added simple traffic_light

components/i_feed/traffic_light.py

@@ -1,6 +1,65 @@
+import threading
+import time
+from datetime import datetime
+from enum import Enum
+
 from circuitbreaker import circuit
 
+# Default switching time in seconds
+SWITCHING_TIME = 120
+# Scale speed of switching by factor x
+SCALING = 100
+
+
+class TrafficLight:
+    class Color(Enum):
+        GREEN = 0
+        RED = 1
+
+    # time between switches in seconds
+    switching_time: int
+    # timestamp of last switch
+    last_switch: datetime
+    # currently lit color
+    current_color: Color
+    # marks if traffic light started
+    running: bool = False
+    # stores starting color
+    _starting_color: Color
+    # stores runner thread
+    _t: threading.Thread
+
+    def __init__(self, switching_time: int = SWITCHING_TIME, starting_color: Color = Color.RED):
+        self.switching_time = switching_time
+        self._starting_color = starting_color
+
+    def start(self):
+        self.running = True
+
+        def switcher():
+            num_colors = len(self.Color)
+            # set current color to the one before starting color, because switch immediately happens in loop
+            # therefore it sleeps on the end of the loop and first status is immediately sent to msg broker
+            self.current_color = TrafficLight.Color((self._starting_color.value - 1) % num_colors)
+            while self.running:
+                self.current_color = self.Color((self.current_color.value + 1) % num_colors)
+                self.last_switch = datetime.now()
+                self.send_status_update()
+                time.sleep(self.switching_time / SCALING)
+
+        self._t = threading.Thread(target=switcher)
+        self._t.start()
+
+    def stop(self):
+        self.running = False
+
+    @circuit(failure_threshold=10, expected_exception=ConnectionError)
+    def send_status_update(self):
+        # TODO inform the message broker about the current status
+        print(self.current_color, self.last_switch)
+
+
+if __name__ == '__main__':
+    tl1 = TrafficLight(3)
+    tl1.start()
 
-@circuit(failure_threshold=10, expected_exception=ConnectionError)
-def external_call():
-    ...

components/i_feed/vehicle.py

@@ -184,7 +184,7 @@ class Vehicle:
     @circuit(failure_threshold=10, expected_exception=ConnectionError)
     def send_status_update(self):
         # TODO inform the message broker about the current status
-        print(v1.driven_kms, '\t', v1.daf)
+        print(self.driven_kms, '\t', self.daf)
 
     # TODO adapt the vehicle's velocity to the suggestion of the orchestration service
     def new_velocity(self):