/*
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 (
	"context"
	"errors"
	"strconv"

	"github.com/vmware/govmomi/vim25"
	"github.com/vmware/govmomi/vim25/methods"
	"github.com/vmware/govmomi/vim25/mo"
	"github.com/vmware/govmomi/vim25/types"
)

var (
	ErrKeyNameNotFound = errors.New("key name not found")
)

type CustomFieldsManager struct {
	Common
}

// GetCustomFieldsManager wraps NewCustomFieldsManager, returning ErrNotSupported
// when the client is not connected to a vCenter instance.
func GetCustomFieldsManager(c *vim25.Client) (*CustomFieldsManager, error) {
	if c.ServiceContent.CustomFieldsManager == nil {
		return nil, ErrNotSupported
	}
	return NewCustomFieldsManager(c), nil
}

func NewCustomFieldsManager(c *vim25.Client) *CustomFieldsManager {
	m := CustomFieldsManager{
		Common: NewCommon(c, *c.ServiceContent.CustomFieldsManager),
	}

	return &m
}

func (m CustomFieldsManager) Add(ctx context.Context, name string, moType string, fieldDefPolicy *types.PrivilegePolicyDef, fieldPolicy *types.PrivilegePolicyDef) (*types.CustomFieldDef, error) {
	req := types.AddCustomFieldDef{
		This:           m.Reference(),
		Name:           name,
		MoType:         moType,
		FieldDefPolicy: fieldDefPolicy,
		FieldPolicy:    fieldPolicy,
	}

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

	return &res.Returnval, nil
}

func (m CustomFieldsManager) Remove(ctx context.Context, key int32) error {
	req := types.RemoveCustomFieldDef{
		This: m.Reference(),
		Key:  key,
	}

	_, err := methods.RemoveCustomFieldDef(ctx, m.c, &req)
	return err
}

func (m CustomFieldsManager) Rename(ctx context.Context, key int32, name string) error {
	req := types.RenameCustomFieldDef{
		This: m.Reference(),
		Key:  key,
		Name: name,
	}

	_, err := methods.RenameCustomFieldDef(ctx, m.c, &req)
	return err
}

func (m CustomFieldsManager) Set(ctx context.Context, entity types.ManagedObjectReference, key int32, value string) error {
	req := types.SetField{
		This:   m.Reference(),
		Entity: entity,
		Key:    key,
		Value:  value,
	}

	_, err := methods.SetField(ctx, m.c, &req)
	return err
}

type CustomFieldDefList []types.CustomFieldDef

func (m CustomFieldsManager) Field(ctx context.Context) (CustomFieldDefList, error) {
	var fm mo.CustomFieldsManager

	err := m.Properties(ctx, m.Reference(), []string{"field"}, &fm)
	if err != nil {
		return nil, err
	}

	return fm.Field, nil
}

func (m CustomFieldsManager) FindKey(ctx context.Context, name string) (int32, error) {
	field, err := m.Field(ctx)
	if err != nil {
		return -1, err
	}

	for _, def := range field {
		if def.Name == name {
			return def.Key, nil
		}
	}

	k, err := strconv.Atoi(name)
	if err == nil {
		// assume literal int key
		return int32(k), nil
	}

	return -1, ErrKeyNameNotFound
}

func (l CustomFieldDefList) ByKey(key int32) *types.CustomFieldDef {
	for _, def := range l {
		if def.Key == key {
			return &def
		}
	}
	return nil
}