(Feat): Initial Commit

internal/mailer/transport/smtp_config.go

@@ -0,0 +1,81 @@
+package transport
+
+import (
+	"crypto/tls"
+	"fmt"
+	"strings"
+)
+
+type SMTPAuthType int
+
+const (
+	// SMTPAuthTypeNone indicates no SMTP authentication should be performed.
+	SMTPAuthTypeNone SMTPAuthType = iota
+	// SMTPAuthTypePlain indicates SMTP authentication should be performed using the "AUTH PLAIN" protocol.
+	SMTPAuthTypePlain
+	// SMTPAuthTypeCRAMMD5 indicates SMTP authentication should be performed using the "CRAM-MD5" protocol.
+	SMTPAuthTypeCRAMMD5
+	// SMTPAuthTypeLogin indicates SMTP authentication should be performed using the "LOGIN" protocol.
+	SMTPAuthTypeLogin
+)
+
+func (t SMTPAuthType) String() string {
+	switch t {
+	case SMTPAuthTypeNone:
+		return "none"
+	case SMTPAuthTypePlain:
+		return "plain"
+	case SMTPAuthTypeCRAMMD5:
+		return "cram-md5"
+	case SMTPAuthTypeLogin:
+		return "login"
+	default:
+		return fmt.Sprintf("unknown (%d)", t)
+	}
+}
+
+func SMTPAuthTypeFromString(s string) SMTPAuthType {
+	switch strings.ToLower(s) {
+	case "plain":
+		return SMTPAuthTypePlain
+	case "cram-md5":
+		return SMTPAuthTypeCRAMMD5
+	case "login":
+		return SMTPAuthTypeLogin
+	default:
+		return SMTPAuthTypeNone
+	}
+}
+
+type SMTPEncryption string
+
+const (
+	SMTPEncryptionNone     SMTPEncryption = "none"
+	SMTPEncryptionTLS      SMTPEncryption = "tls"
+	SMTPEncryptionStartTLS SMTPEncryption = "starttls"
+)
+
+func (e SMTPEncryption) String() string {
+	return string(e)
+}
+
+func SMTPEncryptionFromString(s string) SMTPEncryption {
+	switch strings.ToLower(s) {
+	case "tls":
+		return SMTPEncryptionTLS
+	case "starttls":
+		return SMTPEncryptionStartTLS
+	default:
+		return SMTPEncryptionNone
+	}
+}
+
+type SMTPMailTransportConfig struct {
+	Host       string
+	Port       int
+	AuthType   SMTPAuthType `json:"-"` // iota
+	Username   string
+	Password   string         `json:"-"` // sensitive
+	Encryption SMTPEncryption `json:"-"` // iota
+	TLSConfig  *tls.Config    `json:"-"` // pointer
+}