using System.Net;
using System.Text;
using Omika.Core.Observability.Forwarding;
using Omika.Core.Observability.Outbox;

namespace Omika.Tests.Observability.Forwarding;

/// <summary>Tests du client HTTP du forwarder (mapping de statuts, headers, jamais de levée).</summary>
public class DiagnosticsForwarderClientTests
{
    private static DiagnosticsForwarderClient NewClient(FakeHandler handler) =>
        new(new HttpClient(handler), "https://diagnostics.example/api/v1/diagnostics/batches", TimeSpan.FromSeconds(5));

    [Fact]
    public async Task SendAsync_2xx_ReturnsSuccess_WithAcceptedCount()
    {
        var handler = new FakeHandler(HttpStatusCode.OK, "{\"batchId\":\"00000000-0000-0000-0000-000000000000\",\"acceptedCount\":7}");
        var client = NewClient(handler);

        DiagnosticsForwardResult result = await client.SendAsync(Batch(), "BATIK.01", "omkdiag_x");

        Assert.Equal(DiagnosticsForwardOutcome.Success, result.Outcome);
        Assert.Equal(7, result.AcceptedCount);
    }

    [Fact]
    public async Task SendAsync_401_ReturnsUnauthorized() =>
        await AssertOutcomeAsync(HttpStatusCode.Unauthorized, DiagnosticsForwardOutcome.Unauthorized);

    [Fact]
    public async Task SendAsync_403_ReturnsForbidden() =>
        await AssertOutcomeAsync(HttpStatusCode.Forbidden, DiagnosticsForwardOutcome.Forbidden);

    [Fact]
    public async Task SendAsync_400_ReturnsRejected() =>
        await AssertOutcomeAsync(HttpStatusCode.BadRequest, DiagnosticsForwardOutcome.Rejected);

    [Fact]
    public async Task SendAsync_503_ReturnsTransient() =>
        await AssertOutcomeAsync(HttpStatusCode.ServiceUnavailable, DiagnosticsForwardOutcome.Transient);

    [Fact]
    public async Task SendAsync_SetsClientCodeAndKeyHeaders()
    {
        var handler = new FakeHandler(HttpStatusCode.OK, "{}");
        var client = NewClient(handler);

        await client.SendAsync(Batch(), "BATIK.01", "omkdiag_secret_key");

        Assert.Equal("BATIK.01", handler.LastRequest?.Headers.GetValues("X-Omika-Client-Code").FirstOrDefault());
        Assert.Equal("omkdiag_secret_key", handler.LastRequest?.Headers.GetValues("X-Omika-Diagnostics-Key").FirstOrDefault());
    }

    private static async Task AssertOutcomeAsync(HttpStatusCode status, DiagnosticsForwardOutcome expected)
    {
        var handler = new FakeHandler(status, "{}");
        var client = NewClient(handler);

        DiagnosticsForwardResult result = await client.SendAsync(Batch(), "BATIK.01", "omkdiag_x");

        Assert.Equal(expected, result.Outcome);
    }

    private static CentralDiagnosticBatchDto Batch() =>
        new() { Events = [ForwardingTestHarness.NewRecord()] };

    private sealed class FakeHandler : HttpMessageHandler
    {
        private readonly HttpStatusCode _status;
        private readonly string _body;

        public FakeHandler(HttpStatusCode status, string body)
        {
            _status = status;
            _body = body;
        }

        public HttpRequestMessage? LastRequest { get; private set; }

        protected override Task<HttpResponseMessage> SendAsync(HttpRequestMessage request, CancellationToken cancellationToken)
        {
            LastRequest = request;
            return Task.FromResult(new HttpResponseMessage(_status)
            {
                Content = new StringContent(_body, Encoding.UTF8, "application/json")
            });
        }
    }
}