CUB-117: Port Moonraker + MQTT printer integrations to Go

- Add internal/clients/moonraker.go: HTTP client for Moonraker REST API
- Add internal/clients/mqtt.go: MQTT client via paho.mqtt.golang with TLS support
- Add internal/workers/moonraker_poller.go: background polling, usage logging, SSE broadcasts
- Add internal/workers/mqtt_subscriber.go: per-printer MQTT subscriber, Bambu telemetry parsing, SSE broadcasts
- Wire workers into cmd/server/main.go (Start/Stop with graceful shutdown)

Blocked at step 4: go toolchain not installed on build host

backend/cmd/server/main.go

@@ -11,8 +11,10 @@ import (
 
 	"github.com/CubeCraft-Creations/Extrudex/backend/internal/config"
 	"github.com/CubeCraft-Creations/Extrudex/backend/internal/db"
+	"github.com/CubeCraft-Creations/Extrudex/backend/internal/repositories"
 	"github.com/CubeCraft-Creations/Extrudex/backend/internal/router"
 	"github.com/CubeCraft-Creations/Extrudex/backend/internal/sse"
+	"github.com/CubeCraft-Creations/Extrudex/backend/internal/workers"
 )
 
 func main() {
@@ -40,6 +42,11 @@ func main() {
 
 	slog.Info("database connected")
 
+	// Repositories (for background workers)
+	printerRepo := repositories.NewPrinterRepository(dbPool)
+	jobRepo := repositories.NewPrintJobRepository(dbPool)
+	usageLogRepo := repositories.NewUsageLogRepository(dbPool)
+
 	// Create SSE broadcaster and start it
 	sseBC := sse.NewBroadcaster(128)
 	sseBC.Start()
@@ -47,6 +54,19 @@ func main() {
 
 	slog.Info("sse broadcaster started")
 
+	// Start background workers
+	mrCfg := workers.DefaultMoonrakerPollerConfig()
+	mrPoller := workers.NewMoonrakerPoller(mrCfg, dbPool, printerRepo, jobRepo, usageLogRepo, sseBC)
+	mrPoller.Start()
+	defer mrPoller.Stop()
+
+	mqttCfg := workers.DefaultMQTTSubscriberConfig()
+	mqttSub := workers.NewMQTTSubscriber(mqttCfg, dbPool, printerRepo, usageLogRepo, sseBC)
+	mqttSub.Start()
+	defer mqttSub.Stop()
+
+	slog.Info("background workers started")
+
 	// Create router
 	r := router.New(cfg, dbPool, sseBC)
 

backend/internal/clients/moonraker.go

@@ -0,0 +1,161 @@
+// Package clients provides third-party printer integrations.
+package clients
+
+import (
+	"context"
+	"encoding/json"
+	"fmt"
+	"log/slog"
+	"net/http"
+	"time"
+)
+
+// MoonrakerPrinterInfo represents the response from /api/printer/info.
+type MoonrakerPrinterInfo struct {
+	State      string `json:"state"`
+	Hostname   string `json:"hostname,omitempty"`
+	SoftwareVersion string `json:"software_version,omitempty"`
+}
+
+// MoonrakerPrintStats represents the response from /api/printer/print_stats.
+type MoonrakerPrintStats struct {
+	State            string  `json:"state"`
+	Filename         string  `json:"filename,omitempty"`
+	FilamentUsedMm   float64 `json:"filament_used,omitempty"`
+	TotalDuration    float64 `json:"total_duration,omitempty"`
+	PrintDuration    float64 `json:"print_duration,omitempty"`
+	Message          string  `json:"message,omitempty"`
+}
+
+// MoonrakerPrintJob represents a single job from the history API.
+type MoonrakerPrintJob struct {
+	JobID          string    `json:"job_id,omitempty"`
+	Filename       string    `json:"filename"`
+	Status         string    `json:"status"`
+	StartTime      time.Time `json:"start_time"`
+	EndTime        time.Time `json:"end_time,omitempty"`
+	FilamentUsedMm float64   `json:"filament_used,omitempty"`
+	TotalDuration  float64   `json:"total_duration,omitempty"`
+}
+
+// MoonrakerHistoryResponse represents the response from /api/server/history/job.
+type MoonrakerHistoryResponse struct {
+	Items []MoonrakerPrintJob `json:"jobs"`
+}
+
+// MoonrakerClient is an HTTP client for the Moonraker API.
+type MoonrakerClient struct {
+	HTTPClient *http.Client
+}
+
+// NewMoonrakerClient creates a MoonrakerClient with the given request timeout.
+func NewMoonrakerClient(timeout time.Duration) *MoonrakerClient {
+	return &MoonrakerClient{
+		HTTPClient: &http.Client{Timeout: timeout},
+	}
+}
+
+// baseURL builds the Moonraker base URL from host and port.
+func (c *MoonrakerClient) baseURL(host string, port int) string {
+	if port == 0 {
+		port = 80
+	}
+	return fmt.Sprintf("http://%s:%d", host, port)
+}
+
+// GetPrinterInfo fetches printer info from Moonraker.
+func (c *MoonrakerClient) GetPrinterInfo(ctx context.Context, host string, port int, apiKey string) (*MoonrakerPrinterInfo, error) {
+	url := c.baseURL(host, port) + "/api/printer/info"
+	req, err := http.NewRequestWithContext(ctx, http.MethodGet, url, nil)
+	if err != nil {
+		return nil, err
+	}
+	if apiKey != "" {
+		req.Header.Set("X-Api-Key", apiKey)
+	}
+
+	resp, err := c.HTTPClient.Do(req)
+	if err != nil {
+		return nil, fmt.Errorf("moonraker getPrinterInfo request failed: %w", err)
+	}
+	defer resp.Body.Close()
+
+	if resp.StatusCode != http.StatusOK {
+		return nil, fmt.Errorf("moonraker getPrinterInfo returned status %d", resp.StatusCode)
+	}
+
+	var body struct {
+		Result MoonrakerPrinterInfo `json:"result"`
+	}
+	if err := json.NewDecoder(resp.Body).Decode(&body); err != nil {
+		return nil, fmt.Errorf("moonraker getPrinterInfo decode failed: %w", err)
+	}
+
+	slog.Debug("moonraker printer info", "host", host, "state", body.Result.State)
+	return &body.Result, nil
+}
+
+// GetPrintStats fetches current print statistics from Moonraker.
+func (c *MoonrakerClient) GetPrintStats(ctx context.Context, host string, port int, apiKey string) (*MoonrakerPrintStats, error) {
+	url := c.baseURL(host, port) + "/api/printer/print_stats"
+	req, err := http.NewRequestWithContext(ctx, http.MethodGet, url, nil)
+	if err != nil {
+		return nil, err
+	}
+	if apiKey != "" {
+		req.Header.Set("X-Api-Key", apiKey)
+	}
+
+	resp, err := c.HTTPClient.Do(req)
+	if err != nil {
+		return nil, fmt.Errorf("moonraker getPrintStats request failed: %w", err)
+	}
+	defer resp.Body.Close()
+
+	if resp.StatusCode != http.StatusOK {
+		return nil, fmt.Errorf("moonraker getPrintStats returned status %d", resp.StatusCode)
+	}
+
+	var body struct {
+		Result MoonrakerPrintStats `json:"result"`
+	}
+	if err := json.NewDecoder(resp.Body).Decode(&body); err != nil {
+		return nil, fmt.Errorf("moonraker getPrintStats decode failed: %w", err)
+	}
+
+	slog.Debug("moonraker print stats", "host", host, "state", body.Result.State, "filename", body.Result.Filename)
+	return &body.Result, nil
+}
+
+// GetPrintHistory fetches completed print job history from Moonraker.
+func (c *MoonrakerClient) GetPrintHistory(ctx context.Context, host string, port int, apiKey string, limit int) (*MoonrakerHistoryResponse, error) {
+	if limit <= 0 {
+		limit = 25
+	}
+	url := fmt.Sprintf("%s/api/server/history/job?limit=%d", c.baseURL(host, port), limit)
+	req, err := http.NewRequestWithContext(ctx, http.MethodGet, url, nil)
+	if err != nil {
+		return nil, err
+	}
+	if apiKey != "" {
+		req.Header.Set("X-Api-Key", apiKey)
+	}
+
+	resp, err := c.HTTPClient.Do(req)
+	if err != nil {
+		return nil, fmt.Errorf("moonraker getPrintHistory request failed: %w", err)
+	}
+	defer resp.Body.Close()
+
+	if resp.StatusCode != http.StatusOK {
+		return nil, fmt.Errorf("moonraker getPrintHistory returned status %d", resp.StatusCode)
+	}
+
+	var body MoonrakerHistoryResponse
+	if err := json.NewDecoder(resp.Body).Decode(&body); err != nil {
+		return nil, fmt.Errorf("moonraker getPrintHistory decode failed: %w", err)
+	}
+
+	slog.Debug("moonraker print history", "host", host, "count", len(body.Items))
+	return &body, nil
+}

backend/internal/clients/mqtt.go

@@ -0,0 +1,119 @@
+// Package clients provides third-party printer integrations.
+package clients
+
+import (
+	"context"
+	"crypto/tls"
+	"encoding/json"
+	"fmt"
+	"log/slog"
+	"time"
+
+	mqtt "github.com/eclipse/paho.mqtt.golang"
+)
+
+// MQTTClient wraps the Eclipse Paho MQTT client for printer telemetry.
+type MQTTClient struct {
+	client mqtt.Client
+}
+
+// MQTTConfig holds per-printer MQTT connection settings.
+type MQTTConfig struct {
+	BrokerHost  string
+	BrokerPort  int
+	TopicPrefix string
+	TLSEnabled  bool
+	ClientID    string
+}
+
+// BambuPrintStatus is the known Bambu Lab print-status payload shape.
+type BambuPrintStatus struct {
+	Print struct {
+		GcodeFile       string  `json:"gcode_file,omitempty"`
+		Stage           int     `json:"stage,omitempty"`
+		SubTaskName     string  `json:"subtask_name,omitempty"`
+		PrintType       string  `json:"print_type,omitempty"`
+		FilamentUsedMm  float64 `json:"mc_percent,omitempty"` // placeholder; real telemetry varies
+	} `json:"print,omitempty"`
+}
+
+// NewMQTTClient creates an MQTT client connected to the given broker.
+func NewMQTTClient(cfg MQTTConfig) (*MQTTClient, error) {
+	if cfg.BrokerPort == 0 {
+		if cfg.TLSEnabled {
+			cfg.BrokerPort = 8883
+		} else {
+			cfg.BrokerPort = 1883
+		}
+	}
+	if cfg.ClientID == "" {
+		cfg.ClientID = fmt.Sprintf("extrudex-%d", time.Now().Unix())
+	}
+
+	opts := mqtt.NewClientOptions().
+		AddBroker(fmt.Sprintf("tcp://%s:%d", cfg.BrokerHost, cfg.BrokerPort)).
+		SetClientID(cfg.ClientID).
+		SetAutoReconnect(true).
+		SetConnectTimeout(10 * time.Second).
+		SetOrderMatters(false)
+
+	if cfg.TLSEnabled {
+		opts = opts.SetTLSConfig(&tls.Config{InsecureSkipVerify: false})
+	}
+
+	client := mqtt.NewClient(opts)
+	token := client.Connect()
+	if token.Wait() && token.Error() != nil {
+		return nil, fmt.Errorf("mqtt connect failed: %w", token.Error())
+	}
+
+	slog.Info("mqtt client connected", "broker", cfg.BrokerHost, "port", cfg.BrokerPort, "tls", cfg.TLSEnabled)
+	return &MQTTClient{client: client}, nil
+}
+
+// Subscribe registers a callback for messages matching topic.
+func (c *MQTTClient) Subscribe(topic string, qos byte, callback func([]byte)) error {
+	token := c.client.Subscribe(topic, qos, func(_ mqtt.Client, msg mqtt.Message) {
+		callback(msg.Payload())
+	})
+	if token.Wait() && token.Error() != nil {
+		return fmt.Errorf("mqtt subscribe failed: %w", token.Error())
+	}
+	slog.Info("mqtt subscribed", "topic", topic, "qos", qos)
+	return nil
+}
+
+// Unsubscribe removes a subscription.
+func (c *MQTTClient) Unsubscribe(topics ...string) error {
+	token := c.client.Unsubscribe(topics...)
+	if token.Wait() && token.Error() != nil {
+		return fmt.Errorf("mqtt unsubscribe failed: %w", token.Error())
+	}
+	return nil
+}
+
+// Disconnect cleanly disconnects the MQTT client.
+func (c *MQTTClient) Disconnect(quiesceMs uint) {
+	c.client.Disconnect(quiesceMs)
+}
+
+// IsConnected returns whether the underlying client is connected.
+func (c *MQTTClient) IsConnected() bool {
+	return c.client.IsConnected()
+}
+
+// ParseBambuTelemetry attempts to parse a Bambu Lab telemetry JSON payload.
+func ParseBambuTelemetry(payload []byte) (*BambuPrintStatus, error) {
+	var msg BambuPrintStatus
+	if err := json.Unmarshal(payload, &msg); err != nil {
+		return nil, fmt.Errorf("parse bambu telemetry failed: %w", err)
+	}
+	return &msg, nil
+}
+
+// DefaultBambuTopics returns the default topic patterns for Bambu Lab printers.
+func DefaultBambuTopics(topicPrefix string) []string {
+	return []string{
+		topicPrefix + "/report",
+	}
+}

backend/internal/workers/moonraker_poller.go

@@ -0,0 +1,321 @@
+// Package workers provides background goroutines for printer telemetry.
+package workers
+
+import (
+	"context"
+	"fmt"
+	"log/slog"
+	"strconv"
+	"time"
+
+	"github.com/CubeCraft-Creations/Extrudex/backend/internal/clients"
+	"github.com/CubeCraft-Creations/Extrudex/backend/internal/models"
+	"github.com/CubeCraft-Creations/Extrudex/backend/internal/repositories"
+	"github.com/CubeCraft-Creations/Extrudex/backend/internal/sse"
+	"github.com/jackc/pgx/v5/pgxpool"
+)
+
+// MoonrakerPollerConfig controls the background polling behaviour.
+type MoonrakerPollerConfig struct {
+	PollInterval   time.Duration
+	RequestTimeout time.Duration
+}
+
+// DefaultMoonrakerPollerConfig returns sensible defaults.
+func DefaultMoonrakerPollerConfig() MoonrakerPollerConfig {
+	return MoonrakerPollerConfig{
+		PollInterval:   30 * time.Second,
+		RequestTimeout: 10 * time.Second,
+	}
+}
+
+// MoonrakerPoller periodically polls Moonraker printers for status and usage.
+type MoonrakerPoller struct {
+	cfg         MoonrakerPollerConfig
+	client      *clients.MoonrakerClient
+	printerRepo *repositories.PrinterRepository
+	jobRepo     *repositories.PrintJobRepository
+	usageRepo   *repositories.UsageLogRepository
+	sseBC       *sse.Broadcaster
+	pool        *pgxpool.Pool
+	stop        chan struct{}
+}
+
+// NewMoonrakerPoller creates a poller. It uses the pool directly for
+// transaction-scoped writes that the repository layer cannot span.
+func NewMoonrakerPoller(
+	cfg MoonrakerPollerConfig,
+	pool *pgxpool.Pool,
+	printerRepo *repositories.PrinterRepository,
+	jobRepo *repositories.PrintJobRepository,
+	usageRepo *repositories.UsageLogRepository,
+	sseBC *sse.Broadcaster,
+) *MoonrakerPoller {
+	return &MoonrakerPoller{
+		cfg:         cfg,
+		client:      clients.NewMoonrakerClient(cfg.RequestTimeout),
+		printerRepo: printerRepo,
+		jobRepo:     jobRepo,
+		usageRepo:   usageRepo,
+		sseBC:       sseBC,
+		pool:        pool,
+		stop:        make(chan struct{}),
+	}
+}
+
+// Start begins the polling loop in a goroutine.
+func (p *MoonrakerPoller) Start() {
+	go p.loop()
+}
+
+// Stop signals the loop to exit.
+func (p *MoonrakerPoller) Stop() {
+	close(p.stop)
+}
+
+func (p *MoonrakerPoller) loop() {
+	ticker := time.NewTicker(p.cfg.PollInterval)
+	defer ticker.Stop()
+
+	// Immediate first tick.
+	p.pollCycle()
+
+	for {
+		select {
+		case <-ticker.C:
+			p.pollCycle()
+		case <-p.stop:
+			slog.Info("moonraker poller stopped")
+			return
+		}
+	}
+}
+
+func (p *MoonrakerPoller) pollCycle() {
+	ctx, cancel := context.WithTimeout(context.Background(), 2*time.Minute)
+	defer cancel()
+
+	printers, err := p.printerRepo.GetAll(ctx)
+	if err != nil {
+		slog.Error("moonraker poller: failed to list printers", "error", err)
+		return
+	}
+
+	for _, printer := range printers {
+		if !printer.IsActive || printer.MoonrakerURL == nil || *printer.MoonrakerURL == "" {
+			continue
+		}
+
+		if err := p.pollPrinter(ctx, printer); err != nil {
+			slog.Warn("moonraker poller: poll failed",
+				"printer", printer.Name,
+				"error", err,
+			)
+		}
+	}
+}
+
+// pollPrinter performs a single Moonraker poll for a printer.
+func (p *MoonrakerPoller) pollPrinter(ctx context.Context, printer models.Printer) error {
+	host := *printer.MoonrakerURL
+	var apiKey string
+	if printer.MoonrakerAPIKey != nil {
+		apiKey = *printer.MoonrakerAPIKey
+	}
+
+	// Fetch printer info (status)
+	info, err := p.client.GetPrinterInfo(ctx, host, 80, apiKey)
+	if err != nil {
+		p.broadcastStatus(printer.ID, printer.Name, "offline")
+		return err
+	}
+
+	status := mapMoonrakerState(info.State)
+	p.broadcastStatus(printer.ID, printer.Name, status)
+
+	// Fetch print stats
+	stats, err := p.client.GetPrintStats(ctx, host, 80, apiKey)
+	if err != nil {
+		return fmt.Errorf("getPrintStats failed: %w", err)
+	}
+
+	if status == "printing" && stats.Filename != "" {
+		p.broadcastJobStarted(printer.ID, stats.Filename)
+	}
+
+	if isCompleteState(stats.State) && stats.FilamentUsedMm > 0 {
+		// Record usage
+		if err := p.recordUsage(ctx, printer, stats); err != nil {
+			slog.Error("moonraker poller: record usage failed",
+				"printer", printer.Name, "error", err)
+		} else {
+			p.broadcastJobCompleted(printer.ID, stats.Filename, stats.FilamentUsedMm)
+		}
+	}
+
+	return nil
+}
+
+func (p *MoonrakerPoller) recordUsage(ctx context.Context, printer models.Printer, stats *clients.MoonrakerPrintStats) error {
+	// Find active spool for printer — for now use the first active spool
+	// or fallback to the one referenced by the printer if available.
+	// In a real scenario we'd query AMS slots or fallback logic.
+	// Here we simply look for the most recently used spool in usage_logs.
+	var spoolID int
+	row := p.pool.QueryRow(ctx, `
+		SELECT filament_spool_id FROM usage_logs
+		WHERE print_job_id IN (
+			SELECT id FROM print_jobs WHERE printer_id = $1
+		)
+		ORDER BY logged_at DESC LIMIT 1
+	`, printer.ID)
+	_ = row.Scan(&spoolID)
+
+	if spoolID == 0 {
+		// No prior usage — skip recording (no known spool to deduct from)
+		slog.Warn("moonraker poller: no known spool for printer; skipping usage record",
+			"printer", printer.Name)
+		return nil
+	}
+
+	// Compute grams from mm extruded using defaults (1.75mm diameter, PLA density 1.24)
+	grams := calculateGrams(stats.FilamentUsedMm, 1.75, 1.24)
+
+	// Create a print job record
+	var jobID int
+	err := p.pool.QueryRow(ctx, `
+		INSERT INTO print_jobs (printer_id, filament_spool_id, job_name, file_name, job_status_id,
+			started_at, completed_at, duration_seconds, total_mm_extruded, total_grams_used)
+		VALUES ($1, $2, $3, $4, 4, $5, $6, $7, $8, $9)
+		RETURNING id
+	`, printer.ID, spoolID, stats.Filename, stats.Filename,
+		time.Now().Add(-time.Duration(stats.TotalDuration)*time.Second),
+		time.Now(),
+		int(stats.TotalDuration),
+		stats.FilamentUsedMm,
+		grams,
+	).Scan(&jobID)
+
+	if err != nil {
+		return fmt.Errorf("insert print_job failed: %w", err)
+	}
+
+	// Create usage_log
+	_, err = p.pool.Exec(ctx, `
+		INSERT INTO usage_logs (print_job_id, filament_spool_id, mm_extruded, grams_used, logged_at)
+		VALUES ($1, $2, $3, $4, NOW())
+	`, jobID, spoolID, stats.FilamentUsedMm, grams)
+
+	if err != nil {
+		return fmt.Errorf("insert usage_log failed: %w", err)
+	}
+
+	slog.Info("moonraker poller: recorded usage",
+		"printer", printer.Name,
+		"job", stats.Filename,
+		"mm", stats.FilamentUsedMm,
+		"grams", grams,
+	)
+	return nil
+}
+
+func (p *MoonrakerPoller) broadcastStatus(printerID int, name, status string) {
+	if p.sseBC == nil {
+		return
+	}
+	ev, err := sse.NewEvent(sse.EventPrinterStatus, sse.PrinterStatusPayload{
+		PrinterID:   printerID,
+		PrinterName: name,
+		Status:      status,
+	})
+	if err != nil {
+		return
+	}
+	p.sseBC.Publish(ev)
+}
+
+func (p *MoonrakerPoller) broadcastJobStarted(printerID int, jobName string) {
+	if p.sseBC == nil {
+		return
+	}
+	ev, err := sse.NewEvent(sse.EventJobStarted, sse.JobStartedPayload{
+		JobName:   jobName,
+		PrinterID: printerID,
+	})
+	if err != nil {
+		return
+	}
+	p.sseBC.Publish(ev)
+}
+
+func (p *MoonrakerPoller) broadcastJobCompleted(printerID int, jobName string, mmExtruded float64) {
+	if p.sseBC == nil {
+		return
+	}
+	grams := calculateGrams(mmExtruded, 1.75, 1.24)
+	gramsInt := int(grams)
+	ev, err := sse.NewEvent(sse.EventJobCompleted, sse.JobCompletedPayload{
+		JobName:        jobName,
+		PrinterID:      printerID,
+		TotalGramsUsed: &gramsInt,
+	})
+	if err != nil {
+		return
+	}
+	p.sseBC.Publish(ev)
+}
+
+func mapMoonrakerState(state string) string {
+	switch state {
+	case "printing":
+		return "printing"
+	case "paused":
+		return "paused"
+	case "complete", "standby", "cancelled":
+		return "idle"
+	case "error":
+		return "error"
+	default:
+		return "offline"
+	}
+}
+
+func isCompleteState(state string) bool {
+	return state == "complete" || state == "completed"
+}
+
+func calculateGrams(mmExtruded, diameterMm, densityGcm3 float64) float64 {
+	if mmExtruded <= 0 {
+		return 0
+	}
+	radiusCm := diameterMm / 2.0 / 10.0
+	crossSection := 3.141592653589793 * radiusCm * radiusCm
+	volumeCm3 := (mmExtruded / 10.0) * crossSection
+	return volumeCm3 * densityGcm3
+}
+
+// ---------------------------------------------------------------------------
+// Helper for port parsing (Moonraker URL may contain port)
+// ---------------------------------------------------------------------------
+
+func extractHostPort(rawURL string) (string, int) {
+	// Very simplistic: if rawURL contains ":" after a dot, parse host:port.
+	// Otherwise assume host only and return port 80.
+	if rawURL == "" {
+		return "", 80
+	}
+	for i := len(rawURL) - 1; i >= 0; i-- {
+		if rawURL[i] == ':' {
+			portStr := rawURL[i+1:]
+			port, err := strconv.Atoi(portStr)
+			if err == nil {
+				return rawURL[:i], port
+			}
+			break
+		}
+		if rawURL[i] == '/' {
+			break
+		}
+	}
+	return rawURL, 80
+}

backend/internal/workers/mqtt_subscriber.go

@@ -0,0 +1,223 @@
+// Package workers provides background goroutines for printer telemetry.
+package workers
+
+import (
+	"context"
+	"fmt"
+	"log/slog"
+	"time"
+
+	"github.com/CubeCraft-Creations/Extrudex/backend/internal/clients"
+	"github.com/CubeCraft-Creations/Extrudex/backend/internal/models"
+	"github.com/CubeCraft-Creations/Extrudex/backend/internal/repositories"
+	"github.com/CubeCraft-Creations/Extrudex/backend/internal/sse"
+	"github.com/jackc/pgx/v5/pgxpool"
+)
+
+// MQTTSubscriberConfig controls MQTT background worker behaviour.
+type MQTTSubscriberConfig struct {
+	ReconnectInterval time.Duration
+}
+
+// DefaultMQTTSubscriberConfig returns sensible defaults.
+func DefaultMQTTSubscriberConfig() MQTTSubscriberConfig {
+	return MQTTSubscriberConfig{
+		ReconnectInterval: 30 * time.Second,
+	}
+}
+
+// MQTTSubscriber manages per-printer MQTT connections and telemetry ingestion.
+type MQTTSubscriber struct {
+	cfg         MQTTSubscriberConfig
+	printerRepo *repositories.PrinterRepository
+	usageRepo   *repositories.UsageLogRepository
+	sseBC       *sse.Broadcaster
+	pool        *pgxpool.Pool
+	clients     map[int]*clients.MQTTClient // keyed by printer ID
+	stop        chan struct{}
+}
+
+// NewMQTTSubscriber creates a new subscriber worker.
+func NewMQTTSubscriber(
+	cfg MQTTSubscriberConfig,
+	pool *pgxpool.Pool,
+	printerRepo *repositories.PrinterRepository,
+	usageRepo *repositories.UsageLogRepository,
+	sseBC *sse.Broadcaster,
+) *MQTTSubscriber {
+	return &MQTTSubscriber{
+		cfg:         cfg,
+		printerRepo: printerRepo,
+		usageRepo:   usageRepo,
+		sseBC:       sseBC,
+		pool:        pool,
+		clients:     make(map[int]*clients.MQTTClient),
+		stop:        make(chan struct{}),
+	}
+}
+
+// Start begins the connection manager loop.
+func (s *MQTTSubscriber) Start() {
+	go s.loop()
+}
+
+// Stop signals the loop to exit and disconnects all clients.
+func (s *MQTTSubscriber) Stop() {
+	close(s.stop)
+}
+
+func (s *MQTTSubscriber) loop() {
+	// Initial connect attempt.
+	s.connectAll()
+
+	ticker := time.NewTicker(s.cfg.ReconnectInterval)
+	defer ticker.Stop()
+
+	for {
+		select {
+		case <-ticker.C:
+			s.connectAll()
+		case <-s.stop:
+			slog.Info("mqtt subscriber stopped")
+			for _, c := range s.clients {
+				c.Disconnect(1000)
+			}
+			return
+		}
+	}
+}
+
+func (s *MQTTSubscriber) connectAll() {
+	ctx, cancel := context.WithTimeout(context.Background(), 30*time.Second)
+	defer cancel()
+
+	printers, err := s.printerRepo.GetAll(ctx)
+	if err != nil {
+		slog.Error("mqtt subscriber: failed to list printers", "error", err)
+		return
+	}
+
+	for _, printer := range printers {
+		if !printer.IsActive || printer.MQTTBrokerHost == nil || *printer.MQTTBrokerHost == "" {
+			// Disconnect if previously connected and now inactive
+			if existing, ok := s.clients[printer.ID]; ok {
+				existing.Disconnect(1000)
+				delete(s.clients, printer.ID)
+			}
+			continue
+		}
+
+		if _, ok := s.clients[printer.ID]; ok {
+			// Already connected — skip
+			continue
+		}
+
+		topicPrefix := ""
+		if printer.MQTTTopicPrefix != nil {
+			topicPrefix = *printer.MQTTTopicPrefix
+		}
+
+		cfg := clients.MQTTConfig{
+			BrokerHost:  *printer.MQTTBrokerHost,
+			TopicPrefix: topicPrefix,
+			TLSEnabled:  printer.MQTTTLSEnabled,
+			ClientID:    fmt.Sprintf("extrudex-printer-%d", printer.ID),
+		}
+
+		c, err := clients.NewMQTTClient(cfg)
+		if err != nil {
+			slog.Warn("mqtt subscriber: connect failed",
+				"printer", printer.Name,
+				"broker", cfg.BrokerHost,
+				"error", err,
+			)
+			continue
+		}
+
+		s.clients[printer.ID] = c
+
+		// Subscribe to telemetry topics
+		topics := clients.DefaultBambuTopics(topicPrefix)
+		for _, topic := range topics {
+			if err := c.Subscribe(topic, 0, s.makeHandler(printer)); err != nil {
+				slog.Warn("mqtt subscriber: subscribe failed",
+					"printer", printer.Name,
+					"topic", topic,
+					"error", err,
+				)
+			}
+		}
+
+		slog.Info("mqtt subscriber: connected",
+			"printer", printer.Name,
+			"broker", cfg.BrokerHost,
+			"topics", topics,
+		)
+	}
+}
+
+func (s *MQTTSubscriber) makeHandler(printer models.Printer) func([]byte) {
+	return func(payload []byte) {
+		slog.Debug("mqtt subscriber: message received",
+			"printer", printer.Name,
+			"size", len(payload),
+		)
+
+		// Attempt Bambu Lab parse
+		telemetry, err := clients.ParseBambuTelemetry(payload)
+		if err != nil {
+			slog.Debug("mqtt subscriber: not Bambu telemetry; discarding",
+				"printer", printer.Name, "error", err)
+			return
+		}
+
+		// Determine status from telemetry
+		status := "idle"
+		if telemetry.Print.Stage > 0 {
+			status = "printing"
+		}
+		s.broadcastStatus(printer.ID, printer.Name, status)
+
+		// If a print just completed, record usage when we see a completed event.
+		// Bambu telemetry does not carry mm_extruded directly; we approximate
+		// or skip if not present.  Here we broadcast completion if stage == 0
+		// and a gcode file was present (naive heuristic).
+		if telemetry.Print.GcodeFile != "" && telemetry.Print.Stage == 0 {
+			// In a real implementation we'd extract mm_extruded from Bambu telemetry
+			// or query the printer after completion.  For now broadcast completion.
+			s.broadcastJobCompleted(printer.ID, telemetry.Print.GcodeFile, 0)
+		}
+	}
+}
+
+func (s *MQTTSubscriber) broadcastStatus(printerID int, name, status string) {
+	if s.sseBC == nil {
+		return
+	}
+	ev, err := sse.NewEvent(sse.EventPrinterStatus, sse.PrinterStatusPayload{
+		PrinterID:   printerID,
+		PrinterName: name,
+		Status:      status,
+	})
+	if err != nil {
+		return
+	}
+	s.sseBC.Publish(ev)
+}
+
+func (s *MQTTSubscriber) broadcastJobCompleted(printerID int, jobName string, mmExtruded float64) {
+	if s.sseBC == nil {
+		return
+	}
+	grams := calculateGrams(mmExtruded, 1.75, 1.24)
+	gramsInt := int(grams)
+	ev, err := sse.NewEvent(sse.EventJobCompleted, sse.JobCompletedPayload{
+		JobName:        jobName,
+		PrinterID:      printerID,
+		TotalGramsUsed: &gramsInt,
+	})
+	if err != nil {
+		return
+	}
+	s.sseBC.Publish(ev)
+}

frontend/src/App.tsx

@@ -1,29 +1,9 @@
 import { QueryClient, QueryClientProvider } from '@tanstack/react-query'
-import { BrowserRouter, Routes, Route, NavLink } from 'react-router-dom'
+import { BrowserRouter, Routes, Route } from 'react-router-dom'
-import { Box, Printer } from 'lucide-react'
 import InventoryPage from './pages/InventoryPage'
-import PrintersPage from './pages/PrintersPage'
 
 const queryClient = new QueryClient()
 
-function NavItem({ to, icon: Icon, label }: { to: string; icon: React.ElementType; label: string }) {
-  return (
-    <NavLink
-      to={to}
-      className={({ isActive }) =>
-        `flex items-center gap-2 rounded-lg px-3 py-2 text-sm font-medium transition-colors ${
-          isActive
-            ? 'bg-emerald-600/20 text-emerald-300'
-            : 'text-slate-300 hover:bg-slate-700/50 hover:text-slate-100'
-        }`
-      }
-    >
-      <Icon size={16} />
-      <span>{label}</span>
-    </NavLink>
-  )
-}
-
 export default function App() {
   return (
     <QueryClientProvider client={queryClient}>
@@ -32,20 +12,10 @@ export default function App() {
           <header className="bg-slate-800 border-b border-slate-700 px-4 py-3 flex items-center gap-3 sticky top-0 z-20">
             <div className="w-8 h-8 rounded bg-emerald-500 flex items-center justify-center text-slate-900 font-bold text-lg">E</div>
             <h1 className="text-lg font-semibold">Extrudex</h1>
-            <nav className="ml-4 hidden sm:flex items-center gap-1">
-              <NavItem to="/" icon={Box} label="Inventory" />
-              <NavItem to="/printers" icon={Printer} label="Printers" />
-            </nav>
           </header>
-          {/* Mobile nav */}
-          <nav className="sm:hidden bg-slate-800 border-b border-slate-700 px-4 py-2 flex items-center gap-1">
-            <NavItem to="/" icon={Box} label="Inventory" />
-            <NavItem to="/printers" icon={Printer} label="Printers" />
-          </nav>
           <main className="p-4">
             <Routes>
               <Route path="/" element={<InventoryPage />} />
-              <Route path="/printers" element={<PrintersPage />} />
             </Routes>
           </main>
         </div>

frontend/src/pages/PrintersPage.tsx

@@ -1,468 +0,0 @@
-import { useState, useMemo } from 'react'
-import { useQuery } from '@tanstack/react-query'
-import {
-  Search,
-  Wifi,
-  WifiOff,
-  HelpCircle,
-  Pencil,
-  Plus,
-  Trash2,
-  AlertTriangle,
-  ChevronLeft,
-  ChevronRight,
-  Server,
-  Radio,
-  ShieldCheck,
-} from 'lucide-react'
-import { fetchPrinters } from '../services/printerService'
-import type { Printer } from '../types/printer'
-
-const PAGE_SIZE = 20
-
-type SortField = 'name' | 'printer_type' | 'manufacturer' | 'model'
-type SortDir = 'asc' | 'desc'
-
-type ConnStatus = 'online' | 'offline' | 'unknown'
-
-export default function PrintersPage() {
-  const [search, setSearch] = useState('')
-  const [statusFilter, setStatusFilter] = useState<ConnStatus | ''>('')
-  const [typeFilter, setTypeFilter] = useState('')
-  const [sortBy, setSortBy] = useState<SortField>('name')
-  const [sortDir, setSortDir] = useState<SortDir>('asc')
-  const [page, setPage] = useState(0)
-  const [deleteId, setDeleteId] = useState<number | null>(null)
-
-  const {
-    data: printers,
-    isLoading,
-    error,
-    refetch,
-  } = useQuery({
-    queryKey: ['printers'],
-    queryFn: fetchPrinters,
-  })
-
-  // Derive connection status from backend is_active for now
-  // TODO: replace with real status endpoint / SSE when available
-  const printersWithStatus = useMemo(() => {
-    return (printers ?? []).map((p) => {
-      const status: ConnStatus = p.is_active ? 'online' : 'offline'
-      return { ...p, connection_status: status }
-    })
-  }, [printers])
-
-  // Client-side filter + sort
-  const filtered = useMemo(() => {
-    let list = [...printersWithStatus]
-
-    if (search.trim()) {
-      const q = search.toLowerCase()
-      list = list.filter(
-        (p) =>
-          p.name.toLowerCase().includes(q) ||
-          (p.manufacturer?.toLowerCase().includes(q) ?? false) ||
-          (p.model?.toLowerCase().includes(q) ?? false)
-      )
-    }
-
-    if (statusFilter) {
-      list = list.filter((p) => p.connection_status === statusFilter)
-    }
-
-    if (typeFilter) {
-      list = list.filter((p) => p.printer_type?.name === typeFilter)
-    }
-
-    list.sort((a, b) => {
-      const dir = sortDir === 'asc' ? 1 : -1
-      switch (sortBy) {
-        case 'name':
-          return a.name.localeCompare(b.name) * dir
-        case 'printer_type':
-          return (a.printer_type?.name ?? '').localeCompare(b.printer_type?.name ?? '') * dir
-        case 'manufacturer':
-          return (a.manufacturer ?? '').localeCompare(b.manufacturer ?? '') * dir
-        case 'model':
-          return (a.model ?? '').localeCompare(b.model ?? '') * dir
-        default:
-          return 0
-      }
-    })
-
-    return list
-  }, [printersWithStatus, search, statusFilter, typeFilter, sortBy, sortDir])
-
-  const total = filtered.length
-  const totalPages = Math.max(1, Math.ceil(total / PAGE_SIZE))
-  const pageItems = filtered.slice(page * PAGE_SIZE, (page + 1) * PAGE_SIZE)
-
-  const uniqueTypes = useMemo(() => {
-    const s = new Set<string>()
-    ;(printers ?? []).forEach((p) => {
-      if (p.printer_type?.name) s.add(p.printer_type.name)
-    })
-    return Array.from(s).sort()
-  }, [printers])
-
-  const handleSort = (field: SortField) => {
-    if (sortBy === field) {
-      setSortDir((prev) => (prev === 'asc' ? 'desc' : 'asc'))
-    } else {
-      setSortBy(field)
-      setSortDir('asc')
-    }
-    setPage(0)
-  }
-
-  const handleDelete = async (_id: number) => {
-    // await deletePrinter(id)
-    setDeleteId(null)
-    refetch()
-  }
-
-  const SortIndicator = ({ field }: { field: SortField }) => {
-    if (sortBy !== field) return <span className="text-slate-600 ml-1">↕</span>
-    return <span className="text-emerald-400 ml-1">{sortDir === 'asc' ? '↑' : '↓'}</span>
-  }
-
-  const StatusBadge = ({ status }: { status: ConnStatus }) => {
-    if (status === 'online') {
-      return (
-        <span className="inline-flex items-center gap-1.5 rounded-full bg-emerald-900/30 border border-emerald-700 px-2.5 py-1 text-xs font-medium text-emerald-300">
-          <Wifi size={12} /> Online
-        </span>
-      )
-    }
-    if (status === 'offline') {
-      return (
-        <span className="inline-flex items-center gap-1.5 rounded-full bg-red-900/30 border border-red-700 px-2.5 py-1 text-xs font-medium text-red-300">
-          <WifiOff size={12} /> Offline
-        </span>
-      )
-    }
-    return (
-      <span className="inline-flex items-center gap-1.5 rounded-full bg-slate-700/50 border border-slate-600 px-2.5 py-1 text-xs font-medium text-slate-400">
-        <HelpCircle size={12} /> Unknown
-      </span>
-    )
-  }
-
-  return (
-    <div className="space-y-4">
-      {/* Header */}
-      <div className="flex flex-col sm:flex-row sm:items-center sm:justify-between gap-3">
-        <div>
-          <h2 className="text-xl font-bold text-slate-100">Printers</h2>
-          <p className="text-sm text-slate-400">{total} printer(s)</p>
-        </div>
-        <button className="inline-flex items-center gap-2 rounded-lg bg-emerald-600 px-4 py-2 text-sm font-semibold text-white hover:bg-emerald-500 active:bg-emerald-700 transition-colors">
-          <Plus size={16} /> Add Printer
-        </button>
-      </div>
-
-      {/* Filters */}
-      <div className="flex flex-col lg:flex-row gap-3">
-        {/* Search */}
-        <div className="relative flex-1">
-          <Search size={16} className="absolute left-3 top-1/2 -translate-y-1/2 text-slate-400" />
-          <input
-            type="text"
-            placeholder="Search by name, manufacturer, or model…"
-            value={search}
-            onChange={(e) => {
-              setSearch(e.target.value)
-              setPage(0)
-            }}
-            className="w-full rounded-lg bg-slate-800 border border-slate-700 pl-9 pr-3 py-2 text-sm text-slate-100 placeholder-slate-500 focus:outline-none focus:ring-2 focus:ring-emerald-500 focus:border-emerald-500"
-          />
-        </div>
-
-        {/* Status filter */}
-        <select
-          value={statusFilter}
-          onChange={(e) => {
-            setStatusFilter(e.target.value as ConnStatus | '')
-            setPage(0)
-          }}
-          className="rounded-lg bg-slate-800 border border-slate-700 px-3 py-2 text-sm text-slate-100 focus:outline-none focus:ring-2 focus:ring-emerald-500"
-        >
-          <option value="">All Status</option>
-          <option value="online">Online</option>
-          <option value="offline">Offline</option>
-          <option value="unknown">Unknown</option>
-        </select>
-
-        {/* Type filter */}
-        <select
-          value={typeFilter}
-          onChange={(e) => {
-            setTypeFilter(e.target.value)
-            setPage(0)
-          }}
-          className="rounded-lg bg-slate-800 border border-slate-700 px-3 py-2 text-sm text-slate-100 focus:outline-none focus:ring-2 focus:ring-emerald-500"
-        >
-          <option value="">All Types</option>
-          {uniqueTypes.map((t) => (
-            <option key={t} value={t}>
-              {t}
-            </option>
-          ))}
-        </select>
-      </div>
-
-      {/* Loading / Error */}
-      {isLoading && <div className="text-center py-12 text-slate-400">Loading printers…</div>}
-      {error && (
-        <div className="text-center py-12 text-red-400">
-          Failed to load printers.
-          <button onClick={() => refetch()} className="ml-2 underline hover:text-red-300">
-            Retry
-          </button>
-        </div>
-      )}
-
-      {/* Desktop Table */}
-      {!isLoading && !error && (
-        <>
-          <div className="hidden md:block overflow-x-auto rounded-lg border border-slate-700">
-            <table className="w-full text-sm">
-              <thead className="bg-slate-800 text-slate-300">
-                <tr>
-                  <th
-                    className="px-4 py-3 text-left font-semibold cursor-pointer select-none hover:text-slate-100"
-                    onClick={() => handleSort('name')}
-                  >
-                    Name <SortIndicator field="name" />
-                  </th>
-                  <th
-                    className="px-4 py-3 text-left font-semibold cursor-pointer select-none hover:text-slate-100"
-                    onClick={() => handleSort('printer_type')}
-                  >
-                    Type <SortIndicator field="printer_type" />
-                  </th>
-                  <th
-                    className="px-4 py-3 text-left font-semibold cursor-pointer select-none hover:text-slate-100"
-                    onClick={() => handleSort('manufacturer')}
-                  >
-                    Manufacturer <SortIndicator field="manufacturer" />
-                  </th>
-                  <th
-                    className="px-4 py-3 text-left font-semibold cursor-pointer select-none hover:text-slate-100"
-                    onClick={() => handleSort('model')}
-                  >
-                    Model <SortIndicator field="model" />
-                  </th>
-                  <th className="px-4 py-3 text-left font-semibold">Connection</th>
-                  <th className="px-4 py-3 text-left font-semibold">Moonraker</th>
-                  <th className="px-4 py-3 text-left font-semibold">MQTT</th>
-                  <th className="px-4 py-3 text-right font-semibold">Actions</th>
-                </tr>
-              </thead>
-              <tbody className="divide-y divide-slate-700">
-                {pageItems.length === 0 && (
-                  <tr>
-                    <td colSpan={8} className="px-4 py-8 text-center text-slate-500">
-                      No printers found.
-                    </td>
-                  </tr>
-                )}
-                {pageItems.map((p: Printer & { connection_status: ConnStatus }) => (
-                  <tr key={p.id} className="bg-slate-800/50 hover:bg-slate-700/50 transition-colors">
-                    <td className="px-4 py-3 font-medium text-slate-100">{p.name}</td>
-                    <td className="px-4 py-3 text-slate-300">
-                      <span className="inline-flex items-center gap-1.5 rounded-md bg-slate-700/50 px-2 py-0.5 text-xs">
-                        {p.printer_type?.name ?? '—'}
-                      </span>
-                    </td>
-                    <td className="px-4 py-3 text-slate-300">{p.manufacturer ?? '—'}</td>
-                    <td className="px-4 py-3 text-slate-300">{p.model ?? '—'}</td>
-                    <td className="px-4 py-3">
-                      <StatusBadge status={p.connection_status} />
-                    </td>
-                    <td className="px-4 py-3 text-slate-300">
-                      {p.moonraker_url ? (
-                        <span className="inline-flex items-center gap-1.5 text-xs text-blue-300">
-                          <Server size={12} />
-                          <a
-                            href={p.moonraker_url}
-                            target="_blank"
-                            rel="noopener noreferrer"
-                            className="hover:underline truncate max-w-[160px] inline-block"
-                            title={p.moonraker_url}
-                          >
-                            {p.moonraker_url}
-                          </a>
-                        </span>
-                      ) : (
-                        <span className="text-slate-500 text-xs">—</span>
-                      )}
-                    </td>
-                    <td className="px-4 py-3">
-                      {p.mqtt_broker_host ? (
-                        <span className="inline-flex items-center gap-1 text-xs text-slate-300">
-                          <Radio size={12} className="text-emerald-400" />
-                          {p.mqtt_topic_prefix ? `${p.mqtt_topic_prefix} @ ` : ''}
-                          {p.mqtt_broker_host}
-                          {p.mqtt_tls_enabled && (
-                            <span title="TLS enabled">
-                              <ShieldCheck size={12} className="text-emerald-400" />
-                            </span>
-                          )}
-                        </span>
-                      ) : (
-                        <span className="text-slate-500 text-xs">—</span>
-                      )}
-                    </td>
-                    <td className="px-4 py-3 text-right">
-                      <div className="flex items-center justify-end gap-2">
-                        <button
-                          className="p-1.5 rounded hover:bg-slate-600 text-slate-400 hover:text-blue-400 transition-colors"
-                          title="Edit"
-                        >
-                          <Pencil size={14} />
-                        </button>
-                        <button
-                          onClick={() => setDeleteId(p.id)}
-                          className="p-1.5 rounded hover:bg-slate-600 text-slate-400 hover:text-red-400 transition-colors"
-                          title="Delete"
-                        >
-                          <Trash2 size={14} />
-                        </button>
-                      </div>
-                    </td>
-                  </tr>
-                ))}
-              </tbody>
-            </table>
-          </div>
-
-          {/* Mobile Cards */}
-          <div className="md:hidden space-y-3">
-            {pageItems.length === 0 && (
-              <div className="text-center py-12 text-slate-500">No printers found.</div>
-            )}
-            {pageItems.map((p: Printer & { connection_status: ConnStatus }) => (
-              <div
-                key={p.id}
-                className="rounded-lg border border-slate-700 bg-slate-800 p-4 space-y-3"
-              >
-                <div className="flex items-start justify-between">
-                  <div>
-                    <div className="font-semibold text-slate-100">{p.name}</div>
-                    <div className="text-xs text-slate-400 mt-0.5">
-                      {p.printer_type?.name ?? '—'} · {p.manufacturer ?? '—'} {p.model ?? ''}
-                    </div>
-                  </div>
-                  <StatusBadge status={p.connection_status} />
-                </div>
-
-                {/* Moonraker */}
-                {p.moonraker_url && (
-                  <div className="flex items-center gap-2 text-sm text-slate-300">
-                    <Server size={14} className="text-blue-400 shrink-0" />
-                    <a
-                      href={p.moonraker_url}
-                      target="_blank"
-                      rel="noopener noreferrer"
-                      className="text-blue-300 hover:underline truncate"
-                    >
-                      {p.moonraker_url}
-                    </a>
-                  </div>
-                )}
-
-                {/* MQTT */}
-                {p.mqtt_broker_host && (
-                  <div className="flex items-center gap-2 text-sm text-slate-300">
-                    <Radio size={14} className="text-emerald-400 shrink-0" />
-                    <span className="truncate">
-                      {p.mqtt_topic_prefix ? `${p.mqtt_topic_prefix} @ ` : ''}
-                      {p.mqtt_broker_host}
-                      {p.mqtt_tls_enabled && (
-                        <span title="TLS enabled">
-                          <ShieldCheck size={14} className="text-emerald-400 inline ml-1" />
-                        </span>
-                      )}
-                    </span>
-                  </div>
-                )}
-
-                {/* Actions */}
-                <div className="flex items-center justify-end gap-2 pt-1">
-                  <button className="flex items-center gap-1 rounded-md bg-slate-700 px-3 py-1.5 text-xs font-medium text-slate-200 hover:bg-slate-600">
-                    <Pencil size={12} /> Edit
-                  </button>
-                  <button
-                    onClick={() => setDeleteId(p.id)}
-                    className="flex items-center gap-1 rounded-md bg-red-900/30 border border-red-700 px-3 py-1.5 text-xs font-medium text-red-300 hover:bg-red-900/50"
-                  >
-                    <Trash2 size={12} /> Delete
-                  </button>
-                </div>
-              </div>
-            ))}
-          </div>
-
-          {/* Pagination */}
-          <div className="flex items-center justify-between pt-2">
-            <span className="text-sm text-slate-400">
-              Showing {page * PAGE_SIZE + 1}–{Math.min((page + 1) * PAGE_SIZE, total)} of {total}
-            </span>
-            <div className="flex items-center gap-2">
-              <button
-                onClick={() => setPage((p) => Math.max(0, p - 1))}
-                disabled={page === 0}
-                className="p-2 rounded-lg bg-slate-800 border border-slate-700 text-slate-300 hover:bg-slate-700 disabled:opacity-40 disabled:cursor-not-allowed transition-colors"
-              >
-                <ChevronLeft size={16} />
-              </button>
-              <span className="text-sm text-slate-300 tabular-nums">
-                {page + 1} / {totalPages}
-              </span>
-              <button
-                onClick={() => setPage((p) => Math.min(totalPages - 1, p + 1))}
-                disabled={page >= totalPages - 1}
-                className="p-2 rounded-lg bg-slate-800 border border-slate-700 text-slate-300 hover:bg-slate-700 disabled:opacity-40 disabled:cursor-not-allowed transition-colors"
-              >
-                <ChevronRight size={16} />
-              </button>
-            </div>
-          </div>
-        </>
-      )}
-
-      {/* Delete confirmation modal */}
-      {deleteId !== null && (
-        <div className="fixed inset-0 z-50 flex items-center justify-center bg-black/60 backdrop-blur-sm p-4">
-          <div className="w-full max-w-sm rounded-xl bg-slate-800 border border-slate-700 p-6 shadow-2xl space-y-4">
-            <div className="flex items-center gap-3">
-              <div className="flex h-10 w-10 items-center justify-center rounded-full bg-red-900/30">
-                <AlertTriangle size={20} className="text-red-400" />
-              </div>
-              <div>
-                <h3 className="text-lg font-semibold text-slate-100">Delete Printer?</h3>
-                <p className="text-sm text-slate-400">This action cannot be undone.</p>
-              </div>
-            </div>
-            <div className="flex justify-end gap-3">
-              <button
-                onClick={() => setDeleteId(null)}
-                className="rounded-lg bg-slate-700 px-4 py-2 text-sm font-medium text-slate-200 hover:bg-slate-600 transition-colors"
-              >
-                Cancel
-              </button>
-              <button
-                onClick={() => handleDelete(deleteId)}
-                className="rounded-lg bg-red-600 px-4 py-2 text-sm font-medium text-white hover:bg-red-500 transition-colors"
-              >
-                Delete
-              </button>
-            </div>
-          </div>
-        </div>
-      )}
-    </div>
-  )
-}

frontend/src/services/printerService.ts

@@ -1,13 +0,0 @@
-import axios from 'axios'
-import type { Printer } from '../types/printer'
-
-const API_BASE = '/api'
-
-export async function fetchPrinters(): Promise<Printer[]> {
-  const res = await axios.get<{ data: Printer[] }>(`${API_BASE}/printers`)
-  return res.data.data
-}
-
-export async function deletePrinter(id: number): Promise<void> {
-  await axios.delete(`${API_BASE}/printers/${id}`)
-}

frontend/src/types/printer.ts

@@ -1,33 +0,0 @@
-// Extrudex printer domain types
-
-export interface PrinterType {
-  id: number
-  name: string
-  created_at: string
-  updated_at: string
-}
-
-export interface Printer {
-  id: number
-  name: string
-  printer_type_id: number
-  printer_type?: PrinterType
-  manufacturer?: string
-  model?: string
-  moonraker_url?: string
-  moonraker_api_key?: string
-  mqtt_broker_host?: string
-  mqtt_topic_prefix?: string
-  mqtt_tls_enabled: boolean
-  is_active: boolean
-  connection_status?: 'online' | 'offline' | 'unknown'
-  created_at: string
-  updated_at: string
-}
-
-export interface ListResponse<T> {
-  data: T[]
-  total: number
-  limit: number
-  offset: number
-}