package options

import (
	"fmt"
	"strings"
	"time"

	"github.com/spf13/pflag"
	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
	"k8s.io/client-go/tools/leaderelection/resourcelock"
	componentbaseconfig "k8s.io/component-base/config"

	"github.com/karmada-io/karmada/pkg/sharedcli/ratelimiterflag"
	"github.com/karmada-io/karmada/pkg/util"
)

// DefaultKarmadaClusterNamespace defines the default namespace where the member cluster secrets are stored.
const DefaultKarmadaClusterNamespace = "karmada-cluster"

// Options contains everything necessary to create and run controller-manager.
type Options struct {
	// Controllers contains all controller names.
	Controllers       []string
	LeaderElection    componentbaseconfig.LeaderElectionConfiguration
	KarmadaKubeConfig string
	// ClusterContext is the name of the cluster context in control plane KUBECONFIG file.
	// Default value is the current-context.
	KarmadaContext string
	ClusterName    string
	// ClusterNamespace holds the namespace name where the member cluster secrets are stored.
	ClusterNamespace string
	// ClusterStatusUpdateFrequency is the frequency that controller computes and report cluster status.
	// It must work with ClusterMonitorGracePeriod(--cluster-monitor-grace-period) in karmada-controller-manager.
	ClusterStatusUpdateFrequency metav1.Duration
	// ClusterLeaseDuration is a duration that candidates for a lease need to wait to force acquire it.
	// This is measure against time of last observed RenewTime.
	ClusterLeaseDuration metav1.Duration
	// ClusterLeaseRenewIntervalFraction is a fraction coordinated with ClusterLeaseDuration that
	// how long the current holder of a lease has last updated the lease.
	ClusterLeaseRenewIntervalFraction float64
	// ClusterAPIQPS is the QPS to use while talking with cluster kube-apiserver.
	ClusterAPIQPS float32
	// ClusterAPIBurst is the burst to allow while talking with cluster kube-apiserver.
	ClusterAPIBurst int
	// KubeAPIQPS is the QPS to use while talking with karmada-apiserver.
	KubeAPIQPS float32
	// KubeAPIBurst is the burst to allow while talking with karmada-apiserver.
	KubeAPIBurst int

	ClusterCacheSyncTimeout metav1.Duration
	// ResyncPeriod is the base frequency the informers are resynced.
	// Defaults to 0, which means the created informer will never do resyncs.
	ResyncPeriod metav1.Duration

	// ClusterAPIEndpoint holds the apiEndpoint of the cluster.
	ClusterAPIEndpoint string
	// ProxyServerAddress holds the proxy server address that is used to proxy to the cluster.
	ProxyServerAddress string
	// concurrentClusterSyncs is the number of cluster objects that are
	// allowed to sync concurrently.
	ConcurrentClusterSyncs int
	// ConcurrentWorkSyncs is the number of work objects that are
	// allowed to sync concurrently.
	ConcurrentWorkSyncs int

	RateLimiterOpts ratelimiterflag.Options
}

// NewOptions builds an default scheduler options.
func NewOptions() *Options {
	return &Options{
		LeaderElection: componentbaseconfig.LeaderElectionConfiguration{
			LeaderElect:       true,
			ResourceLock:      resourcelock.LeasesResourceLock,
			ResourceNamespace: util.NamespaceKarmadaSystem,
		},
	}
}

// AddFlags adds flags of scheduler to the specified FlagSet
func (o *Options) AddFlags(fs *pflag.FlagSet, allControllers []string) {
	if o == nil {
		return
	}

	fs.StringSliceVar(&o.Controllers, "controllers", []string{"*"}, fmt.Sprintf(
		"A list of controllers to enable. '*' enables all on-by-default controllers, 'foo' enables the controller named 'foo', '-foo' disables the controller named 'foo'. All controllers: %s.",
		strings.Join(allControllers, ", "),
	))
	fs.BoolVar(&o.LeaderElection.LeaderElect, "leader-elect", true, "Start a leader election client and gain leadership before executing the main loop. Enable this when running replicated components for high availability.")
	fs.StringVar(&o.LeaderElection.ResourceNamespace, "leader-elect-resource-namespace", util.NamespaceKarmadaSystem, "The namespace of resource object that is used for locking during leader election.")
	fs.StringVar(&o.KarmadaKubeConfig, "karmada-kubeconfig", o.KarmadaKubeConfig, "Path to karmada control plane kubeconfig file.")
	fs.StringVar(&o.KarmadaContext, "karmada-context", "", "Name of the cluster context in karmada control plane kubeconfig file.")
	fs.StringVar(&o.ClusterName, "cluster-name", o.ClusterName, "Name of member cluster that the agent serves for.")
	fs.StringVar(&o.ClusterNamespace, "cluster-namespace", DefaultKarmadaClusterNamespace, "Namespace in the control plane where member cluster secrets are stored.")
	fs.DurationVar(&o.ClusterStatusUpdateFrequency.Duration, "cluster-status-update-frequency", 10*time.Second, "Specifies how often karmada-agent posts cluster status to karmada-apiserver. Note: be cautious when changing the constant, it must work with ClusterMonitorGracePeriod in karmada-controller-manager.")
	fs.DurationVar(&o.ClusterLeaseDuration.Duration, "cluster-lease-duration", 40*time.Second,
		"Specifies the expiration period of a cluster lease.")
	fs.Float64Var(&o.ClusterLeaseRenewIntervalFraction, "cluster-lease-renew-interval-fraction", 0.25,
		"Specifies the cluster lease renew interval fraction.")
	fs.Float32Var(&o.ClusterAPIQPS, "cluster-api-qps", 40.0, "QPS to use while talking with cluster kube-apiserver. Doesn't cover events and node heartbeat apis which rate limiting is controlled by a different set of flags.")
	fs.IntVar(&o.ClusterAPIBurst, "cluster-api-burst", 60, "Burst to use while talking with cluster kube-apiserver. Doesn't cover events and node heartbeat apis which rate limiting is controlled by a different set of flags.")
	fs.Float32Var(&o.KubeAPIQPS, "kube-api-qps", 40.0, "QPS to use while talking with karmada-apiserver. Doesn't cover events and node heartbeat apis which rate limiting is controlled by a different set of flags.")
	fs.IntVar(&o.KubeAPIBurst, "kube-api-burst", 60, "Burst to use while talking with karmada-apiserver. Doesn't cover events and node heartbeat apis which rate limiting is controlled by a different set of flags.")
	fs.DurationVar(&o.ClusterCacheSyncTimeout.Duration, "cluster-cache-sync-timeout", util.CacheSyncTimeout, "Timeout period waiting for cluster cache to sync.")
	fs.StringVar(&o.ClusterAPIEndpoint, "cluster-api-endpoint", o.ClusterAPIEndpoint, "APIEndpoint of the cluster.")
	fs.StringVar(&o.ProxyServerAddress, "proxy-server-address", o.ProxyServerAddress, "Address of the proxy server that is used to proxy to the cluster.")
	fs.DurationVar(&o.ResyncPeriod.Duration, "resync-period", 0, "Base frequency the informers are resynced.")
	fs.IntVar(&o.ConcurrentClusterSyncs, "concurrent-cluster-syncs", 5, "The number of Clusters that are allowed to sync concurrently.")
	fs.IntVar(&o.ConcurrentWorkSyncs, "concurrent-work-syncs", 5, "The number of Works that are allowed to sync concurrently.")
	o.RateLimiterOpts.AddFlags(fs)
}