package imap

import (
	"fmt"
	"net/mail"
	"strings"

	"github.com/emersion/go-imap/v2"
)

func parseAddressList(s string) ([]imap.Address, error) {
	if s == "" {
		return []imap.Address{}, nil
	}

	addresses, err := mail.ParseAddressList(s)
	if err != nil {
		return nil, err
	}

	result := make([]imap.Address, 0, len(addresses))
	for _, a := range addresses {
		atSignPosition := strings.LastIndex(a.Address, "@")
		if atSignPosition <= 0 { // need at least one character before the '@' sign
			return nil, fmt.Errorf("invalid address: %s", a.Address)
		}

		local, host := a.Address[:atSignPosition], a.Address[atSignPosition+1:]

		result = append(result, imap.Address{
			Name:    a.Name,
			Mailbox: local,
			Host:    host,
		})
	}
	return result, nil
}