/*
Copyright 2017 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"
	"strings"

	"github.com/golang/glog"

	"github.com/container-storage-interface/spec/lib/go/csi"
	"golang.org/x/net/context"
	"google.golang.org/grpc/codes"
	"google.golang.org/grpc/status"
	"k8s.io/kubernetes/pkg/volume"
	"k8s.io/utils/mount"
)

type nodeServer struct {
	Driver  *nfsDriver
	mounter mount.Interface
}

func (ns *nodeServer) NodePublishVolume(ctx context.Context, req *csi.NodePublishVolumeRequest) (*csi.NodePublishVolumeResponse, error) {
	if req.GetVolumeCapability() == nil {
		return nil, status.Error(codes.InvalidArgument, "Volume capability missing in request")
	}
	if len(req.GetVolumeId()) == 0 {
		return nil, status.Error(codes.InvalidArgument, "Volume ID missing in request")
	}

	targetPath := req.GetTargetPath()
	if len(targetPath) == 0 {
		return nil, status.Error(codes.InvalidArgument, "Target path not provided")
	}

	notMnt, err := ns.mounter.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
	}

	mo := req.GetVolumeCapability().GetMount().GetMountFlags()
	if req.GetReadonly() {
		mo = append(mo, "ro")
	}

	s := req.GetVolumeContext()[paramServer]
	ep := req.GetVolumeContext()[paramShare]
	source := fmt.Sprintf("%s:%s", s, ep)

	err = ns.mounter.Mount(source, targetPath, "nfs", mo)
	if err != nil {
		if os.IsPermission(err) {
			return nil, status.Error(codes.PermissionDenied, err.Error())
		}
		if strings.Contains(err.Error(), "invalid argument") {
			return nil, status.Error(codes.InvalidArgument, err.Error())
		}
		return nil, status.Error(codes.Internal, err.Error())
	}

	if ns.Driver.perm != nil {
		if err := os.Chmod(targetPath, os.FileMode(*ns.Driver.perm)); err != nil {
			return nil, status.Error(codes.Internal, err.Error())
		}
	}

	return &csi.NodePublishVolumeResponse{}, nil
}

func (ns *nodeServer) NodeUnpublishVolume(ctx context.Context, req *csi.NodeUnpublishVolumeRequest) (*csi.NodeUnpublishVolumeResponse, error) {
	if len(req.GetVolumeId()) == 0 {
		return nil, status.Error(codes.InvalidArgument, "Volume ID missing in request")
	}
	if len(req.GetTargetPath()) == 0 {
		return nil, status.Error(codes.InvalidArgument, "Target path missing in request")
	}
	targetPath := req.GetTargetPath()
	notMnt, err := ns.mounter.IsLikelyNotMountPoint(targetPath)

	if err != nil {
		if os.IsNotExist(err) {
			return nil, status.Error(codes.NotFound, "Targetpath not found")
		} else {
			return nil, status.Error(codes.Internal, err.Error())
		}
	}
	if notMnt {
		return nil, status.Error(codes.NotFound, "Volume not mounted")
	}

	err = mount.CleanupMountPoint(req.GetTargetPath(), ns.mounter, false)
	if err != nil {
		return nil, status.Error(codes.Internal, err.Error())
	}

	return &csi.NodeUnpublishVolumeResponse{}, nil
}

func (ns *nodeServer) NodeGetInfo(ctx context.Context, req *csi.NodeGetInfoRequest) (*csi.NodeGetInfoResponse, error) {
	glog.V(5).Infof("Using default NodeGetInfo")

	return &csi.NodeGetInfoResponse{
		NodeId: ns.Driver.nodeID,
	}, nil
}

func (ns *nodeServer) NodeGetCapabilities(ctx context.Context, req *csi.NodeGetCapabilitiesRequest) (*csi.NodeGetCapabilitiesResponse, error) {
	glog.V(5).Infof("Using default NodeGetCapabilities")

	return &csi.NodeGetCapabilitiesResponse{
		Capabilities: []*csi.NodeServiceCapability{
			{
				Type: &csi.NodeServiceCapability_Rpc{
					Rpc: &csi.NodeServiceCapability_RPC{
						Type: csi.NodeServiceCapability_RPC_UNKNOWN,
					},
				},
			},
		},
	}, nil
}

func (ns *nodeServer) NodeGetVolumeStats(ctx context.Context, in *csi.NodeGetVolumeStatsRequest) (*csi.NodeGetVolumeStatsResponse, error) {
	return nil, status.Error(codes.Unimplemented, "")
}

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

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

func (ns *nodeServer) NodeExpandVolume(ctx context.Context, req *csi.NodeExpandVolumeRequest) (*csi.NodeExpandVolumeResponse, error) {
	return nil, status.Error(codes.Unimplemented, "")
}

func getVolumeMetrics(volumePath string) (*volume.Metrics, error) {
	return volume.NewMetricsStatFS(volumePath).GetMetrics()
}