writefreely/mailer/mailer.go
2025-01-25 12:57:53 +01:00

181 lines
4.6 KiB
Go

/*
* Copyright © 2024 Musing Studio LLC.
*
* This file is part of WriteFreely.
*
* WriteFreely is free software: you can redistribute it and/or modify
* it under the terms of the GNU Affero General Public License, included
* in the LICENSE file in this source code package.
*/
package mailer
import (
"fmt"
"github.com/mailgun/mailgun-go"
"github.com/writeas/web-core/log"
"github.com/writefreely/writefreely/config"
mail "github.com/xhit/go-simple-mail/v2"
"strings"
)
type (
// Mailer holds configurations for the preferred mailing provider.
Mailer struct {
smtp *mail.SMTPServer
mailGun *mailgun.MailgunImpl
}
// Message holds the email contents and metadata for the preferred mailing provider.
Message struct {
mgMsg *mailgun.Message
smtpMsg *SmtpMessage
}
SmtpMessage struct {
from string
replyTo string
subject string
recipients []Recipient
html string
text string
}
Recipient struct {
email string
vars map[string]string
}
)
// New creates a new Mailer from the instance's config.EmailCfg, returning an error if not properly configured.
func New(eCfg config.EmailCfg) (*Mailer, error) {
m := &Mailer{}
if eCfg.Domain != "" && eCfg.MailgunPrivate != "" {
m.mailGun = mailgun.NewMailgun(eCfg.Domain, eCfg.MailgunPrivate)
if eCfg.MailgunEurope {
m.mailGun.SetAPIBase("https://api.eu.mailgun.net/v3")
}
} else if eCfg.Username != "" && eCfg.Password != "" && eCfg.Host != "" && eCfg.Port > 0 {
m.smtp = mail.NewSMTPClient()
m.smtp.Host = eCfg.Host
m.smtp.Port = eCfg.Port
m.smtp.Username = eCfg.Username
m.smtp.Password = eCfg.Password
if eCfg.EnableStartTLS {
m.smtp.Encryption = mail.EncryptionSTARTTLS
}
// To allow sending multiple email
m.smtp.KeepAlive = true
} else {
return nil, fmt.Errorf("no email provider is configured")
}
return m, nil
}
// NewMessage creates a new Message from the given parameters.
func (m *Mailer) NewMessage(from, subject, text string, to ...string) (*Message, error) {
msg := &Message{}
if m.mailGun != nil {
msg.mgMsg = m.mailGun.NewMessage(from, subject, text, to...)
} else if m.smtp != nil {
msg.smtpMsg = &SmtpMessage{
from: from,
replyTo: "",
subject: subject,
recipients: make([]Recipient, len(to)),
html: "",
text: text,
}
for _, r := range to {
msg.smtpMsg.recipients = append(msg.smtpMsg.recipients, Recipient{r, make(map[string]string)})
}
}
return msg, nil
}
// SetHTML sets the body of the message.
func (m *Message) SetHTML(html string) {
if m.smtpMsg != nil {
m.smtpMsg.html = html
} else if m.mgMsg != nil {
m.mgMsg.SetHtml(html)
}
}
func (m *Message) SetReplyTo(replyTo string) {
if m.smtpMsg != nil {
m.smtpMsg.replyTo = replyTo
} else {
m.mgMsg.SetReplyTo(replyTo)
}
}
// AddTag attaches a tag to the Message for providers that support it.
func (m *Message) AddTag(tag string) {
if m.mgMsg != nil {
m.mgMsg.AddTag(tag)
}
}
func (m *Message) AddRecipientAndVariables(r string, vars map[string]string) error {
if m.smtpMsg != nil {
m.smtpMsg.recipients = append(m.smtpMsg.recipients, Recipient{r, vars})
return nil
} else {
varsInterfaces := make(map[string]interface{}, len(vars))
for k, v := range vars {
varsInterfaces[k] = v
}
return m.mgMsg.AddRecipientAndVariables(r, varsInterfaces)
}
}
// Send sends the given message via the preferred provider.
func (m *Mailer) Send(msg *Message) error {
if m.smtp != nil {
client, err := m.smtp.Connect()
if err != nil {
return err
}
emailSent := false
for _, r := range msg.smtpMsg.recipients {
customMsg := mail.NewMSG()
customMsg.SetFrom(msg.smtpMsg.from)
if msg.smtpMsg.replyTo != "" {
customMsg.SetReplyTo(msg.smtpMsg.replyTo)
}
customMsg.SetSubject(msg.smtpMsg.subject)
customMsg.AddTo(r.email)
cText := msg.smtpMsg.text
cHtml := msg.smtpMsg.html
for v, value := range r.vars {
placeHolder := fmt.Sprintf("%%recipient.%s%%", v)
cText = strings.ReplaceAll(cText, placeHolder, value)
cHtml = strings.ReplaceAll(cHtml, placeHolder, value)
}
customMsg.SetBody(mail.TextHTML, cHtml)
customMsg.AddAlternative(mail.TextPlain, cText)
e := customMsg.Error
if e == nil {
e = customMsg.Send(client)
}
if e == nil {
emailSent = true
} else {
log.Error("Unable to send email to %s: %v", r.email, e)
err = e
}
}
if !emailSent {
// only send an error if no email could be sent (to avoid retry of successfully sent emails)
return err
}
} else if m.mailGun != nil {
_, _, err := m.mailGun.Send(msg.mgMsg)
if err != nil {
return err
}
}
return nil
}