/*
Copyright 2023 The Kubernetes Authors.

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

    http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/

package main

import (
	"flag"
	"fmt"
	"os"
	"time"

	"k8s.io/klog/v2"

	nfdgarbagecollector "sigs.k8s.io/node-feature-discovery/pkg/nfd-gc"
	"sigs.k8s.io/node-feature-discovery/pkg/version"
)

const (
	// ProgramName is the canonical name of this program
	ProgramName = "nfd-gc"
)

func main() {
	flags := flag.NewFlagSet(ProgramName, flag.ExitOnError)

	printVersion := flags.Bool("version", false, "Print version and exit.")

	args := parseArgs(flags, os.Args[1:]...)

	if *printVersion {
		fmt.Println(ProgramName, version.Get())
		os.Exit(0)
	}

	// Assert that the version is known
	if version.Undefined() {
		klog.InfoS("version not set! Set -ldflags \"-X sigs.k8s.io/node-feature-discovery/pkg/version.version=`git describe --tags --dirty --always --match 'v*'`\" during build or run.")
	}

	// Get new garbage collector instance
	gc, err := nfdgarbagecollector.New(args)
	if err != nil {
		klog.ErrorS(err, "failed to initialize nfd garbage collector instance")
		os.Exit(1)
	}

	if err = gc.Run(); err != nil {
		klog.ErrorS(err, "error while running")
		os.Exit(1)
	}
}

func parseArgs(flags *flag.FlagSet, osArgs ...string) *nfdgarbagecollector.Args {
	args := initFlags(flags)

	_ = flags.Parse(osArgs)
	if len(flags.Args()) > 0 {
		fmt.Fprintf(flags.Output(), "unknown command line argument: %s\n", flags.Args()[0])
		flags.Usage()
		os.Exit(2)
	}

	return args
}

func initFlags(flagset *flag.FlagSet) *nfdgarbagecollector.Args {
	args := &nfdgarbagecollector.Args{}

	flagset.DurationVar(&args.GCPeriod, "gc-interval", time.Duration(1)*time.Hour,
		"interval between cleanup of obsolete api objects")
	flagset.StringVar(&args.Kubeconfig, "kubeconfig", "",
		"Kubeconfig to use")
	flagset.IntVar(&args.MetricsPort, "metrics", 8081,
		"Port on which to expose metrics.")

	klog.InitFlags(flagset)

	return args
}