IM_NEW/MessageService.Domain/Entities/Conversation.cs

using IM.DomainCommons;
using MessageService.Domain.Enums;
using MessageService.Domain.Events;
using MessageService.Domain.Tools;

namespace MessageService.Domain.Entities
{
    public class Conversation : AggregateRootEntity
    {
        /// <summary>
        /// 用户
        /// </summary>
        public Guid UserId { get; private set; }

        /// <summary>
        /// 对方ID（群聊为群聊ID，单聊为单聊ID）	
        /// </summary>
        public Guid TargetId { get; private set; }
        public string TargetAvatar { get; private set; }
        public string TargetName { get; private set; }

        /// <summary>
        /// 最后一条未读消息ID	
        /// </summary>
        public long? LastReadSequenceId { get; private set; }

        /// <summary>
        /// 未读消息数	
        /// </summary>
        public int UnreadCount { get; private set; }

        public ChatType ChatType { get; private set; }

        /// <summary>
        /// 消息推送唯一标识符
        /// </summary>
        public string StreamKey { get; private set; }

        /// <summary>
        /// 最后一条最新消息
        /// </summary>
        public string LastMessage { get; private set; }

        /// <summary>
        /// 最后一条消息产生的时间。已读状态等会话元数据更新不得改变该值。
        /// </summary>
        public DateTimeOffset? LastMessageTime { get; private set; }
        private Conversation() { }

        public Conversation(Guid userId, Guid targetId, string targetAvatar, string targetName, long? lastReadSequenceId, int unreadCount, ChatType chatType, string lastMessage)
        {
            UserId = userId;
            TargetId = targetId;
            TargetAvatar = targetAvatar;
            TargetName = targetName;
            LastReadSequenceId = lastReadSequenceId;
            UnreadCount = unreadCount;
            ChatType = chatType;
            LastMessage = lastMessage;
            LastMessageTime = DateTimeOffset.Now;
            ModificationTime = DateTime.Now;
            StreamKey = ChatType == ChatType.GROUP ? StreamKeyBuilder.Group(targetId) : StreamKeyBuilder.Private(userId, targetId);
            AddDomainEvent(new ConversationCreatedDomainEvent(this));
        }

        public void SetLastReadSequence(long sequenceId)
        {
            LastReadSequenceId = sequenceId;
            NotifyModified();
        }

        public void IncrementUnread()
        {
            UnreadCount += 1;
            NotifyModified();
        }

        public void UpdateLastMessage(string lastMessage, DateTimeOffset messageTime)
        {
            LastMessage = lastMessage;
            LastMessageTime = messageTime;
            NotifyModified();
        }


        /// <summary>
        /// 标记会话已读（清零未读数，更新最后已读消息序列号）
        /// </summary>
        public void MarkAsRead(long? lastReadSequenceId)
        {
            UnreadCount = 0;
            if (lastReadSequenceId.HasValue)
                LastReadSequenceId = lastReadSequenceId.Value;
            NotifyModified();
        }

        public void UpdateProfile(string name, string avatar)
        {
            TargetAvatar = avatar;
            TargetName = name;
        }


    }
}