using System.Net;
using System.Text;
using BuildFlow.Application.AiModel.Handlers;
using BuildFlow.Application.AiModel.Queries;
using BuildFlow.Domain.Enums;
using BuildFlow.Shared.Domain.Errors;
using BuildFlow.Shared.Domain.Exceptions;
using FluentAssertions;
using Xunit;

namespace BuildFlow.Rag.Tests;

/// <summary>
/// 发现 LM Studio 本地模型处理器测试。
/// 成功路径用本地 HttpListener 伪服务（绕过真实 LM Studio/网络）；异常分支覆盖非法 BaseUrl（依赖调用前校验）。
/// </summary>
public class DiscoverLmStudioModelsQueryHandlerTests
{
    [Fact]
    public async Task Handle_LocalServer_ReturnsDiscoveredModels()
    {
        var port = 18731;
        using var listener = new HttpListener();
        listener.Prefixes.Add($"http://127.0.0.1:{port}/");
        listener.Start();

        var serveTask = Task.Run(async () =>
        {
            var context = await listener.GetContextAsync();
            var body = Encoding.UTF8.GetBytes("{\"data\":[{\"id\":\"local-llm\"}]}");
            context.Response.ContentType = "application/json";
            await context.Response.OutputStream.WriteAsync(body);
            context.Response.Close();
        });

        var handler = new DiscoverLmStudioModelsQueryHandler();
        var result = await handler.Handle(
            new DiscoverLmStudioModelsQuery($"http://127.0.0.1:{port}/v1"),
            CancellationToken.None);

        await serveTask;
        result.Should().ContainSingle();
        result[0].ModelId.Should().Be("local-llm");
        result[0].Provider.Should().Be((int)ModelProviderEnum.LMStudio);
    }

    [Fact]
    public async Task Handle_InvalidBaseUrl_ThrowsInvalidParam()
    {
        var handler = new DiscoverLmStudioModelsQueryHandler();

        var act = async () => await handler.Handle(
            new DiscoverLmStudioModelsQuery("ftp://not-http"),
            CancellationToken.None);
        var ex = await act.Should().ThrowAsync<BusinessException>();
        ex.Which.Code.Should().Be(ErrorCode.InvalidParam);
    }

    [Fact]
    public async Task Handle_RelativeBaseUrl_ThrowsInvalidParam()
    {
        var handler = new DiscoverLmStudioModelsQueryHandler();

        var act = async () => await handler.Handle(
            new DiscoverLmStudioModelsQuery("localhost:1234"),
            CancellationToken.None);
        var ex = await act.Should().ThrowAsync<BusinessException>();
        ex.Which.Code.Should().Be(ErrorCode.InvalidParam);
    }
}