"""
消息统计器模块

提供消息处理的统计功能：
- 消息计数
- 过滤率统计
- 按类型统计
"""

import time
from collections import defaultdict
from threading import Lock
from typing import Any, Dict


class MessageStats:
    """
    消息统计器

    线程安全的消息统计实现
    """

    def __init__(self):
        self._lock = Lock()
        self._total_count = 0
        self._filtered_count = 0
        self._processed_count = 0
        self._duplicate_count = 0
        self._error_count = 0
        self._by_type: Dict[str, int] = defaultdict(int)
        self._start_time = time.time()

    def record_received(self):
        """记录收到消息"""
        with self._lock:
            self._total_count += 1

    def record_filtered(self):
        """记录被过滤的消息"""
        with self._lock:
            self._filtered_count += 1

    def record_processed(self, event_type: str = None):
        """
        记录已处理的消息

        Args:
            event_type: 消息事件类型（可选）
        """
        with self._lock:
            self._processed_count += 1
            if event_type:
                self._by_type[event_type] += 1

    def record_duplicate(self):
        """记录重复消息"""
        with self._lock:
            self._duplicate_count += 1

    def record_error(self):
        """记录处理错误"""
        with self._lock:
            self._error_count += 1

    def get_stats(self) -> Dict[str, Any]:
        """获取统计信息"""
        with self._lock:
            uptime = time.time() - self._start_time
            total = max(self._total_count, 1)  # 避免除零

            return {
                "total_messages": self._total_count,
                "filtered_messages": self._filtered_count,
                "processed_messages": self._processed_count,
                "duplicate_messages": self._duplicate_count,
                "error_count": self._error_count,
                "filter_rate": self._filtered_count / total,
                "process_rate": self._processed_count / total,
                "duplicate_rate": self._duplicate_count / total,
                "messages_per_minute": (self._total_count / uptime) * 60 if uptime > 0 else 0,
                "uptime_seconds": uptime,
                "by_type": dict(self._by_type),
            }

    def reset(self):
        """重置统计"""
        with self._lock:
            self._total_count = 0
            self._filtered_count = 0
            self._processed_count = 0
            self._duplicate_count = 0
            self._error_count = 0
            self._by_type.clear()
            self._start_time = time.time()


# 全局单例（可选使用）
_global_stats: MessageStats = None
_stats_lock = Lock()


def get_message_stats() -> MessageStats:
    """获取全局消息统计器实例"""
    global _global_stats
    if _global_stats is None:
        with _stats_lock:
            if _global_stats is None:
                _global_stats = MessageStats()
    return _global_stats


# ==================== 导出 ====================

__all__ = ['MessageStats', 'get_message_stats']