package mailmux

import (
	"errors"
)

// User represents a mailmux user.
type User struct {
	// The name should be a valid email address.
	name     string
	password Password
}

type Password []byte

// A UserStore provides storage and authentication of users.
type UserStore interface {
	// Change creates or updates the named user with the new password.
	Change(name string, new Password) error
	// Lookup returns the User with name.
	// The error should be ErrUnknownUser if the user is not found.
	Lookup(name string) (User, error)
	// Delete removes the user from the store.
	Delete(name string) error
	// Authenticate authenticates the user identified by username with pw.
	// error is non-nil if the password is incorrect or on any other error.
	Authenticate(username string, pw Password) error
}

type ticket []byte

var testTicket = []byte(`TEST NOT REAL`)

var (
	ErrUserExist   = errors.New("user already exists")
	ErrUnknownUser = errors.New("unknown user")
)

// verified checks whether ownership of username's address has
// been confirmed.
// func (store *astore) verified(username string) (bool, error) {
// 	_, err := store.Lookup(username)
// 	if errors.Is(err, ErrUnknownUser) {
// 		return false, err
// 	}
//
// 	_, err = os.Stat(path.Join(store.confirmDir, username))
// 	if err == nil {
// 		return false, nil
// 	}
// 	if errors.Is(err, fs.ErrNotExist) {
// 		return true, nil
// 	}
// 	return false, fmt.Errorf("check confirm file: %w", err)
// }

// verify attempts to verify the username using the given token.
// func (store *astore) verify(username string, tok token) error {
// 	f, err := os.Open(path.Join(store.confirmDir, username))
// 	if errors.Is(err, fs.ErrNotExist) {
// 		return ErrUnknownUser
// 	} else if err != nil {
// 		return err
// 	}
// 	defer f.Close()
// 	b, err := io.ReadAll(f)
// 	if err != nil {
// 		return err
// 	}
// 	if bytes.Equal(b, []byte(tok)) {
// 		return os.Remove(path.Join(store.confirmDir, username))
// 	}
// 	return errors.New("mismatched token")
// }

func SendConfirmationMail(from, to string, tik ticket) error {
	return nil
	// From: $from
	// To: $to
	// Subject: Confirm address ownership
	//
	// Thanks for signing up to mailmux.net!
	// Confirm ownership of $address by accessing the following link:
	// https://mailmux.net/confirm?username=test@example.com&token=abcd12345
	// Alternatively, go to https://mailmux.net/confirm
	// enter your email address and your token:
	//	abcd12345
	//
	// If you have not signed up for mailmux.net, please
	// let us know by forwarding this mail to abuse@mailmux.net.
	// Thank you for helping us fight spam!
}