cml04-falcon-system/sap/app/app.go

package app

import (
	"bytes"
	"context"
	"encoding/json"
	"fmt"
	"os"
	"os/signal"
	"syscall"

	cml04eventer "git.espin.casa/albert/cml04-eventer"
	"git.espin.casa/albert/cml04-falcon-system/internal/storage"
	"git.espin.casa/albert/cml04-falcon-system/internal/types"
	"git.espin.casa/albert/logger"
	"github.com/nats-io/nats.go"
	"github.com/spf13/cobra"
)

func Run(cmd *cobra.Command, args []string) {
	// read flags
	logLevel, _ := cmd.Flags().GetString("log-level")
	dbUser, _ := cmd.Flags().GetString("db-username")
	dbPass, _ := cmd.Flags().GetString("db-password")
	dbHost, _ := cmd.Flags().GetString("db-host")
	dbPort, _ := cmd.Flags().GetInt("db-port")
	dbName, _ := cmd.Flags().GetString("db-name")
	natsHost, _ := cmd.Flags().GetString("nats-host")
	natsPort, _ := cmd.Flags().GetInt("nats-port")
	nsqHost, _ := cmd.Flags().GetString("nsq-host")
	nsqPort, _ := cmd.Flags().GetInt("nsq-port")
	// setup logger
	log := logger.New(os.Stdout, logLevel)
	// log fields
	logFields := logger.LogFields{
		"nsq_host":  nsqHost,
		"nsq_port":  nsqPort,
		"nats_host": natsHost,
		"nats_port": natsPort,
		"log_level": logLevel,
	}
	// NATS connect
	nc, err := nats.Connect(fmt.Sprintf("nats://%s:%d", natsHost, natsPort))
	if err != nil {
		log.Error("create nats connection failed", err, logFields)
		return
	}
	// on close disconnects
	defer nc.Close()
	// create storager
	storage, err := storage.New(&storage.DBConfig{
		Username: dbUser,
		Password: dbPass,
		Host:     dbHost,
		Port:     dbPort,
		Name:     dbName,
	})
	// handle error
	if err != nil {
		log.Error("create storage failed", err, logFields)
		return
	}
	// create nsq subscriber
	subscriber, err := cml04eventer.NewSubscriber(&cml04eventer.SubscriberConfig{
		NSQAddress:  nsqHost,
		NSQPort:     nsqPort,
		Unmarshaler: cml04eventer.JSONMarshaler{},
		Channel:     "CML04-FALCON",
	}, log)
	// handle error
	if err != nil {
		log.Error("create nsq subscriber failed", err, logFields)
		return
	}
	// on exit close subscriber
	defer subscriber.Close()
	// create context with cancel
	ctx, cancel := context.WithCancel(context.Background())
	defer cancel()
	eventChan, err := subscriber.SubscribeEvent(ctx, "SAP-IN")
	// handle error
	if err != nil {
		log.Error("nsq subscription failed", err, logFields)
		return
	}
	go func() {
		for event := range eventChan {
			// create buffer
			buffer := bytes.NewBuffer(event.EventData)
			// get event message subject
			subject, err := event.EventMeta.Get("subject")
			if err != nil {
				log.Error("get event metada data failed", err, logFields)
			}
			switch subject {
			case "sap.in.telegramas.z_sms_10001":
				po := &types.ProductionOrder{}
				if err := json.Unmarshal(buffer.Bytes(), po); err != nil {
					log.Error("decode event message data failed", err, logFields)
					continue
				}
				// log info banner
				log.Info("received new production data from SAP event", logFields.Add(
					logger.LogFields{
						"event_id":         event.EventID,
						"production_order": po.POrderNo,
					}))
				if err := storage.StoreProductionOrder(ctx, po); err != nil {
					log.Error("store production order data failed", err, logFields)
					continue
				}
			case "sap.in.telegramas.z_sms-10002":
			default:
				continue
			}
		}
	}()
	// info banner
	log.Info("started cml04-falcon-sap service", logFields)
	// wait signal to finish
	signal := WaitSignal()
	log.Info("signal received", logFields.Add(logger.LogFields{
		"signal": signal,
	}))
}

// 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
		}
	}
}