from __future__ import annotations

import asyncio
import logging
from typing import Any, Callable, Awaitable

import aiohttp

from channels.base import BaseChannel
from config import settings

logger = logging.getLogger(__name__)


class WhatsAppChannel(BaseChannel):
    """WhatsApp-Kanal via Green API (https://green-api.com)."""

    def __init__(self) -> None:
        self._base_url = (
            f"https://api.green-api.com/waInstance{settings.whatsapp_id_instance}"
        )
        self._token = settings.whatsapp_api_token
        self._session: aiohttp.ClientSession | None = None
        self._polling_task: asyncio.Task | None = None
        self._inbound_callback: Callable[[dict[str, Any]], Awaitable[None]] | None = None

    def set_inbound_callback(self, cb: Callable[[dict[str, Any]], Awaitable[None]]) -> None:
        self._inbound_callback = cb

    # ── BaseChannel interface ──────────────────────────────────────────────────

    async def send_message(
        self,
        recipient: str,
        text: str,
        reply_to_id: str | None = None,
    ) -> dict[str, Any]:
        if not settings.whatsapp_enabled:
            return {"success": False, "channel_message_id": None, "error": "WhatsApp not configured"}

        # chatId: Telefonnummer ohne + gefolgt von @c.us, z.B. "4917612345678@c.us"
        chat_id = recipient.replace("@c.us", "").lstrip("+") + "@c.us"
        url = f"{self._base_url}/sendMessage/{self._token}"
        body: dict[str, Any] = {"chatId": chat_id, "message": text}
        if reply_to_id:
            body["quotedMessageId"] = reply_to_id

        try:
            async with self._get_session().post(url, json=body) as resp:
                data = await resp.json()
                if resp.status == 200 and "idMessage" in data:
                    return {"success": True, "channel_message_id": data["idMessage"], "error": None}
                return {"success": False, "channel_message_id": None, "error": str(data)}
        except Exception as exc:
            logger.error("WhatsApp send error: %s", exc)
            return {"success": False, "channel_message_id": None, "error": str(exc)}

    async def check_connection(self) -> tuple[bool, str]:
        if not settings.whatsapp_enabled:
            return False, "Not configured"
        url = f"{self._base_url}/getStateInstance/{self._token}"
        try:
            async with self._get_session().get(url) as resp:
                data = await resp.json()
                state = data.get("stateInstance", "unknown")
                return state == "authorized", state
        except Exception as exc:
            return False, str(exc)

    async def start(self) -> None:
        if not settings.whatsapp_enabled:
            logger.info("WhatsApp disabled (no credentials configured)")
            return
        self._session = aiohttp.ClientSession()
        await self._ensure_incoming_enabled()
        self._polling_task = asyncio.create_task(self._polling_loop(), name="whatsapp-polling")
        logger.info("WhatsApp channel started")

    async def stop(self) -> None:
        if self._polling_task and not self._polling_task.done():
            self._polling_task.cancel()
            try:
                await self._polling_task
            except asyncio.CancelledError:
                pass
            self._polling_task = None
        if self._session and not self._session.closed:
            await self._session.close()
        logger.info("WhatsApp channel stopped")

    # ── Polling-Schleife ───────────────────────────────────────────────────────

    async def _polling_loop(self) -> None:
        """Endlos-Polling: direkt nach Antwort wieder starten, kein Overlap möglich."""
        url = f"{self._base_url}/receiveNotification/{self._token}"
        timeout = aiohttp.ClientTimeout(total=15)
        while True:
            try:
                async with self._get_session().get(
                    url, params={"receiveTimeout": 5}, timeout=timeout
                ) as resp:
                    if resp.status == 200:
                        data = await resp.json()
                        if data:
                            receipt_id = data.get("receiptId")
                            body = data.get("body", {})
                            await self._process_notification(body)
                            if receipt_id:
                                await self._delete_notification(receipt_id)
            except asyncio.CancelledError:
                break
            except Exception as exc:
                logger.error("WhatsApp poll error: %s", exc)
                await asyncio.sleep(5)

    async def _delete_notification(self, receipt_id: int) -> None:
        url = f"{self._base_url}/deleteNotification/{self._token}/{receipt_id}"
        try:
            async with self._get_session().delete(url) as resp:
                await resp.read()
        except Exception as exc:
            logger.warning("WhatsApp delete notification error: %s", exc)

    async def _process_notification(self, body: dict[str, Any]) -> None:
        if not self._inbound_callback:
            return
        msg_type = body.get("typeWebhook")
        if msg_type != "incomingMessageReceived":
            return
        sender_data = body.get("senderData", {})
        message_data = body.get("messageData", {})
        text_data = message_data.get("textMessageData", {})
        payload: dict[str, Any] = {
            "channel": "whatsapp",
            "channel_message_id": body.get("idMessage"),
            "sender_phone": sender_data.get("sender", "").replace("@c.us", ""),
            "sender_name": sender_data.get("senderName", ""),
            "chat_id": sender_data.get("chatId", ""),
            "text": text_data.get("textMessage", ""),
            "reply_to_id": None,
        }
        await self._inbound_callback(payload)


    async def _ensure_incoming_enabled(self) -> None:
        """Stellt sicher dass incomingWebhook in der Green-API-Instanz aktiviert ist."""
        url = f"{self._base_url}/setSettings/{self._token}"
        try:
            async with self._get_session().post(
                url,
                json={"incomingWebhook": "yes", "outgoingWebhook": "yes"},
                timeout=aiohttp.ClientTimeout(total=10),
            ) as resp:
                data = await resp.json()
                if data.get("saveSettings"):
                    logger.info("WhatsApp: incomingWebhook aktiviert")
                else:
                    logger.warning("WhatsApp: setSettings Antwort: %s", data)
        except Exception as exc:
            logger.warning("WhatsApp: incomingWebhook konnte nicht gesetzt werden: %s", exc)

    def _get_session(self) -> aiohttp.ClientSession:
        if not self._session or self._session.closed:
            self._session = aiohttp.ClientSession()
        return self._session