/*
Copyright 2018 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 rbd

import (
	"fmt"
	"os"
	"strings"

	"github.com/golang/glog"
	"golang.org/x/net/context"

	"github.com/container-storage-interface/spec/lib/go/csi/v0"
	"google.golang.org/grpc/codes"
	"google.golang.org/grpc/status"

	"k8s.io/kubernetes/pkg/util/mount"

	"github.com/kubernetes-csi/drivers/pkg/csi-common"
)

type nodeServer struct {
	*csicommon.DefaultNodeServer
}

func (ns *nodeServer) NodePublishVolume(ctx context.Context, req *csi.NodePublishVolumeRequest) (*csi.NodePublishVolumeResponse, error) {
	targetPath := req.GetTargetPath()

	if !strings.HasSuffix(targetPath, "/mount") {
		return nil, fmt.Errorf("rnd: malformed the value of target path: %s", targetPath)
	}
	s := strings.Split(strings.TrimSuffix(targetPath, "/mount"), "/")
	volName := s[len(s)-1]

	notMnt, err := mount.New("").IsLikelyNotMountPoint(targetPath)
	if err != nil {
		if os.IsNotExist(err) {
			if err = os.MkdirAll(targetPath, 0750); err != nil {
				return nil, status.Error(codes.Internal, err.Error())
			}
			notMnt = true
		} else {
			return nil, status.Error(codes.Internal, err.Error())
		}
	}

	if !notMnt {
		return &csi.NodePublishVolumeResponse{}, nil
	}
	volOptions, err := getRBDVolumeOptions(req.VolumeAttributes)
	if err != nil {
		return nil, err
	}
	volOptions.VolName = volName
	// Mapping RBD image
	devicePath, err := attachRBDImage(volOptions, volOptions.UserId, req.GetNodePublishSecrets())
	if err != nil {
		return nil, err
	}
	glog.V(4).Infof("rbd image: %s/%s was succesfully mapped at %s\n", req.GetVolumeId(), volOptions.Pool, devicePath)
	fsType := req.GetVolumeCapability().GetMount().GetFsType()

	readOnly := req.GetReadonly()
	attrib := req.GetVolumeAttributes()
	mountFlags := req.GetVolumeCapability().GetMount().GetMountFlags()

	glog.V(4).Infof("target %v\nfstype %v\ndevice %v\nreadonly %v\nattributes %v\n mountflags %v\n",
		targetPath, fsType, devicePath, readOnly, attrib, mountFlags)

	options := []string{}
	if readOnly {
		options = append(options, "ro")
	}

	diskMounter := &mount.SafeFormatAndMount{Interface: mount.New(""), Exec: mount.NewOsExec()}
	if err := diskMounter.FormatAndMount(devicePath, targetPath, fsType, options); err != nil {
		return nil, err
	}

	return &csi.NodePublishVolumeResponse{}, nil
}

func (ns *nodeServer) NodeUnpublishVolume(ctx context.Context, req *csi.NodeUnpublishVolumeRequest) (*csi.NodeUnpublishVolumeResponse, error) {
	targetPath := req.GetTargetPath()
	mounter := mount.New("")

	notMnt, err := mounter.IsLikelyNotMountPoint(targetPath)
	if err != nil {
		return nil, status.Error(codes.Internal, err.Error())
	}
	if notMnt {
		return nil, status.Error(codes.NotFound, "Volume not mounted")
	}

	devicePath, cnt, err := mount.GetDeviceNameFromMount(mounter, targetPath)
	if err != nil {
		return nil, status.Error(codes.Internal, err.Error())
	}

	// Unmounting the image
	err = mounter.Unmount(targetPath)
	if err != nil {
		return nil, status.Error(codes.Internal, err.Error())
	}

	cnt--
	if cnt != 0 {
		return &csi.NodeUnpublishVolumeResponse{}, nil
	}

	// Unmapping rbd device
	if err := detachRBDDevice(devicePath); err != nil {
		glog.V(3).Infof("failed to unmap rbd device: %s with error: %v", devicePath, err)
		return nil, err
	}

	return &csi.NodeUnpublishVolumeResponse{}, nil
}

func (ns *nodeServer) NodeStageVolume(
	ctx context.Context,
	req *csi.NodeStageVolumeRequest) (
	*csi.NodeStageVolumeResponse, error) {

	return nil, status.Error(codes.Unimplemented, "")
}

func (ns *nodeServer) NodeUnstageVolume(
	ctx context.Context,
	req *csi.NodeUnstageVolumeRequest) (
	*csi.NodeUnstageVolumeResponse, error) {

	return nil, status.Error(codes.Unimplemented, "")
}