core/auth/ui/validation.go

package main

import (
	"strings"
	"unicode"
)

type ValidationError struct {
	Field   string `json:"field"`
	Message string `json:"message"`
}

func validateUsername(username string) []ValidationError {
	var errors []ValidationError
	if len(username) < 3 {
		errors = append(errors, ValidationError{"username", "Username must be at least 3 characters long."})
	}
	// TODO other validations
	return errors
}

func validatePassword(password string) []ValidationError {
	var errors []ValidationError
	if len(password) < 20 {
		errors = append(errors, ValidationError{"password", "Password must be at least 20 characters long."})
	}
	digit := false
	lowerCase := false
	upperCase := false
	special := false
	for _, c := range password {
		if unicode.IsDigit(c) {
			digit = true
		} else if unicode.IsLower(c) {
			lowerCase = true
		} else if unicode.IsUpper(c) {
			upperCase = true
		} else if strings.Contains(" !\"#$%&'()*+,-./:;<=>?@[\\]^_{|}~", string(c)) {
			special = true
		}
	}
	if !digit || !lowerCase || !upperCase || !special {
		errors = append(errors, ValidationError{"password", "Password must contain at least one digit, lower&upper case and special characters"})
	}
	// TODO other validations
	return errors
}