using Novell.Directory.Ldap;
using ZB.MOM.WW.Auth.Abstractions.Ldap;

namespace ZB.MOM.WW.Auth.Ldap.Tests;

/// <summary>
/// <see cref="LdapBindMode.User"/>: bind as the signing-in user, then read their own entry on the
/// same connection. The service account in <see cref="Opts"/> is deliberately populated so the
/// tests prove it is never used.
/// </summary>
public class LdapAuthServiceUserBindTests
{
    private static LdapOptions Opts(params string[] fallbacks) => new()
    {
        Enabled = true,
        Server = "dc1",
        Port = 636,
        Transport = LdapTransport.Ldaps,
        SearchBase = "dc=x",
        UserNameAttribute = "sAMAccountName",
        DisplayNameAttribute = "displayName",
        GroupAttribute = "memberOf",
        BindMode = LdapBindMode.User,
        UserBindTemplate = "{0}@corp.test",
        ServiceAccountDn = "cn=svc,dc=x",
        ServiceAccountPassword = "svcpw",
        FallbackServers = fallbacks,
    };

    private static FakeLdapConnection Jane() => new FakeLdapConnection()
        .WithUserEntry("CN=Jane Doe,OU=u,DC=x", new[] { "CN=UG_A,OU=g,DC=x", "CN=UG_B,OU=g,DC=x" }, "Jane Doe");

    private static Task<LdapAuthResult> Login(LdapAuthService svc, string user, string pw = "pw") =>
        svc.AuthenticateAsync(user, pw, CancellationToken.None);

    [Fact]
    public async Task Success_BindsAsUser_ThenSearchesOnTheSameConnection()
    {
        var factory = new SequenceLdapConnectionFactory(Jane());
        var result = await Login(new LdapAuthService(Opts(), factory), "jdoe");

        Assert.True(result.Succeeded);
        Assert.Equal("jdoe", result.Username);
        Assert.Equal("Jane Doe", result.DisplayName);
        Assert.Equal(new[] { "UG_A", "UG_B" }, result.Groups);
        var conn = Assert.Single(factory.Created);
        Assert.Equal(new[] { "connect", "bind:jdoe@corp.test", "search:(sAMAccountName=jdoe)" }, conn.Calls);
        Assert.Equal(new[] { "jdoe@corp.test" }, conn.BoundDns);
    }

    [Theory]
    [InlineData(@"NAM\jdoe")]
    [InlineData("jdoe@corp.test")]
    [InlineData("  jdoe ")]
    public async Task QualifiedNames_BindAsTheTemplate_AndReturnTheBareName(string typed)
    {
        var factory = new SequenceLdapConnectionFactory(Jane());
        var result = await Login(new LdapAuthService(Opts(), factory), typed);

        Assert.True(result.Succeeded);
        Assert.Equal("jdoe", result.Username);
        Assert.Equal(new[] { "jdoe@corp.test" }, factory.Created[0].BoundDns);
    }

    [Fact]
    public async Task EmptyPassword_IsRefused_WithoutContactingTheDirectory()
    {
        var factory = new SequenceLdapConnectionFactory(Jane());
        var result = await Login(new LdapAuthService(Opts(), factory), "jdoe", "");

        Assert.Equal(LdapAuthFailure.BadCredentials, result.Failure);
        Assert.Empty(factory.Created);
    }

    [Theory]
    [InlineData("@x")]
    [InlineData(@"a\b\c")]
    [InlineData("a@b@c")]
    public async Task UnusableNames_AreRefused_WithoutContactingTheDirectory(string typed)
    {
        var factory = new SequenceLdapConnectionFactory(Jane());
        var result = await Login(new LdapAuthService(Opts(), factory), typed);

        Assert.Equal(LdapAuthFailure.BadCredentials, result.Failure);
        Assert.Empty(factory.Created);
    }

    [Fact]
    public async Task StrictMode_RefusesQualifiedNames_WithoutContactingTheDirectory()
    {
        var factory = new SequenceLdapConnectionFactory(Jane());
        var svc = new LdapAuthService(Opts() with { AcceptDomainQualifiedNames = false }, factory);

        var result = await Login(svc, @"NAM\jdoe");

        Assert.Equal(LdapAuthFailure.BadCredentials, result.Failure);
        Assert.Empty(factory.Created);
    }

    [Fact]
    public async Task WrongPassword_IsFinal_AndNeverAsksTheFallback()
    {
        var factory = new SequenceLdapConnectionFactory(
            Jane().ThrowOnFirstBind(LdapException.InvalidCredentials), Jane());
        var result = await Login(new LdapAuthService(Opts("dc2"), factory), "jdoe", "wrong");

        Assert.Equal(LdapAuthFailure.BadCredentials, result.Failure);
        Assert.Single(factory.Created);
    }

    [Fact]
    public async Task NonCredentialBindError_FailsOver()
    {
        var factory = new SequenceLdapConnectionFactory(
            Jane().ThrowOnFirstBind(LdapException.Unavailable), Jane());
        var result = await Login(new LdapAuthService(Opts("dc2"), factory), "jdoe");

        Assert.True(result.Succeeded);
        Assert.Equal(2, factory.Created.Count);
        Assert.Equal("dc2", factory.Created[1].ConnectArgs!.Value.Host);
    }

    [Fact]
    public async Task ConnectFailure_FailsOver()
    {
        var factory = new SequenceLdapConnectionFactory(new FakeLdapConnection().ThrowOnConnect(), Jane());
        var result = await Login(new LdapAuthService(Opts("dc2"), factory), "jdoe");

        Assert.True(result.Succeeded);
        Assert.Equal(2, factory.Created.Count);
    }

    [Fact]
    public async Task SearchFailure_FailsOver()
    {
        var factory = new SequenceLdapConnectionFactory(Jane().ThrowOnSearch(), Jane());
        var result = await Login(new LdapAuthService(Opts("dc2"), factory), "jdoe");

        Assert.True(result.Succeeded);
        Assert.Equal(2, factory.Created.Count);
    }

    [Fact]
    public async Task EveryEndpointDown_IsSystemSide()
    {
        var factory = new SequenceLdapConnectionFactory(
            new FakeLdapConnection().ThrowOnConnect(), new FakeLdapConnection().ThrowOnConnect());
        var result = await Login(new LdapAuthService(Opts("dc2"), factory), "jdoe");

        Assert.Equal(LdapAuthFailure.ServiceAccountBindFailed, result.Failure);
    }

    [Fact]
    public async Task NoEntryAfterAGoodBind_IsGroupLookupFailed()
    {
        var factory = new SequenceLdapConnectionFactory(new FakeLdapConnection().WithNoMatch());
        var result = await Login(new LdapAuthService(Opts("dc2"), factory), "jdoe");

        Assert.Equal(LdapAuthFailure.GroupLookupFailed, result.Failure);
        Assert.Single(factory.Created);
    }

    [Fact]
    public async Task TwoEntriesAfterAGoodBind_IsGroupLookupFailed()
    {
        var factory = new SequenceLdapConnectionFactory(new FakeLdapConnection().WithDuplicateMatch());
        var result = await Login(new LdapAuthService(Opts(), factory), "jdoe");

        Assert.Equal(LdapAuthFailure.GroupLookupFailed, result.Failure);
    }

    [Fact]
    public async Task NoGroups_IsGroupLookupFailed()
    {
        var factory = new SequenceLdapConnectionFactory(
            new FakeLdapConnection().WithUserEntry("CN=Jane,DC=x", Array.Empty<string>(), "Jane"));
        var result = await Login(new LdapAuthService(Opts(), factory), "jdoe");

        Assert.Equal(LdapAuthFailure.GroupLookupFailed, result.Failure);
    }

    [Fact]
    public async Task Username_IsCanonicalisedFromTheEntry_NotTheTypedCase()
    {
        var factory = new SequenceLdapConnectionFactory(new FakeLdapConnection().WithUserEntry(
            "CN=Jane Doe,OU=u,DC=x", new[] { "CN=UG_A,OU=g,DC=x" }, "Jane Doe",
            new Dictionary<string, string[]> { ["sAMAccountName"] = new[] { "jdoe" } }));
        var result = await Login(new LdapAuthService(Opts(), factory), @"NAM\JDOE");

        Assert.True(result.Succeeded);
        Assert.Equal("jdoe", result.Username);
    }

    [Fact]
    public async Task Username_FallsBackToTheTypedName_WhenTheEntryLacksTheAttribute()
    {
        var factory = new SequenceLdapConnectionFactory(Jane());
        var result = await Login(new LdapAuthService(Opts(), factory), "JDOE");

        Assert.True(result.Succeeded);
        Assert.Equal("JDOE", result.Username);
    }

    [Fact]
    public async Task Search_RequestsTheUserNameAttribute()
    {
        var factory = new SequenceLdapConnectionFactory(Jane());
        await Login(new LdapAuthService(Opts(), factory), "jdoe");

        Assert.Equal(new[] { "displayName", "memberOf", "sAMAccountName" }, factory.Created[0].SearchAttributes);
    }

    [Fact]
    public async Task Search_DeDuplicatesTheUserNameAttribute_CaseInsensitively()
    {
        var factory = new SequenceLdapConnectionFactory(Jane());
        var svc = new LdapAuthService(Opts() with { DisplayNameAttribute = "SAMACCOUNTNAME" }, factory);
        await Login(svc, "jdoe");

        Assert.Equal(new[] { "SAMACCOUNTNAME", "memberOf" }, factory.Created[0].SearchAttributes);
    }
}