using Grpc.Core;
using MxGateway.Contracts.Proto;

namespace MxGateway.Client;

/// <summary>
/// gRPC implementation of IMxGatewayClientTransport.
/// </summary>
internal sealed class GrpcMxGatewayClientTransport(
    MxGatewayClientOptions options,
    MxAccessGateway.MxAccessGatewayClient rawClient) : IMxGatewayClientTransport
{
    /// <summary>
    /// Gets the gateway client options.
    /// </summary>
    public MxGatewayClientOptions Options { get; } = options;

    /// <summary>
    /// Gets the underlying gRPC client.
    /// </summary>
    public MxAccessGateway.MxAccessGatewayClient RawClient { get; } = rawClient;

    /// <inheritdoc />
    MxAccessGateway.MxAccessGatewayClient? IMxGatewayClientTransport.RawClient => RawClient;

    /// <inheritdoc />
    public async Task<OpenSessionReply> OpenSessionAsync(
        OpenSessionRequest request,
        CallOptions callOptions)
    {
        try
        {
            return await RawClient.OpenSessionAsync(request, callOptions)
                .ResponseAsync
                .ConfigureAwait(false);
        }
        catch (RpcException exception)
        {
            throw RpcExceptionMapper.Map(exception, callOptions.CancellationToken);
        }
    }

    /// <inheritdoc />
    public async Task<CloseSessionReply> CloseSessionAsync(
        CloseSessionRequest request,
        CallOptions callOptions)
    {
        try
        {
            return await RawClient.CloseSessionAsync(request, callOptions)
                .ResponseAsync
                .ConfigureAwait(false);
        }
        catch (RpcException exception)
        {
            throw RpcExceptionMapper.Map(exception, callOptions.CancellationToken);
        }
    }

    /// <inheritdoc />
    public async Task<MxCommandReply> InvokeAsync(
        MxCommandRequest request,
        CallOptions callOptions)
    {
        try
        {
            return await RawClient.InvokeAsync(request, callOptions)
                .ResponseAsync
                .ConfigureAwait(false);
        }
        catch (RpcException exception)
        {
            throw RpcExceptionMapper.Map(exception, callOptions.CancellationToken);
        }
    }

    /// <inheritdoc />
    public async IAsyncEnumerable<MxEvent> StreamEventsAsync(
        StreamEventsRequest request,
        CallOptions callOptions,
        [System.Runtime.CompilerServices.EnumeratorCancellation] CancellationToken cancellationToken = default)
    {
        CancellationToken effectiveCancellationToken = cancellationToken.CanBeCanceled
            ? cancellationToken
            : callOptions.CancellationToken;

        using AsyncServerStreamingCall<MxEvent> call = RawClient.StreamEvents(request, callOptions);

        IAsyncStreamReader<MxEvent> responseStream = call.ResponseStream;
        while (true)
        {
            MxEvent? gatewayEvent;
            try
            {
                if (!await responseStream.MoveNext(effectiveCancellationToken).ConfigureAwait(false))
                {
                    break;
                }

                gatewayEvent = responseStream.Current;
            }
            catch (RpcException exception)
            {
                throw RpcExceptionMapper.Map(exception, effectiveCancellationToken);
            }

            yield return gatewayEvent;
        }
    }

    /// <inheritdoc />
    IAsyncEnumerable<MxEvent> IMxGatewayClientTransport.StreamEventsAsync(
        StreamEventsRequest request,
        CallOptions callOptions)
    {
        return StreamEventsAsync(request, callOptions);
    }

    /// <inheritdoc />
    public async Task<AcknowledgeAlarmReply> AcknowledgeAlarmAsync(
        AcknowledgeAlarmRequest request,
        CallOptions callOptions)
    {
        try
        {
            return await RawClient.AcknowledgeAlarmAsync(request, callOptions)
                .ResponseAsync
                .ConfigureAwait(false);
        }
        catch (RpcException exception)
        {
            throw RpcExceptionMapper.Map(exception, callOptions.CancellationToken);
        }
    }

    /// <inheritdoc />
    public async IAsyncEnumerable<AlarmFeedMessage> StreamAlarmsAsync(
        StreamAlarmsRequest request,
        CallOptions callOptions,
        [System.Runtime.CompilerServices.EnumeratorCancellation] CancellationToken cancellationToken = default)
    {
        CancellationToken effectiveCancellationToken = cancellationToken.CanBeCanceled
            ? cancellationToken
            : callOptions.CancellationToken;

        using AsyncServerStreamingCall<AlarmFeedMessage> call = RawClient.StreamAlarms(request, callOptions);

        IAsyncStreamReader<AlarmFeedMessage> responseStream = call.ResponseStream;
        while (true)
        {
            AlarmFeedMessage? message;
            try
            {
                if (!await responseStream.MoveNext(effectiveCancellationToken).ConfigureAwait(false))
                {
                    break;
                }

                message = responseStream.Current;
            }
            catch (RpcException exception)
            {
                throw RpcExceptionMapper.Map(exception, effectiveCancellationToken);
            }

            yield return message;
        }
    }

    /// <inheritdoc />
    IAsyncEnumerable<AlarmFeedMessage> IMxGatewayClientTransport.StreamAlarmsAsync(
        StreamAlarmsRequest request,
        CallOptions callOptions)
    {
        return StreamAlarmsAsync(request, callOptions);
    }
}