refac: code refactor and example improvements

Author: AmirmohammadZarif

avisengine.py

@@ -14,89 +14,64 @@
 __email__ = "amir@avisengine.com"
 
 
-class Car():
+class Car:
     '''
     AVIS Engine Main Car class
-    
-    Attributes
-    ----------
-
-    Public:
-        steering_value
-        speed_value
-        sensor_status
-        image_mode
-        get_Speed
-        data_arr
-        data_str
-        sock
-        image
-        sensors
-        current_speed
-        sensor_angle
     '''
-
-    #Attributes to kind of replicate a Pub-sub pattern messaging to request data  
-    steering_value = 0
-    speed_value = 0
-    sensor_status = 1
-    image_mode = 1
-    get_Speed = 1
-    sensor_angle = 30
-    
-    sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
-
-    #Data format for request
-    data_arr = [speed_value, steering_value, image_mode, sensor_status, get_Speed, sensor_angle]
-    _data_format = "Speed:{},Steering:{},ImageStatus:{},SensorStatus:{},GetSpeed:{},SensorAngle:{}"
-    data_str = _data_format.format(data_arr[0], data_arr[1], data_arr[2], data_arr[3], data_arr[4], data_arr[5])
-    
-    image = None
-    sensors = None
-    current_speed = None
-
-    def connect(self,server,port):
+    def __init__(self) -> None:
+        # Instance variables for car state
+        self.steering_value: int = 0
+        self.speed_value: int = 0
+        self.sensor_status: int = 1
+        self.image_mode: int = 1
+        self.get_Speed: int = 1
+        self.sensor_angle: int = 30
+        self.sock: socket.socket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
+        self._data_format: str = "Speed:{},Steering:{},ImageStatus:{},SensorStatus:{},GetSpeed:{},SensorAngle:{}"
+        self.data_str: str = self._data_format.format(
+            self.speed_value, self.steering_value, self.image_mode, self.sensor_status, self.get_Speed, self.sensor_angle
+        )
+        self.image = None
+        self.sensors = None
+        self.current_speed = None
+        self._is_initialized = False
+        self._init_frames_needed = 4  # Number of frames needed for stabilization
+
+    def connect(self, server: str, port: int) -> bool:
         '''
         Connecting to the simulator (server)
         '''
         try:
             self.sock.connect((server, port))
             self.sock.settimeout(5.0)
-            
-            print("connected to ", server, port)
+            print(f"connected to {server} {port}")
+            # Give simulator time to initialize
+            time.sleep(3)
+            # Request initial data frames for stabilization
+            for _ in range(self._init_frames_needed):
+                self.getData()
+            self._is_initialized = True
             return True
-        except:
-            print("Failed to connect to ", server, port)
+        except Exception as e:
+            print(f"Failed to connect to {server} {port}: {e}")
             return False
 
-  
-    def recvall(self, socket):
+    def recvall(self, sock: socket.socket) -> str:
         '''
         Function to receive all the data chunks
         '''
         BUFFER_SIZE = 131072  # Increased buffer size for better performance
-        data = bytearray()  # Use a bytearray for better performance
-
+        data = bytearray()
         while True:
-            part = socket.recv(BUFFER_SIZE)
+            part = sock.recv(BUFFER_SIZE)
             data.extend(part)
-
-            # Use KMP search to find the <EOF>, KMPSearch() returns -1 if the pattern was not found
-            # It is 9 times faster than the simple python search
-            if utils.KMPSearch(b"<EOF>", data) > -1:  # Convert "<EOF>" to bytes              
+            if utils.KMPSearch(b"<EOF>", data) > -1:
                 break
-
         return data.decode("utf-8")
 
-        
-    def setSteering(self,steering):
+    def setSteering(self, steering: int) -> None:
         '''
         Setting the steering of the car
-        
-        Parameters
-        ----------
-            steering : int
-                Steering value in degree
         '''
         self.steering_value = steering
         self.image_mode = 0
@@ -105,13 +80,9 @@ def setSteering(self,steering):
         self.sock.sendall(self.data_str.encode("utf-8"))
         time.sleep(0.01)
 
-    def setSpeed(self,speed):
+    def setSpeed(self, speed: int) -> None:
         '''
         Setting the speed of the car
-        
-        Parameters
-        ----------
-            speed : int
         '''
         self.speed_value = speed
         self.image_mode = 0
@@ -120,61 +91,49 @@ def setSpeed(self,speed):
         self.sock.sendall(self.data_str.encode("utf-8"))
         time.sleep(0.01)
 
-    def setSensorAngle(self, angle):
+    def setSensorAngle(self, angle: int) -> None:
         '''
         Setting the angle between each sensor ray
-        
-        Parameters
-        ----------
-            angle : int
-                In degrees
         '''
-
         self.image_mode = 0
         self.sensor_status = 0
         self.sensor_angle = angle
         self.updateData()
         self.sock.sendall(self.data_str.encode("utf-8"))
-        
-    def getData(self):
+
+    def getData(self) -> None:
         '''
         Requesting for the data from the simulator
         '''
         self.image_mode = 1
         self.sensor_status = 1
         self.updateData()
         self.sock.sendall(self.data_str.encode("utf-8"))
-
         receive = self.recvall(self.sock)
-
         imageTagCheck = re.search('<image>(.*?)<\/image>', receive)
         sensorTagCheck = re.search('<sensor>(.*?)<\/sensor>', receive)
-        speedTagCheck = re.search('<speed>(.*?)<\/speed>', receive)            
-        
+        speedTagCheck = re.search('<speed>(.*?)<\/speed>', receive)
         try:
-            if(imageTagCheck):
+            if imageTagCheck:
                 imageData = imageTagCheck.group(1)
                 im_bytes = base64.b64decode(imageData)
-                im_arr = np.frombuffer(im_bytes, dtype=np.uint8)  # im_arr is one-dim Numpy array
+                im_arr = np.frombuffer(im_bytes, dtype=np.uint8)
                 imageOpenCV = cv2.imdecode(im_arr, flags=cv2.IMREAD_COLOR)
                 self.image = imageOpenCV
-            
-            if(sensorTagCheck):
+            if sensorTagCheck:
                 sensorData = sensorTagCheck.group(1)
                 sensor_arr = re.findall("\d+", sensorData)
-                sensor_int_arr = list(map(int, sensor_arr)) 
+                sensor_int_arr = list(map(int, sensor_arr))
                 self.sensors = sensor_int_arr
             else:
-                self.sensors = [1500,1500,1500]
-
-            if(speedTagCheck):
+                self.sensors = [1500, 1500, 1500]
+            if speedTagCheck:
                 current_sp = speedTagCheck.group(1)
                 self.current_speed = int(current_sp)
             else:
                 self.current_speed = 0
-        except:
-            print("Failed to receive data")
-
+        except Exception as e:
+            print(f"Failed to receive data: {e}")
 
     def getImage(self):
         '''
@@ -185,36 +144,59 @@ def getImage(self):
     def getSensors(self):
         '''
         Returns the sensor data
-            A List: 
-                [Left Sensor: int, Middle Sensor: int, Right Sensor: int]
         '''
         return self.sensors
-    
+
     def getSpeed(self):
         '''
         Returns the speed of the car
         '''
         return self.current_speed
-    
-    def updateData(self):
+
+    def updateData(self) -> None:
         '''
         Updating the request data array and data string
         '''
-        data = [self.speed_value,self.steering_value,self.image_mode,self.sensor_status,self.get_Speed, self.sensor_angle]
-        self.data_str = self._data_format.format(data[0], data[1], data[2], data[3], data[4], data[5])
-        
-    def stop(self):
+        data = [self.speed_value, self.steering_value, self.image_mode, self.sensor_status, self.get_Speed, self.sensor_angle]
+        self.data_str = self._data_format.format(*data)
+
+    def stop(self) -> None:
         '''
-        Stoping the car and closing the socket
+        Stopping the car and closing the socket
         '''
-        self.setSpeed(0)
-        self.setSteering(0)
-        self.sock.sendall("stop".encode("utf-8"))
-        self.sock.close()
-        print("Process stopped successfully!")
-    
-    def __del__(self):
-        self.stop()
-    
-        
+        try:
+            self.setSpeed(0)
+            self.setSteering(0)
+            self.sock.sendall("stop".encode("utf-8"))
+            self.sock.close()
+            print("Process stopped successfully!")
+        except Exception as e:
+            print(f"Error during stop: {e}")
+
+    def is_ready(self) -> bool:
+        '''
+        Check if the car is initialized and ready for operation
         
+        Returns
+        -------
+            bool: True if the car is initialized and ready for operation
+        '''
+        return self._is_initialized
+
+    def __enter__(self):
+        '''Enable use as a context manager.'''
+        return self
+
+    def __exit__(self, exc_type, exc_val, exc_tb):
+        '''Ensure resources are cleaned up when exiting context.'''
+        self.stop()
+        return False  # Do not suppress exceptions
+
+    def __del__(self):
+        try:
+            self.stop()
+        except Exception:
+            pass
+
+
+