package service

import (
	"errors"
	"unicode/utf8"
)

const (
	MinPasswordLength = 6
	MaxPasswordBytes  = 72
)

// ValidatePassword enforces the frozen Sense policy. Lowercase-only passwords
// are valid; complexity rules are intentionally not added here.
func ValidatePassword(password string) error {
	if utf8.RuneCountInString(password) < MinPasswordLength {
		return errors.New("密码至少需要 6 个字符")
	}
	if len(password) > MaxPasswordBytes {
		return errors.New("密码不能超过 72 个字节")
	}
	return nil
}