TravelMate/lib/services/error_service.dart

import 'package:flutter/material.dart';
import '../components/error/error_content.dart';

/// Service for handling application errors and user notifications.
/// 
/// This singleton service provides centralized error handling capabilities
/// including displaying error dialogs, snackbars, and logging errors for
/// debugging purposes. It uses a global navigator key to show notifications
/// from anywhere in the application.
class ErrorService {
  static final ErrorService _instance = ErrorService._internal();
  
  /// Factory constructor that returns the singleton instance.
  factory ErrorService() => _instance;
  
  /// Private constructor for singleton pattern.
  ErrorService._internal();

  /// Global navigator key for accessing context from anywhere in the app.
  /// 
  /// This key should be assigned to the MaterialApp's navigatorKey property
  /// to enable error notifications from any part of the application.
  static GlobalKey<NavigatorState> navigatorKey = GlobalKey<NavigatorState>();

  /// Displays an error message in a dialog.
  /// 
  /// Shows a modal dialog with the error message and optional retry functionality.
  /// The dialog appearance can be customized with different icons and colors.
  /// 
  /// [message] - The error message to display
  /// [title] - The dialog title (defaults to 'Error')
  /// [onRetry] - Optional callback for retry functionality
  /// [icon] - Icon to display in the dialog
  /// [iconColor] - Color of the icon
  void showError({
    required String message,
    String title = 'Error',
    VoidCallback? onRetry,
    IconData icon = Icons.error_outline,
    Color? iconColor,
  }) {
    final context = navigatorKey.currentContext;
    if (context != null) {
      showErrorDialog(
        context,
        title: title,
        message: message,
        icon: icon,
        iconColor: iconColor,
        onRetry: onRetry,
      );
    }
  }

  /// Displays an error or success message in a snackbar.
  /// 
  /// Shows a floating snackbar at the bottom of the screen with the message.
  /// The appearance changes based on whether it's an error or success message.
  /// 
  /// [message] - The message to display
  /// [onRetry] - Optional callback for retry functionality
  /// [isError] - Whether this is an error (true) or success (false) message
  void showSnackbar({
    required String message,
    VoidCallback? onRetry,
    bool isError = true,
  }) {
    final context = navigatorKey.currentContext;
    if (context != null) {
      ScaffoldMessenger.of(context).showSnackBar(
        SnackBar(
          content: Text(message),
          backgroundColor: isError ? Colors.red[400] : Colors.green[600],
          duration: const Duration(seconds: 4),
          action: onRetry != null
              ? SnackBarAction(
                  label: 'Retry',
                  textColor: Colors.white,
                  onPressed: onRetry,
                )
              : null,
          behavior: SnackBarBehavior.floating,
          shape: RoundedRectangleBorder(
            borderRadius: BorderRadius.circular(10),
          ),
        ),
      );
    }
  }

  /// Logs error messages to the console during development.
  /// 
  /// Formats and displays error information including source, error message,
  /// and optional stack trace in a visually distinct format.
  /// 
  /// [source] - The source or location where the error occurred
  /// [error] - The error object or message
  /// [stackTrace] - Optional stack trace for debugging
  void logError(String source, dynamic error, [StackTrace? stackTrace]) {
    print('═══════════════════════════════════');
    print('❌ ERROR in $source');
    print('Message: $error');
    if (stackTrace != null) {
      print('StackTrace: $stackTrace');
    }
    print('═══════════════════════════════════');
  }

  /// Logs informational messages to the console during development.
  /// 
  /// [source] - The source or location of the information
  /// [message] - The informational message
  void logInfo(String source, String message) {
    print('ℹ️ [$source] $message');
  }

  /// Logs success messages to the console during development.
  /// 
  /// [source] - The source or location of the success
  /// [message] - The success message
  void logSuccess(String source, String message) {
    print('✅ [$source] $message');
  }
}