feature: 数据库连接与SQL集中管理，提高代码可读性

db/message_storage.py

@@ -0,0 +1,69 @@
+# -*- coding: utf-8 -*-
+from datetime import datetime
+from typing import Dict, List, Optional
+
+from wcferry import WxMsg
+
+from db.base import BaseDBOperator
+from db.connection import DBConnectionManager
+
+
+class MessageStorageDB(BaseDBOperator):
+    """消息存储相关数据库操作"""
+    
+    def __init__(self, db_manager: DBConnectionManager):
+        super().__init__(db_manager)
+    
+    def archive_message(self, msg: WxMsg) -> bool:
+        """存档消息"""
+        now_time = datetime.now().strftime("%Y-%m-%d %H:%M:%S")
+        sql = """
+        INSERT INTO messages (group_id, timestamp, sender, content, message_type, attachment_url, message_id, message_xml, message_thumb)
+        VALUES (%s, %s, %s, %s, %s, %s, %s, %s, %s)
+        """
+        params = (msg.roomid, now_time, msg.sender, msg.content, msg.type, msg.extra, msg.id, msg.xml, msg.thumb)
+        result = self.execute_update(sql, params)
+        if result:
+            self.LOG.info(f"消息存档成功: {now_time}:{msg.roomid}:{msg.sender}")
+        return result
+    
+    def get_recent_messages(self, group_id: str, hours_ago: int = 8, min_content_length: int = 6) -> List[Dict]:
+        """获取最近的消息"""
+        sql = """
+        SELECT timestamp, sender, content, message_type
+        FROM messages
+        WHERE timestamp >= DATE_SUB(NOW(), INTERVAL %s HOUR)
+          AND message_type in (1, 49)
+          AND group_id = %s 
+          AND length(content) > %s
+          AND content NOT LIKE '/%'
+        """
+        params = (hours_ago, group_id, min_content_length)
+        return self.execute_query(sql, params) or []
+    
+    def get_message_count_by_date(self, date: str) -> List[Dict]:
+        """获取指定日期的消息统计"""
+        sql = """
+        SELECT group_id, sender, COUNT(*) as count
+        FROM messages
+        WHERE DATE(timestamp) = %s
+        GROUP BY group_id, sender
+        """
+        return self.execute_query(sql, (date,)) or []
+    
+    # 在 MessageStorageDB 类中添加以下方法
+    
+    def get_speech_ranking(self, date: str, group_id: str, limit: int = 20) -> List[Dict]:
+        """获取指定日期和群组的发言排名"""
+        sql = """
+        SELECT wx_id, count AS speech_count
+        FROM speech_counts
+        WHERE date = %s
+        AND group_id = %s
+        GROUP BY wx_id
+        ORDER BY count DESC
+        LIMIT %s
+        """
+        params = (date, group_id, limit)
+        results = self.execute_query(sql, params)
+        return results or []