/*
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"

	"github.com/pkg/errors"
	"k8s.io/apimachinery/pkg/util/validation"
	"k8s.io/klog"
)

// 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
)

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, driverName string) (CachePersister, error) {
	var err error
	if err = createPersistentStorage(path.Join(sPath, "controller")); err != nil {
		klog.Errorf("failed to create persistent storage for controller: %v", err)
		return nil, err
	}

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

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

func createPersistentStorage(persistentStoragePath string) error {
	return os.MkdirAll(persistentStoragePath, os.FileMode(0755))
}

// 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
}