from __future__ import annotations

from typing import Any, Dict, List
from datetime import datetime, timezone
import threading


class DecisionStore:
    def __init__(self) -> None:
        self._lock = threading.Lock()
        self._items: List[Dict[str, Any]] = []

    def add(self, item: Dict[str, Any]) -> None:
        with self._lock:
            self._items.append(item)
            if len(self._items) > 1000:
                # keep last 1000
                self._items = self._items[-1000:]

    def latest(self, limit: int = 50) -> List[Dict[str, Any]]:
        with self._lock:
            return list(reversed(self._items[-limit:]))


# singleton store
store = DecisionStore()


def log_decision(
    *,
    symbol: str,
    timeframe: str,
    style: str,
    recommendation: str,
    confidence: float,
    risk_level: str,
    rationale: str,
    inputs_hash: str | None = None,
    cost: Dict[str, Any] | None = None,
) -> Dict[str, Any]:
    now = datetime.now(timezone.utc).isoformat()
    item = {
        "id": f"dec_{int(datetime.now(timezone.utc).timestamp()*1000)}",
        "time": now,
        "symbol": symbol,
        "timeframe": timeframe,
        "style": style,
        "recommendation": recommendation,
        "confidence": confidence,
        "risk_level": risk_level,
        "rationale": rationale,
        "inputs_hash": inputs_hash,
        "cost": cost or {},
    }
    store.add(item)
    return item