package main

import (
	"golang.org/x/net/context"

	"github.com/go-kit/kit/examples/addsvc/pb"
	"github.com/go-kit/kit/examples/addsvc/server"
	servergrpc "github.com/go-kit/kit/examples/addsvc/server/grpc"
	"github.com/go-kit/kit/log"
	kitot "github.com/go-kit/kit/tracing/opentracing"
	"github.com/go-kit/kit/transport/grpc"
	"github.com/opentracing/opentracing-go"
)

type grpcBinding struct {
	sum, concat grpc.Handler
}

func newGRPCBinding(ctx context.Context, tracer opentracing.Tracer, svc server.AddService, tracingLogger log.Logger) grpcBinding {
	return grpcBinding{
		sum: grpc.NewServer(
			ctx,
			kitot.TraceServer(tracer, "sum")(makeSumEndpoint(svc)),
			servergrpc.DecodeSumRequest,
			servergrpc.EncodeSumResponse,
			grpc.ServerBefore(kitot.FromGRPCRequest(tracer, "", tracingLogger)),
		),
		concat: grpc.NewServer(
			ctx,
			kitot.TraceServer(tracer, "concat")(makeConcatEndpoint(svc)),
			servergrpc.DecodeConcatRequest,
			servergrpc.EncodeConcatResponse,
			grpc.ServerBefore(kitot.FromGRPCRequest(tracer, "", tracingLogger)),
		),
	}
}

func (b grpcBinding) Sum(ctx context.Context, req *pb.SumRequest) (*pb.SumReply, error) {
	_, resp, err := b.sum.ServeGRPC(ctx, req)
	return resp.(*pb.SumReply), err
}

func (b grpcBinding) Concat(ctx context.Context, req *pb.ConcatRequest) (*pb.ConcatReply, error) {
	_, resp, err := b.concat.ServeGRPC(ctx, req)
	return resp.(*pb.ConcatReply), err
}