// Copyright (c) 2015-present Mattermost, Inc. All Rights Reserved.
// See LICENSE.txt for license information.

package users

import (
	"strings"

	"github.com/mattermost/mattermost/server/public/model"
)

func (us *UserService) isPasswordValid(password string) error {
	return IsPasswordValidWithSettings(password, &us.config().PasswordSettings)
}

// IsPasswordValidWithSettings is a utility functions that checks if the given password
// conforms to the password settings. It returns the error id as error value.
func IsPasswordValidWithSettings(password string, settings *model.PasswordSettings) error {
	id := "model.user.is_valid.pwd"
	isError := false
	isMinMaxError := false

	if len(password) < *settings.MinimumLength {
		isError = true
		isMinMaxError = true
		id = id + "_min_length"
	}

	if len(password) > model.PasswordMaximumLength {
		isError = true
		isMinMaxError = true
		id = id + "_max_length"
	}

	if !isMinMaxError {
		if *settings.Lowercase {
			if !strings.ContainsAny(password, model.LowercaseLetters) {
				isError = true
				id = id + "_lowercase"
			}
		}

		if *settings.Uppercase {
			if !strings.ContainsAny(password, model.UppercaseLetters) {
				isError = true
				id = id + "_uppercase"
			}
		}

		if *settings.Number {
			if !strings.ContainsAny(password, model.NUMBERS) {
				isError = true
				id = id + "_number"
			}
		}

		if *settings.Symbol {
			if !strings.ContainsAny(password, model.SYMBOLS) {
				isError = true
				id = id + "_symbol"
			}
		}
	}

	if isError {
		return NewErrInvalidPassword(id + ".app_error")
	}

	return nil
}