from __future__ import annotations

import logging

from fastapi import APIRouter, HTTPException, Request

from yuxi.channel.extensions.pinduoduo.dedupe import PddMessageDeduplicator
from yuxi.channel.extensions.pinduoduo.monitor import PinduoduoMonitor
from yuxi.channel.extensions.pinduoduo.signature import verify_push_sign
from yuxi.channel.extensions.pinduoduo.types import PinduoduoAccount
from yuxi.channel.extensions.pinduoduo.window import PinduoduoWindowTracker

logger = logging.getLogger(__name__)

_handlers: dict[str, dict] = {}


def register_handler(
    account_id: str,
    account: PinduoduoAccount,
    monitor: PinduoduoMonitor,
    deduplicator: PddMessageDeduplicator,
    put_fn,
    window_tracker: PinduoduoWindowTracker | None = None,
) -> None:
    _handlers[account_id] = {
        "account": account,
        "monitor": monitor,
        "deduplicator": deduplicator,
        "put_fn": put_fn,
        "window_tracker": window_tracker,
    }
    logger.info("Webhook handler registered for account=%s", account_id)


def unregister_handler(account_id: str) -> None:
    _handlers.pop(account_id, None)
    logger.info("Webhook handler unregistered for account=%s", account_id)


def create_webhook_router() -> APIRouter:
    router = APIRouter(prefix="/webhook/pinduoduo", tags=["pinduoduo"])

    @router.post("/callback")
    async def handle_push(request: Request):
        try:
            body = await request.json()
        except Exception:
            raise HTTPException(status_code=400, detail="Invalid JSON")

        sign = request.headers.get("X-Pdd-Sign", "")
        mall_id = str(body.get("mall_id", ""))

        handler = None
        for h in _handlers.values():
            if h["account"].mall_id == mall_id:
                handler = h
                break

        if handler is None:
            logger.warning("No handler found for mall_id=%s", mall_id)
            return {"status": "no_handler"}

        if handler["account"].client_secret:
            body_str = (await request.body()).decode("utf-8")
            if not verify_push_sign(body_str, handler["account"].client_secret, sign, handler["account"].sign_method):
                logger.warning("Push signature verification failed for mall_id=%s", mall_id)
                raise HTTPException(status_code=403, detail="Invalid signature")

        monitor: PinduoduoMonitor = handler["monitor"]
        messages = monitor.parse_push_event(body)

        for msg in messages:
            if handler["deduplicator"].is_duplicate(msg.msg_id):
                continue

            if handler.get("window_tracker") and msg.buyer_id:
                handler["window_tracker"].record(msg.buyer_id)

            unified = monitor.to_unified_message(msg)
            await handler["put_fn"](unified)

        return {"status": "ok", "message_count": len(messages)}

    @router.post("/callback/verify")
    async def verify_push_url(request: Request):
        params = request.query_params
        echostr = params.get("echostr", "")
        if echostr:
            return {"echostr": echostr}
        return {"status": "ok"}

    return router