// Copyright 2019, OpenTelemetry Authors
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

package main

import (
	"context"
	"log"
	"net"

	"go.opentelemetry.io/otel/example/grpc/api"
	"go.opentelemetry.io/otel/example/grpc/config"

	"google.golang.org/grpc"

	"go.opentelemetry.io/otel/example/grpc/middleware/tracing"
)

const (
	port = ":7777"
)

// server is used to implement api.HelloServiceServer
type server struct {
	api.UnimplementedHelloServiceServer
}

// SayHello implements api.HelloServiceServer
func (s *server) SayHello(ctx context.Context, in *api.HelloRequest) (*api.HelloResponse, error) {
	log.Printf("Received: %v", in.GetGreeting())
	return &api.HelloResponse{Reply: "Hello " + in.Greeting}, nil
}

func main() {
	config.Init()

	lis, err := net.Listen("tcp", port)
	if err != nil {
		log.Fatalf("failed to listen: %v", err)
	}

	s := grpc.NewServer(grpc.UnaryInterceptor(tracing.UnaryServerInterceptor))

	api.RegisterHelloServiceServer(s, &server{})
	if err := s.Serve(lis); err != nil {
		log.Fatalf("failed to serve: %v", err)
	}
}