/*
Copyright 2021.

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"
	"net/http"
	"net/http/pprof"
	"os"

	"github.com/ViaQ/logerr/log"
	// Import all Kubernetes client auth plugins (e.g. Azure, GCP, OIDC, etc.)
	// to ensure that exec-entrypoint and run can make use of them.
	_ "k8s.io/client-go/plugin/pkg/client/auth"

	lokiv1beta1 "github.com/ViaQ/loki-operator/api/v1beta1"
	"github.com/ViaQ/loki-operator/controllers"
	"github.com/ViaQ/loki-operator/internal/manifests"
	"github.com/ViaQ/loki-operator/internal/metrics"
	monitoringv1 "github.com/prometheus-operator/prometheus-operator/pkg/apis/monitoring/v1"
	"k8s.io/apimachinery/pkg/runtime"
	utilruntime "k8s.io/apimachinery/pkg/util/runtime"
	clientgoscheme "k8s.io/client-go/kubernetes/scheme"
	ctrl "sigs.k8s.io/controller-runtime"
	"sigs.k8s.io/controller-runtime/pkg/healthz"
	// +kubebuilder:scaffold:imports
)

var scheme = runtime.NewScheme()

func init() {
	utilruntime.Must(clientgoscheme.AddToScheme(scheme))

	utilruntime.Must(lokiv1beta1.AddToScheme(scheme))
	// +kubebuilder:scaffold:scheme
}

func main() {
	var (
		metricsAddr              string
		enableLeaderElection     bool
		probeAddr                string
		enableCertSigning        bool
		enableServiceMonitors    bool
		enableTLSServiceMonitors bool
		enableGateway            bool
	)

	flag.StringVar(&metricsAddr, "metrics-bind-address", ":8080", "The address the metric endpoint binds to.")
	flag.StringVar(&probeAddr, "health-probe-bind-address", ":8081", "The address the probe endpoint binds to.")
	flag.BoolVar(&enableLeaderElection, "leader-elect", false,
		"Enable leader election for controller manager. "+
			"Enabling this will ensure there is only one active controller manager.")
	flag.BoolVar(&enableCertSigning, "with-cert-signing-service", false,
		"Enables features in an Openshift cluster.")
	flag.BoolVar(&enableServiceMonitors, "with-service-monitors", false, "Enables service monitoring")
	flag.BoolVar(&enableTLSServiceMonitors, "with-tls-service-monitors", false,
		"Enables loading of a prometheus service monitor.")
	flag.BoolVar(&enableGateway, "with-lokistack-gateway", false,
		"Enables the manifest creation for the entire lokistack-gateway.")
	flag.Parse()

	log.Init("loki-operator")
	ctrl.SetLogger(log.GetLogger())

	if enableServiceMonitors || enableTLSServiceMonitors {
		utilruntime.Must(monitoringv1.AddToScheme(scheme))
	}

	mgr, err := ctrl.NewManager(ctrl.GetConfigOrDie(), ctrl.Options{
		Scheme:                 scheme,
		MetricsBindAddress:     metricsAddr,
		Port:                   9443,
		HealthProbeBindAddress: probeAddr,
		LeaderElection:         enableLeaderElection,
		LeaderElectionID:       "e3716011.openshift.io",
	})
	if err != nil {
		log.Error(err, "unable to start manager")
		os.Exit(1)
	}

	featureFlags := manifests.FeatureFlags{
		EnableCertificateSigningService: enableCertSigning,
		EnableServiceMonitors:           enableServiceMonitors,
		EnableTLSServiceMonitorConfig:   enableTLSServiceMonitors,
		EnableGateway:                   enableGateway,
	}

	if err = (&controllers.LokiStackReconciler{
		Client: mgr.GetClient(),
		Log:    log.WithName("controllers").WithName("LokiStack"),
		Scheme: mgr.GetScheme(),
		Flags:  featureFlags,
	}).SetupWithManager(mgr); err != nil {
		log.Error(err, "unable to create controller", "controller", "LokiStack")
		os.Exit(1)
	}
	// +kubebuilder:scaffold:builder

	if err = mgr.AddHealthzCheck("health", healthz.Ping); err != nil {
		log.Error(err, "unable to set up health check")
		os.Exit(1)
	}
	if err = mgr.AddReadyzCheck("check", healthz.Ping); err != nil {
		log.Error(err, "unable to set up ready check")
		os.Exit(1)
	}

	log.Info("registering metrics")
	metrics.RegisterMetricCollectors()

	log.Info("Registring profiling endpoints.")
	err = registerProfiler(mgr)
	if err != nil {
		log.Error(err, "failed to register extra pprof handler")
		os.Exit(1)
	}

	log.Info("starting manager")
	if err := mgr.Start(ctrl.SetupSignalHandler()); err != nil {
		log.Error(err, "problem running manager")
		os.Exit(1)
	}
}

func registerProfiler(m ctrl.Manager) error {
	endpoints := map[string]http.HandlerFunc{
		"/debug/pprof/":        pprof.Index,
		"/debug/pprof/cmdline": pprof.Cmdline,
		"/debug/pprof/profile": pprof.Profile,
		"/debug/pprof/symbol":  pprof.Symbol,
		"/debug/pprof/trace":   pprof.Trace,
	}

	for path, handler := range endpoints {
		err := m.AddMetricsExtraHandler(path, handler)
		if err != nil {
			return err
		}
	}

	return nil
}