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(120.0, 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]:
        """拉取已发布知识库文章（分页 + records 解析，避免单次响应过大 / 返回 dict 结构）"""
        client = await self._get_client()
        page = 1
        size = 50
        records = []
        while True:
            resp = await client.post("/api/article/list", json={"status": "published", "page": page, "size": size})
            data = resp.json()
            if data.get("code") != 200:
                break
            body = data.get("data", {}) or {}
            items = body.get("records", []) or []
            records.extend(items)
            total = body.get("total", 0)
            if page * size >= int(total or 0) or not items:
                break
            page += 1
        return records

    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 {}

    async def get_microbiome_articles(self) -> list[dict]:
        """拉取菌群知识库文章（分页，避免单次响应过大导致 Broken pipe）"""
        client = await self._get_client()
        page = 1
        size = 50
        records = []
        while True:
            resp = await client.post("/api/microbiome/article/list",
                                     json={"page": page, "size": size, "keyword": "", "category": ""})
            data = resp.json()
            if data.get("code") != 200:
                break
            body = data.get("data", {}) or {}
            items = body.get("records", []) or []
            records.extend(items)
            total = body.get("total", 0)
            if page * size >= int(total or 0) or not items:
                break
            page += 1
        return records

    async def get_dan_knowledge_base(self) -> list[dict]:
        """拉取知识库内容（dan_knowledge_base 表，仅启用 status=1）"""
        client = await self._get_client()
        page = 1
        size = 1000
        records = []
        while True:
            resp = await client.post("/api/admin/knowledge-base/list", json={"page": page, "size": size, "status": 1})
            data = resp.json()
            if data.get("code") != 200:
                break
            body = data.get("data", {}) or {}
            items = body.get("records", []) or []
            records.extend(items)
            total = body.get("total", 0)
            if page * size >= int(total or 0) or not items:
                break
            page += 1
        return records

    async def get_member_reports(self, member_id: int) -> list[dict]:
        """获取某个家庭成员的健康报告列表"""
        client = await self._get_client()
        resp = await client.post("/api/health/report/list", json={"memberId": member_id})
        data = resp.json()
        if data.get("code") == 200:
            return data.get("data", [])
        return []

    async def get_report_indicators(self, report_id: int) -> list[dict]:
        """获取健康报告的所有指标明细"""
        client = await self._get_client()
        resp = await client.post("/api/health/report/indicator/list", json={"reportId": report_id})
        data = resp.json()
        if data.get("code") == 200:
            return data.get("data", [])
        return []

    async def query_health_knowledge(self, item_type: str, item_name: str) -> dict | None:
        """查询健康知识库中某个指标/菌属/营养素的定义"""
        client = await self._get_client()
        resp = await client.post("/api/health/knowledge/query", json={
            "itemType": item_type, "itemName": item_name,
        })
        data = resp.json()
        if data.get("code") == 200 and data.get("data"):
            return data["data"]
        return None

    async def batch_query_health_knowledge(self, queries: list[dict]) -> list[dict]:
        """批量查询健康知识库"""
        client = await self._get_client()
        resp = await client.post("/api/health/knowledge/batch-query", json={"queries": queries})
        data = resp.json()
        if data.get("code") == 200:
            return data.get("data", [])
        return []

    async def get_family_context(self, user_id: int, intent_type: str = "child_info", params: dict | None = None) -> dict:
        """获取家庭上下文数据（通过公开的 /api/ai/context 端点）"""
        client = await self._get_client()
        body = {"user_id": str(user_id), "intent_type": intent_type}
        if params:
            body["params"] = params
        resp = await client.post("/api/ai/context", json=body)
        data = resp.json()
        if data.get("code") == 200:
            return data.get("data", {})
        return {}