package app

import (
	"bytes"
	"context"
	"encoding/json"
	"fmt"
	"os"
	"os/signal"
	"strings"
	"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")
	userName, _ := cmd.Flags().GetString("db-username")
	userPass, _ := 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")
	// setup logger
	log := logger.New(os.Stdout, logLevel)
	// log fields
	logFields := logger.LogFields{
		"db_username": userName,
		"db_password": "*****",
		"db_host":     dbHost,
		"db_port":     dbPort,
		"db_name":     dbName,
		"nats_host":   natsHost,
		"nats_port":   natsPort,
		"log_level":   logLevel,
	}
	// create storager
	storage, err := storage.New(&storage.DBConfig{
		Username: userName,
		Password: userPass,
		Host:     dbHost,
		Port:     dbPort,
		Name:     dbName,
	})
	// handler error
	if err != nil {
		log.Error("create storage failed", err, logFields)
		return
	}
	// 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
	}
	defer nc.Close()
	// create context
	ctx, cancel := context.WithCancel(context.Background())
	defer cancel()
	// NATS subscribe subject
	nc.Subscribe("barcode.new", func(msg *nats.Msg) {
		go func(log logger.LoggerAdapter) {
			if err := ProcessMessage(ctx, msg, storage, log); err != nil {
				log.Error("process message failed", err, logger.LogFields{})
				return
			}
		}(log)
	})
	// info banner
	log.Info("started falcon barcoder service", logFields)
	// wait signal to finish
	signal := WaitSignal()
	log.Info("signal received", logFields.Add(logger.LogFields{
		"signal": signal,
	}))
}

func LoadingBed(barcode string) types.LoadingBed {
	if strings.HasPrefix(barcode, "940") {
		return types.ATA12
	}
	return types.ATA345
}

func ProcessMessage(ctx context.Context, msg *nats.Msg, storage storage.Storager, log logger.LoggerAdapter) error {
	// event holder
	event := &cml04eventer.Event{}
	// create new buffer based on message data
	buff := bytes.NewBuffer(msg.Data)
	// decode message
	if err := json.NewDecoder(buff).Decode(event); err != nil {
		return err
	}
	// info banner
	log.Info("received event bus message", logger.LogFields{
		"event_id":    event.EventID,
		"event_topic": event.EventTopic,
	})
	// barcode
	bar := string(event.EventData)
	// create and fill barcode type
	barcode := &types.Barcode{
		Barcode:    bar,
		LoadingBed: LoadingBed(bar),
	}
	// store barcode
	return storage.StoreBarcode(ctx, barcode)
}

// 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
		}
	}
}