weather/cmd/poller/main.go

package main

import (
	"flag"
	"go/weather/internal"
	"go/weather/internal/poller"
	"go/weather/internal/storage"
	"go/weather/internal/web"
	"go/weather/pkg/logger"
	"os"
	"os/signal"
	"strings"
	"time"

	"go.uber.org/zap"
	"go.uber.org/zap/zapcore"
)

const bucket = "weather"

func main() {
	f := flagDefinition()

	loggerLevel := zap.NewAtomicLevelAt(f.logLevel)
	defaultLogger := logger.NewLogger("poller", f.logOutput, loggerLevel)
	sLogger := defaultLogger.Sugar()
	defer defaultLogger.Sync()

	config := internal.ParseConfiguration(sLogger, f.filename)

	addr := web.NewListenAddr("api.openweathermap.org", 443)

	poller := poller.NewWeatherPoller(defaultLogger, addr, 45.75, 4.85, config.OpenweatherSecret)
	s3storage := storage.NewS3Storage(defaultLogger, config.S3Storage, bucket)

	go func() {
		for {
			data := poller.Poll()
			defer data.Close()
			s3storage.Store(data)

			defaultLogger.Sugar().Debug("Wait next poll")
			time.Sleep(f.interval)
		}
	}()

	c := make(chan os.Signal, 1)
	signal.Notify(c, os.Interrupt)

	<-c

	defaultLogger.Sugar().Info("shutting down")
	os.Exit(0)
}

//flagParameter contain all application customizable parameter
type flagParameter struct {
	interval  time.Duration
	filename  string
	logLevel  zapcore.Level
	logOutput string
}

func flagDefinition() flagParameter {
	var logLevel string
	f := flagParameter{}
	flag.DurationVar(&f.interval, "check-interval", time.Second*30, "the sleep duration between multiple call to remote weather api")
	flag.StringVar(&f.filename, "filename", "config.hcl", "configuration filename")
	flag.StringVar(&logLevel, "logLevel", "info", "Log level")
	flag.StringVar(&f.logOutput, "logOutput", "weather.log", "Output log path")
	flag.Parse()
	f.logLevel = parseLogLevel(logLevel)

	return f
}

func parseLogLevel(logLevel string) zapcore.Level {
	zapLevel := zap.InfoLevel
	switch strings.ToUpper(logLevel) {
	case "DEBUG":
		zapLevel = zapcore.DebugLevel
	case "INFO":
		zapLevel = zapcore.InfoLevel
	case "WARN":
		zapLevel = zapcore.WarnLevel
	case "ERROR":
		zapLevel = zapcore.ErrorLevel
	case "PANIC":
		zapLevel = zapcore.PanicLevel
	case "FATAL":
		zapLevel = zapcore.FatalLevel
	}
	return zapLevel
}