/*
Copyright 2018 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 rbd

import (
	csicommon "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 (
	rbdDefaultAdminID = "admin"
	rbdDefaultUserID  = rbdDefaultAdminID
)

// PluginFolder defines the location of ceph plugin
var PluginFolder = "/var/lib/kubelet/plugins/"

// 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"
	// confStore is the global config store
	confStore *util.ConfigStore
)

// 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, configRoot string, containerized bool, cachePersister util.CachePersister) {
	var err error
	klog.Infof("Driver: %v version: %v", driverName, version)

	// Initialize config store
	confStore, err = util.NewConfigStore(configRoot)
	if err != nil {
		klog.Fatalln("Failed to initialize config store.")
	}

	// 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_LIST_VOLUMES,
		csi.ControllerServiceCapability_RPC_CREATE_DELETE_SNAPSHOT,
		csi.ControllerServiceCapability_RPC_LIST_SNAPSHOTS,
		csi.ControllerServiceCapability_RPC_CLONE_VOLUME,
	})

	// We only support the multi-writer option when using block, but it's a supported capability for the plugin in general
	// In addition, we want to add the remaining modes like MULTI_NODE_READER_ONLY,
	// MULTI_NODE_SINGLE_WRITER etc, but need to do some verification of RO modes first
	// will work those as follow up features
	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()
}