/*
Copyright 2024 Angelo Conforti.

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"

	ciliumv2 "github.com/cilium/cilium/pkg/k8s/apis/cilium.io/v2"
	//log "github.com/sirupsen/logrus"
	"k8s.io/apimachinery/pkg/runtime"
	utilruntime "k8s.io/apimachinery/pkg/util/runtime"
	clientgoscheme "k8s.io/client-go/kubernetes/scheme"
	_ "k8s.io/client-go/plugin/pkg/client/auth"
	ctrl "sigs.k8s.io/controller-runtime"
	"sigs.k8s.io/controller-runtime/pkg/healthz"
	"sigs.k8s.io/controller-runtime/pkg/log/zap"
	metricsserver "sigs.k8s.io/controller-runtime/pkg/metrics/server"

	ciliumv1alpha1 "github.com/angeloxx/cilium-haegress-operator/api/v2"
	"github.com/angeloxx/cilium-haegress-operator/controllers"
	//+kubebuilder:scaffold:imports
)

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

const inClusterNamespacePath = "/var/run/secrets/kubernetes.io/serviceaccount/namespace"

func init() {
	utilruntime.Must(clientgoscheme.AddToScheme(scheme))
	err := ciliumv2.AddToScheme(scheme)
	if err != nil {
		return
	}

	utilruntime.Must(ciliumv1alpha1.AddToScheme(scheme))
	//+kubebuilder:scaffold:scheme
}

func main() {
	var metricsAddr string
	var enableLeaderElection bool
	var probeAddr string
	var haegressNamespace string
	var loadBalancerClass string
	var k8sClientQPS int
	var k8sClientBurst int
	var backgroundCheckerSeconds int
	var leaderElectionNamespace string

	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(&haegressNamespace, "egress-default-namespace", "egress-system", "The namespace where the services will be created if no namespaces were specified")
	flag.StringVar(&loadBalancerClass, "load-balancer-class", "kube-vip.io/kube-vip-class", "The LoadBalancer class to use for the services")

	flag.BoolVar(&enableLeaderElection, "leader-elect", false,
		"Enable leader election for controller manager. "+
			"Enabling this will ensure there is only one active controller manager.")
	flag.IntVar(&k8sClientQPS, "k8s-client-qps", 20, "The maximum QPS to the Kubernetes API server")
	flag.IntVar(&k8sClientBurst, "k8s-client-burst", 100, "The maximum burst for throttle to the Kubernetes API server")
	flag.IntVar(&backgroundCheckerSeconds, "background-checker-seconds", 60, "The time in seconds to check all the HAEgressGatewayPolicies in the background, zero to disable it")
	flag.StringVar(&leaderElectionNamespace, "leader-election-namespace", "", "The namespace where the leader election lease will be created, if empty it will try to find the namespace from the environment")

	opts := zap.Options{
		Development: false,
	}
	opts.BindFlags(flag.CommandLine)
	flag.Parse()

	ctrl.SetLogger(zap.New(zap.UseFlagOptions(&opts)))

	ctrl.Log.V(1).Info("Test debug")

	config := ctrl.GetConfigOrDie()
	config.QPS = float32(k8sClientQPS)
	config.Burst = k8sClientBurst

	if leaderElectionNamespace == "" {
		var err error
		leaderElectionNamespace, err = getInClusterNamespace()
		if err != nil {
			setupLog.Error(err, "error checking the leader election namespace")
		}
	}

	mgr, err := ctrl.NewManager(config, ctrl.Options{
		Scheme: scheme,
		Metrics: metricsserver.Options{
			BindAddress: metricsAddr,
		},
		HealthProbeBindAddress:        probeAddr,
		LeaderElection:                enableLeaderElection,
		LeaderElectionID:              "cilium-haegress-operator.angeloxx.ch",
		LeaderElectionNamespace:       leaderElectionNamespace,
		LeaderElectionReleaseOnCancel: true,
	})
	if err != nil {
		setupLog.Error(err, "unable to start manager")
		os.Exit(1)
	}

	if err = (&controllers.HAEgressGatewayPolicyReconciler{
		Client:                   mgr.GetClient(),
		Log:                      ctrl.Log.WithName("controllers").WithName("HAEgressGatewayPolicy"),
		Scheme:                   mgr.GetScheme(),
		Recorder:                 mgr.GetEventRecorderFor("cilium-haegress-operator"),
		EgressNamespace:          haegressNamespace,
		LoadBalancerClass:        loadBalancerClass,
		BackgroundCheckerSeconds: backgroundCheckerSeconds,
	}).SetupWithManager(mgr); err != nil {
		setupLog.Error(err, "unable to create controller", "controller", "HAEgressGatewayPolicy")
		os.Exit(1)
	}
	if err = (&controllers.ServicesController{
		Client:          mgr.GetClient(),
		Log:             ctrl.Log.WithName("controllers").WithName("Services"),
		Scheme:          mgr.GetScheme(),
		Recorder:        mgr.GetEventRecorderFor("cilium-haegress-operator"),
		EgressNamespace: haegressNamespace,
	}).SetupWithManager(mgr); err != nil {
		setupLog.Error(err, "unable to create controller", "controller", "Services")
		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)
	}

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

func getInClusterNamespace() (string, error) {
	// Check whether the namespace file exists.
	// If not, we are not running in cluster so can't guess the namespace.
	_, err := os.Stat(inClusterNamespacePath)
	if os.IsNotExist(err) {
		return "", fmt.Errorf("not running in a cluster, please supply --cluster-resource-namespace: %w", err)
	} else if err != nil {
		return "", fmt.Errorf("error checking namespace file: %w", err)
	}

	// Load the namespace file and return its content
	namespace, err := os.ReadFile(inClusterNamespacePath)
	if err != nil {
		return "", fmt.Errorf("error reading namespace file: %w", err)
	}
	return string(namespace), nil
}
