IM_NEW/MessageService.WebApi/Application/EventHandlers/ConversationAddHandler.cs

using IM.Commons.IntegrationEvents;
using MassTransit;
using MessageService.Domain.IReposities;
using MessageService.Infrastructure;

namespace MessageService.WebApi.Application.EventHandlers
{
    public class ConversationAddHandler : IConsumer<GroupMemberJoinedEvent>,
        IConsumer<FriendAddedEvent>, IConsumer<GroupMemberLeftEvent>
    {

        private readonly IConversationReposity reposity;
        private readonly MessageDbContext messageDb;

        public ConversationAddHandler(IConversationReposity reposity, MessageDbContext messageDb)
        {
            this.reposity = reposity;
            this.messageDb = messageDb;
        }

        public async Task Consume(ConsumeContext<GroupMemberJoinedEvent> context)
        {
            var @event = context.Message;
            var existing = await reposity.FindByTargetIdAsync(@event.GroupId);
            if (existing.Any(x => x.UserId == @event.UserId && x.ChatType == Domain.Enums.ChatType.GROUP))
            {
                return;
            }
            reposity.Create(new Domain.Entities.Conversation(
                userId: @event.UserId,
                targetId: @event.GroupId,
                targetAvatar: @event.GroupAvatar ?? @event.Avatar,
                targetName: @event.GroupName,
                lastReadSequenceId: null,
                unreadCount:0,
                chatType: Domain.Enums.ChatType.GROUP,
                lastMessage: string.Empty
                ));

            await messageDb.SaveChangesAsync(context.CancellationToken);
        }

        public async Task Consume(ConsumeContext<FriendAddedEvent> context)
        {
            var @event = context.Message;
            var existing = await reposity.FindByUserIdAsync(@event.OwnerId);
            if (existing.Any(x => x.TargetId == @event.TargetId && x.ChatType == Domain.Enums.ChatType.PRIVATE))
            {
                return;
            }
            reposity.Create(new Domain.Entities.Conversation(
                userId: @event.OwnerId,
                targetId: @event.TargetId,
                targetAvatar: @event.TargetAvatar,
                targetName: @event.TargetNickName,
                lastReadSequenceId: null,
                unreadCount: 0,
                chatType: Domain.Enums.ChatType.PRIVATE,
                lastMessage: string.Empty
                ));

            await messageDb.SaveChangesAsync(context.CancellationToken);
        }

        public async Task Consume(ConsumeContext<GroupMemberLeftEvent> context)
        {
            var conversations = await reposity.FindByTargetIdAsync(context.Message.GroupId);
            foreach (var conversation in conversations.Where(x =>
                x.UserId == context.Message.UserId && x.ChatType == Domain.Enums.ChatType.GROUP))
            {
                conversation.SoftDelete();
            }
            await messageDb.SaveChangesAsync(context.CancellationToken);
        }
    }
}