ESP32 Emulator: веб-морда контроллера гроубокса поверх MQTT

Go-сервис без внешних фронтенд-зависимостей: embedded HTML-страница
с SVG-изображением платы (датчик + вентилятор + свет + помпа) и
Server-Sent Events для live-обновления. Слушает devices/+/commands
и реально отвечает ack'ом, публикует devices/{id}/telemetry —
протокол зеркалит ingest-service/device-control-service основного
репозитория, общего кода между репозиториями нет. Дефолтные
external_id (sensor-1/fan-1/light-1/pump-1) совпадают с
DemoGrowboxSeeder платформы.

internal/mqttclient/client.go

@@ -0,0 +1,123 @@
+// Package mqttclient speaks the same wire protocol a real device would:
+// publish to devices/{id}/telemetry and devices/{id}/ack, subscribe to
+// devices/{id}/commands. Topic and payload shapes are dictated by
+// ingest-service and device-control-service in the main platform repo —
+// this client exists to match them, not to define them.
+package mqttclient
+
+import (
+	"encoding/json"
+	"fmt"
+	"log/slog"
+	"strings"
+	"time"
+
+	mqtt "github.com/eclipse/paho.mqtt.golang"
+)
+
+type Config struct {
+	BrokerURL string
+	ClientID  string
+}
+
+// CommandHandler receives one decoded devices/{id}/commands message.
+// hasLevel distinguishes "level omitted" from "level is zero".
+type CommandHandler func(externalID, action string, level float64, hasLevel bool)
+
+type Client struct {
+	client mqtt.Client
+	logger *slog.Logger
+}
+
+func Connect(cfg Config, logger *slog.Logger) (*Client, error) {
+	opts := mqtt.NewClientOptions().
+		AddBroker(cfg.BrokerURL).
+		SetClientID(cfg.ClientID).
+		SetAutoReconnect(true).
+		SetConnectRetry(true).
+		SetConnectionLostHandler(func(_ mqtt.Client, err error) {
+			logger.Warn("mqtt connection lost", "error", err)
+		})
+
+	client := mqtt.NewClient(opts)
+	token := client.Connect()
+	token.Wait()
+	if err := token.Error(); err != nil {
+		return nil, fmt.Errorf("connect to mqtt broker %s: %w", cfg.BrokerURL, err)
+	}
+
+	return &Client{client: client, logger: logger}, nil
+}
+
+// SubscribeCommands listens on devices/+/commands for every device the
+// emulator might represent — one subscription covers the whole board.
+func (c *Client) SubscribeCommands(handler CommandHandler) error {
+	token := c.client.Subscribe("devices/+/commands", 1, func(_ mqtt.Client, msg mqtt.Message) {
+		externalID, ok := externalIDFromTopic(msg.Topic())
+		if !ok {
+			return
+		}
+
+		var cmd struct {
+			Action string   `json:"action"`
+			Level  *float64 `json:"level"`
+		}
+		if err := json.Unmarshal(msg.Payload(), &cmd); err != nil {
+			c.logger.Warn("dropping invalid command payload", "device_id", externalID, "error", err)
+			return
+		}
+
+		level := 0.0
+		hasLevel := cmd.Level != nil
+		if hasLevel {
+			level = *cmd.Level
+		}
+		handler(externalID, cmd.Action, level, hasLevel)
+	})
+	token.Wait()
+	return token.Error()
+}
+
+func externalIDFromTopic(topic string) (string, bool) {
+	parts := strings.Split(topic, "/")
+	if len(parts) != 3 || parts[0] != "devices" {
+		return "", false
+	}
+	return parts[1], true
+}
+
+// PublishTelemetry sends one sensor_type reading, matching the payload
+// shape services/ingest-service/internal/telemetry.ParseReading expects.
+func (c *Client) PublishTelemetry(externalID, zoneID, sensorType string, value float64) error {
+	body, err := json.Marshal(map[string]any{
+		"device_id":   externalID,
+		"zone_id":     zoneID,
+		"sensor_type": sensorType,
+		"value":       value,
+		"timestamp":   time.Now().UTC().Format(time.RFC3339),
+	})
+	if err != nil {
+		return err
+	}
+	return c.publish(fmt.Sprintf("devices/%s/telemetry", externalID), body)
+}
+
+// PublishAck reports an actuator's new state after a command, matching the
+// shape services/device-control-service/cmd/.../ackHandler expects.
+func (c *Client) PublishAck(externalID string, reportedState map[string]any) error {
+	body, err := json.Marshal(map[string]any{"state": reportedState})
+	if err != nil {
+		return err
+	}
+	return c.publish(fmt.Sprintf("devices/%s/ack", externalID), body)
+}
+
+func (c *Client) publish(topic string, body []byte) error {
+	token := c.client.Publish(topic, 1, false, body)
+	token.Wait()
+	return token.Error()
+}
+
+func (c *Client) Close() {
+	c.client.Disconnect(250)
+}