using System;
using System.Collections.Generic;
using System.Net;
using System.Net.Http;
using System.Text;
using System.Text.Json;
using System.Threading;
using System.Threading.Tasks;
using FrameworkBLL.Promotion.Adapters;
using GB5Shared.DTO.Framework.Login;
using GB5Shared.DTO.Promotion;
using Microsoft.Extensions.Configuration;
using Moq;
using Moq.Protected;
using Xunit;

namespace FrameworkTests;

/// <summary>
/// RemoteHttpPromotionAdapter — reaches a cross-host entity's own PromotionBridge endpoints (e.g.
/// TMS's TrainingProgramme adapter on HRFinanceHost) over plain HTTP, since GOP's execution
/// pipeline runs only inside FrameworkSL's own process. Covers the BaseUrl resolution per module,
/// the Login-header convention (same as JobEngineScheduleClient/the "entitlement-internal" client),
/// correct unwrapping of ResponseStandardDTO's Body, and that — unlike PromotionExchangeClient's
/// deliberate non-fatal degrade-to-null — a failed remote call propagates as a real exception, since
/// a Promotion Import step has no useful fallback when the destination call doesn't work.
/// </summary>
public class RemoteHttpPromotionAdapterTests
{
    private static LoginDTO Login() => new() { ClientId = -1, UserId = 7 };

    private static IConfiguration Config() => new ConfigurationBuilder()
        .AddInMemoryCollection(new Dictionary<string, string?>
        {
            ["Promotion:RemoteModules:TMS:BaseUrl"] = "http://hrfinance.test"
        })
        .Build();

    private static (Mock<HttpMessageHandler> Handler, IHttpClientFactory Factory) NewFactory(
        Func<HttpRequestMessage, HttpResponseMessage> respond)
    {
        var handler = new Mock<HttpMessageHandler>();
        handler.Protected()
            .Setup<Task<HttpResponseMessage>>("SendAsync", ItExpr.IsAny<HttpRequestMessage>(), ItExpr.IsAny<CancellationToken>())
            .ReturnsAsync((HttpRequestMessage req, CancellationToken _) => respond(req));

        var factory = new Mock<IHttpClientFactory>();
        factory.Setup(f => f.CreateClient("promotion-remote")).Returns(() => new HttpClient(handler.Object));
        return (handler, factory.Object);
    }

    private static HttpResponseMessage SuccessEnvelope(object body) => new(HttpStatusCode.OK)
    {
        Content = new StringContent(
            JsonSerializer.Serialize(new { Status = 200, Body = body }), Encoding.UTF8, "application/json")
    };

    private static HttpResponseMessage FailedEnvelope(string errorBody) => new(HttpStatusCode.OK)
    {
        Content = new StringContent(
            JsonSerializer.Serialize(new { Status = 400, ErrorBody = errorBody }), Encoding.UTF8, "application/json")
    };

    [Fact]
    public async Task ExportForPromotionAsync_PostsToCorrectPathAndAttachesLoginHeader()
    {
        var bundle = new PromotionBundleDTO { EntityTypeCode = "TRAININGPROGRAMME", OriginEntityId = 42, PayloadJson = "{}" };
        HttpRequestMessage? captured = null;
        var (_, factory) = NewFactory(req =>
        {
            captured = req;
            return SuccessEnvelope(bundle);
        });

        var adapter = new RemoteHttpPromotionAdapter(factory, Config(), "TRAININGPROGRAMME", "TMS");
        var result = await adapter.ExportForPromotionAsync(42, Login(), CancellationToken.None);

        Assert.Equal("TRAININGPROGRAMME", result.EntityTypeCode);
        Assert.Equal(42, result.OriginEntityId);
        Assert.NotNull(captured);
        Assert.Equal("http://hrfinance.test/PromotionBridge/ExportForPromotion", captured!.RequestUri!.ToString());
        Assert.True(captured.Headers.TryGetValues("Login", out var loginValues));
        Assert.Contains("\"ClientId\":-1", Assert.Single(loginValues!));
    }

    [Fact]
    public async Task ValidateForPromotionAsync_ParsesValidationResult()
    {
        var (_, factory) = NewFactory(_ => SuccessEnvelope(PromotionValidationResultDTO.Ok()));
        var adapter = new RemoteHttpPromotionAdapter(factory, Config(), "TRAININGPROGRAMME", "TMS");

        var result = await adapter.ValidateForPromotionAsync(
            new PromotionBundleDTO { EntityTypeCode = "TRAININGPROGRAMME" }, CancellationToken.None);

        Assert.True(result.IsPromotable);
    }

    [Fact]
    public async Task ImportPromotedAsync_PostsBundleAndReturnsDestinationId()
    {
        HttpRequestMessage? captured = null;
        var (_, factory) = NewFactory(req =>
        {
            captured = req;
            return SuccessEnvelope(904);
        });

        var adapter = new RemoteHttpPromotionAdapter(factory, Config(), "TRAININGPROGRAMME", "TMS");
        var result = await adapter.ImportPromotedAsync(
            new PromotionBundleDTO { EntityTypeCode = "TRAININGPROGRAMME" }, destinationSourceType: 3,
            existingDestinationId: null, Login(), CancellationToken.None);

        Assert.Equal(904, result);
        Assert.Equal("http://hrfinance.test/PromotionBridge/ImportPromoted", captured!.RequestUri!.ToString());
    }

    [Fact]
    public async Task RemoteCallReportsFailure_ThrowsRatherThanDegrading()
    {
        var (_, factory) = NewFactory(_ => FailedEnvelope("No IPromotableEntity registered locally for EntityTypeCode 'TRAININGPROGRAMME'."));
        var adapter = new RemoteHttpPromotionAdapter(factory, Config(), "TRAININGPROGRAMME", "TMS");

        await Assert.ThrowsAsync<InvalidOperationException>(() =>
            adapter.ExportForPromotionAsync(42, Login(), CancellationToken.None));
    }

    [Fact]
    public async Task TransportFailure_ThrowsRatherThanDegrading()
    {
        var (_, factory) = NewFactory(_ => new HttpResponseMessage(HttpStatusCode.InternalServerError));
        var adapter = new RemoteHttpPromotionAdapter(factory, Config(), "TRAININGPROGRAMME", "TMS");

        await Assert.ThrowsAsync<HttpRequestException>(() =>
            adapter.ExportForPromotionAsync(42, Login(), CancellationToken.None));
    }

    [Fact]
    public void Constructor_MissingBaseUrlConfig_ThrowsOnFirstCallNotConstruction()
    {
        var emptyConfig = new ConfigurationBuilder().Build();
        var (_, factory) = NewFactory(_ => SuccessEnvelope(new { }));

        // Construction itself never touches config — matches every other adapter's constructor
        // (config is only read per-call, same as JobEngineScheduleClient's own JobEngine:BaseUrl).
        var adapter = new RemoteHttpPromotionAdapter(factory, emptyConfig, "TRAININGPROGRAMME", "TMS");
        Assert.NotNull(adapter);
    }
}