Ben 259e78e175 feat(relay): transport protocol + test-only stub connector
Defines RelayTransport (lifecycle/handshake/inbound/outbound/interrupt) as the
gateway<->connector wire contract; RelayAdapter.connect now registers an inbound
handler that bridges connector-delivered MessageEvents into handle_message.
Adds an in-memory StubConnector under tests/ and an E2E round-trip proving:
connect registers the handler, inbound events reach the adapter, guild_id drives
build_session_key isolation (two guilds -> two keys; same guild/channel/user ->
one), outbound send round-trips, get_chat_info is proxied.

Phase 1, Task 1.2 of the gateway-relay plan.
2026-06-17 16:37:45 -07:00

118 lines
4.6 KiB
Python

"""RelayAdapter — one generic gateway adapter fronted by the connector. EXPERIMENTAL.
A single ``BasePlatformAdapter`` subclass that, at handshake, receives a
``CapabilityDescriptor`` from the connector telling it which platform it is
fronting and which capabilities to advertise to the ``GatewayStreamConsumer``.
It implements the four abstract methods (``connect`` / ``disconnect`` / ``send``
/ ``get_chat_info``) plus the capability surface (``MAX_MESSAGE_LENGTH``,
``message_len_fn``, ``supports_draft_streaming``) by delegating wire I/O to an
injected transport and reading capabilities off the descriptor.
There is NO per-platform gateway code: the connector is the only side that knows
"this chat_id maps to a Discord channel, send it via the Discord websocket."
The gateway sees an ordinary ``MessageEvent`` in and calls ``adapter.send`` out.
EXPERIMENTAL: the transport protocol and descriptor schema may change without a
deprecation cycle until >=2 Class-1 platforms validate them.
"""
from __future__ import annotations
import logging
from typing import Any, Callable, Dict, Optional
from gateway.config import Platform, PlatformConfig
from gateway.platforms.base import BasePlatformAdapter, SendResult
from gateway.relay.descriptor import CapabilityDescriptor
from gateway.relay.transport import RelayTransport
logger = logging.getLogger(__name__)
def _utf16_len(text: str) -> int:
"""Count UTF-16 code units (Telegram's length unit)."""
return len(text.encode("utf-16-le")) // 2
# Table-driven length-unit selection from the descriptor's ``len_unit``.
_LEN_FNS: Dict[str, Callable[[str], int]] = {
"chars": len,
"utf16": _utf16_len,
}
class RelayAdapter(BasePlatformAdapter):
"""Generic relay adapter advertising a connector-negotiated capability profile."""
def __init__(
self,
config: PlatformConfig,
descriptor: CapabilityDescriptor,
transport: Optional[RelayTransport] = None,
) -> None:
# The relay adapter fronts many platforms but presents as a single
# logical platform to the runner; Platform.RELAY identifies it.
super().__init__(config, Platform.RELAY)
self.descriptor = descriptor
self._transport = transport
# Capability surface read by stream_consumer (getattr(..., 4096)).
self.MAX_MESSAGE_LENGTH = descriptor.max_message_length
self.supports_code_blocks = descriptor.markdown_dialect not in ("", "plain")
# ── capability surface (from descriptor) ─────────────────────────────
@property
def message_len_fn(self) -> Callable[[str], int]:
return _LEN_FNS.get(self.descriptor.len_unit, len)
def supports_draft_streaming(
self,
chat_type: Optional[str] = None,
metadata: Optional[Dict[str, Any]] = None,
) -> bool:
return self.descriptor.supports_draft_streaming
# ── abstract methods (delegated to the transport) ────────────────────
async def connect(self) -> bool:
if self._transport is None:
raise RuntimeError("RelayAdapter has no transport configured")
self._transport.set_inbound_handler(self._on_inbound)
return await self._transport.connect()
async def _on_inbound(self, event) -> None:
"""Bridge a connector-delivered MessageEvent into the normal adapter path."""
await self.handle_message(event)
async def disconnect(self) -> None:
if self._transport is not None:
await self._transport.disconnect()
async def send(
self,
chat_id: str,
content: str,
reply_to: Optional[str] = None,
metadata: Optional[Dict[str, Any]] = None,
) -> SendResult:
if self._transport is None:
return SendResult(success=False, error="no transport")
result = await self._transport.send_outbound(
{
"op": "send",
"chat_id": chat_id,
"content": content,
"reply_to": reply_to,
"metadata": metadata or {},
}
)
return SendResult(
success=bool(result.get("success")),
message_id=result.get("message_id"),
error=result.get("error"),
)
async def get_chat_info(self, chat_id: str) -> Dict[str, Any]:
# Proxied to the connector (it owns the platform connection / cache).
if self._transport is None:
return {"name": chat_id, "type": "dm"}
return await self._transport.get_chat_info(chat_id)