historyposter/hp/historyposter.go

package process

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

	"github.com/k0kubun/pp"
	"github.com/mattn/go-isatty"
	"github.com/rs/zerolog"
	"github.com/rs/zerolog/log"
	"github.com/spf13/viper"
)

// CLIEntry is the main entrypoint
func CLIEntry(version, buildarch string) int {
	hp := new(HistoryPoster)
	hp.version = version
	hp.buildarch = buildarch
	hp.startup = time.Now()
	hp.newUrlChan = make(chan string)

	c := make(chan os.Signal)
	signal.Ignore(syscall.SIGPIPE)
	signal.Notify(c, os.Interrupt, syscall.SIGTERM)

	hp.configure()
	hp.setupLogging()

	hp.appCtx, hp.shutdownFunc = context.WithCancel(context.Background())
	go func() {
		// this sits and waits for an interrupt to be received
		sig := <-c
		log.Info().Msgf("signal received: %+v", sig)
		hp.shutdownFunc()
	}()
	return hp.runForever(hp.appCtx)
}

// HistoryPoster is the main app framework object
type HistoryPoster struct {
	version      string
	buildarch    string
	startup      time.Time
	appCtx       context.Context
	shutdownFunc context.CancelFunc
	newUrlChan   chan string
}

func (hp *HistoryPoster) configure() {
	viper.SetConfigName("historyposter")
	viper.SetConfigType("yaml")
	viper.AddConfigPath("/etc/historyposter")          // path to look for the config file in
	viper.AddConfigPath("$HOME/.config/historyposter") // call multiple times to add many search paths

	viper.SetEnvPrefix("HISTORYPOSTER")
	viper.AutomaticEnv()

	viper.SetDefault("Debug", false)

	if err := viper.ReadInConfig(); err != nil {
		if _, ok := err.(viper.ConfigFileNotFoundError); ok {
			// Config file not found; ignore error if desired
		} else {
			// Config file was found but another error was produced
			log.Panic().
				Err(err).
				Msg("cannot read config file")
		}
	}

	if viper.GetBool("debug") {
		pp.Print(viper.AllSettings())
	}
}

func (hp *HistoryPoster) runForever(ctx context.Context) int {

	log.Info().Msg("this is where i do stuff")

	_ = findHistoryFiles()

	<-ctx.Done()
	log.Info().Msgf("shutting down")
	return 0
}

func (hp *HistoryPoster) setupLogging() {
	log.Logger = log.With().Caller().Logger()

	tty := isatty.IsTerminal(os.Stdin.Fd()) || isatty.IsCygwinTerminal(os.Stdin.Fd())

	if tty {
		out := zerolog.NewConsoleWriter(
			func(w *zerolog.ConsoleWriter) {
				// Customize time format
				w.TimeFormat = time.RFC3339
			},
		)
		log.Logger = log.Output(out)
	}

	// always log in UTC
	zerolog.TimestampFunc = func() time.Time {
		return time.Now().UTC()
	}

	zerolog.SetGlobalLevel(zerolog.InfoLevel)
	if viper.GetBool("debug") {
		zerolog.SetGlobalLevel(zerolog.DebugLevel)
	}

	hp.identify()
}

func (hp *HistoryPoster) identify() {
	log.Info().
		Str("version", hp.version).
		Str("buildarch", hp.buildarch).
		Str("os", runtime.GOOS).
		Msg("starting")
}