From dd4b8b0eb2ead66e449c93ae9c5222288774ad2a Mon Sep 17 00:00:00 2001
From: Artur Borecki <me@pufereq.pl>
Date: Thu, 28 Aug 2025 13:10:05 +0200
Subject: [PATCH] feat(message.py): add `Message` class

---
 src/judas_protocol/message.py | 108 ++++++++++++++++++++++++++++++++++
 1 file changed, 108 insertions(+)
 create mode 100644 src/judas_protocol/message.py

diff --git a/src/judas_protocol/message.py b/src/judas_protocol/message.py
new file mode 100644
index 0000000..c702958
--- /dev/null
+++ b/src/judas_protocol/message.py
@@ -0,0 +1,108 @@
+# -*- coding: utf-8 -*-
+from __future__ import annotations
+
+from enum import Enum
+import json
+from typing import Any
+
+from judas_protocol.types import Category, ControlAction
+
+
+class Message:
+    """A message in the judas protocol."""
+
+    def __init__(
+        self,
+        category: Category,
+        action: Enum,
+        payload: dict[str, Any] | None = None,
+    ) -> None:
+        """Initialize a Message.
+
+        Args:
+            category (Category): The category of the message.
+            action (Enum): The action of the message.
+            payload (dict[str, Any] | None): The payload of the message.
+        """
+        self.category: Category = category
+        self.action: Enum = action
+        self.payload: dict[str, Any] = payload or {}
+
+    def to_dict(self) -> dict[str, Any]:
+        """Convert the message to a dictionary.
+
+        Returns:
+            dict[str, Any]: The message as a dictionary.
+        """
+        return {
+            "category": self.category,
+            "action": self.action,
+            "payload": self.payload,
+        }
+
+    def to_json(self) -> str:
+        """Convert the message to a JSON string.
+
+        Returns:
+            str: The message as a JSON string.
+        """
+        return json.dumps(self.to_dict())
+
+    @classmethod
+    def from_dict(cls, data: dict[str, Any]) -> Message:
+        """Create a Message from a dictionary.
+
+        Args:
+            data (dict[str, Any]): The dictionary to create the message from.
+
+        Returns:
+            Message: The created message.
+        """
+        category = Category(data["category"])
+        action_str = data["action"]
+
+        match category:
+            case Category.CONTROL:
+                action = ControlAction(action_str)
+            case _:
+                raise ValueError(f"Unknown category: {category}")
+
+        payload = data.get("payload", {})
+        return cls(category=category, action=action, payload=payload)
+
+    @classmethod
+    def from_json(cls, data: str) -> Message:
+        """Create a Message from a JSON string.
+
+        Args:
+            data (str): The JSON string to create the message from.
+        Returns:
+            Message: The created message.
+        """
+        return cls.from_dict(json.loads(data))
+
+    @classmethod
+    def ack(cls) -> Message:
+        """Create an ACK message.
+
+        Returns:
+            Message: The created ACK message.
+        """
+        return cls(
+            category=Category.CONTROL, action=ControlAction.ACK, payload={}
+        )
+
+    @classmethod
+    def hello(cls, mac: str) -> Message:
+        """Create a HELLO message.
+
+        Args:
+            mac (str): The MAC address to include in the HELLO message.
+        Returns:
+            Message: The created HELLO message.
+        """
+        return cls(
+            category=Category.CONTROL,
+            action=ControlAction.HELLO,
+            payload={"mac": mac},
+        )