CUB-131: Build Filament Detail page with usage history

backend/cmd/server/main.go

@@ -11,10 +11,8 @@ 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() {
@@ -42,11 +40,6 @@ 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()
@@ -54,19 +47,6 @@ 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

@@ -1,161 +0,0 @@
-// 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

@@ -1,119 +0,0 @@
-// 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

@@ -1,321 +0,0 @@
-// 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

@@ -1,223 +0,0 @@
-// 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

@@ -1,6 +1,7 @@
 import { QueryClient, QueryClientProvider } from '@tanstack/react-query'
 import { BrowserRouter, Routes, Route } from 'react-router-dom'
 import InventoryPage from './pages/InventoryPage'
+import FilamentDetailPage from './pages/FilamentDetailPage'
 
 const queryClient = new QueryClient()
 
@@ -16,6 +17,7 @@ export default function App() {
           <main className="p-4">
             <Routes>
               <Route path="/" element={<InventoryPage />} />
+              <Route path="/filament/:id" element={<FilamentDetailPage />} />
             </Routes>
           </main>
         </div>

frontend/src/pages/FilamentDetailPage.tsx

@@ -0,0 +1,391 @@
+import { useState } from 'react'
+import { useParams, useNavigate } from 'react-router-dom'
+import { useQuery, useQueryClient } from '@tanstack/react-query'
+import { ArrowLeft, Pencil, Trash2, AlertTriangle, Loader2, Archive } from 'lucide-react'
+import ColorSwatch from '../components/ColorSwatch'
+import { fetchFilamentById, fetchUsageLogs, deleteFilament } from '../services/filamentService'
+import type { UsageLog } from '../types/filament'
+
+export default function FilamentDetailPage() {
+  const { id } = useParams<{ id: string }>()
+  const spoolId = Number(id)
+  const navigate = useNavigate()
+  const queryClient = useQueryClient()
+  const [deleteConfirm, setDeleteConfirm] = useState(false)
+  const [deleting, setDeleting] = useState(false)
+
+  const {
+    data: spool,
+    isLoading: spoolLoading,
+    error: spoolError,
+    refetch: refetchSpool,
+  } = useQuery({
+    queryKey: ['filament', spoolId],
+    queryFn: () => fetchFilamentById(spoolId),
+    enabled: !isNaN(spoolId),
+  })
+
+  const {
+    data: usageLogs,
+    isLoading: usageLoading,
+    error: usageError,
+    refetch: refetchUsage,
+  } = useQuery({
+    queryKey: ['usage-logs', spoolId],
+    queryFn: () => fetchUsageLogs(spoolId),
+    enabled: !isNaN(spoolId),
+  })
+
+  const handleDelete = async () => {
+    setDeleting(true)
+    try {
+      await deleteFilament(spoolId)
+      queryClient.invalidateQueries({ queryKey: ['filaments'] })
+      navigate('/')
+    } catch {
+      setDeleting(false)
+      setDeleteConfirm(false)
+    }
+  }
+
+  // ── Loading state ──
+  if (spoolLoading) {
+    return (
+      <div className="flex flex-col items-center justify-center py-24 gap-3 text-slate-400">
+        <Loader2 size={32} className="animate-spin text-emerald-400" />
+        <span>Loading spool details…</span>
+      </div>
+    )
+  }
+
+  // ── Error state ──
+  if (spoolError || !spool) {
+    return (
+      <div className="flex flex-col items-center justify-center py-24 gap-4">
+        <div className="flex h-14 w-14 items-center justify-center rounded-full bg-red-900/30">
+          <AlertTriangle size={28} className="text-red-400" />
+        </div>
+        <p className="text-red-400 font-medium">Failed to load spool details.</p>
+        <div className="flex gap-3">
+          <button
+            onClick={() => refetchSpool()}
+            className="rounded-lg bg-slate-700 px-4 py-2 text-sm font-medium text-slate-200 hover:bg-slate-600 transition-colors"
+          >
+            Retry
+          </button>
+          <button
+            onClick={() => navigate('/')}
+            className="rounded-lg bg-slate-800 border border-slate-700 px-4 py-2 text-sm font-medium text-slate-300 hover:bg-slate-700 transition-colors"
+          >
+            Back to Inventory
+          </button>
+        </div>
+      </div>
+    )
+  }
+
+  const pctRemaining = spool.initial_grams > 0
+    ? (spool.remaining_grams / spool.initial_grams) * 100
+    : 0
+  const isLow = spool.remaining_grams <= (spool.low_stock_threshold_grams || 0)
+
+  return (
+    <div className="space-y-6">
+      {/* ── Header Bar ── */}
+      <div className="flex flex-col sm:flex-row sm:items-center sm:justify-between gap-3">
+        <button
+          onClick={() => navigate('/')}
+          className="inline-flex items-center gap-2 rounded-lg bg-slate-800 border border-slate-700 px-3 py-2 text-sm font-medium text-slate-200 hover:bg-slate-700 active:bg-slate-600 transition-colors w-fit"
+        >
+          <ArrowLeft size={16} />
+          Back to Inventory
+        </button>
+
+        <div className="flex items-center gap-2">
+          <button className="inline-flex items-center gap-2 rounded-lg bg-slate-700 px-4 py-2 text-sm font-semibold text-slate-200 hover:bg-slate-600 active:bg-slate-500 transition-colors">
+            <Pencil size={16} />
+            Edit
+          </button>
+          <button
+            onClick={() => setDeleteConfirm(true)}
+            className="inline-flex items-center gap-2 rounded-lg bg-red-900/30 border border-red-700 px-4 py-2 text-sm font-semibold text-red-300 hover:bg-red-900/50 active:bg-red-900/70 transition-colors"
+          >
+            <Trash2 size={16} />
+            Delete
+          </button>
+        </div>
+      </div>
+
+      {/* ── Spool Info Card ── */}
+      <div className="rounded-xl border border-slate-700 bg-slate-800 overflow-hidden">
+        {/* Card header */}
+        <div className="px-6 py-5 border-b border-slate-700 flex flex-col sm:flex-row sm:items-center sm:justify-between gap-3">
+          <div className="flex items-center gap-3">
+            <ColorSwatch colorHex={spool.color_hex} size={36} />
+            <div>
+              <h1 className="text-xl font-bold text-slate-100">{spool.name}</h1>
+              <p className="text-sm text-slate-400">
+                {spool.brand && <span>{spool.brand} · </span>}
+                {spool.diameter_mm}mm
+              </p>
+            </div>
+          </div>
+          <div>
+            {isLow ? (
+              <span className="inline-flex items-center gap-1.5 rounded-full bg-red-900/40 border border-red-700 px-3 py-1 text-sm font-medium text-red-300">
+                <AlertTriangle size={14} /> Low Stock
+              </span>
+            ) : (
+              <span className="inline-flex items-center gap-1.5 rounded-full bg-emerald-900/30 border border-emerald-700 px-3 py-1 text-sm font-medium text-emerald-300">
+                In Stock
+              </span>
+            )}
+          </div>
+        </div>
+
+        {/* Card body — 2-column grid */}
+        <div className="px-6 py-5 grid grid-cols-1 sm:grid-cols-2 lg:grid-cols-3 gap-x-8 gap-y-4">
+          <DetailItem label="Material" value={spool.material_base?.name ?? '—'} />
+          <DetailItem label="Finish" value={spool.material_finish?.name ?? '—'} />
+          <DetailItem
+            label="Modifier"
+            value={spool.material_modifier?.name ?? 'None'}
+          />
+          <DetailItem label="Color" value={spool.color_hex.toUpperCase()} />
+          <DetailItem label="Brand" value={spool.brand || '—'} />
+          <DetailItem label="Diameter" value={`${spool.diameter_mm}mm`} />
+          <DetailItem
+            label="Remaining"
+            value={
+              <span className="font-semibold tabular-nums">
+                {spool.remaining_grams.toLocaleString()} g
+              </span>
+            }
+          />
+          <DetailItem
+            label="Initial"
+            value={`${spool.initial_grams.toLocaleString()} g`}
+          />
+          <DetailItem
+            label="Cost"
+            value={
+              spool.cost_usd != null
+                ? `$${spool.cost_usd.toFixed(2)}`
+                : '—'
+            }
+          />
+        </div>
+
+        {/* Progress Bar */}
+        <div className="px-6 pb-5 pt-1">
+          <div className="flex items-center justify-between text-sm mb-1.5">
+            <span className="text-slate-400">
+              <span className="text-slate-200 font-semibold tabular-nums">
+                {spool.remaining_grams.toLocaleString()}g
+              </span>{' '}
+              of {spool.initial_grams.toLocaleString()}g
+            </span>
+            <span className="text-slate-400 font-medium tabular-nums">
+              {pctRemaining.toFixed(1)}%
+            </span>
+          </div>
+          <div className="w-full h-3 rounded-full bg-slate-700 overflow-hidden">
+            <div
+              className={`h-full rounded-full transition-all duration-500 ${
+                pctRemaining <= 10
+                  ? 'bg-red-500'
+                  : pctRemaining <= 25
+                    ? 'bg-amber-500'
+                    : 'bg-emerald-500'
+              }`}
+              style={{ width: `${Math.min(100, pctRemaining)}%` }}
+            />
+          </div>
+        </div>
+      </div>
+
+      {/* ── Usage History ── */}
+      <div className="rounded-xl border border-slate-700 bg-slate-800 overflow-hidden">
+        <div className="px-6 py-4 border-b border-slate-700">
+          <h2 className="text-lg font-semibold text-slate-100">Usage History</h2>
+        </div>
+
+        {/* Loading sub-state */}
+        {usageLoading && (
+          <div className="px-6 py-8 text-center text-slate-400">
+            <Loader2 size={20} className="animate-spin inline mr-2" />
+            Loading usage history…
+          </div>
+        )}
+
+        {/* Usage error sub-state */}
+        {usageError && !usageLoading && (
+          <div className="px-6 py-8 text-center">
+            <p className="text-red-400 text-sm">
+              Failed to load usage history.
+            </p>
+            <button
+              onClick={() => refetchUsage()}
+              className="mt-2 text-sm text-emerald-400 hover:text-emerald-300 underline"
+            >
+              Retry
+            </button>
+          </div>
+        )}
+
+        {/* Empty state */}
+        {!usageLoading && !usageError && usageLogs && usageLogs.length === 0 && (
+          <div className="px-6 py-10 text-center">
+            <Archive size={32} className="mx-auto text-slate-600 mb-2" />
+            <p className="text-slate-400 text-sm">No usage recorded yet.</p>
+            <p className="text-slate-500 text-xs mt-1">
+              Usage data will appear here when this spool is used in print jobs.
+            </p>
+          </div>
+        )}
+
+        {/* Table — desktop */}
+        {!usageLoading && !usageError && usageLogs && usageLogs.length > 0 && (
+          <>
+            <div className="hidden md:block overflow-x-auto">
+              <table className="w-full text-sm">
+                <thead className="bg-slate-800/50 text-slate-300">
+                  <tr>
+                    <th className="px-6 py-3 text-left font-semibold">Date</th>
+                    <th className="px-6 py-3 text-left font-semibold">Print Job</th>
+                    <th className="px-6 py-3 text-right font-semibold">mm Extruded</th>
+                    <th className="px-6 py-3 text-right font-semibold">Grams Used</th>
+                    <th className="px-6 py-3 text-right font-semibold">Cost</th>
+                  </tr>
+                </thead>
+                <tbody className="divide-y divide-slate-700">
+                  {usageLogs.map((log: UsageLog) => (
+                    <tr
+                      key={log.id}
+                      className="hover:bg-slate-700/30 transition-colors"
+                    >
+                      <td className="px-6 py-3 text-slate-200 tabular-nums">
+                        {new Date(log.logged_at).toLocaleDateString('en-US', {
+                          year: 'numeric',
+                          month: 'short',
+                          day: 'numeric',
+                        })}
+                      </td>
+                      <td className="px-6 py-3 text-slate-300">
+                        {log.print_job_name || `Job #${log.print_job_id ?? log.id}`}
+                      </td>
+                      <td className="px-6 py-3 text-right text-slate-200 tabular-nums">
+                        {log.mm_extruded.toLocaleString()}
+                      </td>
+                      <td className="px-6 py-3 text-right text-slate-200 tabular-nums">
+                        {log.grams_used.toFixed(2)} g
+                      </td>
+                      <td className="px-6 py-3 text-right text-slate-200 tabular-nums">
+                        {log.cost_usd != null ? `$${log.cost_usd.toFixed(3)}` : '—'}
+                      </td>
+                    </tr>
+                  ))}
+                </tbody>
+              </table>
+            </div>
+
+            {/* Mobile cards */}
+            <div className="md:hidden divide-y divide-slate-700">
+              {usageLogs.map((log: UsageLog) => (
+                <div key={log.id} className="px-4 py-4 space-y-2">
+                  <div className="flex items-center justify-between">
+                    <span className="text-sm font-medium text-slate-200">
+                      {log.print_job_name || `Job #${log.print_job_id ?? log.id}`}
+                    </span>
+                    <span className="text-xs text-slate-400 tabular-nums">
+                      {new Date(log.logged_at).toLocaleDateString('en-US', {
+                        month: 'short',
+                        day: 'numeric',
+                      })}
+                    </span>
+                  </div>
+                  <div className="flex items-center justify-between text-sm">
+                    <span className="text-slate-400">
+                      Extruded:{' '}
+                      <span className="text-slate-300 tabular-nums">
+                        {log.mm_extruded.toLocaleString()} mm
+                      </span>
+                    </span>
+                    <span className="text-slate-400">
+                      Used:{' '}
+                      <span className="text-slate-300 tabular-nums">
+                        {log.grams_used.toFixed(2)} g
+                      </span>
+                    </span>
+                    <span className="text-slate-400">
+                      {log.cost_usd != null ? (
+                        <>
+                          Cost:{' '}
+                          <span className="text-slate-300 tabular-nums">
+                            ${log.cost_usd.toFixed(3)}
+                          </span>
+                        </>
+                      ) : (
+                        '—'
+                      )}
+                    </span>
+                  </div>
+                </div>
+              ))}
+            </div>
+          </>
+        )}
+      </div>
+
+      {/* ── Delete Confirmation Modal ── */}
+      {deleteConfirm && (
+        <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 flex-shrink-0">
+                <AlertTriangle size={20} className="text-red-400" />
+              </div>
+              <div>
+                <h3 className="text-lg font-semibold text-slate-100">
+                  Delete &ldquo;{spool.name}&rdquo;?
+                </h3>
+                <p className="text-sm text-slate-400">
+                  This permanently removes the spool and all usage history. This cannot be undone.
+                </p>
+              </div>
+            </div>
+            <div className="flex justify-end gap-3">
+              <button
+                onClick={() => setDeleteConfirm(false)}
+                disabled={deleting}
+                className="rounded-lg bg-slate-700 px-4 py-2 text-sm font-medium text-slate-200 hover:bg-slate-600 transition-colors disabled:opacity-50"
+              >
+                Cancel
+              </button>
+              <button
+                onClick={handleDelete}
+                disabled={deleting}
+                className="inline-flex items-center gap-2 rounded-lg bg-red-600 px-4 py-2 text-sm font-medium text-white hover:bg-red-500 transition-colors disabled:opacity-50"
+              >
+                {deleting && <Loader2 size={16} className="animate-spin" />}
+                {deleting ? 'Deleting…' : 'Delete'}
+              </button>
+            </div>
+          </div>
+        </div>
+      )}
+    </div>
+  )
+}
+
+/** Small detail row for the info card grid */
+function DetailItem({ label, value }: { label: string; value: React.ReactNode }) {
+  return (
+    <div>
+      <dt className="text-xs font-medium uppercase tracking-wider text-slate-500 mb-0.5">
+        {label}
+      </dt>
+      <dd className="text-sm text-slate-200">{value}</dd>
+    </div>
+  )
+}

frontend/src/services/filamentService.ts

@@ -1,5 +1,5 @@
 import axios from 'axios'
-import type { FilamentSpool, ListResponse, FilamentFilter } from '../types/filament'
+import type { FilamentSpool, ListResponse, UsageLog, FilamentFilter } from '../types/filament'
 
 const API_BASE = '/api'
 
@@ -19,6 +19,16 @@ export async function fetchFilaments(filter: FilamentFilter): Promise<ListRespon
   return res.data
 }
 
+export async function fetchFilamentById(id: number): Promise<FilamentSpool> {
+  const res = await axios.get<FilamentSpool>(`${API_BASE}/filaments/${id}`)
+  return res.data
+}
+
+export async function fetchUsageLogs(spoolId: number): Promise<UsageLog[]> {
+  const res = await axios.get<UsageLog[]>(`${API_BASE}/usage-logs?spool_id=${spoolId}`)
+  return res.data
+}
+
 export async function deleteFilament(id: number): Promise<void> {
   await axios.delete(`${API_BASE}/filaments/${id}`)
 }

frontend/src/types/filament.ts

@@ -59,6 +59,19 @@ export interface ListResponse<T> {
   offset: number
 }
 
+export interface UsageLog {
+  id: number
+  spool_id: number
+  print_job_id?: number
+  print_job_name?: string
+  mm_extruded: number
+  grams_used: number
+  cost_usd?: number
+  logged_at: string
+  notes?: string
+  created_at: string
+}
+
 export interface FilamentFilter {
   material?: string
   finish?: string