TravelMate/lib/blocs/group/group_state.dart

/// States for group-related operations in the GroupBloc.
///
/// This file defines all possible states that the GroupBloc can emit in response
/// to group-related events. The states represent different phases of group
/// operations including loading, success, error, and data states.
///
/// State Categories:
/// - **Initial State**: GroupInitial
/// - **Loading States**: GroupLoading
/// - **Success States**: GroupsLoaded, GroupLoaded, GroupCreated, GroupOperationSuccess
/// - **Error States**: GroupError
///
/// All states extend [GroupState] and implement [Equatable] for proper
/// equality comparison and state change detection in the BLoC pattern.
import 'package:equatable/equatable.dart';
import '../../models/group.dart';

/// Base class for all group-related states.
///
/// All group states must extend this class and implement the [props] getter
/// for proper equality comparison in the BLoC pattern.
abstract class GroupState extends Equatable {
  const GroupState();

  @override
  List<Object?> get props => [];
}

// Initial state
/// The initial state of the GroupBloc before any operations are performed.
///
/// This is the default state when the bloc is first created and represents
/// a clean slate with no group data loaded or operations in progress.
class GroupInitial extends GroupState {}

// Loading
/// State indicating that a group operation is currently in progress.
///
/// This state is emitted when the bloc is performing operations like
/// loading groups, creating groups, or updating group information.
/// UI components can use this state to show loading indicators.
class GroupLoading extends GroupState {}

// Groups loaded
/// State containing a list of successfully loaded groups.
///
/// This state is emitted when groups have been successfully retrieved
/// from the repository, either through initial loading or real-time updates.
/// The UI can use this data to display the list of available groups.
///
/// Properties:
///   [groups]: List of Group objects that were loaded
class GroupsLoaded extends GroupState {
  /// The list of loaded groups
  final List<Group> groups;

  /// Creates a GroupsLoaded state.
  ///
  /// Args:
  ///   [groups]: The list of groups to include in this state
  const GroupsLoaded(this.groups);

  @override
  List<Object?> get props => [groups];
}

/// Alternative state for loaded groups (used in some contexts).
///
/// This state serves a similar purpose to GroupsLoaded but may be used
/// in different contexts or for backward compatibility.
///
/// Properties:
///   [groups]: List of Group objects that were loaded
class GroupLoaded extends GroupState {
  /// The list of loaded groups
  final List<Group> groups;

  /// Creates a GroupLoaded state.
  ///
  /// Args:
  ///   [groups]: The list of groups to include in this state
  const GroupLoaded(this.groups);
}

/// State indicating successful group creation.
///
/// This state is emitted when a new group has been successfully created.
/// It contains the ID of the newly created group and an optional success message
/// that can be displayed to the user.
///
/// Properties:
///   [groupId]: The unique identifier of the newly created group
///   [message]: A success message to display to the user
class GroupCreated extends GroupState {
  /// The unique identifier of the newly created group
  final String groupId;
  
  /// Success message for the user
  final String message;

  /// Creates a GroupCreated state.
  ///
  /// Args:
  ///   [groupId]: The ID of the newly created group
  ///   [message]: Optional success message (defaults to "Group created successfully")
  const GroupCreated({
    required this.groupId,
    this.message = 'Group created successfully',
  });
  
  @override
  List<Object?> get props => [groupId, message];
}

// Operation success
/// State indicating successful completion of a group operation.
///
/// This state is emitted when operations like updating, deleting, or
/// member management have completed successfully. It contains a message
/// that can be displayed to inform the user of the successful operation.
///
/// Properties:
///   [message]: A success message describing the completed operation
class GroupOperationSuccess extends GroupState {
  /// The success message to display to the user
  final String message;

  /// Creates a GroupOperationSuccess state.
  ///
  /// Args:
  ///   [message]: The success message to display
  const GroupOperationSuccess(this.message);

  @override
  List<Object?> get props => [message];
}

// Error
/// State indicating that a group operation has failed.
///
/// This state is emitted when any group operation encounters an error.
/// It contains an error message that can be displayed to the user to
/// explain what went wrong.
///
/// Properties:
///   [message]: An error message describing what went wrong
class GroupError extends GroupState {
  /// The error message to display to the user
  final String message;

  /// Creates a GroupError state.
  ///
  /// Args:
  ///   [message]: The error message to display
  const GroupError(this.message);

  @override
  List<Object?> get props => [message];
}