package app

import (
	"flag"
	"net"
	"os"
	"os/signal"
	"syscall"

	"git.espin.casa/albert/cml04-printer-robot/internal/logging"
	"git.espin.casa/albert/cml04-printer-robot/internal/server"
	"git.espin.casa/albert/cml04-printer-robot/internal/service"
	"git.espin.casa/albert/cml04-printer-robot/internal/vnode"
	"git.espin.casa/albert/cml04-printer-robot/pkg/api"
	"git.espin.casa/albert/logger"

	"google.golang.org/grpc"
	"google.golang.org/grpc/reflection"
)

func Run() error {
	// flags
	apiAddr := flag.String("api", "localhost:3333", "API server address")
	logLevel := flag.String("level", "debug", "log level")
	mqttAddr := flag.String("mqtt_addr", "tcp://10.1.152.13:1883", "MQTT address")
	mqttTopic := flag.String("mqtt_topic", "vnode/ata12/robot", "MQTT topic")
	// parse flags
	flag.Parse()
	// setup logger
	log := logger.New(os.Stdout, *logLevel)
	// create log fields
	logFields := logger.LogFields{
		"app_name":         "cml04-printer-robot",
		"debug_legel":      *logLevel,
		"mqtt_address":     *mqttAddr,
		"api_bind_address": *apiAddr,
	}
	// create broker
	broker, err := vnode.NewBroker(*mqttAddr, log)
	if err != nil {
		log.Error("create new broker failed", err, logFields)
		return err
	}
	// start broker
	if err := broker.Connect(); err != nil {
		log.Error("start broker failed", err, logFields)
		return err
	}
	defer broker.Close()
	// create main service
	svc := service.NewService(broker)
	// add logging capabilities to main service
	svc = logging.NewLoggingService(svc, log)
	// create data channel
	dataChannel := make(chan []byte)
	// create error channel
	errorCallback := make(chan error)
	// create done channel
	done := make(chan struct{})
	// subscribe robot data topic
	go broker.SubscribeToMQTTTopic(*mqttTopic, dataChannel, errorCallback, done)
	// get data from channel
	go func() {
		for {
			select {
			case data := <-dataChannel:
				if err := svc.RobotEventDataHandler(data); err != nil {
					log.Error("error robot event handler", err, logFields)
				}
			case err := <-errorCallback:
				log.Error("error callback", err, logFields)
			case <-done:
				log.Info("done callback", logFields)
			}
		}
	}()
	// create grpc server
	s := grpc.NewServer()
	// create api server transport
	server := server.NewAPIServer(svc)
	// register service
	api.RegisterRobotServiceServer(s, server)
	// Reflection grpc server
	reflection.Register(s)
	// create grpc server
	lis, err := net.Listen("tcp", *apiAddr)
	if err != nil {
		log.Error("failed to listen", err, logFields)
		return err
	}
	// start service server
	go func() {
		if err := s.Serve(lis); err != nil {
			log.Error("failed to serve gRPC", err, logFields)
			return
		}
	}()
	// start banner
	log.Info("cml04 printer robot service started", logFields)
	// wait signal to finish
	signal := WaitSignal()
	// end subscriber
	close(done)
	log.Info("signal received", logger.LogFields{
		"signal": signal,
	})
	return nil
}

// WaitSignal catching exit signal
func WaitSignal() os.Signal {
	ch := make(chan os.Signal, 2)
	signal.Notify(
		ch,
		syscall.SIGINT,
		syscall.SIGQUIT,
		syscall.SIGTERM,
	)
	for {
		sig := <-ch
		switch sig {
		case syscall.SIGINT, syscall.SIGQUIT, syscall.SIGTERM:
			return sig
		}
	}
}