Add SQLite database handler

database.py

@@ -0,0 +1,42 @@
+import sqlite3
+import json
+from typing import List, Dict, Any
+
+class Database:
+    def __init__(self, db_file='telegram_bot.db'):
+        self.db_file = db_file
+        self.conn = sqlite3.connect(self.db_file)
+        self.create_tables()
+
+    def create_tables(self):
+        with self.conn:
+            self.conn.execute('''
+                CREATE TABLE IF NOT EXISTS conversations (
+                    user_id INTEGER PRIMARY KEY,
+                    history TEXT
+                )
+            ''')
+
+    def save_conversation(self, user_id: int, history: List[Dict[str, Any]]):
+        with self.conn:
+            self.conn.execute('''
+                INSERT OR REPLACE INTO conversations (user_id, history)
+                VALUES (?, ?)
+            ''', (user_id, json.dumps(history)))
+
+    def get_conversation(self, user_id: int) -> List[Dict[str, Any]]:
+        cursor = self.conn.execute('SELECT history FROM conversations WHERE user_id = ?', (user_id,))
+        result = cursor.fetchone()
+        if result:
+            return json.loads(result[0])
+        return []
+
+    def clear_conversation(self, user_id: int):
+        with self.conn:
+            self.conn.execute('DELETE FROM conversations WHERE user_id = ?', (user_id,))
+
+    def close(self):
+        self.conn.close()
+
+# Create a global instance of the Database class
+db = Database()