/*
Copyright 2020 The Kubernetes 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 nfs

import (
	"fmt"
	"os"
	"path/filepath"
	"strings"
	"sync"
	"time"

	"github.com/container-storage-interface/spec/lib/go/csi"
	"github.com/kubernetes-csi/csi-lib-utils/protosanitizer"
	"golang.org/x/net/context"
	"google.golang.org/grpc"
	"k8s.io/apimachinery/pkg/util/sets"

	"k8s.io/klog/v2"
	netutil "k8s.io/utils/net"
)

//nolint:revive
const (
	separator                       = "#"
	delete                          = "delete"
	retain                          = "retain"
	archive                         = "archive"
	volumeOperationAlreadyExistsFmt = "An operation with the given Volume ID %s already exists"
)

var supportedOnDeleteValues = []string{"", delete, retain, archive}

func validateOnDeleteValue(onDelete string) error {
	for _, v := range supportedOnDeleteValues {
		if strings.EqualFold(v, onDelete) {
			return nil
		}
	}

	return fmt.Errorf("invalid value %s for OnDelete, supported values are %v", onDelete, supportedOnDeleteValues)
}

func NewDefaultIdentityServer(d *Driver) *IdentityServer {
	return &IdentityServer{
		Driver: d,
	}
}

func NewControllerServer(d *Driver) *ControllerServer {
	return &ControllerServer{
		Driver: d,
	}
}

func NewControllerServiceCapability(cap csi.ControllerServiceCapability_RPC_Type) *csi.ControllerServiceCapability {
	return &csi.ControllerServiceCapability{
		Type: &csi.ControllerServiceCapability_Rpc{
			Rpc: &csi.ControllerServiceCapability_RPC{
				Type: cap,
			},
		},
	}
}

func NewNodeServiceCapability(cap csi.NodeServiceCapability_RPC_Type) *csi.NodeServiceCapability {
	return &csi.NodeServiceCapability{
		Type: &csi.NodeServiceCapability_Rpc{
			Rpc: &csi.NodeServiceCapability_RPC{
				Type: cap,
			},
		},
	}
}

func ParseEndpoint(ep string) (string, string, error) {
	if strings.HasPrefix(strings.ToLower(ep), "unix://") || strings.HasPrefix(strings.ToLower(ep), "tcp://") {
		s := strings.SplitN(ep, "://", 2)
		if s[1] != "" {
			return s[0], s[1], nil
		}
	}
	return "", "", fmt.Errorf("Invalid endpoint: %v", ep)
}

func getLogLevel(method string) int32 {
	if method == "/csi.v1.Identity/Probe" ||
		method == "/csi.v1.Node/NodeGetCapabilities" ||
		method == "/csi.v1.Node/NodeGetVolumeStats" {
		return 8
	}
	return 2
}

func logGRPC(ctx context.Context, req interface{}, info *grpc.UnaryServerInfo, handler grpc.UnaryHandler) (interface{}, error) {
	level := klog.Level(getLogLevel(info.FullMethod))
	klog.V(level).Infof("GRPC call: %s", info.FullMethod)
	klog.V(level).Infof("GRPC request: %s", protosanitizer.StripSecrets(req))

	resp, err := handler(ctx, req)
	if err != nil {
		klog.Errorf("GRPC error: %v", err)
	} else {
		klog.V(level).Infof("GRPC response: %s", protosanitizer.StripSecrets(resp))
	}
	return resp, err
}

type VolumeLocks struct {
	locks sets.String //nolint:staticcheck
	mux   sync.Mutex
}

func NewVolumeLocks() *VolumeLocks {
	return &VolumeLocks{
		locks: sets.NewString(),
	}
}

func (vl *VolumeLocks) TryAcquire(volumeID string) bool {
	vl.mux.Lock()
	defer vl.mux.Unlock()
	if vl.locks.Has(volumeID) {
		return false
	}
	vl.locks.Insert(volumeID)
	return true
}

func (vl *VolumeLocks) Release(volumeID string) {
	vl.mux.Lock()
	defer vl.mux.Unlock()
	vl.locks.Delete(volumeID)
}

// getMountOptions get mountOptions value from a map
func getMountOptions(context map[string]string) string {
	for k, v := range context {
		switch strings.ToLower(k) {
		case mountOptionsField:
			return v
		}
	}
	return ""
}

// chmodIfPermissionMismatch only perform chmod when permission mismatches
func chmodIfPermissionMismatch(targetPath string, mode os.FileMode) error {
	info, err := os.Lstat(targetPath)
	if err != nil {
		return err
	}
	perm := info.Mode() & os.ModePerm
	if perm != mode {
		klog.V(2).Infof("chmod targetPath(%s, mode:0%o) with permissions(0%o)", targetPath, info.Mode(), mode)
		if err := os.Chmod(targetPath, mode); err != nil {
			return err
		}
	} else {
		klog.V(2).Infof("skip chmod on targetPath(%s) since mode is already 0%o)", targetPath, info.Mode())
	}
	return nil
}

// getServerFromSource if server is IPv6, return [IPv6]
func getServerFromSource(server string) string {
	if netutil.IsIPv6String(server) {
		return fmt.Sprintf("[%s]", server)
	}
	return server
}

// setKeyValueInMap set key/value pair in map
// key in the map is case insensitive, if key already exists, overwrite existing value
func setKeyValueInMap(m map[string]string, key, value string) {
	if m == nil {
		return
	}
	for k := range m {
		if strings.EqualFold(k, key) {
			m[k] = value
			return
		}
	}
	m[key] = value
}

func waitForPathNotExistWithTimeout(path string, timeout time.Duration) error {
	// Loop until the path no longer exists or the timeout is reached
	timeoutTime := time.Now().Add(time.Duration(timeout) * time.Second)
	for {
		if _, err := os.Lstat(path); err != nil {
			if os.IsNotExist(err) {
				return nil
			}
			return err
		}

		if time.Now().After(timeoutTime) {
			return fmt.Errorf("time out waiting for path %s not exist", path)
		}
		time.Sleep(500 * time.Microsecond)
	}
}

// getRootDir returns the root directory of the given directory
func getRootDir(path string) string {
	parts := strings.Split(path, "/")
	return parts[0]
}

// removeEmptyDirs removes empty directories in the given directory dir until the parent directory parentDir
// It will remove all empty directories in the path from the given directory to the parent directory
// It will not remove the parent directory parentDir
func removeEmptyDirs(parentDir, dir string) error {
	if parentDir == "" || dir == "" {
		return nil
	}

	absParentDir, err := filepath.Abs(parentDir)
	if err != nil {
		return err
	}

	absDir, err := filepath.Abs(dir)
	if err != nil {
		return err
	}

	if !strings.HasPrefix(absDir, absParentDir) {
		return fmt.Errorf("dir %s is not a subdirectory of parentDir %s", dir, parentDir)
	}

	var depth int
	for absDir != absParentDir {
		entries, err := os.ReadDir(absDir)
		if err != nil {
			return err
		}
		if len(entries) == 0 {
			klog.V(2).Infof("Removing empty directory %s", absDir)
			if err := os.Remove(absDir); err != nil {
				return err
			}
		} else {
			klog.V(2).Infof("Directory %s is not empty", absDir)
			break
		}
		if depth++; depth > 10 {
			return fmt.Errorf("depth of directory %s is too deep", dir)
		}
		absDir = filepath.Dir(absDir)
	}

	return nil
}

// ExecFunc returns a exec function's output and error
type ExecFunc func() (err error)

// TimeoutFunc returns output and error if an ExecFunc timeout
type TimeoutFunc func() (err error)

// WaitUntilTimeout waits for the exec function to complete or return timeout error
func WaitUntilTimeout(timeout time.Duration, execFunc ExecFunc, timeoutFunc TimeoutFunc) error {
	// Create a channel to receive the result of the exec function
	done := make(chan bool)
	var err error

	// Start the exec function in a goroutine
	go func() {
		err = execFunc()
		done <- true
	}()

	// Wait for the function to complete or time out
	select {
	case <-done:
		return err
	case <-time.After(timeout):
		return timeoutFunc()
	}
}