feat(gateway): handle WhatsApp Cloud conversations

surfsense_backend/app/gateway/whatsapp/commands.py

@@ -0,0 +1,123 @@
+"""WhatsApp command handlers."""
+
+from __future__ import annotations
+
+from app.gateway.base.adapter import BasePlatformAdapter, ParsedInboundEvent
+from app.gateway.base.commands import BaseGatewayCommands
+from app.gateway.pairing import redeem_pairing_code
+from app.gateway.ratelimit import acquire_token
+
+HELP_TEXT = (
+    "SurfSense WhatsApp commands:\n"
+    "/start <code> - pair this chat\n"
+    "/new - start a fresh conversation\n"
+    "/help - show this help"
+)
+
+
+async def handle_start_command(
+    *,
+    session,
+    adapter: BasePlatformAdapter,
+    event: ParsedInboundEvent,
+) -> bool:
+    text = event.text or ""
+    parts = text.split(maxsplit=1)
+    if len(parts) != 2 or not event.external_peer_id:
+        await adapter.send_message(
+            external_peer_id=event.external_peer_id or "",
+            text=(
+                "Generate a pairing code in SurfSense Settings > Messaging Channels, "
+                "then send /start CODE here."
+            ),
+        )
+        return True
+
+    binding = await redeem_pairing_code(
+        session,
+        code=parts[1].strip(),
+        external_peer_id=event.external_peer_id,
+        external_peer_kind=event.external_peer_kind,
+        external_display_name=event.display_name,
+        external_username=event.username,
+        external_metadata=event.metadata,
+    )
+    if binding is None:
+        await adapter.send_message(
+            external_peer_id=event.external_peer_id,
+            text="That pairing code is invalid or expired. Generate a new code in SurfSense.",
+        )
+        return True
+
+    await adapter.send_message(
+        external_peer_id=event.external_peer_id,
+        text="SurfSense is connected. Send a message here to chat with your agent.",
+    )
+    return True
+
+
+async def handle_help_command(
+    *,
+    adapter: BasePlatformAdapter,
+    event: ParsedInboundEvent,
+) -> bool:
+    if not event.external_peer_id:
+        return True
+    await adapter.send_message(external_peer_id=event.external_peer_id, text=HELP_TEXT)
+    return True
+
+
+async def send_unbound_onboarding(
+    *,
+    adapter: BasePlatformAdapter,
+    event: ParsedInboundEvent,
+    dashboard_url: str,
+) -> None:
+    if not event.external_peer_id:
+        return
+    wait_ms = await acquire_token(
+        f"wa:onboarded:{event.external_peer_id}",
+        capacity=1,
+        refill_per_sec=1 / 3600,
+    )
+    if wait_ms > 0:
+        return
+    await adapter.send_message(
+        external_peer_id=event.external_peer_id,
+        text=(
+            "Hi! To use SurfSense via WhatsApp, generate a pairing code at "
+            f"{dashboard_url} and send /start CODE here."
+        ),
+    )
+
+
+class WhatsAppGatewayCommands(BaseGatewayCommands):
+    async def handle_start_command(
+        self,
+        *,
+        session,
+        adapter: BasePlatformAdapter,
+        event: ParsedInboundEvent,
+    ) -> bool:
+        return await handle_start_command(session=session, adapter=adapter, event=event)
+
+    async def handle_help_command(
+        self,
+        *,
+        adapter: BasePlatformAdapter,
+        event: ParsedInboundEvent,
+    ) -> bool:
+        return await handle_help_command(adapter=adapter, event=event)
+
+    async def send_unbound_onboarding(
+        self,
+        *,
+        adapter: BasePlatformAdapter,
+        event: ParsedInboundEvent,
+        dashboard_url: str,
+    ) -> None:
+        await send_unbound_onboarding(
+            adapter=adapter,
+            event=event,
+            dashboard_url=dashboard_url,
+        )

surfsense_backend/app/gateway/whatsapp/translator.py

@@ -0,0 +1,90 @@
+"""Translate agent stream events into WhatsApp Cloud API messages."""
+
+from __future__ import annotations
+
+import logging
+from collections.abc import AsyncIterator
+
+from app.gateway.base.adapter import BasePlatformAdapter, PlatformSendResult
+from app.gateway.base.formatting import split_text_message
+from app.gateway.base.translator import BaseStreamTranslator, GatewayStreamEvent
+from app.gateway.whatsapp.adapter_cloud import WhatsAppCloudAdapter
+from app.observability.metrics import (
+    record_gateway_hitl_aborted,
+    record_gateway_outbound,
+)
+
+logger = logging.getLogger(__name__)
+
+HITL_UNSUPPORTED_MESSAGE = (
+    "This action requires approval and is not yet supported from WhatsApp. "
+    "Try again with a different request."
+)
+
+
+class WhatsAppCloudStreamTranslator(BaseStreamTranslator):
+    def __init__(
+        self,
+        *,
+        adapter: BasePlatformAdapter,
+        external_peer_id: str,
+        inbound_message_id: str | None = None,
+    ) -> None:
+        self.adapter = adapter
+        self.external_peer_id = external_peer_id
+        self.inbound_message_id = inbound_message_id
+        self._buffer = ""
+        self._typing_sent = False
+
+    async def translate(self, events: AsyncIterator[GatewayStreamEvent]) -> None:
+        async for event in events:
+            if event.type in {"text-delta", "text_delta", "text"}:
+                if not self._typing_sent:
+                    await self._send_typing_indicator()
+                self._buffer += str(event.data.get("text") or event.data.get("delta") or "")
+            elif event.type in {"data-interrupt-request", "interrupt"}:
+                await self._handle_hitl_interrupt()
+                return
+            elif event.type in {"finish", "done"}:
+                break
+
+        await self._flush_final()
+
+    async def _flush_final(self) -> None:
+        if not self._buffer:
+            return
+        for chunk in split_text_message(self._buffer):
+            await self._send_text(chunk)
+
+    async def _send_typing_indicator(self) -> None:
+        self._typing_sent = True
+        if not self.inbound_message_id:
+            return
+        if not isinstance(self.adapter, WhatsAppCloudAdapter):
+            return
+        try:
+            await self.adapter.send_typing_indicator(
+                inbound_message_id=self.inbound_message_id
+            )
+            record_gateway_outbound(platform="whatsapp", kind="typing", status="sent")
+        except Exception:
+            logger.debug("WhatsApp typing indicator failed", exc_info=True)
+            record_gateway_outbound(platform="whatsapp", kind="typing", status="failed")
+
+    async def _send_text(self, text: str) -> PlatformSendResult:
+        try:
+            result = await self.adapter.send_message(
+                external_peer_id=self.external_peer_id,
+                text=text,
+            )
+        except Exception:
+            record_gateway_outbound(platform="whatsapp", kind="send", status="failed")
+            raise
+        record_gateway_outbound(platform="whatsapp", kind="send", status="sent")
+        return result
+
+    async def _handle_hitl_interrupt(self) -> None:
+        if self._buffer:
+            await self._flush_final()
+        await self._send_text(HITL_UNSUPPORTED_MESSAGE)
+        record_gateway_hitl_aborted(platform="whatsapp")