# -*- coding: utf-8 -*-
"""信号冷却过滤模块
- 避免同一标的在冷却期内重复产生同方向信号
- 过滤后附加 generated_at_utc 字段（UTC ISO）
"""
from datetime import datetime, timezone, timedelta
from typing import List, Dict, Any

class SignalCooldownFilter:
    def __init__(self, cooldown_minutes: int = 30):
        self.cooldown = timedelta(minutes=cooldown_minutes)
        # key: (symbol, direction) -> last datetime
        self.last_time: Dict[tuple, datetime] = {}

    def filter(self, signals: List[Dict[str, Any]]) -> List[Dict[str, Any]]:
        now = datetime.now(timezone.utc)
        accepted = []
        for s in signals:
            symbol = s.get('symbol')
            direction = s.get('type') or s.get('direction')
            key = (symbol, direction)
            lt = self.last_time.get(key)
            if lt is not None and now - lt < self.cooldown:
                continue
            # Accept
            self.last_time[key] = now
            s['direction'] = direction  # normalize
            s['generated_at_utc'] = now.strftime('%Y-%m-%dT%H:%M:%SZ')
            accepted.append(s)
        return accepted