添加抓取失败网址记录功能

- 新增 failed_urls 数据库表存储失败URL
- 抓取失败时自动记录URL、标题、错误信息
- 搜索页面显示失败URL列表
- 支持重试单个/全部失败URL
- 支持删除和清空失败记录
- 显示重试次数和时间

models/database.py

@@ -106,6 +106,21 @@ class Database:
                 )
             ''')
             
+            # 失败的URL记录表
+            cursor.execute('''
+                CREATE TABLE IF NOT EXISTS failed_urls (
+                    id INTEGER PRIMARY KEY AUTOINCREMENT,
+                    url TEXT NOT NULL,
+                    title TEXT,
+                    error_message TEXT,
+                    retry_count INTEGER DEFAULT 0,
+                    status TEXT DEFAULT 'failed',
+                    created_at DATETIME DEFAULT CURRENT_TIMESTAMP,
+                    last_retry_at DATETIME,
+                    source TEXT DEFAULT 'search'
+                )
+            ''')
+            
             conn.commit()
 
 # ========== 内容库操作 ==========
@@ -309,5 +324,77 @@ class Database:
             ''', (key, value))
             conn.commit()
 
+# ========== 失败URL操作 ==========
+    def add_failed_url(self, url, title=None, error_message=None, source='search'):
+        """添加失败的URL"""
+        with self.get_connection() as conn:
+            cursor = conn.cursor()
+            # 先检查是否已存在
+            cursor.execute('SELECT id, retry_count FROM failed_urls WHERE url = ?', (url,))
+            existing = cursor.fetchone()
+            
+            if existing:
+                # 更新重试次数和错误信息
+                cursor.execute('''
+                    UPDATE failed_urls 
+                    SET error_message = ?, last_retry_at = CURRENT_TIMESTAMP, retry_count = retry_count + 1
+                    WHERE url = ?
+                ''', (error_message, url))
+            else:
+                # 新增失败记录
+                cursor.execute('''
+                    INSERT INTO failed_urls (url, title, error_message, source)
+                    VALUES (?, ?, ?, ?)
+                ''', (url, title, error_message, source))
+            conn.commit()
+            return cursor.lastrowid
+    
+    def get_failed_urls(self, limit=100, status='failed'):
+        """获取失败的URL列表"""
+        with self.get_connection() as conn:
+            cursor = conn.cursor()
+            cursor.execute('''
+                SELECT * FROM failed_urls 
+                WHERE status = ?
+                ORDER BY created_at DESC 
+                LIMIT ?
+            ''', (status, limit))
+            return [dict(row) for row in cursor.fetchall()]
+    
+    def get_failed_url_count(self):
+        """获取失败URL数量"""
+        with self.get_connection() as conn:
+            cursor = conn.cursor()
+            cursor.execute('SELECT COUNT(*) FROM failed_urls WHERE status = "failed"')
+            return cursor.fetchone()[0]
+    
+    def mark_url_success(self, url):
+        """标记URL为成功（已处理）"""
+        with self.get_connection() as conn:
+            cursor = conn.cursor()
+            cursor.execute('''
+                UPDATE failed_urls 
+                SET status = 'success', last_retry_at = CURRENT_TIMESTAMP
+                WHERE url = ?
+            ''', (url,))
+            conn.commit()
+            return cursor.rowcount > 0
+    
+    def delete_failed_url(self, url_id):
+        """删除失败URL记录"""
+        with self.get_connection() as conn:
+            cursor = conn.cursor()
+            cursor.execute('DELETE FROM failed_urls WHERE id = ?', (url_id,))
+            conn.commit()
+            return cursor.rowcount > 0
+    
+    def clear_failed_urls(self):
+        """清空所有失败URL记录"""
+        with self.get_connection() as conn:
+            cursor = conn.cursor()
+            cursor.execute('DELETE FROM failed_urls WHERE status = "failed"')
+            conn.commit()
+            return cursor.rowcount
+
 # 全局数据库实例
 db = Database()