runnable-mail.go

package jobqueue

import (
	"net/smtp"
)

// MailResult is a result of a email
type MailResult struct {
	Sent           bool
	ServerReply    string
	SmtpStatusCode uint
}

type MailRunnable struct {
	To       string
	From     string
	Subject  string
	Body     string
	Server   string
	Port     string
	Username string
	Password string
	Headers  map[string]string
}

func (m *MailRunnable) Run() (RunResult[MailResult], error) {

	smtpServer := m.Server + ":" + m.Port

	// Connect to the remote SMTP server.
	client, err := smtp.Dial(smtpServer)
	if err != nil {
		return RunResult[MailResult]{Status: ResultStatusFailed}, err
	}

	if client != nil {
		defer client.Close()
	}

	if m.Username != "" && m.Password != "" {
		if err := client.Auth(smtp.PlainAuth("", m.Username, m.Password, m.Server)); err != nil {
			return RunResult[MailResult]{Status: ResultStatusFailed}, err
		}
	}

	// To && From.
	if err := client.Mail(m.From); err != nil {
		return RunResult[MailResult]{Status: ResultStatusFailed}, err
	}
	if err := client.Rcpt(m.To); err != nil {
		return RunResult[MailResult]{Status: ResultStatusFailed}, err
	}

	// Headers and Data.
	writer, err := client.Data()
	if err != nil {
		return RunResult[MailResult]{Status: ResultStatusFailed}, err
	}

	headers := "From: " + m.From + "\r\n"
	headers += "To: " + m.To + "\r\n"
	headers += "Subject: " + m.Subject + "\r\n"

	for key, value := range m.Headers {
		headers += key + ": " + value + "\r\n"
	}

	_, err = writer.Write([]byte(headers + "\r\n" + m.Body))
	if err != nil {
		return RunResult[MailResult]{Status: ResultStatusFailed}, err
	}

	_ = writer.Close()

	// Quit and get the SMTP status code.
	smtpStatusCode, _ := client.Text.Cmd("QUIT")

	return RunResult[MailResult]{Status: ResultStatusSuccess, Data: MailResult{Sent: true, SmtpStatusCode: smtpStatusCode}}, nil
}