feat: MVP phase 1 complete

internal/mail/mail.go

@@ -0,0 +1,124 @@
+// Package mail sends transactional emails via SMTP with STARTTLS.
+package mail
+
+import (
+	"bytes"
+	"fmt"
+	"net"
+	"net/smtp"
+	"strings"
+	"time"
+)
+
+// Config holds SMTP connection settings sourced from environment variables.
+type Config struct {
+	Host       string // SMTP_HOST
+	Port       string // SMTP_PORT  (default "587")
+	Username   string // SMTP_USER
+	Password   string // SMTP_PASS
+	From       string // SMTP_FROM
+	AdminEmail string // ADMIN_EMAIL
+	BaseURL    string // BASE_URL   (used in link generation)
+}
+
+// Mailer sends email using the provided Config.
+type Mailer struct {
+	cfg Config
+}
+
+// New returns a Mailer. Returns an error if required fields are missing.
+func New(cfg Config) (*Mailer, error) {
+	if cfg.Host == "" || cfg.From == "" {
+		return nil, fmt.Errorf("mail: SMTP_HOST and SMTP_FROM are required")
+	}
+	if cfg.Port == "" {
+		cfg.Port = "587"
+	}
+	return &Mailer{cfg: cfg}, nil
+}
+
+// Configured reports whether the mailer has enough config to send.
+func (m *Mailer) Configured() bool {
+	return m.cfg.Host != "" && m.cfg.From != ""
+}
+
+// SendPasswordReset sends a password-reset link to the given address.
+func (m *Mailer) SendPasswordReset(toAddr, toName, token string) error {
+	link := strings.TrimRight(m.cfg.BaseURL, "/") + "/reset?token=" + token
+	subject := "Reset your Arcline Portal password"
+	body := fmt.Sprintf(`Hi %s,
+
+Someone requested a password reset for your Arcline Portal account.
+If that was you, click the link below to set a new password.
+The link expires in 1 hour.
+
+  %s
+
+If you did not request this, you can safely ignore this email.
+
+— Arcline IT
+`, toName, link)
+	return m.send(toAddr, subject, body)
+}
+
+// SendTicketCreated notifies the admin that a new ticket was opened.
+func (m *Mailer) SendTicketCreated(clientName, subject, body string, ticketID int64) error {
+	if m.cfg.AdminEmail == "" {
+		return nil
+	}
+	link := strings.TrimRight(m.cfg.BaseURL, "/") + fmt.Sprintf("/tickets/%d", ticketID)
+	msg := fmt.Sprintf(`New support ticket from %s
+
+Subject: %s
+
+%s
+
+---
+View ticket: %s
+`, clientName, subject, body, link)
+	return m.send(m.cfg.AdminEmail, fmt.Sprintf("[Arcline Portal] New ticket: %s", subject), msg)
+}
+
+// SendTicketReply notifies a party that a reply was added to their ticket.
+// toAddr is the recipient; fromName is who replied.
+func (m *Mailer) SendTicketReply(toAddr, toName, fromName, ticketSubject, replyBody string, ticketID int64) error {
+	if toAddr == "" {
+		return nil
+	}
+	link := strings.TrimRight(m.cfg.BaseURL, "/") + fmt.Sprintf("/tickets/%d", ticketID)
+	msg := fmt.Sprintf(`Hi %s,
+
+%s replied to your ticket "%s":
+
+---
+%s
+---
+
+View the full thread: %s
+
+— Arcline IT
+`, toName, fromName, ticketSubject, replyBody, link)
+	return m.send(toAddr, fmt.Sprintf("[Arcline Portal] Re: %s", ticketSubject), msg)
+}
+
+// send composes and sends a plain-text email via SMTP STARTTLS.
+func (m *Mailer) send(to, subject, body string) error {
+	addr := net.JoinHostPort(m.cfg.Host, m.cfg.Port)
+
+	var buf bytes.Buffer
+	fmt.Fprintf(&buf, "From: %s\r\n", m.cfg.From)
+	fmt.Fprintf(&buf, "To: %s\r\n", to)
+	fmt.Fprintf(&buf, "Subject: %s\r\n", subject)
+	fmt.Fprintf(&buf, "Date: %s\r\n", time.Now().Format("Mon, 02 Jan 2006 15:04:05 -0700"))
+	fmt.Fprintf(&buf, "MIME-Version: 1.0\r\n")
+	fmt.Fprintf(&buf, "Content-Type: text/plain; charset=UTF-8\r\n")
+	fmt.Fprintf(&buf, "\r\n")
+	fmt.Fprintf(&buf, "%s", strings.ReplaceAll(body, "\n", "\r\n"))
+
+	var auth smtp.Auth
+	if m.cfg.Username != "" {
+		auth = smtp.PlainAuth("", m.cfg.Username, m.cfg.Password, m.cfg.Host)
+	}
+
+	return smtp.SendMail(addr, auth, m.cfg.From, []string{to}, buf.Bytes())
+}