add mailer struct, fix download endpoint and make logo path generic

Author: rawdaGastan

server/app/admin_handler.go

@@ -523,7 +523,7 @@ func (a *App) CreateNewAnnouncementHandler(req *http.Request) (interface{}, Resp
 	for _, user := range users {
 		subject, body := internal.AdminAnnouncementMailContent(adminAnnouncement.Subject, adminAnnouncement.Body, a.config.Server.Host, user.Name())
 
-		err = internal.SendMail(a.config.MailSender.Email, a.config.MailSender.SendGridKey, user.Email, subject, body, "")
+		err = a.mailer.SendMail(a.config.MailSender.Email, user.Email, subject, body)
 		if err != nil {
 			log.Error().Err(err).Send()
 			return nil, InternalServerError(errors.New(internalServerErrorMsg))
@@ -585,7 +585,7 @@ func (a *App) SendEmailHandler(req *http.Request) (interface{}, Response) {
 
 	subject, body := internal.AdminMailContent(fmt.Sprintf("Hey! 📢 %s", emailUser.Subject), emailUser.Body, a.config.Server.Host, user.Name())
 
-	err = internal.SendMail(a.config.MailSender.Email, a.config.MailSender.SendGridKey, user.Email, subject, body, "")
+	err = a.mailer.SendMail(a.config.MailSender.Email, user.Email, subject, body)
 	if err != nil {
 		log.Error().Err(err).Send()
 		return nil, InternalServerError(errors.New(internalServerErrorMsg))
@@ -663,7 +663,7 @@ func (a *App) notifyAdmins() {
 			subject, body := internal.NotifyAdminsMailContent(len(pending), a.config.Server.Host)
 
 			for _, admin := range admins {
-				err = internal.SendMail(a.config.MailSender.Email, a.config.MailSender.SendGridKey, admin.Email, subject, body, "")
+				err = a.mailer.SendMail(a.config.MailSender.Email, admin.Email, subject, body)
 				if err != nil {
 					log.Error().Err(err).Send()
 				}
@@ -680,7 +680,7 @@ func (a *App) notifyAdmins() {
 			subject, body := internal.NotifyAdminsMailLowBalanceContent(balance, a.config.Server.Host)
 
 			for _, admin := range admins {
-				err = internal.SendMail(a.config.MailSender.Email, a.config.MailSender.SendGridKey, admin.Email, subject, body, "")
+				err = a.mailer.SendMail(a.config.MailSender.Email, admin.Email, subject, body)
 				if err != nil {
 					log.Error().Err(err).Send()
 				}

server/app/app.go

@@ -26,6 +26,7 @@ type App struct {
 	db       models.DB
 	redis    streams.RedisClient
 	deployer c4sDeployer.Deployer
+	mailer   internal.Mailer
 }
 
 // NewApp creates new server app all configurations
@@ -73,6 +74,7 @@ func NewApp(ctx context.Context, configFile string) (app *App, err error) {
 		db:       db,
 		redis:    redis,
 		deployer: newDeployer,
+		mailer:   internal.NewMailer(config.MailSender.SendGridKey),
 	}, nil
 }
 

server/app/invoice_handler.go

@@ -5,8 +5,6 @@ import (
 	"errors"
 	"fmt"
 	"net/http"
-	"os"
-	"path/filepath"
 	"strconv"
 	"strings"
 	"time"
@@ -158,25 +156,9 @@ func (a *App) DownloadInvoiceHandler(req *http.Request) (interface{}, Response)
 		return nil, NotFound(errors.New("invoice is not found"))
 	}
 
-	// Get downloads dir
-	homeDir, err := os.UserHomeDir()
-	if err != nil {
-		log.Error().Err(err).Send()
-		return nil, InternalServerError(errors.New(internalServerErrorMsg))
-	}
-
-	downloadsDir := filepath.Join(homeDir, "Downloads")
-	pdfPath := filepath.Join(downloadsDir, fmt.Sprintf("invoice-%s-%d.pdf", invoice.UserID, invoice.ID))
-
-	err = os.WriteFile(pdfPath, invoice.FileData, 0644)
-	if err != nil {
-		log.Error().Err(err).Send()
-		return nil, InternalServerError(errors.New(internalServerErrorMsg))
-	}
-
-	return ResponseMsg{
-		Message: fmt.Sprintf("Invoice is downloaded successfully at %s", pdfPath),
-	}, Ok()
+	return invoice.FileData, Ok().
+		WithHeader("Content-Disposition", fmt.Sprintf("attachment; filename=%s", fmt.Sprintf("invoice-%s-%d.pdf", invoice.UserID, invoice.ID))).
+		WithHeader("Content-Type", "application/pdf")
 }
 
 // PayInvoiceHandler pay user's invoice
@@ -524,9 +506,11 @@ func (a *App) sendInvoiceReminderToUser(userID, userEmail, userName string, now
 			subject := "Unpaid Invoice Notification – Action Required"
 			subject, body := internal.AdminMailContent(subject, mailBody, a.config.Server.Host, userName)
 
-			if err = internal.SendMail(
-				a.config.MailSender.Email, a.config.MailSender.SendGridKey, userEmail, subject, body,
-				fmt.Sprintf("invoice-%s-%d.pdf", invoice.UserID, invoice.ID), invoice.FileData,
+			if err = a.mailer.SendMail(
+				a.config.MailSender.Email, userEmail, subject, body, internal.Attachment{
+					FileName: fmt.Sprintf("invoice-%s-%d.pdf", invoice.UserID, invoice.ID),
+					Data:     invoice.FileData,
+				},
 			); err != nil {
 				log.Error().Err(err).Send()
 			}

server/app/user_handler.go

@@ -145,7 +145,7 @@ func (a *App) SignUpHandler(req *http.Request) (interface{}, Response) {
 	// send verification code if user is not verified or not exist
 	code := internal.GenerateRandomCode()
 	subject, body := internal.SignUpMailContent(code, a.config.MailSender.Timeout, fmt.Sprintf("%s %s", signUp.FirstName, signUp.LastName), a.config.Server.Host)
-	err = internal.SendMail(a.config.MailSender.Email, a.config.MailSender.SendGridKey, signUp.Email, subject, body, "")
+	err = a.mailer.SendMail(a.config.MailSender.Email, signUp.Email, subject, body)
 	if err != nil {
 		log.Error().Err(err).Send()
 		return nil, InternalServerError(errors.New(internalServerErrorMsg))
@@ -245,7 +245,7 @@ func (a *App) VerifySignUpCodeHandler(req *http.Request) (interface{}, Response)
 	middlewares.UserCreations.WithLabelValues(user.ID.String(), user.Email).Inc()
 
 	subject, body := internal.WelcomeMailContent(user.Name(), a.config.Server.Host)
-	err = internal.SendMail(a.config.MailSender.Email, a.config.MailSender.SendGridKey, user.Email, subject, body, "")
+	err = a.mailer.SendMail(a.config.MailSender.Email, user.Email, subject, body)
 	if err != nil {
 		log.Error().Err(err).Send()
 		return nil, InternalServerError(errors.New(internalServerErrorMsg))
@@ -405,7 +405,7 @@ func (a *App) ForgotPasswordHandler(req *http.Request) (interface{}, Response) {
 	// send verification code
 	code := internal.GenerateRandomCode()
 	subject, body := internal.ResetPasswordMailContent(code, a.config.MailSender.Timeout, user.Name(), a.config.Server.Host)
-	err = internal.SendMail(a.config.MailSender.Email, a.config.MailSender.SendGridKey, email.Email, subject, body, "")
+	err = a.mailer.SendMail(a.config.MailSender.Email, email.Email, subject, body)
 
 	if err != nil {
 		log.Error().Err(err).Send()

server/app/voucher_handler.go

@@ -176,7 +176,7 @@ func (a *App) UpdateVoucherHandler(req *http.Request) (interface{}, Response) {
 		subject, body = internal.RejectedVoucherMailContent(user.Name(), a.config.Server.Host)
 	}
 
-	err = internal.SendMail(a.config.MailSender.Email, a.config.MailSender.SendGridKey, user.Email, subject, body, "")
+	err = a.mailer.SendMail(a.config.MailSender.Email, user.Email, subject, body)
 	if err != nil {
 		log.Error().Err(err).Send()
 		return nil, InternalServerError(errors.New(internalServerErrorMsg))
@@ -228,7 +228,7 @@ func (a *App) ApproveAllVouchersHandler(req *http.Request) (interface{}, Respons
 		}
 
 		subject, body := internal.ApprovedVoucherMailContent(v.Voucher, user.Name(), a.config.Server.Host)
-		err = internal.SendMail(a.config.MailSender.Email, a.config.MailSender.SendGridKey, user.Email, subject, body, "")
+		err = a.mailer.SendMail(a.config.MailSender.Email, user.Email, subject, body)
 		if err != nil {
 			log.Error().Err(err).Send()
 			return nil, InternalServerError(errors.New(internalServerErrorMsg))

server/app/wrapper.go

@@ -69,6 +69,12 @@ func WrapFunc(a Handler) http.HandlerFunc {
 			status = result.Status()
 		}
 
+		if bytes, ok := object.([]byte); ok {
+			if _, err := w.Write(bytes); err != nil {
+				log.Error().Err(err).Msg("failed to write return object")
+			}
+		}
+
 		if err := json.NewEncoder(w).Encode(object); err != nil {
 			log.Error().Err(err).Msg("failed to encode return object")
 		}

server/internal/email_sender.go

@@ -40,8 +40,23 @@ var (
 	adminAnnouncement []byte
 )
 
+type Mailer struct {
+	client *sendgrid.Client
+}
+
+type Attachment struct {
+	FileName string
+	Data     []byte
+}
+
+func NewMailer(sendGridKey string) Mailer {
+	return Mailer{
+		client: sendgrid.NewSendClient(sendGridKey),
+	}
+}
+
 // SendMail sends verification mails
-func SendMail(sender, sendGridKey, receiver, subject, body, attachmentName string, attachmentBytes ...[]byte) error {
+func (m *Mailer) SendMail(sender, receiver, subject, body string, attachments ...Attachment) error {
 	from := mail.NewEmail("Cloud4All", sender)
 
 	err := validators.ValidMail(receiver)
@@ -53,18 +68,16 @@ func SendMail(sender, sendGridKey, receiver, subject, body, attachmentName strin
 
 	message := mail.NewSingleEmail(from, subject, to, "", body)
 
-	if len(attachmentBytes) > 0 {
+	if len(attachments) > 0 {
 		attachment := mail.NewAttachment()
-		attachment = attachment.SetContent(base64.StdEncoding.EncodeToString(attachmentBytes[0]))
+		attachment = attachment.SetContent(base64.StdEncoding.EncodeToString(attachments[0].Data))
 		attachment = attachment.SetType("application/pdf")
-		attachment = attachment.SetFilename(attachmentName)
+		attachment = attachment.SetFilename(attachments[0].FileName)
 		attachment = attachment.SetDisposition("attachment")
 		message = message.AddAttachment(attachment)
 	}
 
-	client := sendgrid.NewSendClient(sendGridKey)
-	_, err = client.Send(message)
-
+	_, err = m.client.Send(message)
 	return err
 }
 

server/internal/email_sender_test.go

@@ -11,13 +11,15 @@ import (
 )
 
 func TestSendMail(t *testing.T) {
+	m := NewMailer("1234")
+
 	t.Run("send valid mail", func(t *testing.T) {
-		err := SendMail("sender@gmail.com", "1234", "receiver@gmail.com", "subject", "body", "")
+		err := m.SendMail("sender@gmail.com", "receiver@gmail.com", "subject", "body")
 		assert.NoError(t, err)
 	})
 
 	t.Run("send invalid mail", func(t *testing.T) {
-		err := SendMail("sender@gmail.com", "1234", "receiver", "subject", "body", "")
+		err := m.SendMail("sender@gmail.com", "receiver", "subject", "body")
 		assert.Error(t, err)
 	})
 }

server/internal/img/codescalers.png server/internal/img/logo.pngserver/internal/img/codescalers.png renamed to server/internal/img/logo.png

@@ -16,7 +16,7 @@ const (
 	startX float64 = 25
 	startY float64 = 30
 
-	logoPath       = "internal/img/codescalers.png"
+	logoPath       = "internal/img/logo.png"
 	fontPath       = "internal/fonts/Arial.ttf"
 	boldFontPath   = "internal/fonts/Arial-Bold.ttf"
 	italicFontPath = "internal/fonts/Arial-Italic.ttf"