change mailing library dependency and add options management

mailer.go

@@ -6,7 +6,7 @@ import (
 	"html/template"
 
 	"github.com/spf13/viper"
-	gomail "gopkg.in/mail.v2"
+	"github.com/wneessen/go-mail"
 )
 
 type Mailer struct {
@@ -22,6 +22,8 @@ type SMTPConfig struct {
 	Password string
 }
 
+type Option func(*mail.Msg, []mail.Option) ([]mail.Option, error)
+
 func NewMailer(templates_dir string, tplcfg *viper.Viper, smtpconfig *viper.Viper) (*Mailer, error) {
 	return &Mailer{
 		TemplatesDir:    templates_dir,
@@ -35,7 +37,7 @@ func NewMailer(templates_dir string, tplcfg *viper.Viper, smtpconfig *viper.Vipe
 	}, nil
 }
 
-func (m *Mailer) Send(emailcfg string, to string, data any) error {
+func (m *Mailer) Send(emailcfg string, to string, data any, opts ...Option) error {
 	cfg := m.TemplatesConfig.Sub(emailcfg)
 
 	files := cfg.GetStringSlice("files")
@@ -43,27 +45,74 @@ func (m *Mailer) Send(emailcfg string, to string, data any) error {
 	for _, f := range files {
 		prefixed_files = append(prefixed_files, m.TemplatesDir+f)
 	}
-	t := template.Must(template.ParseFiles(prefixed_files...))
+	t := template.New("email").Funcs(
+		template.FuncMap{
+			"unescapeHTML":  UnescapeHTML,
+		},
+	)
+	t = template.Must(t.ParseFiles(prefixed_files...))
 	buf := new(bytes.Buffer)
 	if err := t.ExecuteTemplate(buf, "main", data); err != nil {
-		return err
+		return fmt.Errorf("failed execute mail template : %w", err)
 	}
 	body := buf.String()
 
-	fmt.Println(body)
+	message := mail.NewMsg()
+	if err := message.From(m.SMTPConfig.Username); err != nil {
+		return fmt.Errorf("failed to set From header : %w", err)
+	}
+	if err := message.To(to); err != nil {
+		return fmt.Errorf("failed to set To header : %w", err)
+	}
+	message.Subject(cfg.GetString("subject"))
+	message.SetBodyString(mail.TypeTextHTML, body)
 
-	message := gomail.NewMessage()
+	dialOptions := []mail.Option{
+		//mail.WithSMTPAuth(mail.SMTPAuthAutoDiscover), 
+		mail.WithSMTPAuth(mail.SMTPAuthNoAuth), 
+		mail.WithUsername(m.SMTPConfig.Username), 
+		mail.WithPassword(m.SMTPConfig.Password),
+	}
 
-	message.SetHeader("From", m.SMTPConfig.Username)
-	message.SetHeader("To", to)
-	message.SetHeader("Subject", cfg.GetString("subject"))
-	message.SetBody("text/html", body)
+	fmt.Println(dialOptions)
 
-	d := gomail.NewDialer(m.SMTPConfig.Host, m.SMTPConfig.Port, m.SMTPConfig.Username, m.SMTPConfig.Password)
-	if err := d.DialAndSend(message); err != nil {
-		return err
+	for _, opt := range opts {
+		no, err := opt(message, dialOptions) 
+		if err != nil {
+			return fmt.Errorf("failed to set option : %w", err)
+		}
+		dialOptions = no
+  }
+
+	fmt.Println(dialOptions)
+
+	client, err := mail.NewClient(m.SMTPConfig.Host, dialOptions...)
+	if err != nil {
+		return fmt.Errorf("failed to create mail client : %w", err)
+	}
+
+	if err := client.DialAndSend(message); err != nil {
+		return fmt.Errorf("failed to send message : %w", err)
 	}
 
 	return nil
 
 }
+
+func WithReplyTo(email string) Option {
+	return func(m *mail.Msg, opts []mail.Option) ([]mail.Option, error) {
+		return opts, m.ReplyTo(email)
+	}
+}
+
+func WithTLSOpportunistic() Option {
+	return func(m *mail.Msg, opts []mail.Option) ([]mail.Option, error) {
+		opts = append(opts, mail.WithTLSPolicy(mail.TLSOpportunistic))
+		return opts, nil
+	}
+}
+
+func UnescapeHTML(s string) template.HTML {
+	return template.HTML(s)
+}
+