package smtpclient

import (
	"fmt"
	"net/smtp"
	"strings"

	"github.com/pkg/errors"
)

var ErrAuthRequired = errors.New("auth required")

const CRLF = "\r\n"
const FromEmail = "no-reply@fiskerinc.com"

type SMTPInterface interface {
	Auth(username string, password string)
	Send(from string, to []string, subject string, body string) error
	Close()
}

func NewSMTP(host string, port int) SMTPInterface {
	return &SMTP{
		Host: host,
		Port: port,
	}
}

type SMTP struct {
	Host     string
	Port     int
	Username string
	auth     smtp.Auth
}

func (s *SMTP) Auth(username string, password string) {
	s.auth = smtp.PlainAuth("", username, password, s.Host)
}

func (s *SMTP) Send(from string, to []string, subject string, body string) error {
	if s.auth == nil {
		return ErrAuthRequired
	}

	msg := []string{
		fmt.Sprintf("From: %s", from),
		fmt.Sprintf("To: %s", strings.Join(to, ", ")),
		fmt.Sprintf("Subject: %s", subject),
		"",
		fmt.Sprintf("%s%s", body, CRLF),
	}
	addr := fmt.Sprintf("%s:%d", s.Host, s.Port)

	return smtp.SendMail(addr, s.auth, from, to, []byte(strings.Join(msg, CRLF)))
}

func (s *SMTP) Close() {
	s.Host = ""
	s.Username = ""
	s.auth = nil
}