/*
Copyright 2019 The Ceph-CSI Authors.

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 util

import (
	"os"
	"path"
	"strings"
	"time"

	"github.com/pkg/errors"
	"google.golang.org/grpc/codes"
	"google.golang.org/grpc/status"
	"k8s.io/apimachinery/pkg/util/validation"
	"k8s.io/klog"
	"k8s.io/kubernetes/pkg/util/mount"
)

// remove this once kubernetes v1.14.0 release is done
// https://github.com/kubernetes/cloud-provider/blob/master/volume/helpers/rounding.go
const (
	// MiB - MebiByte size
	MiB = 1024 * 1024
)

// RoundUpToMiB rounds up given quantity upto chunks of MiB
func RoundUpToMiB(size int64) int64 {
	requestBytes := size
	return roundUpSize(requestBytes, MiB)
}

// variables which will be set during the build time
var (
	// GitCommit tell the latest git commit image is built from
	GitCommit string
	// DriverVersion which will be driver version
	DriverVersion string
)

// Config holds the parameters list which can be configured
type Config struct {
	// common flags
	Vtype              string // driver type [rbd|cephfs|liveness]
	Endpoint           string // CSI endpoint
	DriverName         string // name of the driver
	NodeID             string // node id
	InstanceID         string // unique ID distinguishing this instance of Ceph CSI
	MetadataStorage    string // metadata persistence method [node|k8s_configmap]
	PluginPath         string // location of cephcsi plugin
	PidLimit           int    // PID limit to configure through cgroups")
	IsControllerServer bool   // if set to true start provisoner server
	IsNodeServer       bool   // if set to true start node server

	// rbd related flags
	Containerized bool // whether run as containerized

	// cephfs related flags
	VolumeMounter string // default volume mounter (possible options are 'kernel', 'fuse')
	MountCacheDir string // mount info cache save dir

	// livenes related flags
	LivenessPort int           // TCP port for liveness requests"
	LivenessPath string        // path of prometheus endpoint where metrics will be available
	PollTime     time.Duration // time interval in seconds between each poll
	PoolTimeout  time.Duration // probe timeout in seconds

}

func roundUpSize(volumeSizeBytes, allocationUnitBytes int64) int64 {
	roundedUp := volumeSizeBytes / allocationUnitBytes
	if volumeSizeBytes%allocationUnitBytes > 0 {
		roundedUp++
	}
	return roundedUp
}

// CreatePersistanceStorage creates storage path and initializes new cache
func CreatePersistanceStorage(sPath, metaDataStore, pluginPath string) (CachePersister, error) {
	var err error
	if err = CreateMountPoint(path.Join(sPath, "controller")); err != nil {
		klog.Errorf("failed to create persistent storage for controller: %v", err)
		return nil, err
	}

	if err = CreateMountPoint(path.Join(sPath, "node")); err != nil {
		klog.Errorf("failed to create persistent storage for node: %v", err)
		return nil, err
	}

	cp, err := NewCachePersister(metaDataStore, pluginPath)
	if err != nil {
		klog.Errorf("failed to define cache persistence method: %v", err)
		return nil, err
	}
	return cp, err
}

// ValidateDriverName validates the driver name
func ValidateDriverName(driverName string) error {
	if driverName == "" {
		return errors.New("driver name is empty")
	}

	if len(driverName) > 63 {
		return errors.New("driver name length should be less than 63 chars")
	}
	var err error
	for _, msg := range validation.IsDNS1123Subdomain(strings.ToLower(driverName)) {
		if err == nil {
			err = errors.New(msg)
			continue
		}
		err = errors.Wrap(err, msg)
	}
	return err
}

// GenerateVolID generates a volume ID based on passed in parameters and version, to be returned
// to the CO system
func GenerateVolID(monitors string, cr *Credentials, pool, clusterID, objUUID string, volIDVersion uint16) (string, error) {
	poolID, err := GetPoolID(monitors, cr, pool)
	if err != nil {
		return "", err
	}

	// generate the volume ID to return to the CO system
	vi := CSIIdentifier{
		LocationID:      poolID,
		EncodingVersion: volIDVersion,
		ClusterID:       clusterID,
		ObjectUUID:      objUUID,
	}

	volID, err := vi.ComposeCSIID()

	return volID, err
}

// CreateMountPoint creates the directory with given path
func CreateMountPoint(mountPath string) error {
	return os.MkdirAll(mountPath, 0750)
}

// checkDirExists checks directory  exists or not
func checkDirExists(p string) bool {
	if _, err := os.Stat(p); os.IsNotExist(err) {
		return false
	}
	return true
}

// IsMountPoint checks if the given path is mountpoint or not
func IsMountPoint(p string) (bool, error) {
	dummyMount := mount.New("")
	notMnt, err := dummyMount.IsLikelyNotMountPoint(p)
	if err != nil {
		return false, status.Error(codes.Internal, err.Error())
	}

	return !notMnt, nil
}

// Mount mounts the source to target path
func Mount(source, target, fstype string, options []string) error {
	dummyMount := mount.New("")
	return dummyMount.Mount(source, target, fstype, options)
}