package main

import (
	"context"
	"fmt"
	"log"
	"net"
	"time"

	pb_get_currenttime "serve_hours/stubs/serve_currenttime"
	pb_serve_hours "serve_hours/stubs/serve_hours"

	"google.golang.org/grpc"
	"google.golang.org/grpc/credentials/insecure"
)

const SERVE_CURRENTTIME_HOST = "localhost"
const SERVE_CURRENTTIME_PORT = 50000
const SERVE_HOURS_HOST = "localhost"
const SERVE_HOURS_PORT = 50001
const SERVE_MINUTES_HOST = "localhost"
const SERVE_MINUTES_PORT = 50002
const SERVE_SECONDS_HOST = "localhost"
const SERVE_SECONDS_PORT = 50003
const SERVE_MILLISECONDS_HOST = "localhost"
const SERVE_MILLISECONDS_PORT = 50004

type grpc_server struct {
	pb_serve_hours.UnimplementedServeHoursServer
}

type currentTimeResponse struct {
	hours          uint32
	minutes        uint32
	seconds        uint32
	milliseconds   uint32
	formatted_time string
}

func GetCurrentTime(timezone string) currentTimeResponse {
	conn, err := grpc.Dial(
		fmt.Sprintf("%s:%d", SERVE_CURRENTTIME_HOST, SERVE_CURRENTTIME_PORT),
		grpc.WithTransportCredentials(insecure.NewCredentials()),
	)
	if err != nil {
		log.Fatalf("did not connect: %v", err)
	}
	defer conn.Close()
	c := pb_get_currenttime.NewServeCurrentTimeServiceClient(conn)

	// Contact the server and print out its response.
	ctx, cancel := context.WithTimeout(context.Background(), time.Second)
	defer cancel()
	r, err := c.GetCurrentTime(
		ctx,
		&pb_get_currenttime.GetCurrentTimeRequest{Timezone: timezone},
	)
	if err != nil {
		log.Fatalf("could not greet: %v", err)
	}

	result := currentTimeResponse{
		hours:          r.Hours,
		minutes:        r.Minutes,
		seconds:        r.Seconds,
		milliseconds:   r.Milliseconds,
		formatted_time: r.FormattedTime,
	}
	return result
}

func (s *grpc_server) GetHours(ctx context.Context, in *pb_serve_hours.GetHoursRequest) (*pb_serve_hours.GetHoursResponse, error) {
	timezone := in.GetTimezone()
	current_time := GetCurrentTime(timezone)
	return &pb_serve_hours.GetHoursResponse{Hours: current_time.hours}, nil
}

func serve() {
	lis, err := net.Listen("tcp", fmt.Sprintf("%s:%d", SERVE_HOURS_HOST, SERVE_HOURS_PORT))
	if err != nil {
		log.Fatalf("failed to listen: %v", err)
	}

	server := grpc.NewServer()
	pb_serve_hours.RegisterServeHoursServer(server, &grpc_server{})
	log.Printf("server listening at %v", lis.Addr())
	if err := server.Serve(lis); err != nil {
		log.Fatalf("failed to serve: %v", err)
	}
}

func main() {
	serve()
}