
  
  // File Upload Limits
  static const int maxFileSize = 50 * 1024 * 1024; // 50MB
  static const List<String> allowedFileTypes = [
    'pdf', 'doc', 'docx', 'txt', 'jpg', 'jpeg', 'png', 'gif', 'mp4', 'avi', 'mov'
  ];
  
  // Chat Configuration
  static const int maxMessageLength = 500;
  static const int maxChatHistory = 50;
  
  // Quiz Configuration
  static const int defaultQuizTimeLimit = 30; // minutes
  static const int maxQuestionsPerQuiz = 50;
  static const double passingScore = 0.7; // 70%
}