Added PatientLocation.py

Packet/Command/PatientLocation.py

@@ -0,0 +1,66 @@
+from Interfaces.CommandInterface import CommandInterface
+
+import struct
+import json
+import warnings
+
+class PatientLocation(CommandInterface):
+    PAYLOAD = 1 # All commands will have a payload ID of 1
+    COMMAND_ID = 5
+
+    @staticmethod
+    def encode_packet(coordinates: tuple) -> bytes:
+        """Encode data packet
+
+        Args:
+            coordinates: single (x, y) tuple to encode as doubles
+
+        Returns:
+            Encoded data bytes
+        """
+
+        # how struct.pack and its format characters (e.g. "BB" or "dd") are explained here https://docs.python.org/3/library/struct.html 
+        # encodes the header
+        header_byte_struct = "BB"
+        header = struct.pack(header_byte_struct, PatientLocation.PAYLOAD_ID, PatientLocation.COMMAND_ID)
+
+        # encodes the byte stream coordinate data
+        coord_byte_struct = "dd"
+        coord_byte_stream = struct.pack(coord_byte_struct, coordinates[0], coordinates[1])
+
+        encoded_stream = header + coord_byte_stream
+
+        return encoded_stream
+
+
+    @staticmethod
+    def decode_packet(encoded_string, format: str = None):
+        """Decodes data packet
+
+        Args:
+            encoded_string: Encoded data packet
+            format: "tuple" or "json". Defaults to "tuple" with a warning if not provided.
+
+        Returns:
+            (x, y) tuple or JSON string with x and y keys
+        """
+        if format is None:
+            warnings.warn("Format not specified in decode_packet, defaulting to 'tuple'", UserWarning)
+
+        decode_byte_struct = "=BBdd"
+
+        expected_length = struct.calcsize(decode_byte_struct)
+        if len(encoded_string) != expected_length:
+            raise ValueError(f"Encoded string length {len(encoded_string)} does not match expected length {expected_length}")
+
+        unpacked_data = struct.unpack(decode_byte_struct, encoded_string)
+
+        # we are ignoring the "=BB" part here which is the header, "unpacked_data" would look like [1, 5, <some double value>, <some double value>]
+        x, y = unpacked_data[2], unpacked_data[3]
+
+        if format == "json":
+            return json.dumps({"x": x, "y": y}, indent=2)
+
+        return (x, y)
+
+