/*
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 portworx

import (
	"github.com/golang/glog"
	osdapi "github.com/libopenstorage/openstorage/api"
	osdclient "github.com/libopenstorage/openstorage/api/client"
	volumeclient "github.com/libopenstorage/openstorage/api/client/volume"
	osdspec "github.com/libopenstorage/openstorage/api/spec"
	volumeapi "github.com/libopenstorage/openstorage/volume"
	"k8s.io/api/core/v1"
	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
	"k8s.io/kubernetes/pkg/api"
	"k8s.io/kubernetes/pkg/volume"
)

const (
	osdMgmtPort      = "9001"
	osdDriverVersion = "v1"
	pxdDriverName    = "pxd"
	pvcClaimLabel    = "pvc"
	pxServiceName    = "portworx-service"
)

type PortworxVolumeUtil struct {
	portworxClient *osdclient.Client
}

// CreateVolume creates a Portworx volume.
func (util *PortworxVolumeUtil) CreateVolume(p *portworxVolumeProvisioner) (string, int, map[string]string, error) {
	driver, err := util.getPortworxDriver(p.plugin.host)
	if err != nil || driver == nil {
		glog.Errorf("Failed to get portworx driver. Err: %v", err)
		return "", 0, nil, err
	}

	capacity := p.options.PVC.Spec.Resources.Requests[v1.ResourceName(v1.ResourceStorage)]
	// Portworx Volumes are specified in GB
	requestGB := int(volume.RoundUpSize(capacity.Value(), 1024*1024*1024))

	specHandler := osdspec.NewSpecHandler()
	spec, err := specHandler.SpecFromOpts(p.options.Parameters)
	if err != nil {
		return "", 0, nil, err
	}
	spec.Size = uint64(requestGB * 1024 * 1024 * 1024)
	source := osdapi.Source{}
	locator := osdapi.VolumeLocator{
		Name: p.options.PVName,
	}
	// Add claim Name as a part of Portworx Volume Labels
	locator.VolumeLabels = make(map[string]string)
	locator.VolumeLabels[pvcClaimLabel] = p.options.PVC.Name
	volumeID, err := driver.Create(&locator, &source, spec)
	if err != nil {
		glog.V(2).Infof("Error creating Portworx Volume : %v", err)
	}
	return volumeID, requestGB, nil, err
}

// DeleteVolume deletes a Portworx volume
func (util *PortworxVolumeUtil) DeleteVolume(d *portworxVolumeDeleter) error {
	driver, err := util.getPortworxDriver(d.plugin.host)
	if err != nil || driver == nil {
		glog.Errorf("Failed to get portworx driver. Err: %v", err)
		return err
	}

	err = driver.Delete(d.volumeID)
	if err != nil {
		glog.V(2).Infof("Error deleting Portworx Volume (%v): %v", d.volName, err)
		return err
	}
	return nil
}

// AttachVolume attaches a Portworx Volume
func (util *PortworxVolumeUtil) AttachVolume(m *portworxVolumeMounter) (string, error) {
	driver, err := util.getPortworxDriver(m.plugin.host)
	if err != nil || driver == nil {
		glog.Errorf("Failed to get portworx driver. Err: %v", err)
		return "", err
	}

	devicePath, err := driver.Attach(m.volName)
	if err != nil {
		glog.V(2).Infof("Error attaching Portworx Volume (%v): %v", m.volName, err)
		return "", err
	}
	return devicePath, nil
}

// DetachVolume detaches a Portworx Volume
func (util *PortworxVolumeUtil) DetachVolume(u *portworxVolumeUnmounter) error {
	driver, err := util.getPortworxDriver(u.plugin.host)
	if err != nil || driver == nil {
		glog.Errorf("Failed to get portworx driver. Err: %v", err)
		return err
	}

	err = driver.Detach(u.volName)
	if err != nil {
		glog.V(2).Infof("Error detaching Portworx Volume (%v): %v", u.volName, err)
		return err
	}
	return nil
}

// MountVolume mounts a Portworx Volume on the specified mountPath
func (util *PortworxVolumeUtil) MountVolume(m *portworxVolumeMounter, mountPath string) error {
	driver, err := util.getPortworxDriver(m.plugin.host)
	if err != nil || driver == nil {
		glog.Errorf("Failed to get portworx driver. Err: %v", err)
		return err
	}

	err = driver.Mount(m.volName, mountPath)
	if err != nil {
		glog.V(2).Infof("Error mounting Portworx Volume (%v) on Path (%v): %v", m.volName, mountPath, err)
		return err
	}
	return nil
}

// UnmountVolume unmounts a Portworx Volume
func (util *PortworxVolumeUtil) UnmountVolume(u *portworxVolumeUnmounter, mountPath string) error {
	driver, err := util.getPortworxDriver(u.plugin.host)
	if err != nil || driver == nil {
		glog.Errorf("Failed to get portworx driver. Err: %v", err)
		return err
	}

	err = driver.Unmount(u.volName, mountPath)
	if err != nil {
		glog.V(2).Infof("Error unmounting Portworx Volume (%v) on Path (%v): %v", u.volName, mountPath, err)
		return err
	}
	return nil
}

func isClientValid(client *osdclient.Client) (bool, error) {
	if client == nil {
		return false, nil
	}

	_, err := client.Versions(osdapi.OsdVolumePath)
	if err != nil {
		glog.Errorf("portworx client failed driver versions check. Err: %v", err)
		return false, err
	}

	return true, nil
}

func createDriverClient(hostname string) (*osdclient.Client, error) {
	client, err := volumeclient.NewDriverClient("http://"+hostname+":"+osdMgmtPort,
		pxdDriverName, osdDriverVersion)
	if err != nil {
		return nil, err
	}

	if isValid, err := isClientValid(client); isValid {
		return client, nil
	} else {
		return nil, err
	}
}

func (util *PortworxVolumeUtil) getPortworxDriver(volumeHost volume.VolumeHost) (volumeapi.VolumeDriver, error) {
	if isValid, _ := isClientValid(util.portworxClient); isValid {
		return volumeclient.VolumeDriver(util.portworxClient), nil
	}

	// create new client
	var err error
	util.portworxClient, err = createDriverClient(volumeHost.GetHostName()) // for backward compatibility
	if err != nil || util.portworxClient == nil {
		// Create client from portworx service
		kubeClient := volumeHost.GetKubeClient()
		if kubeClient == nil {
			glog.Error("Failed to get kubeclient when creating portworx client")
			return nil, nil
		}

		opts := metav1.GetOptions{}
		svc, err := kubeClient.CoreV1().Services(api.NamespaceSystem).Get(pxServiceName, opts)
		if err != nil {
			glog.Errorf("Failed to get service. Err: %v", err)
			return nil, err
		}

		if svc == nil {
			glog.Errorf("Service: %v not found. Consult Portworx docs to deploy it.", pxServiceName)
			return nil, err
		}

		util.portworxClient, err = createDriverClient(svc.Spec.ClusterIP)
		if err != nil || util.portworxClient == nil {
			glog.Errorf("Failed to connect to portworx service. Err: %v", err)
			return nil, err
		}

		glog.Infof("Using portworx service at: %v as api endpoint", svc.Spec.ClusterIP)
	} else {
		glog.Infof("Using portworx service at: %v as api endpoint", volumeHost.GetHostName())
	}

	return volumeclient.VolumeDriver(util.portworxClient), nil
}