package main

import (
	"flag"
	"os"
	"syscall"

	"github.com/fsnotify/fsnotify"
	log "github.com/sirupsen/logrus"
	pluginapi "k8s.io/kubelet/pkg/apis/deviceplugin/v1beta1"
)

func main() {
	// Parse command-line arguments
	flag.CommandLine = flag.NewFlagSet(os.Args[0], flag.ExitOnError)
	flagLogLevel := flag.String("log-level", "info", "Define the logging level: error, info, debug.")
	flag.Parse()

	switch *flagLogLevel {
	case "debug":
		log.SetLevel(log.DebugLevel)
	case "info":
		log.SetLevel(log.InfoLevel)
	}

	log.Println("Starting FS watcher.")
	watcher, err := newFSWatcher(pluginapi.DevicePluginPath)
	if err != nil {
		log.Printf("Failed to created FS watcher: %s.", err)
		os.Exit(1)
	}
	defer watcher.Close()

	log.Println("Starting OS watcher.")
	sigs := newOSWatcher(syscall.SIGHUP, syscall.SIGINT, syscall.SIGTERM, syscall.SIGQUIT)

	restart := true
	var devicePlugin *FPGADevicePlugin
L:
	for {
		if restart {
			devicePlugin = NewFPGADevicePlugin()
			restart = false
		}

		select {
		case update := <-devicePlugin.updateChan:
			devicePlugin.checkDeviceUpdate(update)

		case event := <-watcher.Events:
			if event.Name == pluginapi.KubeletSocket && event.Op&fsnotify.Create == fsnotify.Create {
				log.Printf("inotify: %s created, restarting.", pluginapi.KubeletSocket)
				restart = true
			}

		case err := <-watcher.Errors:
			log.Printf("inotify: %s", err)

		case s := <-sigs:
			switch s {
			case syscall.SIGHUP:
				log.Println("Received SIGHUP, restarting.")
				restart = true
			default:
				log.Printf("Received signal \"%v\", shutting down.", s)
				break L
			}
		}
	}
}