/*
Copyright (c) 2014-2016 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 flags

import (
	"context"
	"flag"
	"fmt"
	"os"

	"github.com/vmware/govmomi/object"
	"github.com/vmware/govmomi/vim25/types"
)

type NetworkFlag struct {
	common

	*DatacenterFlag

	name    string
	net     object.NetworkReference
	adapter string
	address string
	isset   bool
}

var networkFlagKey = flagKey("network")

func NewNetworkFlag(ctx context.Context) (*NetworkFlag, context.Context) {
	if v := ctx.Value(networkFlagKey); v != nil {
		return v.(*NetworkFlag), ctx
	}

	v := &NetworkFlag{}
	v.DatacenterFlag, ctx = NewDatacenterFlag(ctx)
	ctx = context.WithValue(ctx, networkFlagKey, v)
	return v, ctx
}

func (flag *NetworkFlag) Register(ctx context.Context, f *flag.FlagSet) {
	flag.RegisterOnce(func() {
		flag.DatacenterFlag.Register(ctx, f)

		env := "GOVC_NETWORK"
		value := os.Getenv(env)
		flag.name = value
		usage := fmt.Sprintf("Network [%s]", env)
		f.Var(flag, "net", usage)
		f.StringVar(&flag.adapter, "net.adapter", "e1000", "Network adapter type")
		f.StringVar(&flag.address, "net.address", "", "Network hardware address")
	})
}

func (flag *NetworkFlag) Process(ctx context.Context) error {
	return flag.ProcessOnce(func() error {
		if err := flag.DatacenterFlag.Process(ctx); err != nil {
			return err
		}
		return nil
	})
}

func (flag *NetworkFlag) String() string {
	return flag.name
}

func (flag *NetworkFlag) Set(name string) error {
	flag.name = name
	flag.isset = true
	return nil
}

func (flag *NetworkFlag) IsSet() bool {
	return flag.isset
}

func (flag *NetworkFlag) Network() (object.NetworkReference, error) {
	if flag.net != nil {
		return flag.net, nil
	}

	finder, err := flag.Finder()
	if err != nil {
		return nil, err
	}

	if flag.net, err = finder.NetworkOrDefault(context.TODO(), flag.name); err != nil {
		return nil, err
	}

	return flag.net, nil
}

func (flag *NetworkFlag) Device() (types.BaseVirtualDevice, error) {
	net, err := flag.Network()
	if err != nil {
		return nil, err
	}

	backing, err := net.EthernetCardBackingInfo(context.TODO())
	if err != nil {
		return nil, err
	}

	device, err := object.EthernetCardTypes().CreateEthernetCard(flag.adapter, backing)
	if err != nil {
		return nil, err
	}

	if flag.address != "" {
		card := device.(types.BaseVirtualEthernetCard).GetVirtualEthernetCard()
		card.AddressType = string(types.VirtualEthernetCardMacTypeManual)
		card.MacAddress = flag.address
	}

	return device, nil
}

// Change applies update backing and hardware address changes to the given network device.
func (flag *NetworkFlag) Change(device types.BaseVirtualDevice, update types.BaseVirtualDevice) {
	current := device.(types.BaseVirtualEthernetCard).GetVirtualEthernetCard()
	changed := update.(types.BaseVirtualEthernetCard).GetVirtualEthernetCard()

	current.Backing = changed.Backing

	if changed.MacAddress != "" {
		current.MacAddress = changed.MacAddress
	}

	if changed.AddressType != "" {
		current.AddressType = changed.AddressType
	}
}