import httpx
from typing import Optional
from app.config import settings
import logging

logger = logging.getLogger(__name__)


class JavaClient:
    """Java 后端 HTTP 客户端 (单例, 复用连接池)"""

    _instance: Optional["JavaClient"] = None

    def __new__(cls):
        if cls._instance is None:
            cls._instance = super().__new__(cls)
            cls._instance._client = None
            cls._instance._base_url = settings.java_base_url
        return cls._instance

    async def _get_client(self) -> httpx.AsyncClient:
        if self._client is None:
            limits = httpx.Limits(
                max_connections=10,
                max_keepalive_connections=5,
                keepalive_expiry=30,
            )
            self._client = httpx.AsyncClient(
                base_url=self._base_url,
                timeout=httpx.Timeout(10.0, connect=3.0),
                limits=limits,
            )
        return self._client

    async def close(self):
        if self._client:
            await self._client.aclose()
            self._client = None
            JavaClient._instance = None

    async def get_published_articles(self) -> list[dict]:
        client = await self._get_client()
        resp = await client.post("/api/article/list", json={"status": "published", "limit": 1000})
        data = resp.json()
        if data.get("code") == 200:
            return data.get("data", [])
        return []

    async def search_products(self, keyword: str, limit: int = 5) -> list[dict]:
        client = await self._get_client()
        resp = await client.post("/api/product/search", json={
            "keyword": keyword, "status": "上架", "limit": limit
        })
        data = resp.json()
        if data.get("code") == 200:
            return data.get("data", [])
        return []

    async def search_activities(self, keyword: str, limit: int = 5) -> list[dict]:
        client = await self._get_client()
        resp = await client.post("/api/activity/search", json={
            "keyword": keyword, "status": "published", "limit": limit
        })
        data = resp.json()
        if data.get("code") == 200:
            return data.get("data", [])
        return []

    async def search_articles(self, keyword: str, limit: int = 5) -> list[dict]:
        client = await self._get_client()
        resp = await client.post("/api/article/search", json={
            "keyword": keyword, "status": "published", "limit": limit
        })
        data = resp.json()
        if data.get("code") == 200:
            return data.get("data", [])
        return []

    async def get_user_context(self, user_id: int, params: Optional[dict] = None) -> dict:
        client = await self._get_client()
        resp = await client.post(settings.effective_java_context_url, json={
            "user_id": str(user_id),
            "params": params or {},
        })
        data = resp.json()
        if data.get("code") == 200:
            return data.get("data", {})
        return {}