import 'package:flutter/foundation.dart';
import 'auth_user.dart';

enum AuthStatus {
  initial,
  loading,
  authenticated,
  unauthenticated,
  anonymous,
  error,
}

/// Immutable authentication state representing the user session
/// across both online and offline/unconfigured environments.
@immutable
class AuthState {
  final AuthStatus status;
  final AuthUser? user;
  final String? errorMessage;
  final bool isFirebaseConfigured;

  const AuthState({
    this.status = AuthStatus.initial,
    this.user,
    this.errorMessage,
    this.isFirebaseConfigured = true,
  });

  const AuthState.initial()
      : status = AuthStatus.initial,
        user = null,
        errorMessage = null,
        isFirebaseConfigured = true;

  const AuthState.loading({this.user, this.isFirebaseConfigured = true})
      : status = AuthStatus.loading,
        errorMessage = null;

  const AuthState.authenticated(this.user, {this.isFirebaseConfigured = true})
      : status = AuthStatus.authenticated,
        errorMessage = null;

  const AuthState.anonymous(this.user, {this.isFirebaseConfigured = true})
      : status = AuthStatus.anonymous,
        errorMessage = null;

  const AuthState.unauthenticated({this.isFirebaseConfigured = true})
      : status = AuthStatus.unauthenticated,
        user = null,
        errorMessage = null;

  const AuthState.error(String message, {this.user, this.isFirebaseConfigured = true})
      : status = AuthStatus.error,
        errorMessage = message;

  /// Convenience getters for UI presentation
  bool get isAuthenticated => status == AuthStatus.authenticated && user != null;
  bool get isAnonymous => status == AuthStatus.anonymous || (user?.isAnonymous == true);
  bool get isUnauthenticated => status == AuthStatus.unauthenticated || status == AuthStatus.initial;
  bool get isLoading => status == AuthStatus.loading;
  bool get hasError => status == AuthStatus.error && errorMessage != null;

  AuthState copyWith({
    AuthStatus? status,
    AuthUser? user,
    String? errorMessage,
    bool? isFirebaseConfigured,
    bool clearError = false,
  }) {
    return AuthState(
      status: status ?? this.status,
      user: user ?? this.user,
      errorMessage: clearError ? null : (errorMessage ?? this.errorMessage),
      isFirebaseConfigured: isFirebaseConfigured ?? this.isFirebaseConfigured,
    );
  }

  @override
  bool operator ==(Object other) =>
      identical(this, other) ||
      other is AuthState &&
          runtimeType == other.runtimeType &&
          status == other.status &&
          user == other.user &&
          errorMessage == other.errorMessage &&
          isFirebaseConfigured == other.isFirebaseConfigured;

  @override
  int get hashCode =>
      status.hashCode ^
      user.hashCode ^
      errorMessage.hashCode ^
      isFirebaseConfigured.hashCode;

  @override
  String toString() =>
      'AuthState(status: $status, user: $user, error: $errorMessage, configured: $isFirebaseConfigured)';
}