TravelMate/lib/blocs/message/message_event.dart

/// Events for message-related operations in the MessageBloc.
///
/// This file defines all possible events that can be dispatched to the MessageBloc
/// to trigger message-related state changes and operations such as loading messages,
/// sending messages, managing reactions, and performing CRUD operations on chat messages.
///
/// Event Categories:
/// - **Loading Events**: LoadMessages
/// - **Message Operations**: SendMessage, DeleteMessage, UpdateMessage
/// - **Reaction Management**: ReactToMessage, RemoveReaction
///
/// All events support real-time group chat functionality with features like
/// message editing, deletion, and emoji reactions.
///
/// All events extend [MessageEvent] and implement [Equatable] for proper
/// equality comparison in the BLoC pattern.
library;
import 'package:equatable/equatable.dart';

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

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

/// Event to load messages for a specific group with real-time updates.
///
/// This event initializes the message stream for a group, providing real-time
/// updates as new messages are sent, edited, or deleted. The stream will
/// continue until the bloc is closed or a new LoadMessages event is dispatched.
///
/// Args:
///   [groupId]: The unique identifier of the group whose messages should be loaded
class LoadMessages extends MessageEvent {
  /// The unique identifier of the group
  final String groupId;

  /// Creates a LoadMessages event.
  ///
  /// Args:
  ///   [groupId]: The group ID to load messages for
  const LoadMessages(this.groupId);

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

/// Event to send a new message to a group chat.
///
/// This event creates and sends a new message to the specified group.
/// The message will be immediately visible to all group members through
/// the real-time message stream.
///
/// Args:
///   [groupId]: The unique identifier of the target group
///   [text]: The content of the message to send
///   [senderId]: The unique identifier of the user sending the message
///   [senderName]: The display name of the user sending the message
class SendMessage extends MessageEvent {
  /// The unique identifier of the group
  final String groupId;
  
  /// The content of the message
  final String text;
  
  /// The unique identifier of the sender
  final String senderId;
  
  /// The display name of the sender
  final String senderName;

  /// Creates a SendMessage event.
  ///
  /// Args:
  ///   [groupId]: The target group ID
  ///   [text]: The message content
  ///   [senderId]: The sender's user ID
  ///   [senderName]: The sender's display name
  const SendMessage({
    required this.groupId,
    required this.text,
    required this.senderId,
    required this.senderName,
  });

  @override
  List<Object?> get props => [groupId, text, senderId, senderName];
}

/// Event to delete a message from the group chat.
///
/// This event permanently removes a message from the chat. The deletion
/// will be immediately reflected for all group members through the
/// real-time message stream. This action cannot be undone.
///
/// Args:
///   [groupId]: The unique identifier of the group containing the message
///   [messageId]: The unique identifier of the message to delete
class DeleteMessage extends MessageEvent {
  /// The unique identifier of the group
  final String groupId;
  
  /// The unique identifier of the message to delete
  final String messageId;

  /// Creates a DeleteMessage event.
  ///
  /// Args:
  ///   [groupId]: The group ID containing the message
  ///   [messageId]: The message ID to delete
  const DeleteMessage({
    required this.groupId,
    required this.messageId,
  });

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

/// Event to update/edit an existing message in the group chat.
///
/// This event allows users to modify the content of a previously sent message.
/// The updated message will be immediately visible to all group members
/// through the real-time message stream, typically with an "edited" indicator.
///
/// Args:
///   [groupId]: The unique identifier of the group containing the message
///   [messageId]: The unique identifier of the message to update
///   [newText]: The new content for the message
class UpdateMessage extends MessageEvent {
  /// The unique identifier of the group
  final String groupId;
  
  /// The unique identifier of the message to update
  final String messageId;
  
  /// The new content for the message
  final String newText;

  /// Creates an UpdateMessage event.
  ///
  /// Args:
  ///   [groupId]: The group ID containing the message
  ///   [messageId]: The message ID to update
  ///   [newText]: The new message content
  const UpdateMessage({
    required this.groupId,
    required this.messageId,
    required this.newText,
  });

  @override
  List<Object?> get props => [groupId, messageId, newText];
}

/// Event to add an emoji reaction to a message.
///
/// This event allows users to react to messages with emojis, providing
/// a quick way to express emotions or acknowledgment without sending
/// a full message. The reaction will be immediately visible to all group members.
///
/// Args:
///   [groupId]: The unique identifier of the group containing the message
///   [messageId]: The unique identifier of the message to react to
///   [userId]: The unique identifier of the user adding the reaction
///   [reaction]: The emoji or reaction string to add
class ReactToMessage extends MessageEvent {
  /// The unique identifier of the group
  final String groupId;
  
  /// The unique identifier of the message
  final String messageId;
  
  /// The unique identifier of the user adding the reaction
  final String userId;
  
  /// The emoji or reaction string
  final String reaction;

  /// Creates a ReactToMessage event.
  ///
  /// Args:
  ///   [groupId]: The group ID containing the message
  ///   [messageId]: The message ID to react to
  ///   [userId]: The user ID adding the reaction
  ///   [reaction]: The emoji/reaction to add
  const ReactToMessage({
    required this.groupId,
    required this.messageId,
    required this.userId,
    required this.reaction,
  });

  @override
  List<Object?> get props => [groupId, messageId, userId, reaction];
}

/// Event to remove a user's reaction from a message.
///
/// This event removes a previously added emoji reaction from a message.
/// Only the user who added the reaction can remove it. The removal will
/// be immediately reflected for all group members through the real-time stream.
///
/// Args:
///   [groupId]: The unique identifier of the group containing the message
///   [messageId]: The unique identifier of the message with the reaction
///   [userId]: The unique identifier of the user removing their reaction
class RemoveReaction extends MessageEvent {
  /// The unique identifier of the group
  final String groupId;
  
  /// The unique identifier of the message
  final String messageId;
  
  /// The unique identifier of the user removing the reaction
  final String userId;

  /// Creates a RemoveReaction event.
  ///
  /// Args:
  ///   [groupId]: The group ID containing the message
  ///   [messageId]: The message ID with the reaction
  ///   [userId]: The user ID removing the reaction
  const RemoveReaction({
    required this.groupId,
    required this.messageId,
    required this.userId,
  });

  @override
  List<Object?> get props => [groupId, messageId, userId];
}