from __future__ import annotations

import json
import os
import time
import threading
from datetime import datetime, timezone, timedelta
from decimal import Decimal, ROUND_DOWN
from uuid import uuid4

from fastapi import HTTPException

from .bitstamp import BitstampClient, BitstampError
from .services_bitstamp import get_bitstamp_client, clear_bitstamp_trading_client
from .bitstamp_metadata import load_market_by_symbol
from .storage import get_connection


OPEN_ORDER_STATUSES = {"open", "new", "partially_filled"}
_CANCEL_BREAKER_LOCK = threading.Lock()
_CANCEL_BREAKER_NEXT_ALLOWED: dict[str, float] = {}
_CANCEL_BREAKER_SECONDS = 3.0


def _cancel_breaker_is_open(account_id: str) -> bool:
    with _CANCEL_BREAKER_LOCK:
        return _CANCEL_BREAKER_NEXT_ALLOWED.get(account_id, 0.0) > time.monotonic()


def _cancel_breaker_trip(account_id: str) -> None:
    with _CANCEL_BREAKER_LOCK:
        _CANCEL_BREAKER_NEXT_ALLOWED[account_id] = time.monotonic() + _CANCEL_BREAKER_SECONDS


def _looks_like_auth_failure(detail: str) -> bool:
    text = str(detail or "").lower()
    return "403" in text and ("authentication failed" in text or "nonce" in text or "timestamp" in text)


def _bitstamp_call_delay_seconds() -> float:
    try:
        return max(int(os.getenv("BITSTAMP_CALL_DELAY_MS", "250")) / 1000.0, 0.0)
    except Exception:
        return 0.25


def _utc_now() -> str:
    return datetime.now(timezone.utc).isoformat()


def _get_client(account_id: str) -> BitstampClient:
    return BitstampClientWrapper(account_id)


class BitstampClientWrapper:
    def __init__(self, account_id: str):
        self.trading = get_bitstamp_client(account_id).trading


def _invalidate_client(account_id: str) -> None:
    clear_bitstamp_trading_client(account_id)


def _format_decimal(value, decimals: int) -> str:
    quant = Decimal("1").scaleb(-decimals)
    return str(Decimal(str(value)).quantize(quant, rounding=ROUND_DOWN))


def _normalize_client_id(client_id: str | None) -> str | None:
    if client_id is None:
        return None
    if not isinstance(client_id, str):
        raise HTTPException(status_code=400, detail="client_id must be a string")
    client_id = client_id.strip()
    if not client_id:
        raise HTTPException(status_code=400, detail="client_id must not be empty")
    return client_id


def _normalize_status(status) -> str:
    return str(status or "unknown").strip().lower().replace(" ", "_")


def _set_local_order_status(*, bitstamp_order_id: str, status: str) -> None:
    with get_connection() as conn:
        conn.execute(
            "UPDATE order_records SET status = ?, updated_at = ? WHERE bitstamp_order_id = ?",
            (_normalize_status(status), _utc_now(), bitstamp_order_id),
        )
        conn.commit()


def _validate_order_shape(market: str, side: str, order_type: str, amount, price) -> tuple[str, str | None, dict]:
    meta = load_market_by_symbol(market)
    if meta is None:
        raise HTTPException(status_code=400, detail=f"unknown market {market}")

    base_decimals = int(meta.get("base_decimals", 8))
    counter_decimals = int(meta.get("counter_decimals", 2))
    minimum_order_value = Decimal(str(meta.get("minimum_order_value", "0")))

    amount_dec = Decimal(str(amount))
    amount_fmt = _format_decimal(amount, base_decimals)

    if side == "buy" and order_type == "market":
        if Decimal(amount_fmt) < minimum_order_value:
            raise HTTPException(status_code=400, detail=f"Minimum order size is {minimum_order_value} {meta.get('counter_currency', 'USD')}.")

    if price is not None:
        price_fmt = _format_decimal(price, counter_decimals)
        if Decimal(price_fmt) <= 0:
            raise HTTPException(status_code=400, detail="price must be positive")
    else:
        price_fmt = None

    if amount_dec <= 0:
        raise HTTPException(status_code=400, detail="amount must be positive")

    return amount_fmt, price_fmt, meta


def place_order(*, account_id: str, market: str, side: str, order_type: str, amount, price=None, expire_time: int | None = None, client_id: str | None = None, client_order_id: str | None = None) -> dict:
    client = _get_client(account_id)
    client_id = _normalize_client_id(client_id)
    side = side.lower()
    order_type = order_type.lower()
    market = market.lower()
    if len(market) < 6:
        raise HTTPException(status_code=400, detail="market must look like xrpusd")
    base = market[:-3]
    quote = market[-3:]

    expire_timestamp = None
    if expire_time is not None:
        expire_timestamp = int((datetime.now(timezone.utc) + timedelta(seconds=expire_time)).timestamp() * 1000)

    amount, price, _meta = _validate_order_shape(market, side, order_type, amount, price)

    try:
        if order_type not in {"market", "limit"}:
            raise HTTPException(status_code=400, detail="invalid order_type")
        if side == "buy":
            if expire_timestamp is None:
                result = client.trading.buy_order(amount=amount, price=price or "0", base=base, quote=quote)
            else:
                result = client.trading.buy_gtd_order(amount=amount, price=price or "0", base=base, quote=quote, expire_time=expire_timestamp)
        elif side == "sell":
            if expire_timestamp is None:
                result = client.trading.sell_order(amount=amount, price=price or "0", base=base, quote=quote)
            else:
                result = client.trading.sell_gtd_order(amount=amount, price=price or "0", base=base, quote=quote, expire_time=expire_timestamp)
        else:
            raise HTTPException(status_code=400, detail="invalid side")
    except BitstampError as exc:
        detail = str(exc)
        if _looks_like_auth_failure(detail):
            _invalidate_client(account_id)
        raise HTTPException(status_code=400, detail=detail) from exc

    bitstamp_order_id = str(result.get("id") or result.get("order_id") or "")
    if not bitstamp_order_id:
        return {"ok": False, "error": "missing Bitstamp order id", "details": {"raw": result}}

    record_id = str(uuid4())
    now = _utc_now()
    with get_connection() as conn:
        conn.execute(
            """
            INSERT INTO order_records
            (id, account_id, market, side, order_type, amount, price, expire_time, status, bitstamp_order_id, client_id, client_order_id, raw_json, created_at, updated_at)
            VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?)
            """,
            (record_id, account_id, market, side, order_type, amount, price, expire_time, _normalize_status(result.get("status", "open")), bitstamp_order_id, client_id, client_order_id or result.get("client_order_id"), json.dumps(result), now, now),
        )
        conn.commit()

    return {"ok": True, "bitstamp_order_id": bitstamp_order_id, "record_id": record_id, "status": str(result.get("status", "open")), "raw": result}


def get_open_orders(*, account_id: str, client_id: str | None = None) -> dict:
    client_id = _normalize_client_id(client_id)
    client = _get_client(account_id)
    with get_connection() as conn:
        if client_id is None:
            rows = conn.execute(
                """
                SELECT id, account_id, market, side, order_type, amount, price, expire_time, status, bitstamp_order_id, client_id, client_order_id, raw_json, created_at, updated_at
                FROM order_records
                WHERE account_id = ? AND lower(status) IN ('open', 'new', 'partially_filled')
                ORDER BY created_at DESC
                """,
                (account_id,),
            ).fetchall()
        else:
            rows = conn.execute(
                """
                SELECT id, account_id, market, side, order_type, amount, price, expire_time, status, bitstamp_order_id, client_id, client_order_id, raw_json, created_at, updated_at
                FROM order_records
                WHERE account_id = ? AND client_id = ? AND lower(status) IN ('open', 'new', 'partially_filled')
                ORDER BY created_at DESC
                """,
                (account_id, client_id),
            ).fetchall()

    order_status_v2 = getattr(getattr(client, "trading", None), "order_status_v2", None)
    if order_status_v2 is None:
        return {"ok": True, "client_id": client_id, "orders": [dict(row) for row in rows]}

    orders = []
    delay = _bitstamp_call_delay_seconds()
    for row in rows:
        order = dict(row)
        bitstamp_order_id = order.get("bitstamp_order_id")
        if not bitstamp_order_id:
            continue
        try:
            result = order_status_v2(order_id=str(bitstamp_order_id), omit_transactions=True)
            status = _normalize_status(result.get("status", "unknown"))
            if status not in OPEN_ORDER_STATUSES:
                _set_local_order_status(bitstamp_order_id=str(bitstamp_order_id), status=status)
                continue
            order["status"] = status
            order["raw_json"] = json.dumps(result)
            orders.append(order)
        except Exception as exc:
            msg = str(exc)
            if "not found" in msg.lower():
                _set_local_order_status(bitstamp_order_id=str(bitstamp_order_id), status="missing")
                continue
            # Best effort: keep the local record when the exchange cannot be queried.
            orders.append(order)
        if delay > 0:
            time.sleep(delay)

    return {"ok": True, "client_id": client_id, "orders": orders}


def cancel_all_orders(*, account_id: str, client_id: str | None = None) -> dict:
    client_id = _normalize_client_id(client_id)
    orders = get_open_orders(account_id=account_id, client_id=client_id)["orders"]
    results = []
    delay = _bitstamp_call_delay_seconds()
    for order in orders:
        if _cancel_breaker_is_open(account_id):
            results.append({"ok": False, "order_id": order.get("bitstamp_order_id"), "error": "cancel breaker active", "status": "deferred"})
            continue
        bitstamp_order_id = order.get("bitstamp_order_id")
        if not bitstamp_order_id:
            results.append({"order_id": None, "ok": False, "error": "missing bitstamp_order_id"})
            continue
        try:
            results.append(cancel_order(account_id=account_id, order_id=bitstamp_order_id))
        except HTTPException as exc:
            detail = str(exc.detail)
            if _looks_like_auth_failure(detail):
                _cancel_breaker_trip(account_id)
                results.append({"ok": False, "order_id": bitstamp_order_id, "error": detail, "status": "deferred"})
                break
            if "not found" in detail.lower():
                _set_local_order_status(bitstamp_order_id=bitstamp_order_id, status="missing")
                results.append({"ok": False, "order_id": bitstamp_order_id, "error": detail, "status": "missing"})
                continue
            raise
        if delay > 0:
            time.sleep(delay)
    return {"ok": True, "client_id": client_id, "cancelled": results, "count": len(results)}


def query_order(*, account_id: str, order_id, client_order_id: str | None = None, omit_transactions: bool | None = None) -> dict:
    order_id = str(order_id)
    client = _get_client(account_id)
    try:
        result = client.trading.order_status_v2(order_id=order_id, client_order_id=client_order_id, omit_transactions=omit_transactions)
    except BitstampError as exc:
        detail = str(exc)
        if _looks_like_auth_failure(detail):
            _invalidate_client(account_id)
        raise HTTPException(status_code=400, detail=detail) from exc

    with get_connection() as conn:
        conn.execute(
            "UPDATE order_records SET status = ?, raw_json = ?, updated_at = ? WHERE bitstamp_order_id = ?",
            (_normalize_status(result.get("status", "unknown")), json.dumps(result), _utc_now(), order_id),
        )
        conn.commit()

    return {"ok": True, "order_id": order_id, "raw": result}


def cancel_order(*, account_id: str, order_id) -> dict:
    order_id = str(order_id)
    if _cancel_breaker_is_open(account_id):
        raise HTTPException(status_code=503, detail="cancel breaker active, retry later")
    client = _get_client(account_id)
    try:
        result = client.trading.cancel_order(order_id=order_id, version=2)
    except BitstampError as exc:
        detail = str(exc)
        if _looks_like_auth_failure(detail):
            _cancel_breaker_trip(account_id)
            _invalidate_client(account_id)
        raise HTTPException(status_code=400, detail=detail) from exc

    status = "cancelled" if result else "cancel_failed"
    with get_connection() as conn:
        conn.execute(
            "UPDATE order_records SET status = ?, updated_at = ? WHERE bitstamp_order_id = ?",
            (status, _utc_now(), order_id),
        )
        conn.commit()

    return {"ok": bool(result), "order_id": order_id, "raw": result}