multipart for text fallback

mailer/mailer.go

@@ -21,14 +21,14 @@ func Init() {
 func NewMail(mail structs.Mail) error {
 	gocnjhelper.LogDebug("NEW MAIL")
 
-	body, err := mail.RenderTemplate()
+	htmlBody, textBody, err := mail.RenderTemplate()
 
 	if err != nil {
 		gocnjhelper.LogErrorf("Failed to render template, err: %s", err)
 		return err
 	}
 
-	if err = mail.Send(body); err != nil {
+	if err = mail.Send(htmlBody, textBody); err != nil {
 		gocnjhelper.LogErrorf("Failed to send mail, err: %s", err)
 		return err
 	}

mailer/template.go

@@ -31,7 +31,13 @@ func loadTemplateFiles() {
 	gocnjhelper.LogDebug("STARTING IMPORTING TEMPLATE FILES")
 
 	for templateName := range cache.Templates.Templates {
-		data, err := os.ReadFile(config.Cfg.Templates.FolderPath + templateName + ".html")
+		dataHtml, err := os.ReadFile(config.Cfg.Templates.FolderPath + templateName + ".html")
+
+		if err != nil {
+			gocnjhelper.LogFatalf("Failed to read file, err: %s", err)
+		}
+
+		dataTxt, err := os.ReadFile(config.Cfg.Templates.FolderPath + templateName + ".txt")
 
 		if err != nil {
 			gocnjhelper.LogFatalf("Failed to read file, err: %s", err)
@@ -45,7 +51,11 @@ func loadTemplateFiles() {
 
 		// cache.BodyTemplates[templateName] = []byte(minifiedHtml)
 
-		cache.BodyTemplates[templateName] = []byte(data)
+		//cache.BodyTemplates[templateName] = []byte(data)
+		cache.BodyTemplates[templateName] = cache.BodyContentTemplate{
+			HTML:      dataHtml,
+			PlainText: dataTxt,
+		}
 	}
 
 	gocnjhelper.LogDebug("FINISHED IMPORTING TEMPLATE FILES")

modules/cache/cache.go

@@ -6,7 +6,12 @@ type templates struct {
 	Templates map[string]map[string]map[string]string
 }
 
+type BodyContentTemplate struct {
+	HTML      []byte
+	PlainText []byte // fallback if html is not supported
+}
+
 var Templates templates
-var BodyTemplates = make(map[string][]byte)
+var BodyTemplates = make(map[string]BodyContentTemplate)
 
 var SmtpAuth smtp.Auth

modules/structs/mail.go

@@ -24,16 +24,30 @@ type Mail struct {
 	BodyData   interface{}
 }
 
-func (m *Mail) Send(body string) error {
+func (m *Mail) Send(htmlBody, textBody string) error {
 	cfg := config.Cfg.Mail
 
+	// Generate unique message ID
+	messageID := uuid.New().String() + "@" + strings.Split(cfg.FromEmail, "@")[1]
+
+	// Generate unique boundary string
+	boundary := "boundary" + uuid.New().String()
+
+	// Create MIME message with multipart/alternative content type
 	msg := "From: " + cfg.FromName + " <" + cfg.FromEmail + ">\n" +
 		"To: " + strings.Join(m.To, ",") + "\n" +
 		"Subject: " + m.Subject + "\n" +
 		"Date: " + time.Now().Format("Mon, 02 Jan 2006 15:04:05 -0700") + "\n" +
-		"Message-ID: <" + uuid.New().String() + "@" + strings.Split(cfg.FromEmail, "@")[1] + ">\n" +
+		"Message-ID: <" + messageID + ">\n" +
-		"MIME-version: 1.0;\nContent-Type: text/html; charset=\"UTF-8\";\n\n" +
+		"MIME-version: 1.0;\n" +
-		body
+		"Content-Type: multipart/alternative; boundary=" + boundary + "\n\n" +
+		"--" + boundary + "\n" +
+		"Content-Type: text/plain; charset=\"UTF-8\"\n\n" +
+		textBody + "\n\n" +
+		"--" + boundary + "\n" +
+		"Content-Type: text/html; charset=\"UTF-8\"\n\n" +
+		htmlBody + "\n\n" +
+		"--" + boundary + "--"
 
 	err := smtp.SendMail(cfg.Host+":"+cfg.Port, cache.SmtpAuth, cfg.FromEmail, m.To, []byte(msg))
 
@@ -46,6 +60,94 @@ func (m *Mail) Send(body string) error {
 	return nil
 }
 
+/*
+func (m *Mail) Send(body string) error {
+	cfg := config.Cfg.Mail
+
+	msg := "From: " + cfg.FromName + " <" + cfg.FromEmail + ">\n" +
+		"To: " + strings.Join(m.To, ",") + "\n" +
+		"Subject: " + m.Subject + "\n" +
+		"Date: " + time.Now().Format("Mon, 02 Jan 2006 15:04:05 -0700") + "\n" +
+		"Message-ID: <" + uuid.New().String() + "@" + strings.Split(cfg.FromEmail, "@")[1] + ">\n" +
+		"MIME-version: 1.0;\nContent-Type: multipart/alternative; charset=\"UTF-8\";\n\n" +
+		body
+
+	err := smtp.SendMail(cfg.Host+":"+cfg.Port, cache.SmtpAuth, cfg.FromEmail, m.To, []byte(msg))
+
+	if err != nil {
+		gocnjhelper.LogErrorf("smtp error: %s", err)
+		return err
+	}
+
+	gocnjhelper.LogDebugf("SEND MAIL %s", msg)
+	return nil
+} */
+
+func (m *Mail) RenderTemplate() (htmlBody, textBody string, err error) {
+	body := cache.BodyTemplates[m.TemplateId]
+
+	for templateName, templateData := range cache.Templates.Templates {
+		// Skipping templates if the template ID is not the expected one
+		if templateName != m.TemplateId {
+			continue
+		}
+
+		gocnjhelper.LogDebugf("RENDER TEMPLATE %s %s", templateName, templateData)
+
+		m.Subject = templateData["mailSubject"][m.LanguageId]
+
+		// occurs if the requested language code does not exist
+		if m.Subject == "" {
+			m.Subject = templateData["mailSubject"][config.Cfg.DefaultLanguageCode]
+		}
+
+		// replace body %values% with values in templates config
+		for key, value := range templateData {
+			if key == "mailSubject" {
+				continue
+			}
+
+			v := value[m.LanguageId]
+
+			// occurs if the requested language code does not exist
+			if v == "" {
+				v = value[config.Cfg.DefaultLanguageCode]
+			}
+
+			// escaping so that umlauts are displayed correctly
+			if m.LanguageId == "de" {
+				v = escaper.EscapeHtmlEntites(v)
+			}
+
+			body.HTML = []byte(strings.Replace(string(body.HTML), "%"+key+"%", v, -1))
+		}
+	}
+
+	// The subject line of an email is an independent header and utf 8 must be set for it
+	// https://ncona.com/2011/06/using-utf-8-characters-on-an-e-mail-subject/
+	if m.LanguageId == "de" {
+		m.Subject = EncodeBase64(m.Subject)
+	}
+
+	// Separate rendering for HTML and text bodies
+	htmlTemplate := template.Must(template.New("").Parse(string(body.HTML)))
+	textTemplate := template.Must(template.New("").Parse(string(body.PlainText)))
+
+	htmlBuf := new(bytes.Buffer)
+	textBuf := new(bytes.Buffer)
+
+	if err := htmlTemplate.Execute(htmlBuf, m.BodyData); err != nil {
+		return "", "", err
+	}
+
+	if err := textTemplate.Execute(textBuf, m.BodyData); err != nil {
+		return "", "", err
+	}
+
+	return htmlBuf.String(), textBuf.String(), nil
+}
+
+/*
 func (m *Mail) RenderTemplate() (string, error) {
 	body := cache.BodyTemplates[m.TemplateId]
 
@@ -82,19 +184,17 @@ func (m *Mail) RenderTemplate() (string, error) {
 				v = escaper.EscapeHtmlEntites(v)
 			}
 
-			body = []byte(strings.Replace(string(body), "%"+key+"%", v, -1))
+			body.HTML = []byte(strings.Replace(string(body.HTML), "%"+key+"%", v, -1))
 		}
 	}
 
 	// The subject line of an email is an independent header and utf 8 must be set for it
 	// https://ncona.com/2011/06/using-utf-8-characters-on-an-e-mail-subject/
 	if m.LanguageId == "de" {
-		//m.Subject = "=?utf-8?B?" + base64.StdEncoding.EncodeToString([]byte(m.Subject)) + "?="
-
 		m.Subject = EncodeBase64(m.Subject)
 	}
 
-	t := template.Must(template.New("").Parse(string(body)))
+	t := template.Must(template.New("").Parse(string(body.HTML)))
 
 	buf := new(bytes.Buffer)
 
@@ -103,7 +203,7 @@ func (m *Mail) RenderTemplate() (string, error) {
 	}
 
 	return buf.String(), nil
-}
+} */
 
 // https://ncona.com/2011/06/using-utf-8-characters-on-an-e-mail-subject/
 func EncodeBase64(s string) string {

templates/SignUpSecondStep.html

@@ -1,7 +0,0 @@
-<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
-<html>
-  <body>
-    <h1>%header%</h1>
-    <p>%informationText%</p>
-  </body>
-</html>

templates/emailVerification.html

@@ -1,9 +0,0 @@
-<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
-<html>
-  <body>
-    <h1>%header%</h1>
-    <p>%informationText%</p>
-    <p><b>{{.activation_code}}</b></p>
-    <p>%codeUse%</p>
-  </body>
-</html>

templates/emailVerification2.txt

@@ -0,0 +1,12 @@
+%title%
+%header%
+%text1%
+{{.verifyURL}}
+%cancelText%
+%yourAppointment%
+%appointment1%
+%appointment2%
+%appointment3%
+{{.address}}
+%footer%
+%dsgvo%

templates/emailVerifyFailed.txt

@@ -0,0 +1,11 @@
+%title%
+%header%
+%text1%
+
+%yourAppointment%
+%appointment1%
+%appointment2%
+%appointment3%
+{{.address}}
+
+%dsgvo%

templates/newUserSignIn.html

@@ -1,7 +0,0 @@
-<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
-<html>
-  <body>
-    <h1>%header%</h1>
-    <p>%informationText%</p>
-  </body>
-</html>

templates/templates.json

@@ -1,23 +1,5 @@
 {
     "templates": {
-        "emailVerification": {
-            "mailSubject": {
-                "en": "Your email confirmation code",
-                "de": "Ihr E-Mail-Bestätigungscode"
-            },
-            "header": {
-                "en": "Good day,",
-                "de": "Guten Tag,"
-            },
-            "informationText": {
-                "en": "to confirm your identity we need to verify your email.",
-                "de": "um deine Identität zu bestätigen müssen wir deine E-Mail verifizieren."
-            },
-            "codeUse": {
-                "en": "Please enter this code in the app",
-                "de": "Bitte gebe diesen Code in der App ein"
-            }
-        },
         "emailVerifyFailed": {
             "mailSubject": {
                 "de": "Ihre Buchung wurde storniert"
@@ -89,34 +71,6 @@
             "dsgvo": {
                 "de": "Datenschutzerklärung"
             }
-        },
-        "newUserSignIn": {
-            "mailSubject": {
-                "en": "A new sign-in was detected",
-                "de": "Neue Anmeldung wurde festgestellt"
-            },
-            "header": {
-                "en": "Good day,",
-                "de": "Guten Tag,"
-            },
-            "informationText": {
-                "en": "a new sign-in on <b>{{.device}}</b> was detected",
-                "de": "eine neue Anmeldung auf <b>{{.device}}</b> wurde festgestellt"
-            }
-        },
-        "SignUpSecondStep": {
-            "mailSubject": {
-                "en": "Welcome",
-                "de": "Willkommen"
-            },
-            "header": {
-                "en": "Good day {{.account_name}},",
-                "de": "Guten Tag {{.account_name}},"
-            },
-            "informationText": {
-                "en": "nice that you are here! Your account is created and you can start right away",
-                "de": "schön das du da bist! Dein Account ist erstellt und du kannst sofort loslegen"
-            }
         }
     }
 }