"""计算器：从已配置交易实例读取 USDT 永续合约精度与张数规则。"""

from __future__ import annotations

import json
import threading
import time
import urllib.error
import urllib.request
from typing import Any, Callable, Optional, Tuple
from urllib.parse import urlencode

from manual_trading_hub.settings_store import enabled_exchanges, load_settings

MARKET_CACHE: dict[str, tuple[float, dict[str, Any]]] = {}
MARKET_LOCK = threading.Lock()
MARKET_TTL_SEC = 300.0
HUB_FLASK_TIMEOUT = float(__import__("os").getenv("HUB_FLASK_TIMEOUT", "12"))


def normalize_base_symbol(text: str) -> str:
    s = str(text or "").upper().strip()
    for suf in ("USDT:USDT", "/USDT:USDT", "/USDT", "USDT", "-USDT-SWAP"):
        if s.endswith(suf) and len(s) > len(suf):
            s = s[: -len(suf)].strip("-/")
            break
    if "/" in s:
        s = s.split("/", 1)[0].strip()
    if ":" in s:
        s = s.split(":", 1)[0].strip()
    return s


def resolve_usdt_perp_symbol(exchange: Any, base: str) -> Tuple[Optional[str], Optional[str]]:
    base_u = normalize_base_symbol(base)
    if not base_u:
        return None, "请输入币种，如 ETH"
    candidates = [f"{base_u}/USDT:USDT", f"{base_u}/USDT"]
    markets = getattr(exchange, "markets", None) or {}
    for sym in candidates:
        m = markets.get(sym)
        if not m:
            continue
        if m.get("active") is False:
            continue
        if m.get("swap") or m.get("linear") or m.get("contract"):
            return sym, None
    for sym, m in markets.items():
        if m.get("active") is False:
            continue
        if not (m.get("swap") or m.get("linear")):
            continue
        if (m.get("quote") or "").upper() != "USDT":
            continue
        if (m.get("base") or "").upper() == base_u:
            return sym, None
    return None, f"未找到 {base_u}/USDT 永续合约"


def _decimals_from_precision_value(value: Any) -> Optional[int]:
    if value in (None, ""):
        return None
    try:
        p = float(value)
    except (TypeError, ValueError):
        return None
    if p >= 1 and abs(p - round(p)) < 1e-9 and p <= 12:
        return int(round(p))
    if 0 < p < 1:
        s = f"{p:.12f}".rstrip("0")
        if "." in s:
            return min(12, len(s.split(".", 1)[1]))
    return None


def _decimals_from_ccxt_str(text: str) -> int:
    s = str(text or "").strip()
    if not s or "." not in s:
        return 0
    frac = s.split(".", 1)[1]
    if not frac:
        return 0
    return min(12, len(frac.rstrip("0") or frac))


def amount_decimals_from_exchange(exchange: Any, exchange_symbol: str) -> int:
    try:
        return _decimals_from_ccxt_str(exchange.amount_to_precision(exchange_symbol, 1.23456789))
    except Exception:
        market = exchange.market(exchange_symbol)
        prec = (market.get("precision") or {}).get("amount")
        d = _decimals_from_precision_value(prec)
        return d if d is not None else 4


def price_decimals_from_exchange(
    exchange: Any, exchange_symbol: str, price_tick: Optional[float]
) -> int:
    from hub_ohlcv_lib import normalize_price_tick

    tick = normalize_price_tick(price_tick)
    if tick and tick > 0:
        if tick >= 1:
            return 0
        s = f"{tick:.12f}".rstrip("0")
        if "." in s:
            return min(12, len(s.split(".", 1)[1]))
    try:
        return _decimals_from_ccxt_str(exchange.price_to_precision(exchange_symbol, 12345.678901234))
    except Exception:
        market = exchange.market(exchange_symbol)
        prec = (market.get("precision") or {}).get("price")
        d = _decimals_from_precision_value(prec)
        return d if d is not None else 4


def make_amount_precise_fn_from_market(market: dict[str, Any]) -> Callable[[float], Optional[float]]:
    dec = max(0, int(market.get("amount_decimals") or 4))
    min_amt = market.get("min_amount")

    def _fn(amount: float) -> Optional[float]:
        try:
            v = float(amount)
        except (TypeError, ValueError):
            return None
        if v <= 0:
            return None
        factor = 10**dec
        v = int(v * factor + 1e-12) / factor
        if min_amt is not None:
            try:
                if v < float(min_amt):
                    return None
            except (TypeError, ValueError):
                pass
        if v <= 0:
            return None
        return v

    return _fn


def find_exchange(exchange_id: str) -> dict | None:
    needle = str(exchange_id or "").strip()
    if not needle:
        return None
    for ex in load_settings().get("exchanges") or []:
        if str(ex.get("id") or "").strip() == needle:
            return ex
        if str(ex.get("key") or "").strip().lower() == needle.lower():
            return ex
    return None


def list_calculator_exchanges() -> list[dict[str, Any]]:
    rows: list[dict[str, Any]] = []
    for ex in enabled_exchanges():
        rows.append(
            {
                "id": str(ex.get("id") or ""),
                "key": str(ex.get("key") or ""),
                "name": str(ex.get("name") or ex.get("key") or ""),
                "enabled": bool(ex.get("enabled")),
            }
        )
    return rows


def _hub_headers() -> dict[str, str]:
    import os

    token = (os.getenv("HUB_BRIDGE_TOKEN") or os.getenv("CONTROL_TOKEN") or "").strip()
    if token:
        return {"X-Hub-Token": token}
    return {}


def fetch_instance_market_sync(ex: dict, *, base: str) -> dict[str, Any]:
    base_url = (ex.get("flask_url") or "").rstrip("/")
    if not base_url:
        return {"ok": False, "msg": "未配置 flask_url"}
    params = urlencode({"base": normalize_base_symbol(base) or base})
    url = f"{base_url}/api/hub/market?{params}"
    req = urllib.request.Request(url, headers=_hub_headers(), method="GET")
    try:
        with urllib.request.urlopen(req, timeout=HUB_FLASK_TIMEOUT) as resp:
            status = int(getattr(resp, "status", 200) or 200)
            raw = resp.read().decode("utf-8", errors="replace")
        data = json.loads(raw) if raw else {}
        if not isinstance(data, dict):
            return {"ok": False, "msg": "无效 JSON"}
        if status >= 400:
            data.setdefault("ok", False)
        return data
    except urllib.error.HTTPError as exc:
        try:
            raw = exc.read().decode("utf-8", errors="replace")
            body = json.loads(raw) if raw else {}
        except Exception:
            body = {"ok": False, "msg": raw if "raw" in locals() else str(exc)}
        if isinstance(body, dict):
            body.setdefault("ok", False)
            return body
        return {"ok": False, "msg": f"HTTP {exc.code}"}
    except Exception as exc:
        return {"ok": False, "msg": str(exc)}


def _enrich_market_from_settings(ex: dict, payload: dict[str, Any]) -> dict[str, Any]:
    out = dict(payload)
    out["exchange_id"] = str(ex.get("id") or "")
    out["exchange_key"] = str(ex.get("key") or "")
    out["exchange_name"] = str(ex.get("name") or ex.get("key") or "")
    out["exchange_label"] = out["exchange_name"]
    return out


def get_calculator_market(
    exchange_id: str,
    base: str,
    *,
    ex: dict | None = None,
) -> Tuple[Optional[dict[str, Any]], Optional[str]]:
    """从系统设置中的交易实例拉取合约精度（与实盘一致）。"""
    row = ex or find_exchange(exchange_id)
    if not row:
        return None, "未找到该交易所配置"
    if not row.get("enabled"):
        return None, f"{row.get('name') or exchange_id} 未启用"

    base_u = normalize_base_symbol(base)
    if not base_u:
        return None, "请输入币种，如 ETH"

    cache_key = f"{row.get('id')}:{base_u}"
    now = time.time()
    with MARKET_LOCK:
        cached = MARKET_CACHE.get(cache_key)
        if cached and now - cached[0] < MARKET_TTL_SEC:
            return dict(cached[1]), None

    remote = fetch_instance_market_sync(row, base=base_u)
    if not remote.get("ok"):
        return None, str(remote.get("msg") or "实例返回失败")

    data = _enrich_market_from_settings(row, remote)
    with MARKET_LOCK:
        MARKET_CACHE[cache_key] = (now, data)
    return data, None


def clear_market_cache() -> None:
    with MARKET_LOCK:
        MARKET_CACHE.clear()