using Google.Protobuf;
using ZB.MOM.WW.MxGateway.Contracts.Proto;

namespace ZB.MOM.WW.MxGateway.Client.Tests;

/// <summary>
/// Tests for the credential-scrub (CLI-40) and malformed-reply (CLI-41) contracts on the
/// credential and id-returning session helpers, driven from shared behavior fixtures.
/// </summary>
public sealed class MxGatewaySessionReplyContractTests
{
    /// <summary>
    /// CLI-40: when MXAccess echoes the submitted credential back in its failure diagnostic,
    /// the surfaced exception message must scrub it to the library redaction marker.
    /// </summary>
    [Fact]
    public async Task AuthenticateUserAsync_RedactsEchoedCredentialInFailureMessage()
    {
        const string password = "sup3rSecretVerify9f3a2b";
        FakeGatewayTransport transport = CreateTransport();
        transport.AddInvokeReply(ReadReplyFixture("authenticate-user.echoed-credential.reply.json"));
        await using MxGatewayClient client = CreateClient(transport);
        MxGatewaySession session = await client.OpenSessionAsync();

        MxAccessException exception = await Assert.ThrowsAsync<MxAccessException>(
            async () => await session.AuthenticateUserAsync(12, "operator", password));

        Assert.DoesNotContain(password, exception.Message, StringComparison.Ordinal);
        Assert.Contains("<redacted>", exception.Message, StringComparison.Ordinal);
        // ToString() is what logging frameworks emit; the secret-bearing original must not be
        // chained as an inner exception where it would re-surface the credential verbatim.
        Assert.DoesNotContain(password, exception.ToString(), StringComparison.Ordinal);
    }

    /// <summary>
    /// CLI-40: the redacted exception must not leak the echoed credential through any structured
    /// accessor either — <see cref="MxAccessException.Reply"/> (protocol message, diagnostic
    /// message, and each MXSTATUS_PROXY diagnostic text) and <see cref="MxGatewayException.Statuses"/>
    /// all carry the server-echoed credential verbatim before the fix. Both the OK+negative-HRESULT
    /// and the MXACCESS_FAILURE reply route to <see cref="MxAccessException"/>, so both must scrub.
    /// </summary>
    /// <param name="fixture">The echoed-credential reply fixture to drive.</param>
    [Theory]
    [InlineData("authenticate-user.echoed-credential.reply.json")]
    [InlineData("authenticate-user.echoed-credential-mxaccess-failure.reply.json")]
    public async Task AuthenticateUserAsync_RedactsEchoedCredentialInStructuredAccessors(string fixture)
    {
        const string password = "sup3rSecretVerify9f3a2b";
        FakeGatewayTransport transport = CreateTransport();
        transport.AddInvokeReply(ReadReplyFixture(fixture));
        await using MxGatewayClient client = CreateClient(transport);
        MxGatewaySession session = await client.OpenSessionAsync();

        MxAccessException exception = await Assert.ThrowsAsync<MxAccessException>(
            async () => await session.AuthenticateUserAsync(12, "operator", password));

        Assert.DoesNotContain(password, exception.Message, StringComparison.Ordinal);
        Assert.Contains("<redacted>", exception.Message, StringComparison.Ordinal);
        Assert.DoesNotContain(password, exception.ToString(), StringComparison.Ordinal);
        Assert.DoesNotContain(password, exception.Reply.ProtocolStatus.Message, StringComparison.Ordinal);
        Assert.DoesNotContain(password, exception.Reply.DiagnosticMessage, StringComparison.Ordinal);
        foreach (MxStatusProxy status in exception.Reply.Statuses)
        {
            Assert.DoesNotContain(password, status.DiagnosticText, StringComparison.Ordinal);
        }

        foreach (MxStatusProxy status in exception.Statuses)
        {
            Assert.DoesNotContain(password, status.DiagnosticText, StringComparison.Ordinal);
        }
    }

    /// <summary>
    /// CLI-41: an OK reply that carries neither the typed AuthenticateUser payload nor an
    /// int32 return_value is a malformed reply, surfaced as a typed exception rather than an NRE.
    /// </summary>
    [Fact]
    public async Task AuthenticateUserAsync_MissingPayloadAndReturnValue_ThrowsMalformedReply()
    {
        FakeGatewayTransport transport = CreateTransport();
        transport.AddInvokeReply(ReadReplyFixture("authenticate-user.missing-payload.reply.json"));
        await using MxGatewayClient client = CreateClient(transport);
        MxGatewaySession session = await client.OpenSessionAsync();

        await Assert.ThrowsAsync<MxGatewayMalformedReplyException>(
            async () => await session.AuthenticateUserAsync(12, "operator", "pw"));
    }

    /// <summary>
    /// CLI-41: an OK reply that omits the typed payload but carries an int32 return_value
    /// resolves to that return value.
    /// </summary>
    [Fact]
    public async Task AuthenticateUserAsync_ReturnValueOnly_ResolvesReturnValue()
    {
        FakeGatewayTransport transport = CreateTransport();
        transport.AddInvokeReply(ReadReplyFixture("authenticate-user.return-value-only.reply.json"));
        await using MxGatewayClient client = CreateClient(transport);
        MxGatewaySession session = await client.OpenSessionAsync();

        int userId = await session.AuthenticateUserAsync(12, "operator", "pw");

        Assert.Equal(7, userId);
    }

    /// <summary>
    /// CLI-41: the AddBufferedItem fallback shares the malformed-reply contract — an OK reply
    /// with neither a typed item handle nor an int32 return_value throws the typed exception.
    /// </summary>
    [Fact]
    public async Task AddBufferedItemAsync_MissingPayloadAndReturnValue_ThrowsMalformedReply()
    {
        FakeGatewayTransport transport = CreateTransport();
        transport.AddInvokeReply(new MxCommandReply
        {
            SessionId = "session-fixture",
            Kind = MxCommandKind.AddBufferedItem,
            ProtocolStatus = new ProtocolStatus { Code = ProtocolStatusCode.Ok },
        });
        await using MxGatewayClient client = CreateClient(transport);
        MxGatewaySession session = await client.OpenSessionAsync();

        await Assert.ThrowsAsync<MxGatewayMalformedReplyException>(
            async () => await session.AddBufferedItemAsync(12, "Area001.Pump001.Speed", "runtime"));
    }

    private static MxGatewayClient CreateClient(FakeGatewayTransport transport)
    {
        return new MxGatewayClient(transport.Options, transport);
    }

    private static FakeGatewayTransport CreateTransport()
    {
        return new FakeGatewayTransport(new MxGatewayClientOptions
        {
            Endpoint = new Uri("http://localhost:5000"),
            ApiKey = "test-api-key",
        });
    }

    private static MxCommandReply ReadReplyFixture(string fileName)
    {
        DirectoryInfo directory = new(AppContext.BaseDirectory);
        while (directory is not null)
        {
            string path = Path.Combine(
                directory.FullName,
                "clients",
                "proto",
                "fixtures",
                "behavior",
                "command-replies",
                fileName);

            if (File.Exists(path))
            {
                return JsonParser.Default.Parse<MxCommandReply>(File.ReadAllText(path));
            }

            directory = directory.Parent!;
        }

        throw new FileNotFoundException(fileName);
    }
}