From 8504d0e5ba9e75b2d0aa774c0d3d9afe3ab13257 Mon Sep 17 00:00:00 2001
From: lbenedar <lbenedar@local.lab>
Date: Thu, 19 Mar 2026 18:19:37 +0300
Subject: [PATCH] ch14.3

---
 cmd/api/main.go           | 16 ++++++++++
 cmd/api/users.go          |  6 ++++
 go.mod                    |  2 ++
 go.sum                    |  4 +++
 internal/mailer/mailer.go | 67 +++++++++++++++++++++++++++++++++++++++
 5 files changed, 95 insertions(+)
 create mode 100644 internal/mailer/mailer.go

diff --git a/cmd/api/main.go b/cmd/api/main.go
index eb1e248..510a575 100644
--- a/cmd/api/main.go
+++ b/cmd/api/main.go
@@ -9,6 +9,7 @@ import (
 
 	"gitea.local.lab/Lbenedar/greenlight/internal/data"
 	"gitea.local.lab/Lbenedar/greenlight/internal/jsonlog"
+	"gitea.local.lab/Lbenedar/greenlight/internal/mailer"
 	_ "github.com/lib/pq"
 )
 
@@ -18,6 +19,7 @@ type application struct {
 	config config
 	logger *jsonlog.Logger
 	models data.Models
+	mailer mailer.Mailer
 }
 
 type config struct {
@@ -34,6 +36,13 @@ type config struct {
 		burst   int
 		enabled bool
 	}
+	smtp struct {
+		host     string
+		port     int
+		username string
+		password string
+		sender   string
+	}
 }
 
 func openDB(cfg config) (*sql.DB, error) {
@@ -76,6 +85,12 @@ func main() {
 	flag.IntVar(&cfg.limiter.burst, "limiter-burst", 4, "Rate limiter maximum burst")
 	flag.BoolVar(&cfg.limiter.enabled, "limiter-enabled", true, "Enable rate limiter")
 
+	flag.StringVar(&cfg.smtp.host, "smtp-host", "smtp.mailtrap.io", "SMTP host")
+	flag.IntVar(&cfg.smtp.port, "smtp-port", 25, "SMTP port")
+	flag.StringVar(&cfg.smtp.username, "smtp-username", "0abf276416b183", "SMTP username")
+	flag.StringVar(&cfg.smtp.password, "smtp-password", "d8672aa2264bb5", "SMTP password")
+	flag.StringVar(&cfg.smtp.sender, "smtp-sender", "Greenlight <no-reply@greenlight.net", "SMTP sender")
+
 	flag.Parse()
 
 	logger := jsonlog.New(os.Stdout, jsonlog.LevelInfo)
@@ -92,6 +107,7 @@ func main() {
 		config: cfg,
 		logger: logger,
 		models: data.NewModels(db),
+		mailer: mailer.New(cfg.smtp.host, cfg.smtp.port, cfg.smtp.username, cfg.smtp.password, cfg.smtp.sender),
 	}
 
 	err = app.serve()
diff --git a/cmd/api/users.go b/cmd/api/users.go
index 2fa3992..ef8df08 100644
--- a/cmd/api/users.go
+++ b/cmd/api/users.go
@@ -52,6 +52,12 @@ func (app *application) registerUserHandler(w http.ResponseWriter, r *http.Reque
 		return
 	}
 
+	// err = app.mailer.Send(user.Email, "user_welcome.tmpl", user)
+	// if err != nil {
+	// 	app.serverErrorResponse(w, r, err)
+	// 	return
+	// }
+
 	err = app.writeJSON(w, http.StatusCreated, envelope{"user": user}, nil)
 	if err != nil {
 		app.serverErrorResponse(w, r, err)
diff --git a/go.mod b/go.mod
index 86af9c4..0d53d72 100644
--- a/go.mod
+++ b/go.mod
@@ -3,8 +3,10 @@ module gitea.local.lab/Lbenedar/greenlight
 go 1.25.0
 
 require (
+	github.com/go-mail/mail/v2 v2.3.0 // indirect
 	github.com/julienschmidt/httprouter v1.3.0 // indirect
 	github.com/lib/pq v1.11.2 // indirect
 	golang.org/x/crypto v0.49.0 // indirect
 	golang.org/x/time v0.15.0 // indirect
+	gopkg.in/alexcesaro/quotedprintable.v3 v3.0.0-20150716171945-2caba252f4dc // indirect
 )
diff --git a/go.sum b/go.sum
index 8aa2d87..bc74ee7 100644
--- a/go.sum
+++ b/go.sum
@@ -1,3 +1,5 @@
+github.com/go-mail/mail/v2 v2.3.0 h1:wha99yf2v3cpUzD1V9ujP404Jbw2uEvs+rBJybkdYcw=
+github.com/go-mail/mail/v2 v2.3.0/go.mod h1:oE2UK8qebZAjjV1ZYUpY7FPnbi/kIU53l1dmqPRb4go=
 github.com/julienschmidt/httprouter v1.3.0 h1:U0609e9tgbseu3rBINet9P48AI/D3oJs4dN7jwJOQ1U=
 github.com/julienschmidt/httprouter v1.3.0/go.mod h1:JR6WtHb+2LUe8TCKY3cZOxFyyO8IZAc4RVcycCCAKdM=
 github.com/lib/pq v1.11.2 h1:x6gxUeu39V0BHZiugWe8LXZYZ+Utk7hSJGThs8sdzfs=
@@ -6,3 +8,5 @@ golang.org/x/crypto v0.49.0 h1:+Ng2ULVvLHnJ/ZFEq4KdcDd/cfjrrjjNSXNzxg0Y4U4=
 golang.org/x/crypto v0.49.0/go.mod h1:ErX4dUh2UM+CFYiXZRTcMpEcN8b/1gxEuv3nODoYtCA=
 golang.org/x/time v0.15.0 h1:bbrp8t3bGUeFOx08pvsMYRTCVSMk89u4tKbNOZbp88U=
 golang.org/x/time v0.15.0/go.mod h1:Y4YMaQmXwGQZoFaVFk4YpCt4FLQMYKZe9oeV/f4MSno=
+gopkg.in/alexcesaro/quotedprintable.v3 v3.0.0-20150716171945-2caba252f4dc h1:2gGKlE2+asNV9m7xrywl36YYNnBG5ZQ0r/BOOxqPpmk=
+gopkg.in/alexcesaro/quotedprintable.v3 v3.0.0-20150716171945-2caba252f4dc/go.mod h1:m7x9LTH6d71AHyAX77c9yqWCCa3UKHcVEj9y7hAtKDk=
diff --git a/internal/mailer/mailer.go b/internal/mailer/mailer.go
new file mode 100644
index 0000000..40bff44
--- /dev/null
+++ b/internal/mailer/mailer.go
@@ -0,0 +1,67 @@
+package mailer
+
+import (
+	"bytes"
+	"embed"
+	"html/template"
+	"time"
+
+	"github.com/go-mail/mail/v2"
+)
+
+//go:embed "templates"
+var templateFS embed.FS
+
+type Mailer struct {
+	dialer *mail.Dialer
+	sender string
+}
+
+func New(host string, port int, username, password, sender string) Mailer {
+	dialer := mail.NewDialer(host, port, username, password)
+	dialer.Timeout = 5 * time.Second
+
+	return Mailer{
+		dialer: dialer,
+		sender: sender,
+	}
+}
+
+func (m Mailer) Send(recepient, templateFile string, data any) error {
+	tmpl, err := template.New("email").ParseFS(templateFS, "templates/"+templateFile)
+	if err != nil {
+		return err
+	}
+
+	subject := new(bytes.Buffer)
+	err = tmpl.ExecuteTemplate(subject, "subject", data)
+	if err != nil {
+		return err
+	}
+
+	plainBody := new(bytes.Buffer)
+	err = tmpl.ExecuteTemplate(plainBody, "plainBody", data)
+	if err != nil {
+		return err
+	}
+
+	htmlBody := new(bytes.Buffer)
+	err = tmpl.ExecuteTemplate(htmlBody, "htmlBody", data)
+	if err != nil {
+		return err
+	}
+
+	msg := mail.NewMessage()
+	msg.SetHeader("To", recepient)
+	msg.SetHeader("From", m.sender)
+	msg.SetHeader("Subject", subject.String())
+	msg.SetBody("text/plain", plainBody.String())
+	msg.AddAlternative("text/html", htmlBody.String())
+
+	err = m.dialer.DialAndSend(msg)
+	if err != nil {
+		return err
+	}
+
+	return nil
+}