backend redesign

backend.old/src/gateway/channels/base.py

@@ -0,0 +1,73 @@
+from abc import ABC, abstractmethod
+from typing import AsyncIterator, Dict, Any
+
+from gateway.protocol import UserMessage, AgentMessage, ChannelStatus
+
+
+class Channel(ABC):
+    """Abstract base class for communication channels.
+
+    Channels are the transport layer between users and the agent system.
+    They handle protocol-specific encoding/decoding and maintain connection state.
+    """
+
+    def __init__(self, channel_id: str, channel_type: str):
+        self.channel_id = channel_id
+        self.channel_type = channel_type
+        self._connected = False
+
+    @abstractmethod
+    async def send(self, message: AgentMessage) -> None:
+        """Send a message from the agent to the user through this channel.
+
+        Args:
+            message: AgentMessage to send (may be streaming chunk or complete message)
+        """
+        pass
+
+    @abstractmethod
+    async def receive(self) -> AsyncIterator[UserMessage]:
+        """Receive messages from the user through this channel.
+
+        Yields:
+            UserMessage objects as they arrive
+        """
+        pass
+
+    @abstractmethod
+    async def close(self) -> None:
+        """Close the channel and clean up resources."""
+        pass
+
+    def supports_streaming(self) -> bool:
+        """Whether this channel supports streaming responses.
+
+        Returns:
+            True if the channel can handle streaming chunks
+        """
+        return False
+
+    def supports_attachments(self) -> bool:
+        """Whether this channel supports file attachments.
+
+        Returns:
+            True if the channel can handle attachments
+        """
+        return False
+
+    def get_status(self) -> ChannelStatus:
+        """Get current channel status.
+
+        Returns:
+            ChannelStatus object with connection info and capabilities
+        """
+        return ChannelStatus(
+            channel_id=self.channel_id,
+            channel_type=self.channel_type,
+            connected=self._connected,
+            capabilities={
+                "streaming": self.supports_streaming(),
+                "attachments": self.supports_attachments(),
+                "markdown": True  # Most channels support some form of markdown
+            }
+        )