using FinalFactory.Rendezvous.Contracts;
using FinalFactory.Rendezvous.Server.JoinAttempts;
using FinalFactory.Rendezvous.Server.State;

namespace FinalFactory.Rendezvous.Tests.JoinAttempts;

public sealed class JoinAttemptServiceTests
{
    [Fact]
    public void CreateIsIdempotentAndScopesDistinctRoleCredentials()
    {
        using JoinAttemptFixture fixture = new();
        (RegisterSessionResponse registration, _) = fixture.CreateHost();
        CreateJoinAttemptRequest request = fixture.Request(registration.ListingId, "stable-join-key");

        JoinAttemptServiceResult<CreateJoinAttemptResponse> first = fixture.Service.Create(
            fixture.ClientSubject,
            request);
        JoinAttemptServiceResult<CreateJoinAttemptResponse> replay = fixture.Service.Create(
            fixture.ClientSubject,
            request);

        Assert.True(first.Succeeded);
        Assert.True(replay.Succeeded);
        Assert.Equal(first.Value!.AttemptId, replay.Value!.AttemptId);
        Assert.Equal(first.Value.MediationHandle, replay.Value.MediationHandle);
        Assert.Equal(first.Value.ClientPunchCapability, replay.Value.ClientPunchCapability);
        Assert.True(ContractValidation.IsCapabilityValid(first.Value.ClientPunchCapability));
        Assert.InRange(
            first.Value.ClientPunchCapability.Length,
            1,
            ContractLimits.LiteNetLibNatTokenMaxCharacters);

        HostJoinAttempt host = Assert.Single(fixture.Service.BrowseForHost(
            registration.ListingId,
            ContractLimits.ContractVersion,
            registration.LeaseToken,
            10,
            null).Value!.Items);
        Assert.NotEqual(host.HostPunchCapability, first.Value.ClientPunchCapability);
        Assert.DoesNotContain(first.Value.ClientPunchCapability, fixture.Sessions.Store.ToString(), StringComparison.Ordinal);
    }

    [Fact]
    public void SameIdempotencyKeyWithDifferentRequestConflicts()
    {
        using JoinAttemptFixture fixture = new();
        (RegisterSessionResponse registration, _) = fixture.CreateHost();
        (RegisterSessionResponse other, _) = fixture.CreateHost();
        CreateJoinAttemptRequest request = fixture.Request(registration.ListingId, "reused-key");
        Assert.True(fixture.Service.Create(fixture.ClientSubject, request).Succeeded);

        request.ListingId = other.ListingId;
        JoinAttemptServiceResult<CreateJoinAttemptResponse> conflict = fixture.Service.Create(
            fixture.ClientSubject,
            request);

        Assert.Equal(RendezvousErrorCode.Conflict, conflict.Error);
    }

    [Fact]
    public void CreationRejectsStaleIncompatibleAndCrossTenantListings()
    {
        using JoinAttemptFixture fixture = new();
        (RegisterSessionResponse stale, _) = fixture.CreateHost(bindPresence: false);
        Assert.Equal(
            RendezvousErrorCode.NotFound,
            fixture.Service.Create(fixture.ClientSubject, fixture.Request(stale.ListingId)).Error);

        (RegisterSessionResponse active, _) = fixture.CreateHost();
        CreateJoinAttemptRequest incompatible = fixture.Request(active.ListingId);
        incompatible.ProtocolVersion = 8;
        Assert.Equal(
            RendezvousErrorCode.IncompatibleProtocol,
            fixture.Service.Create(fixture.ClientSubject, incompatible).Error);

        CreateJoinAttemptRequest otherTenant = fixture.Request(active.ListingId);
        otherTenant.GameId = new("other-game");
        Assert.Equal(
            RendezvousErrorCode.NotFound,
            fixture.Service.Create(fixture.ClientSubject, otherTenant).Error);
    }

    [Fact]
    public void HostPollingAuthenticatesLeaseAndUsesScopeBoundCursorPaging()
    {
        using JoinAttemptFixture fixture = new();
        (RegisterSessionResponse registration, _) = fixture.CreateHost();
        fixture.Create(registration.ListingId);
        fixture.Create(registration.ListingId);
        fixture.Create(registration.ListingId);

        JoinAttemptServiceResult<BrowseHostJoinAttemptsResponse> first = fixture.Service.BrowseForHost(
            registration.ListingId,
            ContractLimits.ContractVersion,
            registration.LeaseToken,
            1,
            null);
        Assert.True(first.Succeeded);
        Assert.Single(first.Value!.Items);
        Assert.NotNull(first.Value.NextCursor);

        JoinAttemptServiceResult<BrowseHostJoinAttemptsResponse> second = fixture.Service.BrowseForHost(
            registration.ListingId,
            ContractLimits.ContractVersion,
            registration.LeaseToken,
            1,
            first.Value.NextCursor);
        Assert.True(second.Succeeded);
        Assert.NotEqual(first.Value.Items[0].AttemptId, second.Value!.Items[0].AttemptId);

        Assert.Equal(
            RendezvousErrorCode.NotFound,
            fixture.Service.BrowseForHost(
                registration.ListingId,
                ContractLimits.ContractVersion,
                "AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA",
                1,
                null).Error);
        Assert.Equal(
            RendezvousErrorCode.InvalidRequest,
            fixture.Service.BrowseForHost(
                registration.ListingId,
                ContractLimits.ContractVersion,
                registration.LeaseToken,
                1,
                first.Value.NextCursor + "x").Error);

        (RegisterSessionResponse other, _) = fixture.CreateHost();
        Assert.Equal(
            RendezvousErrorCode.InvalidRequest,
            fixture.Service.BrowseForHost(
                other.ListingId,
                ContractLimits.ContractVersion,
                other.LeaseToken,
                1,
                first.Value.NextCursor).Error);
    }

    [Fact]
    public void CancellationRequiresTheAttemptsClientCapabilityAndRevokesState()
    {
        using JoinAttemptFixture fixture = new();
        (RegisterSessionResponse registration, _) = fixture.CreateHost();
        CreateJoinAttemptResponse created = fixture.Create(registration.ListingId);

        Assert.Equal(
            RendezvousErrorCode.NotFound,
            fixture.Service.Cancel(
                created.AttemptId,
                "AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA").Error);
        Assert.True(fixture.Service.Cancel(
            created.AttemptId,
            created.ClientPunchCapability).Succeeded);
        Assert.Empty(fixture.Service.BrowseForHost(
            registration.ListingId,
            ContractLimits.ContractVersion,
            registration.LeaseToken,
            10,
            null).Value!.Items);
    }

    [Fact]
    public void RoleAndAttemptCapabilitiesCannotCrossWireConcurrentAttempts()
    {
        using JoinAttemptFixture fixture = new();
        (RegisterSessionResponse registration, _) = fixture.CreateHost();
        CreateJoinAttemptResponse first = fixture.Create(registration.ListingId);
        CreateJoinAttemptResponse second = fixture.Create(registration.ListingId);
        StoredJoinAttempt firstStored = fixture.GetAttempt(registration, first.AttemptId);
        Assert.True(fixture.Sessions.Capabilities.TryFingerprint(
            second.ClientPunchCapability,
            out SecretFingerprint secondClientFingerprint));
        Assert.True(fixture.Sessions.Capabilities.TryFingerprint(
            first.ClientPunchCapability,
            out SecretFingerprint firstClientFingerprint));

        Assert.Equal(
            StoreResultCode.NotFound,
            fixture.Sessions.Store.BindAttemptEndpoint(new(
                firstStored.MediationHandle,
                AttemptPeerRole.Client,
                secondClientFingerprint,
                new(AddressFamilyKind.Ipv4, "198.51.100.20", 42_000),
                null)).Code);
        Assert.Equal(
            StoreResultCode.NotFound,
            fixture.Sessions.Store.BindAttemptEndpoint(new(
                firstStored.MediationHandle,
                AttemptPeerRole.Host,
                firstClientFingerprint,
                new(AddressFamilyKind.Ipv4, "203.0.113.20", 41_000),
                null)).Code);
    }

    [Fact]
    public async Task ConnectionTicketIsDistinctExpiringAndAtomicallySingleUse()
    {
        using JoinAttemptFixture fixture = new();
        (RegisterSessionResponse registration, _) = fixture.CreateHost();
        CreateJoinAttemptResponse created = fixture.Create(registration.ListingId);
        IntroductionEndpoints introduction = fixture.Introduce(registration, created);
        JoinAttemptServiceResult<ConnectionTicketGrant> issued = fixture.Service.IssueConnectionTicket(
            introduction.Attempt);
        Assert.True(issued.Succeeded);
        Assert.True(ContractValidation.IsConnectionTicketValid(issued.Value!.Ticket));
        Assert.NotEqual(created.ClientPunchCapability, issued.Value.Ticket);
        Assert.DoesNotContain(issued.Value.Ticket, issued.Value.ToString(), StringComparison.Ordinal);
        Assert.True(fixture.Sessions.Capabilities.TryFingerprint(
            issued.Value.Ticket,
            out SecretFingerprint ticketFingerprint));
        ConsumeConnectionTicketCommand command = new(created.AttemptId, ticketFingerprint);
        using ManualResetEventSlim start = new(false);

        Task<StoreResult<bool>> left = Task.Run(() =>
        {
            start.Wait();
            return fixture.Sessions.Store.ConsumeConnectionTicket(command);
        });
        Task<StoreResult<bool>> right = Task.Run(() =>
        {
            start.Wait();
            return fixture.Sessions.Store.ConsumeConnectionTicket(command);
        });
        start.Set();
        StoreResult<bool>[] results = await Task.WhenAll(left, right);

        Assert.Single(results, static result => result.Succeeded);
        Assert.Single(results, static result => result.Code == StoreResultCode.ReplayRejected);
    }

    [Fact]
    public void TicketRejectsAlteredCrossAttemptPreIntroductionAndExpiry()
    {
        EphemeralStoreOptions options = new()
        {
            ConnectionTicketLifetime = TimeSpan.FromSeconds(5),
        };
        using JoinAttemptFixture fixture = new(options);
        (RegisterSessionResponse registration, _) = fixture.CreateHost();
        CreateJoinAttemptResponse first = fixture.Create(registration.ListingId);
        CreateJoinAttemptResponse second = fixture.Create(registration.ListingId);
        StoredJoinAttempt firstStored = fixture.GetAttempt(registration, first.AttemptId);
        StoredJoinAttempt secondStored = fixture.GetAttempt(registration, second.AttemptId);

        Assert.Equal(
            StoreResultCode.Conflict,
            fixture.Sessions.Store.ConsumeConnectionTicket(new(
                first.AttemptId,
                firstStored.ConnectionTicketFingerprint)).Code);
        Assert.Equal(
            StoreResultCode.NotFound,
            fixture.Sessions.Store.ConsumeConnectionTicket(new(
                second.AttemptId,
                firstStored.ConnectionTicketFingerprint)).Code);

        fixture.Introduce(registration, first);
        fixture.Sessions.Clock.Advance(options.ConnectionTicketLifetime);
        Assert.Equal(
            StoreResultCode.Expired,
            fixture.Sessions.Store.ConsumeConnectionTicket(new(
                first.AttemptId,
                firstStored.ConnectionTicketFingerprint)).Code);
        Assert.False(secondStored.ConnectionTicketConsumed);
    }

    [Fact]
    public void TicketWindowBeginsAtIntroductionAndNeverOutlivesTheAttempt()
    {
        using JoinAttemptFixture fixture = new();
        (RegisterSessionResponse registration, _) = fixture.CreateHost();
        CreateJoinAttemptResponse created = fixture.Create(registration.ListingId);
        fixture.Sessions.Clock.Advance(TimeSpan.FromSeconds(15));

        IntroductionEndpoints introduction = fixture.Introduce(registration, created);
        ConnectionTicketGrant ticket = Assert.IsType<ConnectionTicketGrant>(
            fixture.Service.IssueConnectionTicket(introduction.Attempt).Value);

        Assert.Equal(created.ExpiresAt, ticket.ExpiresAt);
        Assert.Equal(TimeSpan.FromSeconds(15), ticket.ExpiresAt - fixture.Sessions.Clock.UtcNow);
        Assert.DoesNotContain(
            introduction.Attempt.CapabilityDerivationSalt,
            introduction.Attempt.ToString(),
            StringComparison.Ordinal);
    }
}