调整趋势图功能，加入了查询数据库，分析群聊聊天数量的功能

plugins/stats_dashboard/dashboard_server.py

@@ -1,11 +1,13 @@
 import logging
-from typing import Dict, Any, Optional
 import threading
 import time
 import os
+from datetime import datetime
+
 from flask import Flask, render_template, request, jsonify, redirect, url_for, session, send_from_directory
 
 from db.connection import DBConnectionManager
+from db.message_storage import MessageStorageDB
 from db.stats_db import StatsDBOperator
 from utils.wechat.contact_manager import ContactManager
 from robot_cmd.robot_command import GroupBotManager, Feature, PermissionStatus
@@ -24,6 +26,7 @@ class DashboardServer:
         # 修正：使用单例模式获取数据库连接
         self.db_manager = DBConnectionManager.get_instance()
         self.stats_db = StatsDBOperator(self.db_manager)
+        self.message_storage = MessageStorageDB(self.db_manager)
         # 获取联系人管理器实例
         self.contact_manager = ContactManager.get_instance()
         self.app = self._create_app()
@@ -286,6 +289,40 @@ class DashboardServer:
             self.logger.info(f"看板主页/api/plugin_trend: {trend}")
             return jsonify({"success": True, "data": trend})
 
+        @app.route('/api/robot/group/<group_id>/message_trend', methods=['GET'])
+        def get_group_message_trend(group_id):
+            """获取群组消息趋势数据"""
+            try:
+                days = request.args.get('days', default=7, type=int)
+                # 获取消息存储实例
+                trend_data = self.message_storage.get_message_trend(group_id, days)
+                
+                # 格式化数据为前端需要的格式
+                dates = []
+                counts = []
+                for item in trend_data:
+                    # 将日期转换为字符串
+                    if isinstance(item['date'], datetime):
+                        date_str = item['date'].strftime('%Y-%m-%d')
+                    else:
+                        date_str = str(item['date'])
+                    
+                    dates.append(date_str)
+                    counts.append(item['message_count'])
+                
+                return jsonify({
+                    'success': True,
+                    'data': {
+                        'dates': dates,
+                        'counts': counts
+                    }
+                })
+            except Exception as e:
+                return jsonify({
+                    'success': False,
+                    'error': str(e)
+                })
+
         return app
 
     def run(self) -> None: