/*
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 (
	"github.com/ceph/ceph-csi/pkg/csi-common"
	"github.com/ceph/ceph-csi/pkg/util"

	"github.com/container-storage-interface/spec/lib/go/csi"
	"k8s.io/klog"
	"k8s.io/kubernetes/pkg/util/mount"
	"k8s.io/kubernetes/pkg/util/nsenter"
	"k8s.io/utils/exec"
)

// PluginFolder defines the location of rbdplugin
const (
	PluginFolder      = "/var/lib/kubelet/plugins/csi-rbdplugin"
	rbdDefaultAdminID = "admin"
	rbdDefaultUserID  = rbdDefaultAdminID
)

// Driver contains the default identity,node and controller struct
type Driver struct {
	cd *csicommon.CSIDriver

	ids *IdentityServer
	ns  *NodeServer
	cs  *ControllerServer
}

var (
	version = "1.0.0"
)

// NewDriver returns new rbd driver
func NewDriver() *Driver {
	return &Driver{}
}

// NewIdentityServer initialize a identity server for rbd CSI driver
func NewIdentityServer(d *csicommon.CSIDriver) *IdentityServer {
	return &IdentityServer{
		DefaultIdentityServer: csicommon.NewDefaultIdentityServer(d),
	}
}

// NewControllerServer initialize a controller server for rbd CSI driver
func NewControllerServer(d *csicommon.CSIDriver, cachePersister util.CachePersister) *ControllerServer {
	return &ControllerServer{
		DefaultControllerServer: csicommon.NewDefaultControllerServer(d),
		MetadataStore:           cachePersister,
	}
}

// NewNodeServer initialize a node server for rbd CSI driver.
func NewNodeServer(d *csicommon.CSIDriver, containerized bool) (*NodeServer, error) {
	mounter := mount.New("")
	if containerized {
		ne, err := nsenter.NewNsenter(nsenter.DefaultHostRootFsPath, exec.New())
		if err != nil {
			return nil, err
		}
		mounter = mount.NewNsenterMounter("", ne)
	}
	return &NodeServer{
		DefaultNodeServer: csicommon.NewDefaultNodeServer(d),
		mounter:           mounter,
	}, nil
}

// Run start a non-blocking grpc controller,node and identityserver for
// rbd CSI driver which can serve multiple parallel requests
func (r *Driver) Run(driverName, nodeID, endpoint string, containerized bool, cachePersister util.CachePersister) {
	var err error
	klog.Infof("Driver: %v version: %v", driverName, version)

	// Initialize default library driver
	r.cd = csicommon.NewCSIDriver(driverName, version, nodeID)
	if r.cd == nil {
		klog.Fatalln("Failed to initialize CSI Driver.")
	}
	r.cd.AddControllerServiceCapabilities([]csi.ControllerServiceCapability_RPC_Type{
		csi.ControllerServiceCapability_RPC_CREATE_DELETE_VOLUME,
		csi.ControllerServiceCapability_RPC_PUBLISH_UNPUBLISH_VOLUME,
		csi.ControllerServiceCapability_RPC_LIST_VOLUMES,
		csi.ControllerServiceCapability_RPC_CREATE_DELETE_SNAPSHOT,
		csi.ControllerServiceCapability_RPC_LIST_SNAPSHOTS,
		csi.ControllerServiceCapability_RPC_CLONE_VOLUME,
	})

	// TODO: JDG Should also look at remaining modes like MULT_NODE_READER (SINGLE_READER)
	r.cd.AddVolumeCapabilityAccessModes(
		[]csi.VolumeCapability_AccessMode_Mode{
			csi.VolumeCapability_AccessMode_SINGLE_NODE_WRITER,
			csi.VolumeCapability_AccessMode_MULTI_NODE_MULTI_WRITER})

	// Create GRPC servers
	r.ids = NewIdentityServer(r.cd)
	r.ns, err = NewNodeServer(r.cd, containerized)
	if err != nil {
		klog.Fatalf("failed to start node server, err %v\n", err)
	}

	r.cs = NewControllerServer(r.cd, cachePersister)

	if err = r.cs.LoadExDataFromMetadataStore(); err != nil {
		klog.Fatalf("failed to load metadata from store, err %v\n", err)
	}

	s := csicommon.NewNonBlockingGRPCServer()
	s.Start(endpoint, r.ids, r.cs, r.ns)
	s.Wait()
}