chore: move the go code into a subfolder

apps/api/internal/notification/channels/smtp/channel.go

@@ -0,0 +1,209 @@
+package smtp
+
+import (
+	"crypto/tls"
+	"errors"
+	"net"
+	"net/smtp"
+
+	"github.com/zitadel/logging"
+
+	"github.com/zitadel/zitadel/internal/notification/channels"
+	"github.com/zitadel/zitadel/internal/notification/messages"
+	"github.com/zitadel/zitadel/internal/zerrors"
+)
+
+var _ channels.NotificationChannel = (*Email)(nil)
+
+type Email struct {
+	smtpClient     *smtp.Client
+	senderAddress  string
+	senderName     string
+	replyToAddress string
+}
+
+func InitChannel(cfg *Config) (*Email, error) {
+	client, err := cfg.SMTP.connectToSMTP(cfg.Tls)
+	if err != nil {
+		logging.New().WithError(err).Error("could not connect to smtp")
+		return nil, err
+	}
+	logging.New().Debug("successfully initialized smtp email channel")
+	return &Email{
+		smtpClient:     client,
+		senderName:     cfg.FromName,
+		senderAddress:  cfg.From,
+		replyToAddress: cfg.ReplyToAddress,
+	}, nil
+}
+
+func (email *Email) HandleMessage(message channels.Message) error {
+	defer email.smtpClient.Close()
+	emailMsg, ok := message.(*messages.Email)
+	if !ok {
+		return zerrors.ThrowInternal(nil, "EMAIL-s8JLs", "Errors.SMTP.NotEmailMessage")
+	}
+
+	if emailMsg.Content == "" || emailMsg.Subject == "" || len(emailMsg.Recipients) == 0 {
+		return zerrors.ThrowInternal(nil, "EMAIL-zGemZ", "Errors.SMTP.RequiredAttributes")
+	}
+	emailMsg.SenderEmail = email.senderAddress
+	emailMsg.SenderName = email.senderName
+	emailMsg.ReplyToAddress = email.replyToAddress
+	// To && From
+	if err := email.smtpClient.Mail(emailMsg.SenderEmail); err != nil {
+		return zerrors.ThrowInternal(err, "EMAIL-s3is3", "Errors.SMTP.CouldNotSetSender")
+	}
+	for _, recp := range append(append(emailMsg.Recipients, emailMsg.CC...), emailMsg.BCC...) {
+		if err := email.smtpClient.Rcpt(recp); err != nil {
+			return zerrors.ThrowInternal(err, "EMAIL-s4is4", "Errors.SMTP.CouldNotSetRecipient")
+		}
+	}
+
+	// Data
+	w, err := email.smtpClient.Data()
+	if err != nil {
+		return err
+	}
+
+	content, err := emailMsg.GetContent()
+	if err != nil {
+		return err
+	}
+
+	_, err = w.Write([]byte(content))
+	if err != nil {
+		return err
+	}
+
+	err = w.Close()
+	if err != nil {
+		return err
+	}
+
+	return email.smtpClient.Quit()
+}
+
+func (smtpConfig SMTP) connectToSMTP(tlsRequired bool) (client *smtp.Client, err error) {
+	host, _, err := net.SplitHostPort(smtpConfig.Host)
+	if err != nil {
+		return nil, zerrors.ThrowInternal(err, "EMAIL-spR56", "Errors.SMTP.CouldNotSplit")
+	}
+
+	if !tlsRequired {
+		client, err = smtpConfig.getSMTPClient()
+	} else {
+		client, err = smtpConfig.getSMTPClientWithTls(host)
+	}
+	if err != nil {
+		return nil, err
+	}
+
+	err = smtpConfig.smtpAuth(client, host)
+	if err != nil {
+		return nil, err
+	}
+	return client, nil
+}
+
+func (smtpConfig SMTP) getSMTPClient() (*smtp.Client, error) {
+	client, err := smtp.Dial(smtpConfig.Host)
+	if err != nil {
+		return nil, zerrors.ThrowInternal(err, "EMAIL-skwos", "Errors.SMTP.CouldNotDial")
+	}
+	return client, nil
+}
+
+func (smtpConfig SMTP) getSMTPClientWithTls(host string) (*smtp.Client, error) {
+	conn, err := tls.Dial("tcp", smtpConfig.Host, &tls.Config{})
+
+	if errors.As(err, &tls.RecordHeaderError{}) {
+		logging.OnError(err).Warn("could not connect using normal tls. trying starttls instead...")
+		return smtpConfig.getSMTPClientWithStartTls(host)
+	}
+
+	if err != nil {
+		return nil, zerrors.ThrowInternal(err, "EMAIL-sl39s", "Errors.SMTP.CouldNotDialTLS")
+	}
+
+	client, err := smtp.NewClient(conn, host)
+	if err != nil {
+		return nil, zerrors.ThrowInternal(err, "EMAIL-skwi4", "Errors.SMTP.CouldNotCreateClient")
+	}
+	return client, err
+}
+
+func (smtpConfig SMTP) getSMTPClientWithStartTls(host string) (*smtp.Client, error) {
+	client, err := smtpConfig.getSMTPClient()
+	if err != nil {
+		return nil, err
+	}
+
+	if err := client.StartTLS(&tls.Config{
+		ServerName: host,
+	}); err != nil {
+		return nil, zerrors.ThrowInternal(err, "EMAIL-guvsQ", "Errors.SMTP.CouldNotStartTLS")
+	}
+	return client, nil
+}
+
+func (smtpConfig SMTP) smtpAuth(client *smtp.Client, host string) error {
+	if !smtpConfig.HasAuth() {
+		return nil
+	}
+	// Auth
+	err := client.Auth(PlainOrLoginAuth(smtpConfig.User, smtpConfig.Password, host))
+	if err != nil {
+		return zerrors.ThrowInternal(err, "EMAIL-s9kfs", "Errors.SMTP.CouldNotAuth")
+	}
+	return nil
+}
+
+func TestConfiguration(cfg *Config, testEmail string) error {
+	client, err := cfg.SMTP.connectToSMTP(cfg.Tls)
+	if err != nil {
+		return err
+	}
+
+	defer client.Close()
+
+	message := &messages.Email{
+		Recipients:  []string{testEmail},
+		Subject:     "Test email",
+		Content:     "This is a test email to check if your SMTP provider works fine",
+		SenderEmail: cfg.From,
+		SenderName:  cfg.FromName,
+	}
+
+	if err := client.Mail(cfg.From); err != nil {
+		return zerrors.ThrowInternal(err, "EMAIL-s3is3", "Errors.SMTP.CouldNotSetSender")
+	}
+
+	if err := client.Rcpt(testEmail); err != nil {
+		return zerrors.ThrowInternal(err, "EMAIL-s4is4", "Errors.SMTP.CouldNotSetRecipient")
+	}
+
+	// Open data connection
+	w, err := client.Data()
+	if err != nil {
+		return err
+	}
+
+	// Send content
+	content, err := message.GetContent()
+	if err != nil {
+		return err
+	}
+	_, err = w.Write([]byte(content))
+	if err != nil {
+		return err
+	}
+
+	// Close IO and quit smtp connection
+	err = w.Close()
+	if err != nil {
+		return err
+	}
+
+	return client.Quit()
+}