/*
Copyright (c) 2015 VMware, Inc. All Rights Reserved.

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 object

import (
	"errors"
	"fmt"
	"net"

	"github.com/vmware/govmomi/property"
	"github.com/vmware/govmomi/vim25"
	"github.com/vmware/govmomi/vim25/methods"
	"github.com/vmware/govmomi/vim25/mo"
	"github.com/vmware/govmomi/vim25/types"
	"golang.org/x/net/context"
)

const (
	PropRuntimePowerState = "summary.runtime.powerState"
)

type VirtualMachine struct {
	Common

	InventoryPath string
}

func (v VirtualMachine) String() string {
	if v.InventoryPath == "" {
		return v.Common.String()
	}
	return fmt.Sprintf("%v @ %v", v.Common, v.InventoryPath)
}

func NewVirtualMachine(c *vim25.Client, ref types.ManagedObjectReference) *VirtualMachine {
	return &VirtualMachine{
		Common: NewCommon(c, ref),
	}
}

func (v VirtualMachine) Name(ctx context.Context) (string, error) {
	var o mo.VirtualMachine

	err := v.Properties(ctx, v.Reference(), []string{"name"}, &o)
	if err != nil {
		return "", err
	}

	return o.Name, nil
}

func (v VirtualMachine) PowerState(ctx context.Context) (types.VirtualMachinePowerState, error) {
	var o mo.VirtualMachine

	err := v.Properties(ctx, v.Reference(), []string{PropRuntimePowerState}, &o)
	if err != nil {
		return "", err
	}

	return o.Summary.Runtime.PowerState, nil
}

func (v VirtualMachine) PowerOn(ctx context.Context) (*Task, error) {
	req := types.PowerOnVM_Task{
		This: v.Reference(),
	}

	res, err := methods.PowerOnVM_Task(ctx, v.c, &req)
	if err != nil {
		return nil, err
	}

	return NewTask(v.c, res.Returnval), nil
}

func (v VirtualMachine) PowerOff(ctx context.Context) (*Task, error) {
	req := types.PowerOffVM_Task{
		This: v.Reference(),
	}

	res, err := methods.PowerOffVM_Task(ctx, v.c, &req)
	if err != nil {
		return nil, err
	}

	return NewTask(v.c, res.Returnval), nil
}

func (v VirtualMachine) Reset(ctx context.Context) (*Task, error) {
	req := types.ResetVM_Task{
		This: v.Reference(),
	}

	res, err := methods.ResetVM_Task(ctx, v.c, &req)
	if err != nil {
		return nil, err
	}

	return NewTask(v.c, res.Returnval), nil
}

func (v VirtualMachine) Suspend(ctx context.Context) (*Task, error) {
	req := types.SuspendVM_Task{
		This: v.Reference(),
	}

	res, err := methods.SuspendVM_Task(ctx, v.c, &req)
	if err != nil {
		return nil, err
	}

	return NewTask(v.c, res.Returnval), nil
}

func (v VirtualMachine) ShutdownGuest(ctx context.Context) error {
	req := types.ShutdownGuest{
		This: v.Reference(),
	}

	_, err := methods.ShutdownGuest(ctx, v.c, &req)
	return err
}

func (v VirtualMachine) RebootGuest(ctx context.Context) error {
	req := types.RebootGuest{
		This: v.Reference(),
	}

	_, err := methods.RebootGuest(ctx, v.c, &req)
	return err
}

func (v VirtualMachine) Destroy(ctx context.Context) (*Task, error) {
	req := types.Destroy_Task{
		This: v.Reference(),
	}

	res, err := methods.Destroy_Task(ctx, v.c, &req)
	if err != nil {
		return nil, err
	}

	return NewTask(v.c, res.Returnval), nil
}

func (v VirtualMachine) Clone(ctx context.Context, folder *Folder, name string, config types.VirtualMachineCloneSpec) (*Task, error) {
	req := types.CloneVM_Task{
		This:   v.Reference(),
		Folder: folder.Reference(),
		Name:   name,
		Spec:   config,
	}

	res, err := methods.CloneVM_Task(ctx, v.c, &req)
	if err != nil {
		return nil, err
	}

	return NewTask(v.c, res.Returnval), nil
}

func (v VirtualMachine) Customize(ctx context.Context, spec types.CustomizationSpec) (*Task, error) {
	req := types.CustomizeVM_Task{
		This: v.Reference(),
		Spec: spec,
	}

	res, err := methods.CustomizeVM_Task(ctx, v.c, &req)
	if err != nil {
		return nil, err
	}

	return NewTask(v.c, res.Returnval), nil
}

func (v VirtualMachine) Relocate(ctx context.Context, config types.VirtualMachineRelocateSpec, priority types.VirtualMachineMovePriority) (*Task, error) {
	req := types.RelocateVM_Task{
		This:     v.Reference(),
		Spec:     config,
		Priority: priority,
	}

	res, err := methods.RelocateVM_Task(ctx, v.c, &req)
	if err != nil {
		return nil, err
	}

	return NewTask(v.c, res.Returnval), nil
}

func (v VirtualMachine) Reconfigure(ctx context.Context, config types.VirtualMachineConfigSpec) (*Task, error) {
	req := types.ReconfigVM_Task{
		This: v.Reference(),
		Spec: config,
	}

	res, err := methods.ReconfigVM_Task(ctx, v.c, &req)
	if err != nil {
		return nil, err
	}

	return NewTask(v.c, res.Returnval), nil
}

func (v VirtualMachine) WaitForIP(ctx context.Context) (string, error) {
	var ip string

	p := property.DefaultCollector(v.c)
	err := property.Wait(ctx, p, v.Reference(), []string{"guest.ipAddress"}, func(pc []types.PropertyChange) bool {
		for _, c := range pc {
			if c.Name != "guest.ipAddress" {
				continue
			}
			if c.Op != types.PropertyChangeOpAssign {
				continue
			}
			if c.Val == nil {
				continue
			}

			ip = c.Val.(string)
			return true
		}

		return false
	})

	if err != nil {
		return "", err
	}

	return ip, nil
}

// WaitForNetIP waits for the VM guest.net property to report an IP address for all VM NICs.
// Only consider IPv4 addresses if the v4 param is true.
// Returns a map with MAC address as the key and IP address list as the value.
func (v VirtualMachine) WaitForNetIP(ctx context.Context, v4 bool) (map[string][]string, error) {
	macs := make(map[string][]string)

	p := property.DefaultCollector(v.c)

	// Wait for all NICs to have a MacAddress, which may not be generated yet.
	err := property.Wait(ctx, p, v.Reference(), []string{"config.hardware.device"}, func(pc []types.PropertyChange) bool {
		for _, c := range pc {
			if c.Op != types.PropertyChangeOpAssign {
				continue
			}

			devices := c.Val.(types.ArrayOfVirtualDevice).VirtualDevice
			for _, device := range devices {
				if nic, ok := device.(types.BaseVirtualEthernetCard); ok {
					mac := nic.GetVirtualEthernetCard().MacAddress
					if mac == "" {
						return false
					}
					macs[mac] = nil
				}
			}
		}

		return true
	})

	err = property.Wait(ctx, p, v.Reference(), []string{"guest.net"}, func(pc []types.PropertyChange) bool {
		for _, c := range pc {
			if c.Op != types.PropertyChangeOpAssign {
				continue
			}

			nics := c.Val.(types.ArrayOfGuestNicInfo).GuestNicInfo
			for _, nic := range nics {
				mac := nic.MacAddress
				if mac == "" || nic.IpConfig == nil {
					continue
				}

				for _, ip := range nic.IpConfig.IpAddress {
					if _, ok := macs[mac]; !ok {
						continue // Ignore any that don't correspond to a VM device
					}
					if v4 && net.ParseIP(ip.IpAddress).To4() == nil {
						continue // Ignore non IPv4 address
					}
					macs[mac] = append(macs[mac], ip.IpAddress)
				}
			}
		}

		for _, ips := range macs {
			if len(ips) == 0 {
				return false
			}
		}

		return true
	})

	if err != nil {
		return nil, err
	}

	return macs, nil
}

// Device returns the VirtualMachine's config.hardware.device property.
func (v VirtualMachine) Device(ctx context.Context) (VirtualDeviceList, error) {
	var o mo.VirtualMachine

	err := v.Properties(ctx, v.Reference(), []string{"config.hardware.device"}, &o)
	if err != nil {
		return nil, err
	}

	return VirtualDeviceList(o.Config.Hardware.Device), nil
}

func (v VirtualMachine) HostSystem(ctx context.Context) (*HostSystem, error) {
	var o mo.VirtualMachine

	err := v.Properties(ctx, v.Reference(), []string{"summary"}, &o)
	if err != nil {
		return nil, err
	}

	host := o.Summary.Runtime.Host
	if host == nil {
		return nil, errors.New("VM doesn't have a HostSystem")
	}

	return NewHostSystem(v.c, *host), nil
}

func (v VirtualMachine) ResourcePool(ctx context.Context) (*ResourcePool, error) {
	var o mo.VirtualMachine

	err := v.Properties(ctx, v.Reference(), []string{"resourcePool"}, &o)
	if err != nil {
		return nil, err
	}

	rp := o.ResourcePool
	if rp == nil {
		return nil, errors.New("VM doesn't have a resourcePool")
	}

	return NewResourcePool(v.c, *rp), nil
}

func (v VirtualMachine) configureDevice(ctx context.Context, op types.VirtualDeviceConfigSpecOperation, fop types.VirtualDeviceConfigSpecFileOperation, devices ...types.BaseVirtualDevice) error {
	spec := types.VirtualMachineConfigSpec{}

	for _, device := range devices {
		config := &types.VirtualDeviceConfigSpec{
			Device:    device,
			Operation: op,
		}

		if disk, ok := device.(*types.VirtualDisk); ok {
			config.FileOperation = fop

			// Special case to attach an existing disk
			if op == types.VirtualDeviceConfigSpecOperationAdd && disk.CapacityInKB == 0 {
				childDisk := false
				if b, ok := disk.Backing.(*types.VirtualDiskFlatVer2BackingInfo); ok {
					childDisk = b.Parent != nil
				}

				if !childDisk {
					config.FileOperation = "" // existing disk
				}
			}
		}

		spec.DeviceChange = append(spec.DeviceChange, config)
	}

	task, err := v.Reconfigure(ctx, spec)
	if err != nil {
		return err
	}

	return task.Wait(ctx)
}

// AddDevice adds the given devices to the VirtualMachine
func (v VirtualMachine) AddDevice(ctx context.Context, device ...types.BaseVirtualDevice) error {
	return v.configureDevice(ctx, types.VirtualDeviceConfigSpecOperationAdd, types.VirtualDeviceConfigSpecFileOperationCreate, device...)
}

// EditDevice edits the given (existing) devices on the VirtualMachine
func (v VirtualMachine) EditDevice(ctx context.Context, device ...types.BaseVirtualDevice) error {
	return v.configureDevice(ctx, types.VirtualDeviceConfigSpecOperationEdit, types.VirtualDeviceConfigSpecFileOperationReplace, device...)
}

// RemoveDevice removes the given devices on the VirtualMachine
func (v VirtualMachine) RemoveDevice(ctx context.Context, keepFiles bool, device ...types.BaseVirtualDevice) error {
	fop := types.VirtualDeviceConfigSpecFileOperationDestroy
	if keepFiles {
		fop = ""
	}
	return v.configureDevice(ctx, types.VirtualDeviceConfigSpecOperationRemove, fop, device...)
}

// BootOptions returns the VirtualMachine's config.bootOptions property.
func (v VirtualMachine) BootOptions(ctx context.Context) (*types.VirtualMachineBootOptions, error) {
	var o mo.VirtualMachine

	err := v.Properties(ctx, v.Reference(), []string{"config.bootOptions"}, &o)
	if err != nil {
		return nil, err
	}

	return o.Config.BootOptions, nil
}

// SetBootOptions reconfigures the VirtualMachine with the given options.
func (v VirtualMachine) SetBootOptions(ctx context.Context, options *types.VirtualMachineBootOptions) error {
	spec := types.VirtualMachineConfigSpec{}

	spec.BootOptions = options

	task, err := v.Reconfigure(ctx, spec)
	if err != nil {
		return err
	}

	return task.Wait(ctx)
}

// Answer answers a pending question.
func (v VirtualMachine) Answer(ctx context.Context, id, answer string) error {
	req := types.AnswerVM{
		This:         v.Reference(),
		QuestionId:   id,
		AnswerChoice: answer,
	}

	_, err := methods.AnswerVM(ctx, v.c, &req)
	if err != nil {
		return err
	}

	return nil
}

// CreateSnapshot creates a new snapshot of a virtual machine.
func (v VirtualMachine) CreateSnapshot(ctx context.Context, name string, description string, memory bool, quiesce bool) (*Task, error) {
	req := types.CreateSnapshot_Task{
		This:        v.Reference(),
		Name:        name,
		Description: description,
		Memory:      memory,
		Quiesce:     quiesce,
	}

	res, err := methods.CreateSnapshot_Task(ctx, v.c, &req)
	if err != nil {
		return nil, err
	}

	return NewTask(v.c, res.Returnval), nil
}

// RemoveAllSnapshot removes all snapshots of a virtual machine
func (v VirtualMachine) RemoveAllSnapshot(ctx context.Context, consolidate *bool) (*Task, error) {
	req := types.RemoveAllSnapshots_Task{
		This:        v.Reference(),
		Consolidate: consolidate,
	}

	res, err := methods.RemoveAllSnapshots_Task(ctx, v.c, &req)
	if err != nil {
		return nil, err
	}

	return NewTask(v.c, res.Returnval), nil
}

// RevertToSnapshot reverts to a named snapshot
func (v VirtualMachine) RevertToSnapshot(ctx context.Context, name string, suppressPowerOn bool) (*Task, error) {
	var o mo.VirtualMachine

	err := v.Properties(ctx, v.Reference(), []string{"snapshot"}, &o)

	snapshotTree := o.Snapshot.RootSnapshotList
	if len(snapshotTree) < 1 {
		return nil, errors.New("No snapshots for this VM")
	}

	snapshot, err := traverseSnapshotInTree(snapshotTree, name)
	if err != nil {
		return nil, err
	}

	req := types.RevertToSnapshot_Task{
		This:            snapshot,
		SuppressPowerOn: types.NewBool(suppressPowerOn),
	}

	res, err := methods.RevertToSnapshot_Task(ctx, v.c, &req)
	if err != nil {
		return nil, err
	}

	return NewTask(v.c, res.Returnval), nil
}

// traverseSnapshotInTree is a recursive function that will traverse a snapshot tree to find a given snapshot
func traverseSnapshotInTree(tree []types.VirtualMachineSnapshotTree, name string) (types.ManagedObjectReference, error) {
	var o types.ManagedObjectReference
	if tree == nil {
		return o, errors.New("Snapshot tree is empty")
	}
	for _, s := range tree {
		if s.Name == name {
			o = s.Snapshot
			break
		} else {
			childTree := s.ChildSnapshotList
			var err error
			o, err = traverseSnapshotInTree(childTree, name)
			if err != nil {
				return o, err
			}
		}
	}
	if o.Value == "" {
		return o, errors.New("Snapshot not found")
	}

	return o, nil
}

// IsToolsRunning returns true if VMware Tools is currently running in the guest OS, and false otherwise.
func (v VirtualMachine) IsToolsRunning(ctx context.Context) (bool, error) {
	var o mo.VirtualMachine

	err := v.Properties(ctx, v.Reference(), []string{"guest.toolsRunningStatus"}, &o)
	if err != nil {
		return false, err
	}

	return o.Guest.ToolsRunningStatus == string(types.VirtualMachineToolsRunningStatusGuestToolsRunning), nil
}

// Wait for the VirtualMachine to change to the desired power state.
func (v VirtualMachine) WaitForPowerState(ctx context.Context, state types.VirtualMachinePowerState) error {
	p := property.DefaultCollector(v.c)
	err := property.Wait(ctx, p, v.Reference(), []string{PropRuntimePowerState}, func(pc []types.PropertyChange) bool {
		for _, c := range pc {
			if c.Name != PropRuntimePowerState {
				continue
			}
			if c.Val == nil {
				continue
			}

			ps := c.Val.(types.VirtualMachinePowerState)
			if ps == state {
				return true
			}
		}
		return false
	})

	return err
}

func (v VirtualMachine) MarkAsTemplate(ctx context.Context) error {
	req := types.MarkAsTemplate{
		This: v.Reference(),
	}

	_, err := methods.MarkAsTemplate(ctx, v.c, &req)
	if err != nil {
		return err
	}

	return nil
}

func (v VirtualMachine) MarkAsVirtualMachine(ctx context.Context, pool ResourcePool, host *HostSystem) error {
	req := types.MarkAsVirtualMachine{
		This: v.Reference(),
		Pool: pool.Reference(),
	}

	if host != nil {
		ref := host.Reference()
		req.Host = &ref
	}

	_, err := methods.MarkAsVirtualMachine(ctx, v.c, &req)
	if err != nil {
		return err
	}

	return nil
}