Label print API

backend/app/mqtt_service.py

@@ -0,0 +1,57 @@
+import os
+import json
+import logging
+from typing import Optional
+import paho.mqtt.client as mqtt
+
+logger = logging.getLogger(__name__)
+
+# MQTT Configuration from environment
+MQTT_BROKER_HOST = os.getenv("MQTT_BROKER_HOST", "localhost")
+MQTT_BROKER_PORT = int(os.getenv("MQTT_BROKER_PORT", "1883"))
+MQTT_USERNAME = os.getenv("MQTT_USERNAME", "")
+MQTT_PASSWORD = os.getenv("MQTT_PASSWORD", "")
+MQTT_LABEL_TOPIC = os.getenv("MQTT_LABEL_TOPIC", "vet/labels/print")
+
+def publish_label_print(label_data: dict) -> bool:
+    """
+    Publish a label print request to MQTT broker
+    
+    Args:
+        label_data: Dictionary containing label print information
+        
+    Returns:
+        True if successful, False otherwise
+    """
+    try:
+        # Create MQTT client
+        client = mqtt.Client()
+        
+        # Set username and password if provided
+        if MQTT_USERNAME and MQTT_PASSWORD:
+            client.username_pw_set(MQTT_USERNAME, MQTT_PASSWORD)
+        
+        # Connect to broker
+        client.connect(MQTT_BROKER_HOST, MQTT_BROKER_PORT, 60)
+        
+        # Start network loop to process connection
+        client.loop_start()
+        
+        # Publish message with QoS 0 (fire and forget)
+        message = json.dumps(label_data)
+        result = client.publish(MQTT_LABEL_TOPIC, message, qos=0)
+        
+        # Stop loop and disconnect
+        client.loop_stop()
+        client.disconnect()
+        
+        if result.rc == mqtt.MQTT_ERR_SUCCESS:
+            logger.info(f"Successfully published label print request to {MQTT_LABEL_TOPIC}")
+            return True
+        else:
+            logger.error(f"Failed to publish label print request: {result.rc}")
+            return False
+            
+    except Exception as e:
+        logger.error(f"Error publishing MQTT message: {str(e)}")
+        return False