using BuildFlow.Platform.Application.Users.DTOs;
using BuildFlow.Platform.Application.Users.Queries;
using IM.Application.Chat.Handlers;
using IM.Application.Chat.Queries;
using IM.Domain.Common;
using IM.Domain.Enums;
using IM.Infrastructure.Persistence;
using MediatR;
using Microsoft.EntityFrameworkCore;
using Microsoft.Extensions.DependencyInjection;
using Moq;
using Xunit;

namespace BuildFlow.IM.Tests.Chat;

/// <summary>
/// GetConversationsQueryHandler 的会话列表断言：未读数展示必须优先使用 Redis 热数据。
/// </summary>
public class GetConversationsQueryHandlerTests
{
    private static readonly Guid UserId = Guid.Parse("22222222-2222-2222-2222-222222222222");
    private static readonly Guid OtherUserId = Guid.Parse("33333333-3333-3333-3333-333333333333");
    private static readonly Guid ConversationId = Guid.Parse("11111111-1111-1111-1111-111111111111");

    [Fact]
    public async Task Uses_redis_unread_in_conversation_list_when_pg_cold_backup_is_zero()
    {
        await using var db = BuildInMemoryDb();
        db.Conversations.Add(ImTestData.BuildConversation(
            ConversationId,
            ConversationTypeEnum.Private,
            (UserId, 0),
            (OtherUserId, 0)));
        await db.SaveChangesAsync();

        var mediator = new Mock<IMediator>();
        mediator
            .Setup(m => m.Send(
                It.Is<GetUserSummariesQuery>(q => q.UserIds.SequenceEqual(new[] { OtherUserId })),
                It.IsAny<CancellationToken>()))
            .ReturnsAsync(new Dictionary<Guid, UserSummaryDto>
            {
                [OtherUserId] = new(OtherUserId, "Bob", null)
            });

        var unreadCounter = new Mock<IUnreadCounter>();
        unreadCounter
            .Setup(c => c.GetByUserAsync(
                UserId,
                It.Is<IEnumerable<Guid>>(ids => ids.SequenceEqual(new[] { ConversationId })),
                It.IsAny<CancellationToken>()))
            .ReturnsAsync(new Dictionary<Guid, int> { [ConversationId] = 2 });

        var handler = new GetConversationsQueryHandler(db, mediator.Object, unreadCounter.Object);

        var result = await handler.Handle(new GetConversationsQuery(UserId), CancellationToken.None);

        var conversation = Assert.Single(result);
        Assert.Equal(2, conversation.UnreadCount);
        Assert.Equal("Bob", conversation.OtherUserName);
        mediator.Verify(m => m.Send(
            It.Is<GetUserSummariesQuery>(q => q.UserIds.SequenceEqual(new[] { OtherUserId })),
            It.IsAny<CancellationToken>()), Times.Once);
    }

    private static ImDbContext BuildInMemoryDb()
    {
        var services = new ServiceCollection();
        services.AddDbContext<ImDbContext>(o => o.UseInMemoryDatabase($"im-conversation-{Guid.NewGuid()}"));
        return services.BuildServiceProvider().GetRequiredService<ImDbContext>();
    }
}