/* openbills - Server for web based Libre Billing Software
 * Copyright (C) 2023  Vidhu Kant Sharma <vidhukant@vidhukant.com>
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <https://www.gnu.org/licenses/>.
 */

package user

import (
	"strings"
	e "errors"
	"github.com/spf13/viper"
	"vidhukant.com/openbills/errors"
)

func validatePassword(pass string) error {
	// check if password is too short
	if len(pass) < viper.GetInt("security.min_password_length") {
		return errors.ErrPasswordTooShort
	}

	// check if password is too long
	if len(pass) > viper.GetInt("security.max_password_length") {
		return errors.ErrPasswordTooLong
	}

	return nil
}

// NOTE: very inefficient and really really really dumb but it works
// TODO: find a better (or even a remotely good) way
func validateUserField(field, value string) error {
	if value != "" {
		var count int64
		err := db.Model(&User{}).
			Where(field + " = ?", value).
			Count(&count).
			Error

		if err != nil {
			return err
		}

		if count > 0 {
			switch(field) {
			case "username":
				return errors.ErrNonUniqueUsername
			case "email":
				return errors.ErrNonUniqueEmail
			default:
				return e.New(field + " is not unique")
			}
		}
	}

	return nil
}

func (u *User) validate() error {
	u.Username = strings.TrimSpace(u.Username)
	u.Email = strings.TrimSpace(u.Email)
	u.IsVerified = false

	// TODO: validate username length and stuff
	// TODO: validate if email is valid

	var err error
	for _, i := range [][]string{{"username", u.Username}, {"email", u.Email}} {
		err = validateUserField(i[0], i[1])
		if err != nil {
			return err
		}
	}

	return nil
}