feat: add python specs for Gossip Topics (leanEthereum#80)

* feat: add python specs for Gossip Topics

* fix: CI checks

* fix: apply refactor suggestion

Author: varun-doshi

src/lean_spec/subspecs/networking/__init__.py

@@ -13,6 +13,7 @@
     BlocksByRootResponse,
     Status,
 )
+from .topics import GossipTopic
 from .types import DomainType, ProtocolId
 
 __all__ = [
@@ -25,6 +26,7 @@
     "BlocksByRootRequest",
     "BlocksByRootResponse",
     "Status",
+    "GossipTopic",
     "DomainType",
     "ProtocolId",
 ]

src/lean_spec/subspecs/networking/topics.py

@@ -0,0 +1,45 @@
+"""Gossipsub topics"""
+
+from enum import Enum
+from typing import Any, Type
+
+from lean_spec.subspecs.containers.block.block import SignedBlock
+from lean_spec.subspecs.containers.vote import SignedVote
+
+
+class GossipTopic(Enum):
+    """
+    Enumerates gossip topics, bundling a topic's name with its payload type.
+
+    Attributes:
+        value (str): The network name of the topic (e.g., "block").
+        payload_type (Type): The class representing the data structure
+            of the topic's message (e.g., `SignedBlock`).
+    """
+
+    def __init__(self, value: str, payload_type: Type[Any]):
+        """
+        Initializes the GossipTopic.
+
+        Args:
+            value: The topic in string.
+            payload_type: The associated gossip.
+        """
+        self._value_ = value
+        self.payload_type = payload_type
+
+    BLOCK = ("block", SignedBlock)
+    """
+    Topic for gossiping new blocks.
+
+    - `value`: "block"
+    - `payload_type`: `SignedBlock`
+    """
+
+    VOTE = ("vote", SignedVote)
+    """
+    Topic for gossiping new votes (attestations).
+
+    - `value`: "vote"
+    - `payload_type`: `SignedVote`
+    """