// © Broadcom. All Rights Reserved.
// The term “Broadcom” refers to Broadcom Inc. and/or its subsidiaries.
// SPDX-License-Identifier: Apache-2.0

package flags

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

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

type FolderFlag struct {
	common

	*DatacenterFlag

	name   string
	folder *object.Folder
}

var folderFlagKey = flagKey("folder")

func NewFolderFlag(ctx context.Context) (*FolderFlag, context.Context) {
	if v := ctx.Value(folderFlagKey); v != nil {
		return v.(*FolderFlag), ctx
	}

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

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

		env := "GOVC_FOLDER"
		value := os.Getenv(env)
		usage := fmt.Sprintf("Inventory folder [%s]", env)
		f.StringVar(&flag.name, "folder", value, usage)
	})
}

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

func (flag *FolderFlag) IsSet() bool {
	return flag.name != ""
}

func (flag *FolderFlag) Folder() (*object.Folder, error) {
	if flag.folder != nil {
		return flag.folder, nil
	}

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

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

	return flag.folder, nil
}

func (flag *FolderFlag) FolderIfSpecified() (*object.Folder, error) {
	if flag.name == "" {
		return nil, nil
	}
	return flag.Folder()
}

func (flag *FolderFlag) FolderOrDefault(kind string) (*object.Folder, error) {
	if flag.folder != nil {
		return flag.folder, nil
	}

	if flag.name != "" {
		return flag.Folder()
	}

	// RootFolder, no dc required
	if kind == "/" {
		client, err := flag.Client()
		if err != nil {
			return nil, err
		}

		flag.folder = object.NewRootFolder(client)
		return flag.folder, nil
	}

	dc, err := flag.Datacenter()
	if err != nil {
		return nil, err
	}

	folders, err := dc.Folders(context.TODO())
	if err != nil {
		return nil, err
	}

	switch kind {
	case "vm":
		flag.folder = folders.VmFolder
	case "host":
		flag.folder = folders.HostFolder
	case "datastore":
		flag.folder = folders.DatastoreFolder
	case "network":
		flag.folder = folders.NetworkFolder
	default:
		panic(kind)
	}

	return flag.folder, nil
}