add mailer mechanism

app/app.go

@@ -6,6 +6,7 @@ import (
 	"embed"
 	"errors"
 	"fmt"
+	"gopher-toolbox/mail"
 	"gopher-toolbox/utils"
 	"log/slog"
 	"os"
@@ -53,6 +54,7 @@ type App struct {
 	Database AppDatabase
 	Security AppSecurity
 	AppInfo  AppInfo
+	Mailer   mail.Mailer
 }
 
 type AppDatabase struct {
@@ -83,10 +85,7 @@ func New(version string) *App {
 	var durationTime time.Duration
 	var ak paseto.V4AsymmetricSecretKey
 
-	ak, err = paseto.NewV4AsymmetricSecretKeyFromHex(os.Getenv("ASYMMETRICKEY"))
-	if err != nil {
 	ak = paseto.NewV4AsymmetricSecretKey()
-	}
 	pk := ak.Public()
 
 	duration := os.Getenv("DURATION")
@@ -98,6 +97,12 @@ func New(version string) *App {
 	}
 
 	return &App{
+		Mailer: mail.New(
+			os.Getenv("SMTP_HOST"),
+			os.Getenv("SMTP_PORT"),
+			os.Getenv("SMTP_USER"),
+			os.Getenv("SMTP_PASS"),
+		),
 		Database: AppDatabase{
 			Migrate:    utils.GetBool(os.Getenv("MIGRATE")),
 			DriverName: os.Getenv("DRIVERNAME"),

mail/mail.go

@@ -0,0 +1,55 @@
+package mail
+
+import (
+	"bytes"
+	"fmt"
+	"net/smtp"
+	"os"
+	"text/template"
+)
+
+type Mailer struct {
+	smtpHost string
+	smtpPort string
+	smtpUser string
+	smtpPass string
+}
+
+func New(smtpHost string, smtpPort string, smtpUser string, smtpPass string) Mailer {
+	return Mailer{
+		smtpHost: smtpHost,
+		smtpPort: smtpPort,
+		smtpUser: smtpUser,
+		smtpPass: smtpPass,
+	}
+}
+
+func (m *Mailer) SendMail(to []string, templateName string, data interface{}) error {
+	templateContent := getTemplate(templateName)
+	if templateContent == "" {
+		return fmt.Errorf("template %s not found", templateName)
+	}
+
+	tmpl, err := template.New("email").Parse(templateContent)
+	if err != nil {
+		return err
+	}
+
+	buf := new(bytes.Buffer)
+	if err := tmpl.Execute(buf, data); err != nil {
+		return err
+	}
+
+	auth := smtp.PlainAuth(m.smtpUser, m.smtpUser, m.smtpPass, m.smtpHost)
+	return smtp.SendMail(m.smtpHost+":"+m.smtpPort, auth, m.smtpUser, to, buf.Bytes())
+}
+
+func getTemplate(templateName string) string {
+	templatePath := "templates/" + templateName + ".gotmpl"
+	content, err := os.ReadFile(templatePath)
+	if err != nil {
+		fmt.Printf("Error leyendo plantilla: %v\n", err)
+		return ""
+	}
+	return string(content)
+}