/*
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 fields

import (
	"context"
	"flag"
	"strings"

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

type set struct {
	*flags.DatacenterFlag
	add  bool
	kind string
}

func init() {
	cli.Register("fields.set", &set{})
}

func (cmd *set) Register(ctx context.Context, f *flag.FlagSet) {
	cmd.DatacenterFlag, ctx = flags.NewDatacenterFlag(ctx)
	cmd.DatacenterFlag.Register(ctx, f)

	f.StringVar(&cmd.kind, "type", "", "Managed object type on which to add "+
		"the field if it does not exist. This flag is ignored unless -add=true")
	f.BoolVar(&cmd.add, "add", false, "Adds the field if it does not exist. "+
		"Use the -type flag to specify the managed object type to which the "+
		"field is added. Using -add and omitting -kind causes a new, global "+
		"field to be created if a field with the provided name does not "+
		"already exist.")
}

func (cmd *set) Usage() string {
	return "KEY VALUE PATH..."
}

func (cmd *set) Description() string {
	return `Set custom field values for PATH.

Examples:
  govc fields.set my-field-name field-value vm/my-vm
  govc fields.set -add my-new-global-field-name field-value vm/my-vm
  govc fields.set -add -type VirtualMachine my-new-vm-field-name field-value vm/my-vm`
}

func (cmd *set) Run(ctx context.Context, f *flag.FlagSet) error {
	if f.NArg() < 3 {
		return flag.ErrHelp
	}

	c, err := cmd.Client()
	if err != nil {
		return err
	}

	m, err := object.GetCustomFieldsManager(c)
	if err != nil {
		return err
	}

	args := f.Args()

	key, err := m.FindKey(ctx, args[0])
	if err != nil {
		if !(cmd.add && strings.Contains(err.Error(), "key name not found")) {
			return err
		}
		// Add the missing field.
		def, err := m.Add(ctx, args[0], cmd.kind, nil, nil)
		if err != nil {
			return err
		}
		// Assign the new field's key to the "key" var used below when
		// setting the key/value pair on the provided list of objects.
		key = def.Key
	}

	val := args[1]

	objs, err := cmd.ManagedObjects(ctx, args[2:])
	if err != nil {
		return err
	}

	for _, ref := range objs {
		err := m.Set(ctx, ref, key, val)
		if err != nil {
			return err
		}
	}

	return nil
}