package services import ( "errors" "log" "time" "github.com/go-mail/mail" ) var ( ErrMailUninitializedConfig = errors.New("Mail: uninitialized config") ) type EmailConfig struct { From string SMTPServer string SMTPPort int SMTPUsername string SMTPPassword string SMTPTimeout time.Duration } type Email struct { config *EmailConfig mailChan chan *mail.Message } func NewEmail(conf *EmailConfig) *Email { if conf == nil { log.Println(ErrMailUninitializedConfig) } return &Email{ config: conf, mailChan: make(chan *mail.Message, 4), } } // Send sends an email to the receiver func (email *Email) Send(to, subject, text, html string) error { if email.config == nil { log.Print("Error: trying to send mail with uninitialized config.") return ErrMailUninitializedConfig } m := mail.NewMessage() m.SetHeader("From", email.config.From) m.SetHeader("To", to) m.SetHeader("Subject", subject) m.SetBody("text/plain", text) m.AddAlternative("text/html", html) // put email in chan email.mailChan <- m return nil } // Daemon is a function that takes Mail and sends it without blocking. // WIP func (email *Email) Daemon() { if email.config == nil { log.Print("Error: trying to set up mail deamon with uninitialized config.") return } log.Print("Running mail sending routine") d := mail.NewDialer( email.config.SMTPServer, email.config.SMTPPort, email.config.SMTPUsername, email.config.SMTPPassword) var s mail.SendCloser var err error open := false for { select { case m, ok := <-email.mailChan: if !ok { // channel is closed log.Print("Channel closed") return } if !open { if s, err = d.Dial(); err != nil { log.Print(err) return } open = true } log.Printf("Trying to send mail") if err := mail.Send(s, m); err != nil { log.Printf("Mail: %s", err) } // Close the connection if no email was sent in the last X seconds. case <-time.After(email.config.SMTPTimeout): if open { if err := s.Close(); err != nil { log.Printf("Mail: Failed to close connection: %s", err) } open = false } } } }