feat: send email based on template

server/email/email.go

@@ -2,8 +2,8 @@ package email
 
 import (
 	"bytes"
+	"context"
 	"crypto/tls"
-	"encoding/json"
 	"strconv"
 	"text/template"
 
@@ -11,27 +11,75 @@ import (
 	gomail "gopkg.in/mail.v2"
 
 	"github.com/authorizerdev/authorizer/server/constants"
+	"github.com/authorizerdev/authorizer/server/db"
+	"github.com/authorizerdev/authorizer/server/graph/model"
 	"github.com/authorizerdev/authorizer/server/memorystore"
 )
 
-// addEmailTemplate is used to add html template in email body
-func addEmailTemplate(a string, b map[string]interface{}, templateName string) string {
-	tmpl, err := template.New(templateName).Parse(a)
-	if err != nil {
-		output, _ := json.Marshal(b)
-		return string(output)
+func getDefaultTemplate(event string) *model.EmailTemplate {
+	switch event {
+	case constants.VerificationTypeBasicAuthSignup, constants.VerificationTypeMagicLinkLogin:
+		return &model.EmailTemplate{
+			Subject:  emailVerificationSubject,
+			Template: emailVerificationTemplate,
+		}
+	case constants.VerificationTypeForgotPassword:
+		return &model.EmailTemplate{
+			Subject:  forgotPasswordSubject,
+			Template: forgotPasswordTemplate,
+		}
+	case constants.VerificationTypeInviteMember:
+		return &model.EmailTemplate{
+			Subject:  inviteEmailSubject,
+			Template: inviteEmailTemplate,
+		}
+	case constants.VerificationTypeOTP:
+		return &model.EmailTemplate{
+			Subject:  otpEmailSubject,
+			Template: otpEmailTemplate,
+		}
+	default:
+		return nil
 	}
-	buf := &bytes.Buffer{}
-	err = tmpl.Execute(buf, b)
-	if err != nil {
-		panic(err)
-	}
-	s := buf.String()
-	return s
 }
 
-// SendMail function to send mail
-func SendMail(to []string, Subject, bodyMessage string) error {
+func getEmailTemplate(event string, data map[string]interface{}) (*model.EmailTemplate, error) {
+	ctx := context.Background()
+	tmp, err := db.Provider.GetEmailTemplateByEventName(ctx, event)
+	if err != nil || tmp == nil {
+		tmp = getDefaultTemplate(event)
+	}
+
+	templ, err := template.New(event + "_template.tmpl").Parse(tmp.Template)
+	if err != nil {
+		return nil, err
+	}
+	buf := &bytes.Buffer{}
+	err = templ.Execute(buf, data)
+	if err != nil {
+		return nil, err
+	}
+	templateString := buf.String()
+
+	subject, err := template.New(event + "_subject.tmpl").Parse(tmp.Subject)
+	if err != nil {
+		return nil, err
+	}
+	buf = &bytes.Buffer{}
+	err = subject.Execute(buf, data)
+	if err != nil {
+		return nil, err
+	}
+	subjectString := buf.String()
+
+	return &model.EmailTemplate{
+		Template: templateString,
+		Subject:  subjectString,
+	}, nil
+}
+
+// SendEmail function to send mail
+func SendEmail(to []string, event string, data map[string]interface{}) error {
 	// dont trigger email sending in case of test
 	envKey, err := memorystore.Provider.GetStringStoreEnvVariable(constants.EnvKeyEnv)
 	if err != nil {
@@ -40,6 +88,13 @@ func SendMail(to []string, Subject, bodyMessage string) error {
 	if envKey == constants.TestEnv {
 		return nil
 	}
+
+	tmp, err := getEmailTemplate(event, data)
+	if err != nil {
+		log.Errorf("Failed to get event template: ", err)
+		return err
+	}
+
 	m := gomail.NewMessage()
 	senderEmail, err := memorystore.Provider.GetStringStoreEnvVariable(constants.EnvKeySenderEmail)
 	if err != nil {
@@ -79,8 +134,8 @@ func SendMail(to []string, Subject, bodyMessage string) error {
 
 	m.SetHeader("From", senderEmail)
 	m.SetHeader("To", to...)
-	m.SetHeader("Subject", Subject)
-	m.SetBody("text/html", bodyMessage)
+	m.SetHeader("Subject", tmp.Subject)
+	m.SetBody("text/html", tmp.Template)
 	port, _ := strconv.Atoi(smtpPort)
 	d := gomail.NewDialer(smtpHost, port, smtpUsername, smtpPassword)
 	if !isProd {