/*
Copyright (c) 2014-2015 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 network

import (
	"context"
	"errors"
	"flag"
	"fmt"

	"github.com/vmware/govmomi/govc/cli"
	"github.com/vmware/govmomi/govc/flags"
)

type change struct {
	*flags.VirtualMachineFlag
	*flags.NetworkFlag
}

func init() {
	cli.Register("vm.network.change", &change{})
}

func (cmd *change) Register(ctx context.Context, f *flag.FlagSet) {
	cmd.VirtualMachineFlag, ctx = flags.NewVirtualMachineFlag(ctx)
	cmd.VirtualMachineFlag.Register(ctx, f)
	cmd.NetworkFlag, ctx = flags.NewNetworkFlag(ctx)
	cmd.NetworkFlag.Register(ctx, f)
}

func (cmd *change) Process(ctx context.Context) error {
	if err := cmd.VirtualMachineFlag.Process(ctx); err != nil {
		return err
	}
	if err := cmd.NetworkFlag.Process(ctx); err != nil {
		return err
	}
	return nil
}

func (cmd *change) Usage() string {
	return "DEVICE"
}

func (cmd *change) Description() string {
	return `Change network DEVICE configuration.

Note that '-net' is currently required with '-net.address', even when not changing the VM network.

Examples:
  govc vm.network.change -vm $vm -net PG2 ethernet-0
  govc vm.network.change -vm $vm -net PG2 -net.address 00:00:0f:2e:5d:69 ethernet-0 # set to manual MAC address
  govc vm.network.change -vm $vm -net PG2 -net.address - ethernet-0 # set to generated MAC address
  govc device.info -vm $vm ethernet-*`
}

func (cmd *change) Run(ctx context.Context, f *flag.FlagSet) error {
	vm, err := cmd.VirtualMachineFlag.VirtualMachine()
	if err != nil {
		return err
	}

	if vm == nil {
		return errors.New("please specify a vm")
	}

	name := f.Arg(0)

	if name == "" {
		return errors.New("please specify a device name")
	}

	// Set network if specified as extra argument.
	if f.NArg() > 1 {
		err = cmd.NetworkFlag.Set(f.Arg(1))
		if err != nil {
			return fmt.Errorf("couldn't set specified network %v",
				err)
		}
	}

	devices, err := vm.Device(ctx)
	if err != nil {
		return err
	}

	net := devices.Find(name)

	if net == nil {
		return fmt.Errorf("device '%s' not found", name)
	}

	dev, err := cmd.NetworkFlag.Device()
	if err != nil {
		return err
	}

	cmd.NetworkFlag.Change(net, dev)

	return vm.EditDevice(ctx, net)
}