using System.Net;
using System.Net.Http.Headers;
using Microsoft.Extensions.Logging.Abstractions;
using SGU.AuthBroker.Core.Authentication;
using SGU.AuthBroker.Core.Identity;
using SGU.AuthBroker.Options;
using SGU.AuthBroker.Services;
using Xunit;

namespace SGU.AuthBroker.Tests;

public sealed class NtlmCredentialValidatorTests
{
    private static readonly UserIdentity Administrative = new(
        "AD017045",
        "AD",
        "017045",
        InstitutionalRole.Administrative);

    private static readonly UserIdentity Student = new(
        "AL123456",
        "AL",
        "123456",
        InstitutionalRole.Student);

    [Fact]
    public async Task RedirectAndSuccessWithoutChallengeNeverAuthorizes()
    {
        SequenceHandler handler = new(
            Redirect("/psulsa/login.aspx?AspxAutoDetectCookieSupport=1"),
            Response(HttpStatusCode.OK));
        NtlmCredentialValidator validator = CreateValidator(handler);

        NtlmValidationResult result = await validator.ValidateAsync(
            Student,
            "test-password",
            TestContext.Current.CancellationToken);

        Assert.Equal(NtlmValidationStatus.Unavailable, result.Status);
        Assert.Equal("NTLM_CHALLENGE_MISSING", result.ErrorCode);
        Assert.Equal(2, handler.RequestPaths.Count);
    }

    [Fact]
    public async Task CredentialsAreAcceptedOnlyAfterExplicitNtlmChallenge()
    {
        SequenceHandler handler = new(
            Challenge(),
            Response(HttpStatusCode.OK),
            Response(HttpStatusCode.OK));
        NtlmCredentialValidator validator = CreateValidator(handler);

        NtlmValidationResult result = await validator.ValidateAsync(
            Student,
            "test-password",
            TestContext.Current.CancellationToken);

        Assert.Equal(NtlmValidationStatus.Valid, result.Status);
        Assert.Equal(3, handler.RequestPaths.Count);
        Assert.Equal("/psulsa/", handler.RequestPaths[0]);
        Assert.Equal("/psulsa/", handler.RequestPaths[1]);
        Assert.Equal(
            "/psulsa/alumnos/consultainformacionalumnos/consultainformacion.aspx",
            handler.RequestPaths[2]);
    }

    [Fact]
    public async Task RejectedCredentialsAfterChallengeAreInvalid()
    {
        SequenceHandler handler = new(
            Challenge(),
            Challenge());
        NtlmCredentialValidator validator = CreateValidator(handler);

        NtlmValidationResult result = await validator.ValidateAsync(
            Student,
            "wrong-password",
            TestContext.Current.CancellationToken);

        Assert.Equal(NtlmValidationStatus.Invalid, result.Status);
        Assert.Equal("INVALID_INSTITUTIONAL_CREDENTIALS", result.ErrorCode);
        Assert.Equal(2, handler.RequestPaths.Count);
    }

    [Fact]
    public async Task SessionBootstrapRetriesOriginalRoleProfile()
    {
        SequenceHandler handler = new(
            Challenge(),
            Redirect("/psulsa/login.aspx?AspxAutoDetectCookieSupport=1"),
            Redirect("/psulsa/menu.aspx"),
            Response(HttpStatusCode.OK),
            Response(HttpStatusCode.OK));
        NtlmCredentialValidator validator = CreateValidator(handler);

        NtlmValidationResult result = await validator.ValidateAsync(
            Student,
            "test-password",
            TestContext.Current.CancellationToken);

        Assert.Equal(NtlmValidationStatus.Valid, result.Status);
        Assert.Equal(5, handler.RequestPaths.Count);
        Assert.Equal("/psulsa/login.aspx", handler.RequestPaths[2]);
        Assert.Equal("/psulsa/menu.aspx", handler.RequestPaths[3]);
        Assert.Equal(
            "/psulsa/alumnos/consultainformacionalumnos/consultainformacion.aspx",
            handler.RequestPaths[4]);
    }

    [Fact]
    public async Task VerifiedAdministrativeProfileIsEnrichedFromPersonalAndLocationPages()
    {
        SequenceHandler handler = new(
            Challenge(),
            Response(HttpStatusCode.OK),
            Response(
                HttpStatusCode.OK,
                """
                <span id="ctl00_contenedor_decEncabezado_lblNombre">017045 - NOMBRE ANTERIOR</span>
                <span id="ctl00_contenedor_decEncabezado_lblCorreo">persona@lasalle.mx</span>
                <span id="ctl00_contenedor_decEncabezado_lblPuesto">ANALISTA</span>
                """),
            Response(
                HttpStatusCode.OK,
                """
                <input id="ctl00_contenedor_txtNombre" value="MARÍA DEL CARMEN" />
                <input id="ctl00_contenedor_txtApaterno" value="DE LA FUENTE" />
                <input id="ctl00_contenedor_txtAmaterno" value="O'CONNOR" />
                """),
            Response(
                HttpStatusCode.OK,
                """
                <input id="ctl00_contenedor_txtCalle" value="CALLE DEL SOL" />
                <input id="ctl00_contenedor_txtNoExt" value="15" />
                <input id="ctl00_contenedor_txtCP" value="01000" />
                <select id="ctl00_contenedor_ddlEstado">
                  <option selected="selected">CIUDAD DE MÉXICO</option>
                </select>
                <select id="ctl00_contenedor_ddlLocalidad">
                  <option selected="selected">ÁLVARO OBREGÓN</option>
                </select>
                <select id="ctl00_contenedor_ddlColonia">
                  <option>FLORIDA</option>
                </select>
                """));
        NtlmCredentialValidator validator = CreateValidator(handler);

        NtlmValidationResult result = await validator.ValidateAsync(
            Administrative,
            "test-password",
            TestContext.Current.CancellationToken);

        Assert.Equal(NtlmValidationStatus.Valid, result.Status);
        Assert.NotNull(result.Profile);
        Assert.Equal("017045", result.Profile.EmployeeNumber);
        Assert.Equal("María del Carmen de la Fuente O'Connor", result.Profile.DisplayName);
        Assert.Equal("María del Carmen", result.Profile.GivenName);
        Assert.Equal("de la Fuente O'Connor", result.Profile.Surname);
        Assert.Equal("persona@lasalle.mx", result.Profile.Email);
        Assert.Equal("Analista", result.Profile.JobTitle);
        Assert.Equal("Calle del Sol 15\r\nFlorida", result.Profile.StreetAddress);
        Assert.Equal("Álvaro Obregón", result.Profile.City);
        Assert.Equal("Ciudad de México", result.Profile.State);
        Assert.Equal("01000", result.Profile.PostalCode);
        Assert.Equal(
            [
                "/psulsa/",
                "/psulsa/",
                "/psulsa/gadmon/capitalhumano/controlincidencias/incidencias.aspx",
                "/psulsa/gadmon/capitalhumano/datos/personales.aspx",
                "/psulsa/gadmon/capitalhumano/datos/ubicacion.aspx"
            ],
            handler.RequestPaths);
    }

    [Fact]
    public async Task AdministrativeSupplementalPagesRequireAVerifiedEmployeeNumber()
    {
        SequenceHandler handler = new(
            Challenge(),
            Response(HttpStatusCode.OK),
            Response(HttpStatusCode.OK, "<html><body>Datos inesperados</body></html>"));
        NtlmCredentialValidator validator = CreateValidator(handler);

        NtlmValidationResult result = await validator.ValidateAsync(
            Administrative,
            "test-password",
            TestContext.Current.CancellationToken);

        Assert.Equal(NtlmValidationStatus.Valid, result.Status);
        Assert.Null(result.Profile);
        Assert.Equal(3, handler.RequestPaths.Count);
    }

    private static NtlmCredentialValidator CreateValidator(SequenceHandler handler)
    {
        BrokerOptions options = new()
        {
            Ntlm = new NtlmOptions
            {
                Endpoint = "https://sgu.example/",
                AuthenticationPath = "/psulsa/",
                AdministrativeProfilePath = "/psulsa/gadmon/capitalhumano/controlincidencias/incidencias.aspx",
                AdministrativePersonalProfilePath = "/psulsa/gadmon/capitalhumano/datos/personales.aspx",
                AdministrativeLocationProfilePath = "/psulsa/gadmon/capitalhumano/datos/ubicacion.aspx",
                StudentProfilePath = "/psulsa/alumnos/consultainformacionalumnos/consultainformacion.aspx",
                AllowedRedirectHosts = ["sgu.example"],
                TimeoutSeconds = 5,
                ProfileTimeoutSeconds = 5
            }
        };
        return new NtlmCredentialValidator(
            options,
            NullLogger<NtlmCredentialValidator>.Instance,
            (_, _) => handler);
    }

    private static HttpResponseMessage Challenge()
    {
        HttpResponseMessage response = Response(HttpStatusCode.Unauthorized);
        response.Headers.WwwAuthenticate.Add(new AuthenticationHeaderValue("Negotiate"));
        response.Headers.WwwAuthenticate.Add(new AuthenticationHeaderValue("NTLM"));
        return response;
    }

    private static HttpResponseMessage Redirect(string location)
    {
        HttpResponseMessage response = Response(HttpStatusCode.Found);
        response.Headers.Location = new Uri(location, UriKind.Relative);
        return response;
    }

    private static HttpResponseMessage Response(
        HttpStatusCode statusCode,
        string content = "<html></html>") =>
        new(statusCode)
        {
            Content = new StringContent(content)
        };

    private sealed class SequenceHandler(params HttpResponseMessage[] responses) : HttpMessageHandler
    {
        private readonly Queue<HttpResponseMessage> responses = new(responses);

        public List<string> RequestPaths { get; } = [];

        protected override Task<HttpResponseMessage> SendAsync(
            HttpRequestMessage request,
            CancellationToken cancellationToken)
        {
            cancellationToken.ThrowIfCancellationRequested();
            RequestPaths.Add(request.RequestUri!.AbsolutePath);
            if (responses.Count == 0)
            {
                throw new InvalidOperationException("The validator sent more requests than expected.");
            }

            HttpResponseMessage response = responses.Dequeue();
            response.RequestMessage = request;
            return Task.FromResult(response);
        }
    }
}