package main

import (
	"log"
	"os"

	"github.com/open-telemetry/opentelemetry-collector-contrib/exporter/opencensusexporter"
	"github.com/open-telemetry/opentelemetry-collector-contrib/extension/healthcheckextension"
	"github.com/open-telemetry/opentelemetry-collector-contrib/receiver/hostmetricsreceiver"
	flag "github.com/spf13/pflag"
	"go.opentelemetry.io/collector/component"
	"go.opentelemetry.io/collector/exporter/loggingexporter"
	"go.opentelemetry.io/collector/service"
	_ "k8s.io/client-go/plugin/pkg/client/auth/gcp"
)

const (
	buildLabel         = "not_set" // Will be overwritten by the build tag.
	logProfileFlagName = "log-profile"
)

func main() {
	fs := parseFlags()
	if lp := fs.Lookup(logProfileFlagName); lp != nil && lp.Value.String() == "dev" {
		log.SetFlags(log.Llongfile)
	}

	handleErr := func(err error) {
		if err != nil {
			log.Fatalf("Failed to run the service: %v", err)
		}
	}

	extensions, err := component.MakeExtensionFactoryMap(
		healthcheckextension.NewFactory(),
	)
	handleErr(err)

	receivers, err := component.MakeReceiverFactoryMap(
		hostmetricsreceiver.NewFactory(),
	)
	handleErr(err)

	exporters, err := component.MakeExporterFactoryMap(
		// For debugging purposes only
		loggingexporter.NewFactory(),
		opencensusexporter.NewFactory(),
	)
	handleErr(err)

	processors, err := component.MakeProcessorFactoryMap()
	handleErr(err)

	factories := component.Factories{
		Extensions: extensions,
		Receivers:  receivers,
		Processors: processors,
		Exporters:  exporters,
	}

	buildInfo := component.BuildInfo{
		Command:     "otelsvc",
		Description: "SLM Metrics Agent",
	}

	cmd := service.NewCommand(service.CollectorSettings{
		Factories: factories,
		BuildInfo: buildInfo,
	})
	handleErr(err)

	err = cmd.Execute()
	handleErr(err)
}

// parseFlags adds additional flags to the flag set and parses them before OpenTelemetry service.
// This allows metrics agent to perform additional actions based on these flags
// without completely replacing flag processing.
func parseFlags() *flag.FlagSet {
	fs := flag.NewFlagSet("root", flag.ExitOnError)
	fs.String(logProfileFlagName, "", "Duplicates log-profile flag for early parsing")
	fs.ParseErrorsWhitelist.UnknownFlags = true
	fs.Parse(os.Args)
	return fs
}