handle request and repsonses

uds/database/abstract_database.py

@@ -57,7 +57,7 @@ def encode(self,
             raise TypeError("Provided SID value is not int type.")
         if sid not in self.services:
             raise ValueError("Database has no encoding defined for provided SID value.")
-        return self.services[sid].encode(**data_records_values)
+        return self.services[sid].encode(sid=sid, **data_records_values)
 
     def decode(self, message: Union[UdsMessage, UdsMessageRecord]) -> List[DecodedDataRecord]:
         """

uds/database/services/abstract_service.py

@@ -3,14 +3,20 @@
 __all__ = ["AbstractService", "DataRecordValueAlias"]
 
 from abc import ABC, abstractmethod
-from typing import Dict, Iterable, List, Union
+from typing import Dict, Sequence, List, Union
 
 from uds.message import RequestSID, ResponseSID
 from uds.utilities import RawBytesAlias, RawBytesListAlias
 
 from ..data_record import DecodedDataRecord
 
-DataRecordValueAlias = Union[int, float, str, Iterable[Dict[str, "DataRecordValueAlias"]]]
+DataRecordValueAlias = Union[
+    int,  # raw value
+    float,  # physical value calculated through formula
+    str,  # text value decoded either through raw value mapping or text encoding
+    Dict[str, "DataRecordValueAlias"],  # value of container's children
+    Sequence[Dict[str, "DataRecordValueAlias"]],  # multiple records' values
+]
 "Alias of input with Data Records values."
 
 
@@ -37,8 +43,40 @@ def decode(self, payload: RawBytesAlias) -> List[DecodedDataRecord]:
         :return: Decoded Data Records values from provided diagnostic message.
         """
 
+    def encode(self, sid: int, **data_records_values: DataRecordValueAlias) -> RawBytesListAlias:
+        # TODO
+        if sid == self.request_sid:
+            return self.encode_request(**data_records_values)
+        if sid == self.response_sid:
+            return self.encode_response(**data_records_values)
+        raise ValueError
+
+    @abstractmethod
+    def encode_request(self, **data_records_values: DataRecordValueAlias) -> RawBytesListAlias:
+        """
+        Encode diagnostic message payload from data records values.
+
+        :param data_records_values: Value for each Data Record that is part a service message.
+
+            Each type represent other data:
+
+            - int type - raw value of a Data Record
+            - float type - physical value of a Data Record
+            - str type - text value of a Data Record
+            - sequence - contains values for children Data Records
+            - dict type - values of children Data Records
+
+            .. warning:: Providing physical value as float might sometime cause issues due
+                `floating-point precision <https://docs.python.org/3/tutorial/floatingpoint.html>`_.
+                The closest raw value would be evaluated and put into a payload.
+
+                To avoid rounding, provide raw value (int type).
+
+        :return: Payload of a diagnostic message.
+        """
+
     @abstractmethod
-    def encode(self, **data_records_values: DataRecordValueAlias) -> RawBytesListAlias:  # noqa: F841
+    def encode_response(self, **data_records_values: DataRecordValueAlias) -> RawBytesListAlias:
         """
         Encode diagnostic message payload from data records values.
 
@@ -49,7 +87,7 @@ def encode(self, **data_records_values: DataRecordValueAlias) -> RawBytesListAli
             - int type - raw value of a Data Record
             - float type - physical value of a Data Record
             - str type - text value of a Data Record
-            - iterable type - contains values for children Data Records
+            - sequence - contains values for children Data Records
             - dict type - values of children Data Records
 
             .. warning:: Providing physical value as float might sometime cause issues due