using System.Net;
using System.Text.Json;

using StevanFreeborn.Atproto.IdentityResolver.Exceptions;

using RichardSzalay.MockHttp;
using StevanFreeborn.Atproto.IdentityResolver.Retrieval;

namespace StevanFreeborn.Atproto.IdentityResolver.Tests.Unit;

public sealed class DefaultDidRetrieverTests : IDisposable
{
  private readonly MockHttpMessageHandler _mockHttpMessageHandler = new();
  private readonly DefaultDidRetriever _sut;

  public DefaultDidRetrieverTests()
  {
    _sut = new(_mockHttpMessageHandler.ToHttpClient());
  }

  public void Dispose()
  {
    _mockHttpMessageHandler.Dispose();
  }

  [Fact]
  public async Task GetByDnsOrThrowAsync_WhenHandleIsNull_ItShouldThrowArgumentNullException()
  {
    var act = async () => await _sut.GetByDnsOrThrowAsync(null!, TestContext.Current.CancellationToken);

    var e = await act.Should().ThrowAsync<ArgumentNullException>();
  }

  [Fact]
  public async Task GetByDnsOrThrowAsync_WhenResponseIsNotSuccessful_ItShouldThrowDidNotFoundException()
  {
    var handle = "stevan.cc";

    _mockHttpMessageHandler
      .When(HttpMethod.Get, $"https://cloudflare-dns.com/dns-query?name=_atproto.{handle}&type=TXT")
      .Respond(HttpStatusCode.InternalServerError);

    var act = async () => await _sut.GetByDnsOrThrowAsync(Handle.From(handle), TestContext.Current.CancellationToken);

    await act.Should().ThrowAsync<DidNotFoundException>();
  }

  [Fact]
  public async Task GetByDnsOrThrowAsync_WhenResponseIsSuccessfulButDeserialziationFails_ItShouldThrowDidNotFoundException()
  {
    var handle = "stevan.cc";

    _mockHttpMessageHandler
      .When(HttpMethod.Get, $"https://cloudflare-dns.com/dns-query?name=_atproto.{handle}&type=TXT")
      .Respond("application/json", JsonSerializer.Serialize("null"));

    var act = async () => await _sut.GetByDnsOrThrowAsync(Handle.From(handle), TestContext.Current.CancellationToken);

    var e = await act.Should().ThrowAsync<DidNotFoundException>();
    e.WithInnerException<JsonException>();
  }

  [Fact]
  public async Task GetByDnsOrThrowAsync_WhenResponseIsSuccessfulButBodyIsNull_ItShouldThrowDidNotFoundException()
  {
    var handle = "stevan.cc";

    _mockHttpMessageHandler
      .When(HttpMethod.Get, $"https://cloudflare-dns.com/dns-query?name=_atproto.{handle}&type=TXT")
      .Respond("application/json", "null");

    var act = async () => await _sut.GetByDnsOrThrowAsync(Handle.From(handle), TestContext.Current.CancellationToken);

    await act.Should().ThrowAsync<DidNotFoundException>();
  }

  [Fact]
  public async Task GetByDnsOrThrowAsync_WhenResponseIsSuccessfulButNoAnswers_ItShouldThrowDidNotFoundException()
  {
    var handle = "stevan.cc";
    var response = new DnsQueryResponse();

    _mockHttpMessageHandler
      .When(HttpMethod.Get, $"https://cloudflare-dns.com/dns-query?name=_atproto.{handle}&type=TXT")
      .Respond("application/json", JsonSerializer.Serialize(response));

    var act = async () => await _sut.GetByDnsOrThrowAsync(Handle.From(handle), TestContext.Current.CancellationToken);

    await act.Should().ThrowAsync<DidNotFoundException>();
  }

  [Fact]
  public async Task GetByDnsOrThrowAsync_WhenResponseIsSuccessfulButTextRecordValueFormattedIncorrectly_ItShouldThrowDidNotFoundException()
  {
    var handle = "stevan.cc";
    var response = new DnsQueryResponse()
    {
      Answer = [new() { Data = $"did:web:{handle}" }]
    };

    _mockHttpMessageHandler
      .When(HttpMethod.Get, $"https://cloudflare-dns.com/dns-query?name=_atproto.{handle}&type=TXT")
      .Respond("application/json", JsonSerializer.Serialize(response));

    var act = async () => await _sut.GetByDnsOrThrowAsync(Handle.From(handle), TestContext.Current.CancellationToken);

    await act.Should().ThrowAsync<DidNotFoundException>();
  }

  [Fact]
  public async Task GetByDnsOrThrowAsync_WhenResponseIsSuccessfulAndTextRecordValueFormattedCorrectly_ItShouldReturnDid()
  {
    var handle = "stevan.cc";
    var response = new DnsQueryResponse()
    {
      Answer = [new() { Data = $@"did=did:web:{handle}" }]
    };

    _mockHttpMessageHandler
      .When(HttpMethod.Get, $"https://cloudflare-dns.com/dns-query?name=_atproto.{handle}&type=TXT")
      .Respond("application/json", JsonSerializer.Serialize(response));

    var result = await _sut.GetByDnsOrThrowAsync(Handle.From(handle), TestContext.Current.CancellationToken);

    result.Should().BeEquivalentTo(Did.From($"did:web:{handle}"));
  }

  [Fact]
  public async Task GetByWellKnownOrThrowAsync_WhenResponseIsUnsuccessful_ItShouldThrowDidNotFoundException()
  {
    var handle = "stevan.cc";
    var did = $"did:web:{handle}";

    _mockHttpMessageHandler
      .When(HttpMethod.Get, $"https://{handle}/.well-known/atproto-did")
      .Respond(HttpStatusCode.InternalServerError);

    var act = async () => await _sut.GetByWellKnownOrThrowAsync(Handle.From(handle), TestContext.Current.CancellationToken);

    await act.Should().ThrowAsync<DidNotFoundException>();
  }

  [Fact]
  public async Task GetByWellKnownOrThrowAsync_WhenResponseIsSuccessfulAndButDoesNotContainDid_ItShouldThrowDidNotFoundException()
  {
    var handle = "stevan.cc";
    var did = $"did:web:{handle}";

    _mockHttpMessageHandler
      .When(HttpMethod.Get, $"https://{handle}/.well-known/atproto-did")
      .Respond("application/json", JsonSerializer.Serialize(new { did }));

    var act = async () => await _sut.GetByWellKnownOrThrowAsync(Handle.From(handle), TestContext.Current.CancellationToken);

    await act.Should().ThrowAsync<DidNotFoundException>();
  }

  [Fact]
  public async Task GetByWellKnownOrThrowAsync_WhenResponseIsSuccessfulAndContainsDid_ItShouldReturnDid()
  {
    var handle = "stevan.cc";
    var did = $"did:web:{handle}";

    _mockHttpMessageHandler
      .When(HttpMethod.Get, $"https://{handle}/.well-known/atproto-did")
      .Respond("text/plain", did);

    var result = await _sut.GetByWellKnownOrThrowAsync(Handle.From(handle), TestContext.Current.CancellationToken);

    result.Should().BeEquivalentTo(Did.From(did));
  }
}