nanobot/nanobot/channels/whatsapp.py

"""WhatsApp channel implementation using Node.js bridge."""

import asyncio
import json
import mimetypes
import os
import secrets
import shutil
import subprocess
from collections import OrderedDict
from pathlib import Path
from typing import Any, Literal

from loguru import logger
from pydantic import Field

from nanobot.bus.events import OutboundMessage
from nanobot.bus.queue import MessageBus
from nanobot.channels.base import BaseChannel
from nanobot.config.schema import Base


class WhatsAppConfig(Base):
    """WhatsApp channel configuration."""

    enabled: bool = False
    bridge_url: str = "ws://localhost:3001"
    bridge_token: str = ""
    allow_from: list[str] = Field(default_factory=list)
    group_policy: Literal["open", "mention"] = "open"  # "open" responds to all, "mention" only when @mentioned


def _bridge_token_path() -> Path:
    from nanobot.config.paths import get_runtime_subdir

    return get_runtime_subdir("whatsapp-auth") / "bridge-token"


def _load_or_create_bridge_token(path: Path) -> str:
    """Load a persisted bridge token or create one on first use."""
    if path.exists():
        token = path.read_text(encoding="utf-8").strip()
        if token:
            return token

    path.parent.mkdir(parents=True, exist_ok=True)
    token = secrets.token_urlsafe(32)
    path.write_text(token, encoding="utf-8")
    try:
        path.chmod(0o600)
    except OSError:
        pass
    return token


class WhatsAppChannel(BaseChannel):
    """
    WhatsApp channel that connects to a Node.js bridge.

    The bridge uses @whiskeysockets/baileys to handle the WhatsApp Web protocol.
    Communication between Python and Node.js is via WebSocket.
    """

    name = "whatsapp"
    display_name = "WhatsApp"

    @classmethod
    def default_config(cls) -> dict[str, Any]:
        return WhatsAppConfig().model_dump(by_alias=True)

    def __init__(self, config: Any, bus: MessageBus):
        if isinstance(config, dict):
            config = WhatsAppConfig.model_validate(config)
        super().__init__(config, bus)
        self._ws = None
        self._connected = False
        self._processed_message_ids: OrderedDict[str, None] = OrderedDict()
        self._bridge_token: str | None = None

    def _effective_bridge_token(self) -> str:
        """Resolve the bridge token, generating a local secret when needed."""
        if self._bridge_token is not None:
            return self._bridge_token
        configured = self.config.bridge_token.strip()
        if configured:
            self._bridge_token = configured
        else:
            self._bridge_token = _load_or_create_bridge_token(_bridge_token_path())
        return self._bridge_token

    async def login(self, force: bool = False) -> bool:
        """
        Set up and run the WhatsApp bridge for QR code login.

        This spawns the Node.js bridge process which handles the WhatsApp
        authentication flow. The process blocks until the user scans the QR code
        or interrupts with Ctrl+C.
        """
        try:
            bridge_dir = _ensure_bridge_setup()
        except RuntimeError as e:
            logger.error("{}", e)
            return False

        env = {**os.environ}
        env["BRIDGE_TOKEN"] = self._effective_bridge_token()
        env["AUTH_DIR"] = str(_bridge_token_path().parent)

        logger.info("Starting WhatsApp bridge for QR login...")
        try:
            subprocess.run(
                [shutil.which("npm"), "start"], cwd=bridge_dir, check=True, env=env
            )
        except subprocess.CalledProcessError:
            return False

        return True

    async def start(self) -> None:
        """Start the WhatsApp channel by connecting to the bridge."""
        import websockets

        bridge_url = self.config.bridge_url

        logger.info("Connecting to WhatsApp bridge at {}...", bridge_url)

        self._running = True

        while self._running:
            try:
                async with websockets.connect(bridge_url) as ws:
                    self._ws = ws
                    await ws.send(
                        json.dumps({"type": "auth", "token": self._effective_bridge_token()})
                    )
                    self._connected = True
                    logger.info("Connected to WhatsApp bridge")

                    # Listen for messages
                    async for message in ws:
                        try:
                            await self._handle_bridge_message(message)
                        except Exception as e:
                            logger.error("Error handling bridge message: {}", e)

            except asyncio.CancelledError:
                break
            except Exception as e:
                self._connected = False
                self._ws = None
                logger.warning("WhatsApp bridge connection error: {}", e)

                if self._running:
                    logger.info("Reconnecting in 5 seconds...")
                    await asyncio.sleep(5)

    async def stop(self) -> None:
        """Stop the WhatsApp channel."""
        self._running = False
        self._connected = False

        if self._ws:
            await self._ws.close()
            self._ws = None

    async def send(self, msg: OutboundMessage) -> None:
        """Send a message through WhatsApp."""
        if not self._ws or not self._connected:
            logger.warning("WhatsApp bridge not connected")
            return

        chat_id = msg.chat_id

        if msg.content:
            try:
                payload = {"type": "send", "to": chat_id, "text": msg.content}
                await self._ws.send(json.dumps(payload, ensure_ascii=False))
            except Exception as e:
                logger.error("Error sending WhatsApp message: {}", e)
                raise

        for media_path in msg.media or []:
            try:
                mime, _ = mimetypes.guess_type(media_path)
                payload = {
                    "type": "send_media",
                    "to": chat_id,
                    "filePath": media_path,
                    "mimetype": mime or "application/octet-stream",
                    "fileName": media_path.rsplit("/", 1)[-1],
                }
                await self._ws.send(json.dumps(payload, ensure_ascii=False))
            except Exception as e:
                logger.error("Error sending WhatsApp media {}: {}", media_path, e)
                raise

    async def _handle_bridge_message(self, raw: str) -> None:
        """Handle a message from the bridge."""
        try:
            data = json.loads(raw)
        except json.JSONDecodeError:
            logger.warning("Invalid JSON from bridge: {}", raw[:100])
            return

        msg_type = data.get("type")

        if msg_type == "message":
            # Incoming message from WhatsApp
            # Deprecated by whatsapp: old phone number style typically: <phone>@s.whatspp.net
            pn = data.get("pn", "")
            # New LID sytle typically:
            sender = data.get("sender", "")
            content = data.get("content", "")
            message_id = data.get("id", "")

            if message_id:
                if message_id in self._processed_message_ids:
                    return
                self._processed_message_ids[message_id] = None
                while len(self._processed_message_ids) > 1000:
                    self._processed_message_ids.popitem(last=False)

            # Extract just the phone number or lid as chat_id
            is_group = data.get("isGroup", False)
            was_mentioned = data.get("wasMentioned", False)

            if is_group and getattr(self.config, "group_policy", "open") == "mention":
                if not was_mentioned:
                    return

            user_id = pn if pn else sender
            sender_id = user_id.split("@")[0] if "@" in user_id else user_id
            logger.info("Sender {}", sender)

            # Handle voice transcription if it's a voice message
            if content == "[Voice Message]":
                logger.info(
                    "Voice message received from {}, but direct download from bridge is not yet supported.",
                    sender_id,
                )
                content = "[Voice Message: Transcription not available for WhatsApp yet]"

            # Extract media paths (images/documents/videos downloaded by the bridge)
            media_paths = data.get("media") or []

            # Build content tags matching Telegram's pattern: [image: /path] or [file: /path]
            if media_paths:
                for p in media_paths:
                    mime, _ = mimetypes.guess_type(p)
                    media_type = "image" if mime and mime.startswith("image/") else "file"
                    media_tag = f"[{media_type}: {p}]"
                    content = f"{content}\n{media_tag}" if content else media_tag

            await self._handle_message(
                sender_id=sender_id,
                chat_id=sender,  # Use full LID for replies
                content=content,
                media=media_paths,
                metadata={
                    "message_id": message_id,
                    "timestamp": data.get("timestamp"),
                    "is_group": data.get("isGroup", False),
                },
            )

        elif msg_type == "status":
            # Connection status update
            status = data.get("status")
            logger.info("WhatsApp status: {}", status)

            if status == "connected":
                self._connected = True
            elif status == "disconnected":
                self._connected = False

        elif msg_type == "qr":
            # QR code for authentication
            logger.info("Scan QR code in the bridge terminal to connect WhatsApp")

        elif msg_type == "error":
            logger.error("WhatsApp bridge error: {}", data.get("error"))


def _ensure_bridge_setup() -> Path:
    """
    Ensure the WhatsApp bridge is set up and built.

    Returns the bridge directory. Raises RuntimeError if npm is not found
    or bridge cannot be built.
    """
    from nanobot.config.paths import get_bridge_install_dir

    user_bridge = get_bridge_install_dir()

    if (user_bridge / "dist" / "index.js").exists():
        return user_bridge

    npm_path = shutil.which("npm")
    if not npm_path:
        raise RuntimeError("npm not found. Please install Node.js >= 18.")

    # Find source bridge
    current_file = Path(__file__)
    pkg_bridge = current_file.parent.parent / "bridge"
    src_bridge = current_file.parent.parent.parent / "bridge"

    source = None
    if (pkg_bridge / "package.json").exists():
        source = pkg_bridge
    elif (src_bridge / "package.json").exists():
        source = src_bridge

    if not source:
        raise RuntimeError(
            "WhatsApp bridge source not found. "
            "Try reinstalling: pip install --force-reinstall nanobot"
        )

    logger.info("Setting up WhatsApp bridge...")
    user_bridge.parent.mkdir(parents=True, exist_ok=True)
    if user_bridge.exists():
        shutil.rmtree(user_bridge)
    shutil.copytree(source, user_bridge, ignore=shutil.ignore_patterns("node_modules", "dist"))

    logger.info("  Installing dependencies...")
    subprocess.run([npm_path, "install"], cwd=user_bridge, check=True, capture_output=True)

    logger.info("  Building...")
    subprocess.run([npm_path, "run", "build"], cwd=user_bridge, check=True, capture_output=True)

    logger.info("Bridge ready")
    return user_bridge