You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: v161.go
    path of file: ./repos/gitea/models/migrations/v1_14
    
    the code of the file until where you have to start completion: // Copyright 2020 The Gitea Authors. All rights reserved.
// SPDX-License-Identifier: MIT

package v1_14 //nolint

import (
	"context"

	"code.gitea.io/gitea/models/migrations/base"

	"xorm.io/xorm"
)

func Conv
    
func ConvertTaskTypeToString(x *xorm.Engine) error {
	const (
		GOGS int = iota + 1
		SLACK
		GITEA
		DISCORD
		DINGTALK
		TELEGRAM
		MSTEAMS
		FEISHU
		MATRIX
		WECHATWORK
	)

	hookTaskTypes := map[int]string{
		GITEA:      "gitea",
		GOGS:       "gogs",
		SLACK:      "slack",
		DISCORD:    "discord",
		DINGTALK:   "dingtalk",
		TELEGRAM:   "telegram",
		MSTEAMS:    "msteams",
		FEISHU:     "feishu",
		MATRIX:     "matrix",
		WECHATWORK: "wechatwork",
	}

	type HookTask struct {
		Typ string `xorm:"VARCHAR(16) index"`
	}
	if err := x.Sync(new(HookTask)); err != nil {
		return err
	}

	// to keep the migration could be rerun
	exist, err := x.Dialect().IsColumnExist(x.DB(), context.Background(), "hook_task", "type")
	if err != nil {
		return err
	}
	if !exist {
		return nil
	}

	for i, s := range hookTaskTypes {
		if _, err := x.Exec("UPDATE hook_task set typ = ? where `type`=?", s, i); err != nil {
			return err
		}
	}

	sess := x.NewSession()
	defer sess.Close()
	if err := sess.Begin(); err != nil {
		return err
	}
	if err := base.DropTableColumns(sess, "hook_task", "type"); err != nil {
		return err
	}

	return sess.Commit()
}