first commit

internal/mail/mail.go

@@ -0,0 +1,94 @@
+package mail
+
+import (
+	"crypto/tls"
+	"fmt"
+	"net/smtp"
+	"os"
+)
+
+// Config holds outbound mail settings read from environment variables.
+type Config struct {
+	Host string // SMTP_HOST
+	Port string // SMTP_PORT
+	User string // SMTP_USER
+	Pass string // SMTP_PASS
+	From string // SMTP_FROM
+}
+
+// ConfigFromEnv reads SMTP settings from environment variables.
+func ConfigFromEnv() Config {
+	port := os.Getenv("SMTP_PORT")
+	if port == "" {
+		port = "587"
+	}
+	return Config{
+		Host: os.Getenv("SMTP_HOST"),
+		Port: port,
+		User: os.Getenv("SMTP_USER"),
+		Pass: os.Getenv("SMTP_PASS"),
+		From: os.Getenv("SMTP_FROM"),
+	}
+}
+
+// Ready reports whether all required SMTP fields are set.
+func (c Config) Ready() bool {
+	return c.Host != "" && c.User != "" && c.Pass != "" && c.From != ""
+}
+
+// sendEmail sends a plain-text email to a single recipient.
+// It tries implicit TLS first, then falls back to STARTTLS via smtp.SendMail.
+func sendEmail(cfg Config, to, subject, body string) error {
+	addr := cfg.Host + ":" + cfg.Port
+	auth := smtp.PlainAuth("", cfg.User, cfg.Pass, cfg.Host)
+
+	msg := fmt.Sprintf(
+		"From: %s\r\nTo: %s\r\nSubject: %s\r\nMIME-Version: 1.0\r\nContent-Type: text/plain; charset=UTF-8\r\n\r\n%s",
+		cfg.From, to, subject, body,
+	)
+
+	conn, err := tls.Dial("tcp", addr, &tls.Config{ServerName: cfg.Host})
+	if err != nil {
+		return smtp.SendMail(addr, auth, cfg.From, []string{to}, []byte(msg))
+	}
+	defer conn.Close()
+
+	client, err := smtp.NewClient(conn, cfg.Host)
+	if err != nil {
+		return err
+	}
+	defer client.Close()
+
+	if err = client.Auth(auth); err != nil {
+		return err
+	}
+	if err = client.Mail(cfg.From); err != nil {
+		return err
+	}
+	if err = client.Rcpt(to); err != nil {
+		return err
+	}
+	wc, err := client.Data()
+	if err != nil {
+		return err
+	}
+	if _, err = fmt.Fprint(wc, msg); err != nil {
+		return err
+	}
+	return wc.Close()
+}
+
+// SendPasswordReset sends a password-reset email containing resetURL.
+func SendPasswordReset(cfg Config, toEmail, resetURL string) error {
+	subject := "Reset your Arcline IT password"
+	body := fmt.Sprintf(
+		"Hello,\r\n\r\n"+
+			"A password reset was requested for your Arcline IT account.\r\n\r\n"+
+			"Click the link below to set a new password (valid for 1 hour):\r\n\r\n"+
+			"%s\r\n\r\n"+
+			"If you did not request this, you can safely ignore this email.\r\n\r\n"+
+			"-- Arcline IT Support\r\n",
+		resetURL,
+	)
+	return sendEmail(cfg, toEmail, subject, body)
+}