package email import ( "crypto/tls" "fmt" "net" "net/smtp" "strconv" "time" "landing/internal/config" ) type Sender struct { cfg *config.Config } func New(cfg *config.Config) *Sender { return &Sender{cfg: cfg} } func (s *Sender) SendConfirmationEmail( email string, unsubscribeLink string, ) error { // Parse SMTP port from env port, err := strconv.Atoi(s.cfg.SMTPPort) if err != nil { return fmt.Errorf("invalid SMTP port '%s': %w", s.cfg.SMTPPort, err) } // Build email message subject := "Thanks for subscribing!" htmlBody := fmt.Sprintf(`

Welcome to RideAware!

Thank you for subscribing to our newsletter.

Unsubscribe

`, unsubscribeLink) message := fmt.Sprintf( "From: %s\r\nTo: %s\r\nSubject: %s\r\nContent-Type: text/html; charset=utf-8\r\n\r\n%s", s.cfg.SMTPUser, email, subject, htmlBody, ) // Create TLS config tlsConfig := &tls.Config{ ServerName: s.cfg.SMTPHost, } // Send email using smtp.SendMail addr := fmt.Sprintf("%s:%d", s.cfg.SMTPHost, port) auth := smtp.PlainAuth("", s.cfg.SMTPUser, s.cfg.SMTPPass, s.cfg.SMTPHost) // Use a custom dialer with timeout conn, err := net.DialTimeout("tcp", addr, 10*time.Second) if err != nil { return fmt.Errorf("failed to connect to SMTP server: %w", err) } defer conn.Close() client, err := smtp.NewClient(conn, s.cfg.SMTPHost) if err != nil { return fmt.Errorf("failed to create SMTP client: %w", err) } defer client.Close() // Start TLS if err := client.StartTLS(tlsConfig); err != nil { return fmt.Errorf("failed to start TLS: %w", err) } // Authenticate if err := client.Auth(auth); err != nil { return fmt.Errorf("failed to authenticate: %w", err) } // Set recipient and send if err := client.Mail(s.cfg.SMTPUser); err != nil { return fmt.Errorf("failed to set mail from: %w", err) } if err := client.Rcpt(email); err != nil { return fmt.Errorf("failed to set mail to: %w", err) } wc, err := client.Data() if err != nil { return fmt.Errorf("failed to get data writer: %w", err) } defer wc.Close() if _, err := wc.Write([]byte(message)); err != nil { return fmt.Errorf("failed to write message: %w", err) } if err := client.Quit(); err != nil { return fmt.Errorf("failed to quit SMTP: %w", err) } return nil } // TestConnection tests SMTP connection without sending email func (s *Sender) TestConnection() error { port, err := strconv.Atoi(s.cfg.SMTPPort) if err != nil { return fmt.Errorf("invalid SMTP port '%s': %w", s.cfg.SMTPPort, err) } // Test TCP connection addr := fmt.Sprintf("%s:%d", s.cfg.SMTPHost, port) conn, err := net.DialTimeout("tcp", addr, 10*time.Second) if err != nil { return fmt.Errorf("TCP connection failed to %s: %w", addr, err) } defer conn.Close() // Test SMTP connection client, err := smtp.NewClient(conn, s.cfg.SMTPHost) if err != nil { return fmt.Errorf("failed to create SMTP client: %w", err) } defer client.Close() return nil }