using IM.Application.Chat.Queries;
using IM.Domain.Enums;
using IM.Infrastructure.Mongo;
using MongoDB.Entities;
using Xunit;
using Microsoft.AspNetCore.SignalR.Client;
using Microsoft.AspNetCore.SignalR;
using Microsoft.Extensions.DependencyInjection;
using MediatR;

namespace BuildFlow.IM.Integration.Tests;

/// <summary>
/// 权限隔离与消息历史分页用例。
/// 通过 MediatR 直接驱动查询/命令处理器，并验证 ChatHub 的非法访问会被 query 的鉴权副作用拦截。
/// </summary>
[Xunit.Collection(ImServerCollection.Name)]
public class ChatHubAuthAndHistoryTests : IAsyncLifetime
{
    private readonly ImServerFixture _fixture;
    private readonly List<HubConnection> _connections = new();

    public ChatHubAuthAndHistoryTests(ImServerFixture fixture) => _fixture = fixture;

    public Task InitializeAsync() => _fixture.CleanRedisAsync();

    public async Task DisposeAsync()
    {
        foreach (var conn in _connections)
        {
            try { await conn.DisposeAsync(); } catch { }
        }
    }

    private async Task<HubConnection> ConnectAsync(Guid userId, string userName)
    {
        var conn = HubConnectionFactory.Create(_fixture, userId, userName);
        await conn.StartAsync();
        _connections.Add(conn);
        return conn;
    }

    [Fact]
    public async Task Non_participant_cannot_join_conversation_group()
    {
        // Arrange：Alice 与 Bob 的私聊，Outsider 不参与
        _fixture.UserInfoService.SetUser(ImServerFixture.AliceId, "Alice");
        _fixture.UserInfoService.SetUser(ImServerFixture.BobId, "Bob");
        var convId = await ImTestSeeder.SeedPrivateConversationAsync(_fixture, ImServerFixture.AliceId, ImServerFixture.BobId);

        var outsider = await ConnectAsync(ImServerFixture.OutSiderId, "Outsider");

        // Act / Assert：Outsider 调 JoinConversation 应被鉴权拦截（Hub 抛异常）
        // SignalR 客户端会把 hub 抛出的异常转为 HubException
        var ex = await Assert.ThrowsAsync<HubException>(() =>
            outsider.InvokeAsync("JoinConversation", convId));
        Assert.Contains("无权访问该会话", ex.Message);
    }

    [Fact]
    public async Task Get_conversation_participants_rejects_non_participant()
    {
        // Arrange
        var convId = await ImTestSeeder.SeedPrivateConversationAsync(_fixture, ImServerFixture.AliceId, ImServerFixture.BobId);

        await using var scope = _fixture.Services.CreateAsyncScope();
        var mediator = scope.ServiceProvider.GetRequiredService<IMediator>();

        // Act / Assert：非参与者查询参与者列表抛 UnauthorizedException
        await Assert.ThrowsAsync<BuildFlow.Shared.Domain.Exceptions.UnauthorizedException>(() =>
            mediator.Send(new GetConversationParticipantIdsQuery(convId, ImServerFixture.OutSiderId)));
    }

    [Fact]
    public async Task Get_message_history_rejects_non_participant()
    {
        // Arrange
        var convId = await ImTestSeeder.SeedPrivateConversationAsync(_fixture, ImServerFixture.AliceId, ImServerFixture.BobId);

        await using var scope = _fixture.Services.CreateAsyncScope();
        var mediator = scope.ServiceProvider.GetRequiredService<IMediator>();

        // Act / Assert：非参与者拉取历史抛 UnauthorizedException
        await Assert.ThrowsAsync<BuildFlow.Shared.Domain.Exceptions.UnauthorizedException>(() =>
            mediator.Send(new GetMessageHistoryQuery(ImServerFixture.OutSiderId, convId, null, 20)));
    }

    [Fact]
    public async Task Message_history_cursor_pagination_returns_correct_page_and_hasmore()
    {
        // Arrange：直接落多条消息到 MongoDB（绕过 Hub，聚焦分页逻辑）
        _fixture.UserInfoService.SetUser(ImServerFixture.AliceId, "Alice");
        var convId = await ImTestSeeder.SeedPrivateConversationAsync(_fixture, ImServerFixture.AliceId, ImServerFixture.BobId);

        var messageIds = await SeedMessagesAsync(convId, count: 5);

        await using var scope = _fixture.Services.CreateAsyncScope();
        var mediator = scope.ServiceProvider.GetRequiredService<IMediator>();

        // Act ①：第一页取 3 条（Limit+1 → 实际查 4 条，应判定 hasMore=true）
        var page1 = await mediator.Send(new GetMessageHistoryQuery(ImServerFixture.AliceId, convId, null, 3));

        // Assert：hasMore 为 true，返回恰好 3 条，且按时间倒序（最新在前）
        Assert.True(page1.HasMore);
        Assert.Equal(3, page1.Messages.Count);
        Assert.Equal(messageIds[4], page1.Messages[0].Id); // 最新的在第 5 个位置插入

        // Act ②：以第一页最后一条为游标取下一页（取 3 条，剩 2 条 → hasMore=false）
        var cursor = page1.Messages[^1].Id;
        var page2 = await mediator.Send(new GetMessageHistoryQuery(ImServerFixture.AliceId, convId, cursor, 3));

        // Assert：剩余 2 条，无更多
        Assert.False(page2.HasMore);
        Assert.Equal(2, page2.Messages.Count);
    }

    /// <summary>向指定会话连续写入 N 条消息，返回按插入顺序的 ObjectId 列表。</summary>
    private async Task<List<string>> SeedMessagesAsync(Guid conversationId, int count)
    {
        var docs = new List<MessageDocument>();
        var baseTime = DateTime.UtcNow.AddMinutes(-count);
        for (var i = 0; i < count; i++)
        {
            docs.Add(new MessageDocument
            {
                ConversationId = conversationId,
                SenderId = ImServerFixture.AliceId,
                SenderName = "Alice",
                ContentType = MessageContentType.Text,
                Content = $"history-{i}",
                CreatedAt = baseTime.AddSeconds(i),
            });
        }
        await DB.Default.SaveAsync(docs);
        return docs.Select(d => d.ID).ToList();
    }

    private static async Task WaitForAsync(Func<bool> condition, TimeSpan? timeout = null)
    {
        var deadline = DateTime.UtcNow + (timeout ?? TimeSpan.FromSeconds(5));
        while (DateTime.UtcNow < deadline)
        {
            if (condition()) return;
            await Task.Delay(25);
        }
        throw new TimeoutException("等待条件在超时内未满足");
    }
}