first commit

plugin/email/client.go

@@ -0,0 +1,143 @@
+package email
+
+import (
+	"crypto/tls"
+	"net/smtp"
+
+	"github.com/pkg/errors"
+)
+
+// Client represents an SMTP email client.
+type Client struct {
+	config *Config
+}
+
+// NewClient creates a new email client with the given configuration.
+func NewClient(config *Config) *Client {
+	return &Client{
+		config: config,
+	}
+}
+
+// validateConfig validates the client configuration.
+func (c *Client) validateConfig() error {
+	if c.config == nil {
+		return errors.New("email configuration is required")
+	}
+	return c.config.Validate()
+}
+
+// createAuth creates an SMTP auth mechanism if credentials are provided.
+func (c *Client) createAuth() smtp.Auth {
+	if c.config.SMTPUsername == "" && c.config.SMTPPassword == "" {
+		return nil
+	}
+	return smtp.PlainAuth("", c.config.SMTPUsername, c.config.SMTPPassword, c.config.SMTPHost)
+}
+
+// createTLSConfig creates a TLS configuration for secure connections.
+func (c *Client) createTLSConfig() *tls.Config {
+	return &tls.Config{
+		ServerName: c.config.SMTPHost,
+		MinVersion: tls.VersionTLS12,
+	}
+}
+
+// Send sends an email message via SMTP.
+func (c *Client) Send(message *Message) error {
+	// Validate configuration
+	if err := c.validateConfig(); err != nil {
+		return errors.Wrap(err, "invalid email configuration")
+	}
+
+	// Validate message
+	if message == nil {
+		return errors.New("message is required")
+	}
+	if err := message.Validate(); err != nil {
+		return errors.Wrap(err, "invalid email message")
+	}
+
+	// Format the message
+	body := message.Format(c.config.FromEmail, c.config.FromName)
+
+	// Get all recipients
+	recipients := message.GetAllRecipients()
+
+	// Create auth
+	auth := c.createAuth()
+
+	// Send based on encryption type
+	if c.config.UseSSL {
+		return c.sendWithSSL(auth, recipients, body)
+	}
+	return c.sendWithTLS(auth, recipients, body)
+}
+
+// sendWithTLS sends email using STARTTLS (port 587).
+func (c *Client) sendWithTLS(auth smtp.Auth, recipients []string, body string) error {
+	serverAddr := c.config.GetServerAddress()
+
+	if c.config.UseTLS {
+		// Use STARTTLS
+		return smtp.SendMail(serverAddr, auth, c.config.FromEmail, recipients, []byte(body))
+	}
+
+	// Send without encryption (not recommended)
+	return smtp.SendMail(serverAddr, auth, c.config.FromEmail, recipients, []byte(body))
+}
+
+// sendWithSSL sends email using SSL/TLS (port 465).
+func (c *Client) sendWithSSL(auth smtp.Auth, recipients []string, body string) error {
+	serverAddr := c.config.GetServerAddress()
+
+	// Create TLS connection
+	tlsConfig := c.createTLSConfig()
+	conn, err := tls.Dial("tcp", serverAddr, tlsConfig)
+	if err != nil {
+		return errors.Wrapf(err, "failed to connect to SMTP server with SSL: %s", serverAddr)
+	}
+	defer conn.Close()
+
+	// Create SMTP client
+	client, err := smtp.NewClient(conn, c.config.SMTPHost)
+	if err != nil {
+		return errors.Wrap(err, "failed to create SMTP client")
+	}
+	defer client.Quit()
+
+	// Authenticate
+	if auth != nil {
+		if err := client.Auth(auth); err != nil {
+			return errors.Wrap(err, "SMTP authentication failed")
+		}
+	}
+
+	// Set sender
+	if err := client.Mail(c.config.FromEmail); err != nil {
+		return errors.Wrap(err, "failed to set sender")
+	}
+
+	// Set recipients
+	for _, recipient := range recipients {
+		if err := client.Rcpt(recipient); err != nil {
+			return errors.Wrapf(err, "failed to set recipient: %s", recipient)
+		}
+	}
+
+	// Send message body
+	writer, err := client.Data()
+	if err != nil {
+		return errors.Wrap(err, "failed to send DATA command")
+	}
+
+	if _, err := writer.Write([]byte(body)); err != nil {
+		return errors.Wrap(err, "failed to write message body")
+	}
+
+	if err := writer.Close(); err != nil {
+		return errors.Wrap(err, "failed to close message writer")
+	}
+
+	return nil
+}