package user

import (
	"errors"
	"fmt"
	"regexp"
)

type RegisterInput struct {
	Username string
	Email    string
	Phone    string
	Password string
}

type CreateInput struct {
	Username string
	Email    string
	Phone    string
	PwHash   string
}

var ErrInvalidInput = errors.New("invalid input")
var ErrUserExists = errors.New("user already exists")
var ErrUserNotFound = errors.New("user not found")

var usrnameRegExp = regexp.MustCompile(`^[a-zA-Z][a-zA-Z0-9_-]*$`)
var mailRegExp = regexp.MustCompile(`^[^@\s]+@[^@\s]+\.[^@\s]+$`)
var phoneRegExp = regexp.MustCompile(`^\+?[0-9][0-9\s-]*$`)

func (in *RegisterInput) validate() error {
	if len(in.Password) < 8 {
		return fmt.Errorf("%w: password too short - min is 8", ErrInvalidInput)
	}

	if len(in.Password) > 72 {
		return fmt.Errorf("%w: password too long - max is 72", ErrInvalidInput)
	}

	if in.Username == "" {
		return fmt.Errorf("%w: username is mandatory", ErrInvalidInput)
	}

	if !usrnameRegExp.MatchString(in.Username) {
		return fmt.Errorf("%w: bad username - must start with a letter and contain only letters, digits,'_' or '-'", ErrInvalidInput)
	}

	if len(in.Username) < 3 {
		return fmt.Errorf("%w: username too short - min is 3 chars", ErrInvalidInput)
	}

	if in.Email == "" {
		return fmt.Errorf("%w: email is mandatory", ErrInvalidInput)
	}

	if !mailRegExp.MatchString(in.Email) {
		return fmt.Errorf("%w: bad email format", ErrInvalidInput)
	}

	if in.Phone != "" && !phoneRegExp.MatchString(in.Phone) {
		return fmt.Errorf("%w: bad phone format", ErrInvalidInput)
	}

	return nil
}