refac: runtime settings are read once at startup and passed in through the composition root; no handler, router or repository reads environment variables

internal/infrastructure/mailer/mailRepository.go

@@ -2,30 +2,31 @@ package mailer
 
 import (
 	domain "RenewCMS/internal/domain/mail"
+	"RenewCMS/internal/infrastructure/config"
 	"bytes"
 	"embed"
 	"html/template"
 	"log"
-	"os"
-	"strconv"
 
 	"gopkg.in/gomail.v2"
 )
 
-type MailRepository struct{}
+type MailRepository struct {
+	smtp config.SmtpSettings
+}
 
 //go:embed templates/*
 var mailTemplateFiles embed.FS
 
-func NewMailRepository() *MailRepository {
-	return &MailRepository{}
+func NewMailRepository(smtp config.SmtpSettings) *MailRepository {
+	return &MailRepository{smtp: smtp}
 }
 
 func (m MailRepository) Send(receiverAddress string, templateName string, data any) error {
-	from := os.Getenv("SMTP_EMAIL")
-	password := os.Getenv("SMTP_PASSWORD")
-	smtpHost := os.Getenv("SMTP_HOST")
-	smtpPort, _ := strconv.Atoi(os.Getenv("SMTP_PORT"))
+	from := m.smtp.Email
+	password := m.smtp.Password
+	smtpHost := m.smtp.Host
+	smtpPort := m.smtp.Port
 
 	d := gomail.NewDialer(smtpHost, smtpPort, from, password)