ewoooc/services/cache_service.py

#!/usr/bin/env python3
# -*- coding: utf-8 -*-
"""
快取服務模組
集中管理所有快取變數和相關操作
"""

from datetime import datetime, timezone, timedelta

# 台北時區
TAIPEI_TZ = timezone(timedelta(hours=8))

# ==========================================
# 業績分析快取
# ==========================================
_SALES_DF_CACHE = {}
_SALES_PROCESSED_CACHE = {}  # 處理後資料快取 (二級快取)
_SALES_OPTIONS_CACHE = {}    # 下拉選單選項 (類別、品牌、廠商等)
_SALES_ANALYSIS_RESULT_CACHE = {}  # 過濾後的分析結果集

# 快取 TTL 設定
_SALES_CACHE_TTL = 3600      # 業績分析快取: 60 分鐘
_SALES_OPTIONS_TTL = 21600   # 選項快取: 6 小時
_SALES_RESULT_TTL = 3600     # 結果快取: 60 分鐘

# ==========================================
# 商品看板快取
# ==========================================
_DASHBOARD_DATA_CACHE = {
    'consolidated_data': None,
    'consolidated_timestamp': None,
    'full_data': None,
    'full_timestamp': None
}
_DASHBOARD_CACHE_TTL = 1800  # 商品看板快取: 30 分鐘

# ==========================================
# 成長分析快取
# ==========================================
_GROWTH_ANALYSIS_CACHE = {
    'chart_data': None,
    'kpi': None,
    'timestamp': None
}
_GROWTH_CACHE_TTL = 1800  # 成長分析快取: 30 分鐘

# ==========================================
# 慢查詢監控
# ==========================================
_SLOW_QUERY_STATS = {
    'total_queries': 0,
    'slow_queries': 0,
    'very_slow_queries': 0,
    'total_query_time_ms': 0,
    'last_slow_query': None,
    'last_slow_query_time': None,
}
_SLOW_QUERY_THRESHOLD_MS = 1000      # 慢查詢閾值: 1秒
_VERY_SLOW_QUERY_THRESHOLD_MS = 5000  # 極慢查詢閾值: 5秒


def track_query_time(query_name, duration_ms):
    """追蹤查詢時間，更新慢查詢統計"""
    global _SLOW_QUERY_STATS
    _SLOW_QUERY_STATS['total_queries'] += 1
    _SLOW_QUERY_STATS['total_query_time_ms'] += duration_ms

    if duration_ms >= _VERY_SLOW_QUERY_THRESHOLD_MS:
        _SLOW_QUERY_STATS['very_slow_queries'] += 1
        _SLOW_QUERY_STATS['slow_queries'] += 1
        _SLOW_QUERY_STATS['last_slow_query'] = query_name
        _SLOW_QUERY_STATS['last_slow_query_time'] = datetime.now(TAIPEI_TZ).isoformat()
    elif duration_ms >= _SLOW_QUERY_THRESHOLD_MS:
        _SLOW_QUERY_STATS['slow_queries'] += 1
        _SLOW_QUERY_STATS['last_slow_query'] = query_name
        _SLOW_QUERY_STATS['last_slow_query_time'] = datetime.now(TAIPEI_TZ).isoformat()


def get_slow_query_stats():
    """取得慢查詢統計資料"""
    return _SLOW_QUERY_STATS.copy()


def clear_sales_cache():
    """清除業績分析快取"""
    global _SALES_DF_CACHE, _SALES_PROCESSED_CACHE, _SALES_OPTIONS_CACHE, _SALES_ANALYSIS_RESULT_CACHE
    _SALES_DF_CACHE.clear()
    _SALES_PROCESSED_CACHE.clear()
    _SALES_OPTIONS_CACHE.clear()
    _SALES_ANALYSIS_RESULT_CACHE.clear()


def clear_dashboard_cache():
    """清除商品看板快取"""
    global _DASHBOARD_DATA_CACHE
    _DASHBOARD_DATA_CACHE = {
        'consolidated_data': None,
        'consolidated_timestamp': None,
        'full_data': None,
        'full_timestamp': None
    }


def clear_growth_cache():
    """清除成長分析快取"""
    global _GROWTH_ANALYSIS_CACHE
    _GROWTH_ANALYSIS_CACHE = {
        'chart_data': None,
        'kpi': None,
        'timestamp': None
    }


def clear_all_cache():
    """清除所有快取"""
    clear_sales_cache()
    clear_dashboard_cache()
    clear_growth_cache()


def is_cache_valid(timestamp, ttl_seconds):
    """
    檢查快取是否有效

    Args:
        timestamp: 快取時間戳記
        ttl_seconds: 快取有效期(秒)

    Returns:
        bool: True 表示快取有效
    """
    if timestamp is None:
        return False
    now = datetime.now(TAIPEI_TZ)
    if timestamp.tzinfo is None:
        timestamp = timestamp.replace(tzinfo=TAIPEI_TZ)
    age = (now - timestamp).total_seconds()
    return age < ttl_seconds


def get_growth_cache():
    """取得成長分析快取"""
    return _GROWTH_ANALYSIS_CACHE


def set_growth_cache(chart_data, kpi):
    """設定成長分析快取"""
    global _GROWTH_ANALYSIS_CACHE
    _GROWTH_ANALYSIS_CACHE = {
        'chart_data': chart_data,
        'kpi': kpi,
        'timestamp': datetime.now(TAIPEI_TZ)
    }


def is_growth_cache_valid():
    """檢查成長分析快取是否有效"""
    return is_cache_valid(_GROWTH_ANALYSIS_CACHE.get('timestamp'), _GROWTH_CACHE_TTL)