package main

import (
	"context"
	"flag"
	"net/http"
	"net/http/pprof"
	"os"

	cmapi "github.com/cert-manager/cert-manager/pkg/apis/certmanager/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"
	"sigs.k8s.io/controller-runtime/pkg/log/zap"
	"sigs.k8s.io/controller-runtime/pkg/metrics/server"

	"github.com/tidbcloud/alicloud-pca-issuer/pkg/api/v1alpha1"
	"github.com/tidbcloud/alicloud-pca-issuer/pkg/controllers"
)

var (
	scheme   = runtime.NewScheme()
	setupLog = ctrl.Log.WithName("setup")
)

func init() {
	utilruntime.Must(clientgoscheme.AddToScheme(scheme))
	utilruntime.Must(v1alpha1.AddToScheme(scheme))
	utilruntime.Must(cmapi.AddToScheme(scheme))
}

func main() {
	var (
		metricsAddr              string
		probeAddr                string
		clusterResourceNamespace string
		enablePprof              bool
		pprofAddr                string
		zapDevel                 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.StringVar(&clusterResourceNamespace, "cluster-resource-namespace", "", "The namespace for secrets in which cluster-scoped resources are found.")
	flag.BoolVar(&enablePprof, "enable-pprof", false, "Enable pprof for debugging")
	flag.StringVar(&pprofAddr, "pprof-address", ":6060", "The address the pprof endpoint binds to.")
	flag.BoolVar(&zapDevel, "zap-devel", false, "Development Mode defaults(encoder=consoleEncoder,logLevel=Debug,stackTraceLevel=Warn). "+
		"Production Mode defaults(encoder=jsonEncoder,logLevel=Info,stackTraceLevel=Error)")

	flag.Parse()

	opts := zap.Options{
		Development: zapDevel,
	}
	ctrl.SetLogger(zap.New(zap.UseFlagOptions(&opts)))

	// Set default cluster resource namespace
	if clusterResourceNamespace == "" {
		clusterResourceNamespace = "kube-system"
	}

	mgr, err := ctrl.NewManager(ctrl.GetConfigOrDie(), ctrl.Options{
		Scheme: scheme,
		Metrics: server.Options{
			BindAddress: metricsAddr,
		},
		HealthProbeBindAddress: probeAddr,
		LeaderElection:         true,
		LeaderElectionID:       "alicloud-pca-issuer-controller-leader-election",
		// LeaderElectionReleaseOnCancel defines if the leader should step down voluntarily
		// when the Manager ends. This requires the binary to immediately end when the
		// Manager is stopped, otherwise, this setting is unsafe. Setting this significantly
		// speeds up voluntary leader transitions as the new leader don't have to wait
		// LeaseDuration time first.
		//
		// In the default scaffold provided, the program ends immediately after
		// the manager stops, so would be fine to enable this option. However,
		// if you are doing or is intended to do any operation such as perform cleanups
		// after the manager stops then its usage might be unsafe.
		// LeaderElectionReleaseOnCancel: true,
	})
	if err != nil {
		setupLog.Error(err, "unable to start manager")
		os.Exit(1)
	}

	controller := &controllers.Issuer{
		ClusterResourceNamespace: clusterResourceNamespace,
		Log:                      ctrl.Log.WithName("controllers").WithName("AliCloudPCAIssuer"),
	}

	if err = controller.SetupWithManager(context.Background(), mgr); err != nil {
		setupLog.Error(err, "unable to create controller", "controller", "AliCloudPCAIssuer")
		os.Exit(1)
	}

	// Setup the auto-approver controller
	approver := &controllers.CertificateRequestApprover{
		Client: mgr.GetClient(),
		Log:    ctrl.Log.WithName("controllers").WithName("CertificateRequestApprover"),
		Scheme: mgr.GetScheme(),
	}

	if err = approver.SetupWithManager(mgr); err != nil {
		setupLog.Error(err, "unable to create controller", "controller", "CertificateRequestApprover")
		os.Exit(1)
	}

	//+kubebuilder:scaffold:builder

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

	// Start pprof server if enabled
	if enablePprof {
		setupLog.Info("starting pprof server", "address", pprofAddr)
		go func() {
			mux := http.NewServeMux()
			mux.HandleFunc("/debug/pprof/", pprof.Index)
			mux.HandleFunc("/debug/pprof/cmdline", pprof.Cmdline)
			mux.HandleFunc("/debug/pprof/profile", pprof.Profile)
			mux.HandleFunc("/debug/pprof/symbol", pprof.Symbol)
			mux.HandleFunc("/debug/pprof/trace", pprof.Trace)

			server := &http.Server{
				Addr:    pprofAddr,
				Handler: mux,
			}

			if err := server.ListenAndServe(); err != nil && err != http.ErrServerClosed {
				setupLog.Error(err, "pprof server failed")
			}
		}()
	}

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