PKGBUILD/pkg/daemon/daemon.go

package daemon

import (
	"context"
	"os"
	"os/signal"
	"syscall"
	"time"

	"github.com/go-flucky/flucky/pkg/config"
	"github.com/go-flucky/flucky/pkg/logfile"
	"github.com/go-flucky/flucky/pkg/logger"
	"github.com/go-flucky/flucky/pkg/rgbled"
	"github.com/go-flucky/flucky/pkg/sensor"
	"github.com/go-flucky/flucky/pkg/types"
)

// Start the daemon
func Start(cnf *config.Configuration, cleanCacheInterval time.Duration, compression bool, round float64, logger logger.Logger) {

	// Info
	logger.Info("Use clean-cache-interval: %v", cleanCacheInterval.String())
	logger.Info("Use compression: %v", compression)
	logger.Info("Round: %v", round)

	ticker := time.Tick(cleanCacheInterval)

	interrupt := make(chan os.Signal, 1)
	signal.Notify(interrupt, os.Interrupt, os.Kill, syscall.SIGTERM)

	errorChannel := make(chan error, 0)
	measuredValuesChannel := make(chan []*types.MeasuredValue, 0)

	ctx := context.Background()
	childContext, cancel := context.WithCancel(ctx)

	measuredValuesLogfile := logfile.New(cnf.Device.Logfile)

	measuredValuesCache := make([]*types.MeasuredValue, 0)

	go sensor.ReadContinuously(childContext, cnf.GetSensors(config.ENABLED), measuredValuesChannel, errorChannel)

	rgbLEDs := cnf.GetRGBLEDs(config.ENABLED)

	for {

		err := rgbled.Run(rgbLEDs)
		if err != nil {
			logger.Error("Can not turn on green info light: %v", err)
		}

		select {
		case err, _ := <-errorChannel:

			logger.Error("%v", err)

			err = rgbled.Error(rgbLEDs)
			if err != nil {
				logger.Error("Can not turn on red info light: %v", err)
			}

			time.Sleep(time.Second * 2)

		case <-ticker:
			err := rgbled.Logfile(rgbLEDs)
			if err != nil {
				logger.Error("Can not turn on blue info light: %v", err)
			}

			err = logfile.Append(measuredValuesLogfile, compression, round, measuredValuesCache)
			if err != nil {

				err = rgbled.Error(rgbLEDs)
				if err != nil {
					logger.Error("Can not turn on red info light: %v", err)
				}

				cancel()
				logger.Fatal("Can not save temperatures: %v", err)
			}
			measuredValuesCache = make([]*types.MeasuredValue, 0)

		case measuredValues, _ := <-measuredValuesChannel:
			measuredValuesCache = append(measuredValuesCache, measuredValues...)

		case killSignal := <-interrupt:
			logger.Warn("Daemon was interruped by system signal %v\n", killSignal)

			cancel()

			err := rgbled.Error(rgbLEDs)
			if err != nil {
				logger.Error("Can not turn on red info light: %v", err)
			}

			logger.Warn("Save remaining data from the cache")
			err = logfile.Append(measuredValuesLogfile, compression, round, measuredValuesCache)
			if err != nil {
				logger.Fatal("%v", err)
			}

			return
		}
	}
}