feat(email): SMTP welcome email on user creation

src/core/admin/handlers.go

@@ -5,6 +5,8 @@ import (
 	"log/slog"
 	"net/http"
 	"strings"
+
+	"git.lohmar.co.uk/lexton-it/NextWks/core/email"
 )
 
 // Handler bundles admin HTTP handlers and their dependencies.
@@ -12,15 +14,17 @@ type Handler struct {
 	store      *UserStore
 	groupStore *GroupStore
 	syncWriter *SyncWriter
+	emailer    *email.Sender
 	logger     *slog.Logger
 	configPath string
 }
 
-func NewHandler(store *UserStore, groupStore *GroupStore, syncWriter *SyncWriter, logger *slog.Logger, configPath string) *Handler {
+func NewHandler(store *UserStore, groupStore *GroupStore, syncWriter *SyncWriter, emailer *email.Sender, logger *slog.Logger, configPath string) *Handler {
 	return &Handler{
 		store:      store,
 		groupStore: groupStore,
 		syncWriter: syncWriter,
+		emailer:    emailer,
 		logger:     logger,
 		configPath: configPath,
 	}

src/core/admin/ui.go

@@ -283,6 +283,21 @@ func (h *Handler) createUsersHandler(w http.ResponseWriter, r *http.Request) {
 	// Sync to Authelia YAML
 	h.syncWriter.Sync()
 
+	// Send welcome emails
+	for _, r := range results {
+		if r.Error == "" && r.GeneratedPassword != "" {
+			email := ""
+			for _, input := range req.Users {
+				if input.Username == r.Username {
+					email = input.Email
+				}
+			}
+			if email != "" {
+				go h.emailer.SendWelcome(email, r.Username, r.GeneratedPassword, "") // workspace URL from config
+			}
+		}
+	}
+
 	// Convert to template results
 	resultRows := make([]templates.CreateUserResultRow, 0, len(results))
 	for _, r := range results {

src/core/email/email.go

@@ -0,0 +1,76 @@
+package email
+
+import (
+	"fmt"
+	"log/slog"
+	"net/smtp"
+	"strings"
+)
+
+// Sender handles SMTP email delivery.
+type Sender struct {
+	host     string
+	port     string
+	username string
+	password string
+	from     string
+	logger   *slog.Logger
+}
+
+// NewSender creates an email sender from SMTP config.
+func NewSender(host string, port int, username, password, from string, logger *slog.Logger) *Sender {
+	return &Sender{
+		host:     host,
+		port:     fmt.Sprintf("%d", port),
+		username: username,
+		password: password,
+		from:     from,
+		logger:   logger,
+	}
+}
+
+// SendWelcome sends a welcome email with the generated password.
+func (s *Sender) SendWelcome(to, username, password, workspaceURL string) error {
+	subject := "Welcome to Next Workspace"
+	body := fmt.Sprintf(`Hello %s,
+
+Your Next Workspace account has been created.
+
+  Workspace: %s
+  Username:  %s
+  Password:  %s
+
+Please log in and change your password.
+
+Best regards,
+Next Workspace`, username, workspaceURL, username, password)
+
+	return s.send(to, subject, body)
+}
+
+// SendAlert sends a generic alert email.
+func (s *Sender) SendAlert(to, subject, message string) error {
+	return s.send(to, subject, message)
+}
+
+func (s *Sender) send(to, subject, body string) error {
+	if s.host == "" || s.username == "" {
+		s.logger.Warn("email not configured, skipping send", "to", to)
+		return nil
+	}
+
+	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",
+		s.from, to, subject, body)
+
+	addr := fmt.Sprintf("%s:%s", s.host, s.port)
+	auth := smtp.PlainAuth("", s.username, s.password, s.host)
+
+	err := smtp.SendMail(addr, auth, s.from, strings.Split(to, ","), []byte(msg))
+	if err != nil {
+		s.logger.Error("send email failed", "to", to, "error", err)
+		return fmt.Errorf("send email: %w", err)
+	}
+
+	s.logger.Info("email sent", "to", to, "subject", subject)
+	return nil
+}

src/main.go

@@ -16,6 +16,7 @@ import (
 	"git.lohmar.co.uk/lexton-it/NextWks/core/auth"
 	"git.lohmar.co.uk/lexton-it/NextWks/core/config"
 	"git.lohmar.co.uk/lexton-it/NextWks/core/db"
+	"git.lohmar.co.uk/lexton-it/NextWks/core/email"
 	"git.lohmar.co.uk/lexton-it/NextWks/core/ui"
 	"git.lohmar.co.uk/lexton-it/NextWks/core/version"
 )
@@ -70,8 +71,11 @@ func main() {
 		logger.Info("fixed user roles", "count", fixed)
 	}
 
+	// Create email sender
+	emailSender := email.NewSender(cfg.SMTP.Host, cfg.SMTP.Port, cfg.SMTP.Username, cfg.SMTP.Password, cfg.SMTP.From, logger)
+
 	// Create admin handler
-	adminHandler := admin.NewHandler(userStore, admin.NewGroupStore(database.DB), syncWriter, logger, *configPath)
+	adminHandler := admin.NewHandler(userStore, admin.NewGroupStore(database.DB), syncWriter, emailSender, logger, *configPath)
 
 	// Initialize session store and OIDC auth
 	sessionStore := auth.NewSessionStore(database.DB)