REFACT Switch to unified factory class

dmrtools/dmrproto/exceptions.py

@@ -10,14 +10,6 @@ class DMRPFieldOutOfRangeException(Exception):
         super().__init__(f"Field out of range: {field} must be {typename}")
 
 
-class DMRPUnknownPacketTypeException(Exception):
-    """
-    Exception raised when the packet factory cannot recognize the packet type
-    from the given input data.
-    """
-    pass
-
-
 class DMRPBadPacketException(Exception):
     """
     Exception raised when a packet is structurally invalid or corrupted
@@ -30,3 +22,15 @@ class DMRPL2BadDataException(Exception):
     Exception raised when L2 data is invalid or corrupted.
     """
     pass
+
+
+class FactoryException(Exception):
+    pass
+
+
+class DMRPUnknownPacketTypeException(FactoryException):
+    """
+    Exception raised when the packet factory cannot recognize the packet type
+    from the given input data.
+    """
+    pass

dmrtools/dmrproto/factory.py

@@ -0,0 +1,50 @@
+from abc import ABC, abstractmethod
+from typing import Self, Type, NoReturn
+
+from .exceptions import FactoryException
+
+
+class IFactoryProduced(ABC):
+    @abstractmethod
+    def __init__(self, data: bytes) -> None:
+        pass
+
+    @classmethod
+    @abstractmethod
+    def detect_by_data(cls, data: bytes) -> bool:
+        pass
+
+
+class BaseFactory(ABC):
+    __instance: Self|None = None
+
+    @classmethod
+    def fd(cls, data: bytes) -> IFactoryProduced:
+        """
+        Short singleton version of from_data method
+        """
+        if cls.__instance is None:
+            cls.__instance = cls()
+        return cls.__instance.from_data(data)
+
+    def __init__(self,
+                 classes: list[Type[IFactoryProduced]]|None = None) -> None:
+        self._classes: list[Type[IFactoryProduced]] = (
+            classes if classes is not None else [])
+
+    def register(self, cls: Type[IFactoryProduced]) -> None:
+        self._classes.append(cls)
+
+    def from_data(self, data: bytes) -> IFactoryProduced:
+        """
+        Attempts to create an instance of corresponding
+        IFactoryProduced-implementing class based on data
+        """
+        for cls in self._classes:
+            if cls.detect_by_data(data):
+                return cls(data)
+
+        self.not_found(data)
+
+    def not_found(self, data: bytes) -> NoReturn:
+        raise FactoryException(f"No class found for {data.hex()}")

dmrtools/dmrproto/mmdvm_l1.py

@@ -4,14 +4,15 @@ import random
 
 from abc import ABC
 from hashlib import sha256
-from typing import Type, Self, TypeAlias
+from typing import Self, TypeAlias, NoReturn
 
 from .base_fields import DMRPFieldInt, DMRPFieldBytes, DMRPFieldStr
 from .enums import CallType, VoiceType
+from .etsi_l2 import DMRPL2Base, DMRPL2FullLC, DMRPL2VoiceBurst
 from .exceptions import DMRPBadPacketException
 from .exceptions import DMRPFieldOutOfRangeException
 from .exceptions import DMRPUnknownPacketTypeException
-from .etsi_l2 import DMRPL2Base, DMRPL2FullLC, DMRPL2VoiceBurst
+from .factory import BaseFactory, IFactoryProduced
 
 
 #############################
@@ -24,7 +25,7 @@ def calc_password_hash(salt: bytes, password: str) -> bytes:
 #############################
 # Packet classes hierarchy
 #############################
-class DMRPBasePacket(ABC):
+class DMRPBasePacket(IFactoryProduced, ABC):
     """
     Abstract base packet class.
 
@@ -436,66 +437,26 @@ class DMRPPacketData(DMRPBasePeerPacket):
                 f"vt:{'T' if self.is_voice_term else 'f'}")
 
 
-class DMRPPacketFactory:
+class DMRPPacketFactory(BaseFactory):
     """
     A factory class responsible for creating instances of DMRP packet classes
     based on packet data. This class supports both predefined packet types
     and user-registered custom packet types.
     """
 
-    __instance: DMRPPacketFactory|None = None
-
-    @classmethod
-    def fd(cls, data: bytes) -> DMRPBasePacket:
-        """
-        Short singleton version of from_data method
-        """
-        if cls.__instance is None:
-            cls.__instance = cls()
-        return cls.__instance.from_data(data)
-
     def __init__(self) -> None:
         """
         Initializes the packet factory with a list of all packet classes.
-        These classes must implement a `detect_by_data` class method to
-        determine whether they can handle the given input data.
         """
-        self.__pclasses = [
+        super().__init__([
             DMRPPacketMasterNoAck,
             DMRPPacketMasterClose, DMRPPacketRepeaterClose,
             DMRPPacketLogin, DMRPPacketAck, DMRPPacketAuth, DMRPPacketConfig,
             DMRPPacketPing, DMRPPacketPong, DMRPPacketSalt, DMRPPacketBeacon,
             DMRPPacketData, DMRPPacketTalkerAlias,
-        ]
-
-    def register_custom_packet(self, cls: Type[DMRPBasePacket]) -> None:
-        """
-        Registers a custom packet class to the factory.
-
-        Args:
-            cls: A class that implements the static method `detect_by_data`.
-                 If this method returns True, the class is used to create a packet instance.
-        """
-        self.__pclasses.append(cls)
-
-    def from_data(self, data: bytes) -> DMRPBasePacket:
-        """
-        Attempts to create an DMRP packet instance of corresponding packet
-        class based on packet data.
-
-        Args:
-            data (bytes): The raw data from which to create a packet.
-
-        Returns:
-            DMRPBasePacket: An instance of a subclass of DMRPBasePacket that matches the data.
-
-        Raises:
-            DMRPUnknownPacketTypeException: If no registered packet class can handle the data.
-        """
-        for cls in self.__pclasses:
-            if cls.detect_by_data(data):
-                return cls(data)
+        ])
 
+    def not_found(self, data: bytes) -> NoReturn:
         ptypestr = data[0:4].decode(encoding='ascii', errors='ignore')
         raise DMRPUnknownPacketTypeException(f"Unknown packet type {ptypestr}")