auv/backend/services/themes.py

"""东方财富题材数据服务：题材列表、题材详情、题材相关股票

逆向自 emrnweb.eastmoney.com/investment 的 H5 接口：
- 题材列表: POST https://emcfgdata.eastmoney.com/api/themeInvest/getThemeList
- 题材详情: GET  https://emcfgdata.securities.eastmoney.com/api/themeInvest/getDetail/{themeCode}
- 相关股票: POST https://emcfgdata.eastmoney.com/api/themeInvest/getStockList

两个 POST 接口需要「移动端包装结构」：
  {args:{...业务参数}, appKey, client, clientVersion, clientType, randomCode, timestamp}
"""

import asyncio
import json
import random
import string
import time
from datetime import datetime, time as dtime, timedelta, timezone
from typing import Optional

import httpx

from services.cache import get_cache, set_cache

# ---- 东方财富移动端配置中心域名 ----

_PZ_URL = "https://emcfgdata.eastmoney.com"
_PZ_CDN_URL = "https://emcfgdata.securities.eastmoney.com"

# appKey 与页面场景对应：题材列表索引页 / 题材详情页
_APP_KEY_INDEX = "rn-themeIndex"
_APP_KEY_DETAIL = "rn-themeDetail"

_HEADERS = {
    "User-Agent": "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/131.0.0.0 Safari/537.36",
    "Origin": "https://emrnweb.eastmoney.com",
    "Referer": "https://emrnweb.eastmoney.com/",
    "Accept": "application/json",
    "Accept-Language": "zh-CN,zh;q=0.9",
}

# ---- 交易时段感知缓存 ----

_CST = timezone(timedelta(hours=8))  # 北京时间
_TRADING_MORNING = (dtime(9, 30), dtime(11, 30))
_TRADING_AFTERNOON = (dtime(13, 0), dtime(15, 0))


def _is_trading_time() -> bool:
    """判断当前是否为 A 股交易时段（周一至周五 9:30-11:30 / 13:00-15:00）"""
    now = datetime.now(_CST)
    if now.weekday() >= 5:
        return False
    t = now.time()
    return (_TRADING_MORNING[0] <= t <= _TRADING_MORNING[1]
            or _TRADING_AFTERNOON[0] <= t <= _TRADING_AFTERNOON[1])


def _dynamic_ttl() -> int:
    """盘中返回 2 分钟缓存 TTL，非交易时段 18 小时（覆盖到下一交易日）"""
    return 0 if _is_trading_time() else 18


# ---- 请求封装 ----

def _build_payload(args: Optional[dict] = None, app_key: str = _APP_KEY_INDEX) -> dict:
    """构建东方财富移动端请求包装结构"""
    return {
        "args": args or {},
        "appKey": app_key,
        "client": "iOS",
        "clientVersion": "8.3",
        "clientType": "cfw",
        "randomCode": "".join(random.choices(string.ascii_uppercase + string.ascii_lowercase + string.digits, k=16)),
        "timestamp": int(time.time() * 1000),
    }


async def _post(path: str, args: dict, app_key: str = _APP_KEY_INDEX) -> Optional[dict]:
    """POST 到配置中心接口，返回 data 层 JSON"""
    payload = _build_payload(args, app_key)
    try:
        async with httpx.AsyncClient(timeout=15) as client:
            resp = await client.post(_PZ_URL + path, json=payload, headers=_HEADERS)
            if resp.status_code != 200:
                return None
            body = resp.json()
    except Exception as e:
        print(f"[themes] POST {path} 失败: {e}")
        return None
    if body.get("code") != 0:
        print(f"[themes] POST {path} 返回错误: {body.get('message')}")
        return None
    return body.get("data")


async def _get_cdn(path: str, app_key: str = _APP_KEY_DETAIL) -> Optional[dict]:
    """GET 到配置中心 CDN 接口（题材详情），data 包装结构放 query 参数"""
    payload = _build_payload({}, app_key)
    params = {"data": json.dumps(payload, ensure_ascii=False)}
    try:
        async with httpx.AsyncClient(timeout=15) as client:
            resp = await client.get(_PZ_CDN_URL + path, params=params, headers=_HEADERS)
            if resp.status_code != 200:
                return None
            body = resp.json()
    except Exception as e:
        print(f"[themes] GET {path} 失败: {e}")
        return None
    if body.get("code") != 0:
        print(f"[themes] GET {path} 返回错误: {body.get('message')}")
        return None
    return body.get("data")


# ---- 题材列表 ----

# sortField 映射（题材列表页）：1=涨幅(bf3) 3=强度(strengthValue) 4=热度排名(hotRank) 5=成交额(fex5)
_LIST_PAGE_SIZE = 500


async def fetch_theme_list(sort_field: int = 1, asc: bool = False) -> list[dict]:
    """获取全部题材列表（内部循环分页拉全，约 623 个，最多 2 页）

    Args:
        sort_field: 排序字段 1/3/4/5
        asc: True=升序, False=降序
    """
    cache_key = f"theme_list:{sort_field}:{asc}"
    cached = get_cache(cache_key)
    if cached is not None:
        return json.loads(cached)

    sort = 1 if asc else -1
    # hotRank 数值越小越热，"热度降序(最热在前)" 需反转为接口升序
    if sort_field == 4:
        sort = -sort
    items: list[dict] = []
    page = 1
    total = None

    for _ in range(5):  # 安全上限
        data = await _post(
            "/api/themeInvest/getThemeList",
            {"pageSize": _LIST_PAGE_SIZE, "pageNum": page, "sort": sort, "sortField": sort_field},
        )
        if not data:
            break
        if total is None:
            total = data.get("total", 0)
        page_items = data.get("list", [])
        if not page_items:
            break
        items.extend(page_items)
        if len(items) >= total:
            break
        page += 1

    if items:
        ttl = _dynamic_ttl()
        if ttl > 0:
            set_cache(cache_key, json.dumps(items, ensure_ascii=False), ttl_hours=ttl)
    return items


# ---- 题材详情 ----

async def fetch_theme_detail(theme_code: str) -> Optional[dict]:
    """获取题材详情（简介 + 热点事件 + 相关新闻），缓存 1 小时"""
    cache_key = f"theme_detail:{theme_code}"
    cached = get_cache(cache_key)
    if cached is not None:
        return json.loads(cached)

    data = await _get_cdn(f"/api/themeInvest/getDetail/{theme_code}", app_key=_APP_KEY_DETAIL)
    if not data:
        return None

    set_cache(cache_key, json.dumps(data, ensure_ascii=False), ttl_hours=1)
    return data


# ---- 题材相关股票 ----

_STOCK_PAGE_SIZE = 100


async def fetch_theme_stocks(theme_code: str) -> dict:
    """获取题材下全部相关股票（分页拉全），返回 {stockList, statistic, total}"""
    cache_key = f"theme_stocks:{theme_code}"
    cached = get_cache(cache_key)
    if cached is not None:
        return json.loads(cached)

    stock_list: list[dict] = []
    statistic = {}
    total = 0
    page = 1

    for _ in range(20):  # 安全上限
        data = await _post(
            "/api/themeInvest/getStockList",
            {"themeCode": theme_code, "pageSize": _STOCK_PAGE_SIZE, "pageNum": page, "sort": -1, "sortField": "f3"},
            app_key=_APP_KEY_DETAIL,
        )
        if not data:
            break
        if not statistic and data.get("statistic"):
            statistic = data["statistic"]
        page_items = data.get("stockList", [])
        if not page_items:
            break
        stock_list.extend(page_items)
        total = data.get("total", 0)
        if len(stock_list) >= total:
            break
        page += 1

    result = {"stockList": stock_list, "statistic": statistic, "total": total}
    if stock_list:
        ttl = _dynamic_ttl()
        if ttl > 0:
            set_cache(cache_key, json.dumps(result, ensure_ascii=False), ttl_hours=ttl)
    return result