package main

import (
	"fmt"
	"log"
	"net"
	"os"

	"golang.org/x/net/context"
	"google.golang.org/grpc"
	"google.golang.org/grpc/reflection"

	pb "./genproto"
)

const (
	default_port = "50051"
)

// server controls RPC service responses.
type server struct{}

// GetQuote produces a shipping quote (cost) in USD.
func (s *server) GetQuote(ctx context.Context, in *pb.GetQuoteRequest) (*pb.GetQuoteResponse, error) {

	// 1. Our quote system requires the total number of items to be shipped.
	count := 0
	for _, item := range in.Items {
		count += int(item.Quantity)
	}

	// 2. Generate a quote based on the total number of items to be shipped.
	quote := CreateQuoteFromCount(count)

	// 3. Generate a response.
	return &pb.GetQuoteResponse{
		CostUsd: &pb.MoneyAmount{
			Decimal:    quote.Dollars,
			Fractional: quote.Cents,
		},
	}, nil

}

// ShipOrder mocks that the requested items will be shipped.
// It supplies a tracking ID for notional lookup of shipment delivery status.
func (s *server) ShipOrder(ctx context.Context, in *pb.ShipOrderRequest) (*pb.ShipOrderResponse, error) {
	// 1. Create a Tracking ID
	baseAddress := fmt.Sprintf("%s, %s, %s", in.Address.StreetAddress_1, in.Address.StreetAddress_2, in.Address.City)
	id := CreateTrackingId(baseAddress)

	// 2. Generate a response.
	return &pb.ShipOrderResponse{
		TrackingId: id,
	}, nil
}

func main() {
	port := default_port
	if value, ok := os.LookupEnv("APP_PORT"); ok {
		port = value
	}
	port = fmt.Sprintf(":%s", port)

	lis, err := net.Listen("tcp", port)
	if err != nil {
		log.Fatalf("failed to listen: %v", err)
	}
	s := grpc.NewServer()
	pb.RegisterShippingServiceServer(s, &server{})
	log.Printf("Shipping Service listening on port %s", port)

	// Register reflection service on gRPC server.
	reflection.Register(s)
	if err := s.Serve(lis); err != nil {
		log.Fatalf("failed to serve: %v", err)
	}
}