Separate mqtt client in a different package

app/__init__.py

@@ -26,9 +26,11 @@ def setup_blueprints(app):
     from .devices import devices_bp
     from .accounts import accounts_bp
     from .api import api_bp
+    from .mqtt import mqtt_bp
 
     app.register_blueprint(devices_bp)
     app.register_blueprint(accounts_bp)
+    app.register_blueprint(mqtt_bp)
     app.register_blueprint(api_bp, url_prefix='/api')
 
 

app/devices/__init__.py

@@ -1,26 +1,11 @@
-import atexit
+import sys
 from flask import Blueprint
-from .mqtt_client import MqttClient
 from .models import Device, Recording
+from app import app
 
 devices_bp = Blueprint('devices', __name__)
 
 
-# When app dies, stop mqtt connection
-def on_stop():
-    MqttClient.tear_down()
-
-
-atexit.register(on_stop)
-
-
-# Setup
-@devices_bp.record
-def __on_blueprint_setup(setup_state):
-    print('Blueprint setup')
-    MqttClient.setup(setup_state.app)
-
-
 # Public interface
 def create_device(name, device_type=1):
     """
@@ -69,3 +54,33 @@ def get_device(device_id):
         raise ValueError("Device with id %s does not exist" % device_id)
 
     return Device.get(id=device_id)
+
+
+def create_recording(device_id, raw_json):
+    """
+    Tries to create recording with given parameters. Raises error on failure
+
+    :param device_id: Id of device
+    :type device_id: int
+    :param raw_json: Raw json received
+    :type raw_json: json
+    :raises: ValueError if parsing fails or device does not exist
+    """
+    def parse_raw_json_recording(device_id, json_msg) -> Recording:
+        try:
+            return Recording(device_id=device_id,
+                             record_type=json_msg["record_type"],
+                             record_value=json_msg["record_value"],
+                             recorded_at=json_msg["recorded_at"],
+                             raw_json=json_msg)
+        except KeyError:
+            error_type, error_instance, traceback = sys.exc_info()
+            raise ValueError("JSON parsing failed! Key error: "
+                             + str(error_instance))
+
+    if not Device.exists(id=device_id):
+        raise ValueError("Device does not exist!")
+
+    recording = parse_raw_json_recording(device_id, raw_json)
+    with app.app_context():
+        recording.save()

app/mqtt/__init__.py

@@ -0,0 +1,19 @@
+import atexit
+from flask import Blueprint
+from .mqtt_client import MqttClient
+
+mqtt_bp = Blueprint('mqtt', __name__)
+
+
+# Setup
+@mqtt_bp.record
+def __on_blueprint_setup(setup_state):
+    MqttClient.setup(setup_state.app)
+
+
+# When app dies, stop mqtt connection
+def on_stop():
+    MqttClient.tear_down()
+
+
+atexit.register(on_stop)

app/mqtt/mqtt_client.py

@@ -1,8 +1,7 @@
 import sys
 import json
 from flask_mqtt import Mqtt
-from .models import Recording
-from app import app
+import app.devices as devices
 
 
 class MqttClient:
@@ -49,10 +48,9 @@ class MqttClient:
         print("Payload: " + message.payload.decode())
         try:
             # If type is JSON
-            recording = MqttClient.parse_json_message(
-                    message.topic, message.payload.decode())
-            with app.app_context():
-                recording.save()
+            devices.create_recording(
+                    MqttClient.get_device_id(message.topic),
+                    json.loads(message.payload.decode()))
         except ValueError:
             print("ERROR!")
             error_type, error_instance, traceback = sys.exc_info()
@@ -60,21 +58,6 @@ class MqttClient:
             print("Instance: " + str(error_instance))
             return
 
-    @staticmethod
-    def parse_json_message(topic, payload) -> Recording:
-        try:
-            json_msg = json.loads(payload)
-            device_id = MqttClient.get_device_id(topic)
-            return Recording(device_id=device_id,
-                             record_type=json_msg["record_type"],
-                             record_value=json_msg["record_value"],
-                             recorded_at=json_msg["recorded_at"],
-                             raw_json=json_msg)
-        except KeyError:
-            error_type, error_instance, traceback = sys.exc_info()
-            raise ValueError("JSON parsing failed! Key error: "
-                             + str(error_instance))
-
     @staticmethod
     def get_device_id(topic) -> int:
         device_token, device_id = topic.split("/")