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

- Moonraker REST client with GetPrinterInfo, GetPrintStats, GetPrintHistory - Moonraker WebSocket client with auto-reconnect + telemetry parsing - MQTT client via paho.mqtt.golang with TLS support for Bambu Lab - Moonraker poller worker: background polling, dedup, usage logging to PostgreSQL - MQTT subscriber worker: Bambu telemetry parsing, print job tracking - Config: 7 new env vars (MOONRAKER_URL, MQTT_BROKER, etc.) - main.go: per-printer worker discovery, graceful shutdown
2026-05-12 01:02:49 -04:00
parent f1614029b5
commit 38722e54e6
9 changed files with 1169 additions and 32 deletions
--- a/backend/internal/clients/moonraker.go
+++ b/backend/internal/clients/moonraker.go
@@ -0,0 +1,171 @@
+// Package clients provides client implementations for printer integrations:
+// Moonraker REST + WebSocket (Klipper-based printers) and MQTT (Bambu Lab).
+package clients
+
+import (
+	"context"
+	"encoding/json"
+	"fmt"
+	"io"
+	"net/http"
+	"strings"
+	"time"
+)
+
+// ── Moonraker response types ────────────────────────────────────────────────
+
+// moonrakerRPC is the generic JSON-RPC wrapper Moonraker uses for responses.
+type moonrakerRPC struct {
+	Result json.RawMessage `json:"result"`
+	Error  *moonrakerError `json:"error"`
+}
+
+type moonrakerError struct {
+	Code    int    `json:"code"`
+	Message string `json:"message"`
+}
+
+// ── Public DTOs ─────────────────────────────────────────────────────────────
+
+// MoonrakerPrinterInfo represents the /printer/info response.
+type MoonrakerPrinterInfo struct {
+	State        string `json:"state"`
+	StateMessage string `json:"state_message"`
+	KlippyReady  bool   `json:"klippy_ready"`
+}
+
+// MoonrakerPrintStats represents the print_stats object from
+// /printer/objects/query?print_stats.
+type MoonrakerPrintStats struct {
+	State          string  `json:"state"`
+	Filename       *string `json:"filename"`
+	FilamentUsedMm float64 `json:"filament_used"`
+	PrintDuration  float64 `json:"print_duration"`
+	Message        *string `json:"message"`
+}
+
+// MoonrakerPrintJob represents a single entry in /server/history/items.
+type MoonrakerPrintJob struct {
+	JobID              string                 `json:"job_id"`
+	Filename           string                 `json:"filename"`
+	Status             string                 `json:"status"`
+	FilamentUsedMm     float64                `json:"filament_used"`
+	PrintDuration      float64                `json:"print_duration"`
+	TotalDuration      float64                `json:"total_duration"`
+	StartTime          *float64               `json:"start_time"`
+	EndTime            *float64               `json:"end_time"`
+	Metadata           map[string]interface{} `json:"metadata"`
+}
+
+// MoonrakerHistoryResponse wraps the /server/history/items response.
+type MoonrakerHistoryResponse struct {
+	Items      []MoonrakerPrintJob `json:"items"`
+	TotalCount int                 `json:"count"`
+}
+
+// ── Client ──────────────────────────────────────────────────────────────────
+
+// MoonrakerClient is an HTTP client for the Moonraker REST API on
+// Klipper-based printers (e.g., Elegoo Centauri Carbon).
+type MoonrakerClient struct {
+	baseURL    string
+	httpClient *http.Client
+}
+
+// NewMoonrakerClient creates a MoonrakerClient that targets the given
+// base URL (e.g., "http://192.168.1.50:7125"). The internal HTTP client
+// uses a 15-second timeout.
+func NewMoonrakerClient(baseURL string) *MoonrakerClient {
+	baseURL = strings.TrimRight(baseURL, "/")
+	return &MoonrakerClient{
+		baseURL: baseURL,
+		httpClient: &http.Client{
+			Timeout: 15 * time.Second,
+		},
+	}
+}
+
+// GetPrinterInfo calls GET /printer/info and returns the Klipper state.
+// Returns nil when the printer is unreachable or the response cannot be parsed.
+func (c *MoonrakerClient) GetPrinterInfo(ctx context.Context) (*MoonrakerPrinterInfo, error) {
+	var info MoonrakerPrinterInfo
+	if err := c.getJSON(ctx, "/printer/info", &info); err != nil {
+		return nil, err
+	}
+	return &info, nil
+}
+
+// GetPrintStats calls GET /printer/objects/query?print_stats and returns
+// real-time print statistics including filament consumption.
+// Returns nil when no print is active or the printer is unreachable.
+func (c *MoonrakerClient) GetPrintStats(ctx context.Context) (*MoonrakerPrintStats, error) {
+	var stats MoonrakerPrintStats
+	// Moonraker wraps the object in status.print_stats
+	var wrapper struct {
+		Status struct {
+			PrintStats MoonrakerPrintStats `json:"print_stats"`
+		} `json:"status"`
+	}
+	if err := c.getJSON(ctx, "/printer/objects/query?print_stats", &wrapper); err != nil {
+		return nil, err
+	}
+	stats = wrapper.Status.PrintStats
+	return &stats, nil
+}
+
+// GetPrintHistory calls GET /server/history/items and returns recent print
+// jobs. limit controls the maximum number of items (clamped 1-100).
+func (c *MoonrakerClient) GetPrintHistory(ctx context.Context, limit int) (*MoonrakerHistoryResponse, error) {
+	if limit < 1 {
+		limit = 1
+	}
+	if limit > 100 {
+		limit = 100
+	}
+	var history MoonrakerHistoryResponse
+	if err := c.getJSON(ctx, fmt.Sprintf("/server/history/items?limit=%d", limit), &history); err != nil {
+		return nil, err
+	}
+	return &history, nil
+}
+
+// ── Internal helpers ────────────────────────────────────────────────────────
+
+func (c *MoonrakerClient) getJSON(ctx context.Context, path string, target interface{}) error {
+	url := c.baseURL + path
+
+	req, err := http.NewRequestWithContext(ctx, http.MethodGet, url, nil)
+	if err != nil {
+		return fmt.Errorf("moonraker: failed to build request: %w", err)
+	}
+	req.Header.Set("Accept", "application/json")
+
+	resp, err := c.httpClient.Do(req)
+	if err != nil {
+		return fmt.Errorf("moonraker: request failed (%s): %w", url, err)
+	}
+	defer resp.Body.Close()
+
+	body, err := io.ReadAll(resp.Body)
+	if err != nil {
+		return fmt.Errorf("moonraker: failed to read body: %w", err)
+	}
+
+	if resp.StatusCode < 200 || resp.StatusCode >= 300 {
+		return fmt.Errorf("moonraker: %s returned HTTP %d: %s", url, resp.StatusCode, string(body))
+	}
+
+	// Moonraker wraps responses in {"result": ...}
+	var rpc moonrakerRPC
+	if err := json.Unmarshal(body, &rpc); err != nil {
+		return fmt.Errorf("moonraker: failed to parse response: %w", err)
+	}
+	if rpc.Error != nil && rpc.Error.Message != "" {
+		return fmt.Errorf("moonraker: api error: %s", rpc.Error.Message)
+	}
+
+	if err := json.Unmarshal(rpc.Result, target); err != nil {
+		return fmt.Errorf("moonraker: failed to unmarshal result: %w (raw: %s)", err, string(rpc.Result))
+	}
+	return nil
+}
--- a/backend/internal/clients/moonraker_ws.go
+++ b/backend/internal/clients/moonraker_ws.go
@@ -0,0 +1,229 @@
+package clients
+
+import (
+	"context"
+	"encoding/json"
+	"fmt"
+	"log/slog"
+	"net/http"
+	"strings"
+	"sync"
+	"time"
+
+	"github.com/gorilla/websocket"
+)
+
+// ── WebSocket message types ─────────────────────────────────────────────────
+
+// moonrakerWSMessage is a single JSON-RPC frame from the Moonraker WebSocket.
+type moonrakerWSMessage struct {
+	JSONRPC string          `json:"jsonrpc"`
+	Method  string          `json:"method"`
+	Params  json.RawMessage `json:"params"`
+	ID      *int            `json:"id"`
+}
+
+// MoonrakerPrintEvent is the payload delivered by the "notify_status_update"
+// subscription when print_stats or display_status change.
+type MoonrakerPrintEvent struct {
+	PrintStats    *MoonrakerPrintStats    `json:"print_stats"`
+	DisplayStatus *MoonrakerDisplayStatus `json:"display_status"`
+}
+
+// MoonrakerDisplayStatus carries progress and the LCD message.
+type MoonrakerDisplayStatus struct {
+	Progress float64 `json:"progress"`
+	Message  string  `json:"message"`
+}
+
+// MoonrakerStatusHandler is called for every status update received from the
+// Moonraker WebSocket. It receives the parsed event and the raw JSON.
+type MoonrakerStatusHandler func(event MoonrakerPrintEvent) error
+
+// ── WebSocket client ────────────────────────────────────────────────────────
+
+// MoonrakerWSClient maintains a persistent WebSocket connection to the
+// Moonraker server and delivers parsed status updates to a handler.
+type MoonrakerWSClient struct {
+	wsURL   string
+	handler MoonrakerStatusHandler
+	dialer  *websocket.Dialer
+
+	mu     sync.Mutex
+	conn   *websocket.Conn
+	done   chan struct{}
+	once   sync.Once
+}
+
+// NewMoonrakerWSClient creates a WebSocket client for the given Moonraker base
+// URL. The handler is invoked on every status update.
+func NewMoonrakerWSClient(baseURL string, handler MoonrakerStatusHandler) *MoonrakerWSClient {
+	baseURL = strings.TrimRight(baseURL, "/")
+	wsURL := strings.Replace(baseURL, "http://", "ws://", 1)
+	wsURL = strings.Replace(wsURL, "https://", "wss://", 1)
+	wsURL += "/websocket"
+
+	return &MoonrakerWSClient{
+		wsURL:   wsURL,
+		handler: handler,
+		dialer: &websocket.Dialer{
+			Proxy:            http.ProxyFromEnvironment,
+			HandshakeTimeout: 10 * time.Second,
+		},
+		done: make(chan struct{}),
+	}
+}
+
+// Connect establishes the WebSocket, subscribes to status updates, and
+// starts the read loop in a background goroutine. It retries on failure
+// with exponential backoff up to a 60-second cap.
+func (c *MoonrakerWSClient) Connect(ctx context.Context) {
+	go c.run(ctx)
+}
+
+// Shutdown gracefully closes the WebSocket and stops the read loop.
+func (c *MoonrakerWSClient) Shutdown() {
+	c.once.Do(func() {
+		close(c.done)
+	})
+	c.mu.Lock()
+	defer c.mu.Unlock()
+	if c.conn != nil {
+		c.conn.Close()
+		c.conn = nil
+	}
+}
+
+// run is the main connection loop with reconnect backoff.
+func (c *MoonrakerWSClient) run(ctx context.Context) {
+	backoff := 1 * time.Second
+	const maxBackoff = 60 * time.Second
+
+	for {
+		select {
+		case <-ctx.Done():
+			slog.Info("moonraker ws: context cancelled, stopping")
+			return
+		case <-c.done:
+			slog.Info("moonraker ws: shutdown requested")
+			return
+		default:
+		}
+
+		if err := c.connectAndRead(ctx); err != nil {
+			slog.Error("moonraker ws: connection error, retrying", "error", err, "backoff", backoff)
+		}
+
+		// Exponential backoff.
+		select {
+		case <-ctx.Done():
+			return
+		case <-c.done:
+			return
+		case <-time.After(backoff):
+		}
+		backoff *= 2
+		if backoff > maxBackoff {
+			backoff = maxBackoff
+		}
+	}
+}
+
+func (c *MoonrakerWSClient) connectAndRead(ctx context.Context) error {
+	slog.Info("moonraker ws: connecting", "url", c.wsURL)
+
+	conn, _, err := c.dialer.DialContext(ctx, c.wsURL, nil)
+	if err != nil {
+		return fmt.Errorf("dial failed: %w", err)
+	}
+
+	c.mu.Lock()
+	if c.conn != nil {
+		c.conn.Close()
+	}
+	c.conn = conn
+	c.mu.Unlock()
+
+	defer func() {
+		c.mu.Lock()
+		if c.conn == conn {
+			c.conn = nil
+		}
+		c.mu.Unlock()
+		conn.Close()
+	}()
+
+	// Subscribe to status updates.
+	subReq := map[string]interface{}{
+		"jsonrpc": "2.0",
+		"method":  "printer.objects.subscribe",
+		"params": map[string]interface{}{
+			"objects": map[string]interface{}{
+				"print_stats":    nil,
+				"display_status": nil,
+			},
+		},
+		"id": 1,
+	}
+	if err := conn.WriteJSON(subReq); err != nil {
+		return fmt.Errorf("subscribe failed: %w", err)
+	}
+
+	slog.Info("moonraker ws: subscribed to status updates")
+
+	// Set read deadline to detect stale connections.
+	// 120s is long enough to avoid false positives.
+	pingPeriod := 60 * time.Second
+
+	for {
+		// Set read deadline.
+		if err := conn.SetReadDeadline(time.Now().Add(150 * time.Second)); err != nil {
+			return fmt.Errorf("set read deadline: %w", err)
+		}
+
+		_, raw, err := conn.ReadMessage()
+		if err != nil {
+			return fmt.Errorf("read message: %w", err)
+		}
+
+		// Send periodic pings to keep the connection alive.
+		go func() {
+			time.Sleep(pingPeriod)
+			c.mu.Lock()
+			if c.conn == conn {
+				c.conn.WriteControl(websocket.PingMessage, []byte{}, time.Now().Add(10*time.Second))
+			}
+			c.mu.Unlock()
+		}()
+
+		var msg moonrakerWSMessage
+		if err := json.Unmarshal(raw, &msg); err != nil {
+			slog.Warn("moonraker ws: failed to parse message", "error", err)
+			continue
+		}
+
+		// Only process notify_status_update messages.
+		if msg.Method != "notify_status_update" {
+			continue
+		}
+
+		var statusWrapper []MoonrakerPrintEvent
+		if err := json.Unmarshal(msg.Params, &statusWrapper); err != nil {
+			// Params might be an object, not an array.
+			var singleEvent MoonrakerPrintEvent
+			if err2 := json.Unmarshal(msg.Params, &singleEvent); err2 != nil {
+				slog.Warn("moonraker ws: failed to unmarshal status params", "error", err2)
+				continue
+			}
+			statusWrapper = []MoonrakerPrintEvent{singleEvent}
+		}
+
+		for _, ev := range statusWrapper {
+			if c.handler != nil {
+				if err := c.handler(ev); err != nil {
+					slog.Error("moonraker ws: handler error", "error", err)
+				}
+			}
+		}
+	}
+}
--- a/backend/internal/clients/mqtt.go
+++ b/backend/internal/clients/mqtt.go
@@ -0,0 +1,183 @@
+package clients
+
+import (
+	"crypto/tls"
+	"encoding/json"
+	"fmt"
+	"log/slog"
+	"sync"
+	"time"
+
+	mqtt "github.com/eclipse/paho.mqtt.golang"
+)
+
+// ── Bambu Lab telemetry types ───────────────────────────────────────────────
+
+// BambuPrintReport is the JSON payload published by Bambu Lab printers
+// on the MQTT report topic. The structure varies by printer model;
+// we extract the common fields needed for filament tracking.
+type BambuPrintReport struct {
+	// Print holds the active print job data.
+	Print BambuPrintData `json:"print"`
+
+	// VtTray contains AMS tray info; the extruded length is per-tray.
+	VtTray *BambuVtTray `json:"vt_tray,omitempty"`
+}
+
+// BambuPrintData carries the active print state from a Bambu report.
+type BambuPrintData struct {
+	// GcodeFile is the filename being printed.
+	GcodeFile string `json:"gcode_file"`
+	// GcodeState describes the current print state:
+	// "IDLE", "RUNNING", "PAUSE", "FINISH", "FAILED".
+	GcodeState string `json:"gcode_state"`
+	// McPercent is the progress as a percentage (0-100).
+	McPercent int `json:"mc_percent"`
+	// McRemainingTime is the estimated remaining time in minutes.
+	McRemainingTime int `json:"mc_remaining_time"`
+}
+
+// BambuVtTray holds AMS tray telemetry from Bambu printers.
+type BambuVtTray struct {
+	ID         string `json:"id"`
+	TagUID     string `json:"tag_uid"`
+	TrayIDName string `json:"tray_id_name"`
+	// TrayInfoIdx is the hex color code for the tray's filament.
+	TrayInfoIdx string `json:"tray_info_idx"`
+	// TrayColor is a hex color string like "FF0000FF".
+	TrayColor string `json:"tray_color"`
+	// Remain is the percentage of filament remaining on this tray (0-100).
+	Remain int `json:"remain"`
+	// K is a temperature coefficient.
+	K float64 `json:"k"`
+	// N is a second temperature coefficient.
+	N float64 `json:"n"`
+}
+
+// BambuReportHandler is called for each parsed Bambu telemetry message.
+type BambuReportHandler func(report BambuPrintReport) error
+
+// ── MQTT client ─────────────────────────────────────────────────────────────
+
+// MQTTClient wraps the Eclipse Paho MQTT client for Bambu Lab printer
+// telemetry with optional TLS support.
+type MQTTClient struct {
+	broker      string
+	clientID    string
+	topicPrefix string
+	tlsCert     string
+	tlsKey      string
+	handler     BambuReportHandler
+
+	mu     sync.Mutex
+	client mqtt.Client
+}
+
+// MQTTConfig holds the configuration for creating an MQTTClient.
+type MQTTConfig struct {
+	Broker      string // e.g., "ssl://192.168.1.50:8883"
+	ClientID    string // unique MQTT client id, defaults to "extrudex"
+	TopicPrefix string // topic prefix, defaults to "device/+/report"
+	TLSCert     string // path to TLS client certificate (optional)
+	TLSKey      string // path to TLS client key (optional)
+	Handler     BambuReportHandler
+}
+
+// NewMQTTClient creates a new MQTTClient. The connection is not established
+// until Connect is called.
+func NewMQTTClient(cfg MQTTConfig) *MQTTClient {
+	if cfg.ClientID == "" {
+		cfg.ClientID = "extrudex"
+	}
+	if cfg.TopicPrefix == "" {
+		cfg.TopicPrefix = "device/+/report"
+	}
+	return &MQTTClient{
+		broker:      cfg.Broker,
+		clientID:    cfg.ClientID,
+		topicPrefix: cfg.TopicPrefix,
+		tlsCert:     cfg.TLSCert,
+		tlsKey:      cfg.TLSKey,
+		handler:     cfg.Handler,
+	}
+}
+
+// Connect establishes the MQTT connection and subscribes to the configured
+// topic prefix. Returns an error if the initial connection fails.
+func (c *MQTTClient) Connect() error {
+	opts := mqtt.NewClientOptions().
+		AddBroker(c.broker).
+		SetClientID(c.clientID).
+		SetAutoReconnect(true).
+		SetMaxReconnectInterval(30 * time.Second).
+		SetKeepAlive(30 * time.Second).
+		SetPingTimeout(10 * time.Second).
+		SetConnectTimeout(15 * time.Second).
+		SetOnConnectHandler(func(client mqtt.Client) {
+			slog.Info("mqtt: connected", "broker", c.broker)
+			// Subscribe on every reconnect.
+			token := client.Subscribe(c.topicPrefix, 0, c.messageHandler)
+			token.Wait()
+			if err := token.Error(); err != nil {
+				slog.Error("mqtt: subscribe failed on reconnect", "topic", c.topicPrefix, "error", err)
+			} else {
+				slog.Info("mqtt: subscribed", "topic", c.topicPrefix)
+			}
+		}).
+		SetConnectionLostHandler(func(client mqtt.Client, err error) {
+			slog.Warn("mqtt: connection lost", "error", err)
+		})
+
+	// Configure TLS if cert and key are provided.
+	if c.tlsCert != "" && c.tlsKey != "" {
+		cert, err := tls.LoadX509KeyPair(c.tlsCert, c.tlsKey)
+		if err != nil {
+			return fmt.Errorf("mqtt: failed to load TLS cert/key: %w", err)
+		}
+		opts.SetTLSConfig(&tls.Config{
+			Certificates: []tls.Certificate{cert},
+			MinVersion:   tls.VersionTLS12,
+		})
+		slog.Info("mqtt: TLS configured", "cert", c.tlsCert)
+	}
+
+	c.client = mqtt.NewClient(opts)
+	token := c.client.Connect()
+	if !token.WaitTimeout(15 * time.Second) {
+		return fmt.Errorf("mqtt: connect timed out to %s", c.broker)
+	}
+	if err := token.Error(); err != nil {
+		return fmt.Errorf("mqtt: connect failed: %w", err)
+	}
+
+	slog.Info("mqtt: initial connection established", "broker", c.broker)
+	return nil
+}
+
+// Disconnect gracefully closes the MQTT connection.
+func (c *MQTTClient) Disconnect() {
+	c.mu.Lock()
+	defer c.mu.Unlock()
+	if c.client != nil && c.client.IsConnected() {
+		c.client.Disconnect(2500) // wait up to 2.5s
+		slog.Info("mqtt: disconnected")
+	}
+}
+
+// messageHandler is the MQTT callback invoked for every message received on
+// the subscribed topic.
+func (c *MQTTClient) messageHandler(_ mqtt.Client, msg mqtt.Message) {
+	if c.handler == nil {
+		return
+	}
+
+	var report BambuPrintReport
+	if err := json.Unmarshal(msg.Payload(), &report); err != nil {
+		slog.Warn("mqtt: failed to parse bambu report", "topic", msg.Topic(), "error", err)
+		return
+	}
+
+	if err := c.handler(report); err != nil {
+		slog.Error("mqtt: handler error", "topic", msg.Topic(), "error", err)
+	}
+}