import 'app_config.dart';

/// Exception thrown when an invalid environment is provided to [ConfigLoader].
class InvalidEnvironmentException implements Exception {
  /// The invalid environment that was provided.
  final String environment;

  /// Creates an [InvalidEnvironmentException] with the provided environment.
  InvalidEnvironmentException(this.environment);

  @override
  String toString() {
    return 'InvalidEnvironmentException: Invalid environment "$environment". '
        'Valid environments are: dev, prod';
  }
}

/// Loads application configuration based on the specified environment.
/// 
/// This class provides a factory method to load configuration for either
/// 'dev' or 'prod' environments. It throws [InvalidEnvironmentException]
/// if an invalid environment is provided.
class ConfigLoader {
  /// Private constructor to prevent instantiation.
  ConfigLoader._();

  /// Loads configuration for the specified environment.
  /// 
  /// [environment] - The environment to load ('dev' or 'prod').
  /// 
  /// Returns an [AppConfig] instance for the specified environment.
  /// 
  /// Throws [InvalidEnvironmentException] if [environment] is not 'dev' or 'prod'.
  static AppConfig load(String environment) {
    switch (environment.toLowerCase()) {
      case 'dev':
        return const AppConfig(
          apiBaseUrl: 'https://api-dev.example.com',
          enableLogging: true,
          immichBaseUrl: 'https://photos.satoshinakamoto.win',  // ← Change your Immich server URL here
          immichApiKey: '3v2fTujMJHy1T2rrVJVojdJS0ySm7IRcRvEcvvUvs0', // ← Change your Immich API key here
          nostrRelays: [                                         // ← Add Nostr relay URLs for testing
            'wss://nostrum.satoshinakamoto.win',
            'wss://nos.lol',
          ],
        );
      case 'prod':
        return const AppConfig(
          apiBaseUrl: 'https://api.example.com',
          enableLogging: false,
          immichBaseUrl: 'https://photos.satoshinakamoto.win',      // ← Change your Immich server URL here
          immichApiKey: 'your-prod-api-key-here',            // ← Change your Immich API key here
          nostrRelays: [                                         // ← Add Nostr relay URLs for production
            'wss://relay.damus.io',
          ],
        );
      default:
        throw InvalidEnvironmentException(environment);
    }
  }
}