feat(app): 添加日志记录功能

- 新增 logger 模块，用于全局日志记录
- 在关键位置添加日志输出，包括事件处理、文件清理、FFmpeg 检查等
- 优化数据库操作，增加日志记录
- 在主程序启动时添加日志输出

backend/app/db/video_task_dao.py

@@ -1,8 +1,13 @@
 from .sqlite_client import get_connection
-
+from app.utils.logger import get_logger
+logger = get_logger(__name__)
 def init_video_task_table():
     conn = get_connection()
+    if conn is None:
+        logger.error("Failed to connect to the database.")
+        return
     cursor = conn.cursor()
+
     cursor.execute("""
         CREATE TABLE IF NOT EXISTS video_tasks (
             id INTEGER PRIMARY KEY AUTOINCREMENT,
@@ -12,41 +17,62 @@ def init_video_task_table():
             created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP
         )
     """)
-    conn.commit()
-    conn.close()
+    try:
+        conn.commit()
+        conn.close()
+        logger.info("video_tasks table created successfully.")
+    except Exception as e:
+        logger.error(f"Failed to create video_tasks table: {e}")
 
 def insert_video_task(video_id: str, platform: str, task_id: str):
-    conn = get_connection()
-    cursor = conn.cursor()
-    cursor.execute("""
-        INSERT INTO video_tasks (video_id, platform, task_id)
-        VALUES (?, ?, ?)
-    """, (video_id, platform, task_id))
-    conn.commit()
-    conn.close()
+    try:
+        conn = get_connection()
+        cursor = conn.cursor()
+        cursor.execute("""
+            INSERT INTO video_tasks (video_id, platform, task_id)
+            VALUES (?, ?, ?)
+        """, (video_id, platform, task_id))
+        conn.commit()
+        conn.close()
+        logger.info(f"Video task inserted successfully."
+                    f"video_id: {video_id}"
+                    f"platform: {platform}"
+                    f"task_id: {task_id}")
+    except Exception as e:
+        logger.error(f"Failed to insert video task: {e}")
 
 
 def get_task_by_video(video_id: str, platform: str):
-    conn = get_connection()
-    cursor = conn.cursor()
-    cursor.execute("""
-        SELECT task_id FROM video_tasks
-        WHERE video_id = ? AND platform = ?
-        ORDER BY created_at DESC
-        LIMIT 1
-    """, (video_id, platform))
-    result = cursor.fetchone()
-    conn.close()
-    return result[0] if result else None
+    try:
+        conn = get_connection()
+        cursor = conn.cursor()
+        cursor.execute("""
+            SELECT task_id FROM video_tasks
+            WHERE video_id = ? AND platform = ?
+            ORDER BY created_at DESC
+            LIMIT 1
+        """, (video_id, platform))
+        result = cursor.fetchone()
+        conn.close()
+        if result is None:
+            logger.info(f"No task found for video_id: {video_id} and platform: {platform}")
+        logger.info(f"Task found for video_id: {video_id} and platform: {platform}")
+        return result[0] if result else None
+    except Exception as e:
+        logger.error(f"Failed to get task by video: {e}")
 
 
 def delete_task_by_video(video_id: str, platform: str):
-    conn = get_connection()
-    cursor = conn.cursor()
-    cursor.execute("""
-        DELETE FROM video_tasks
-        WHERE video_id = ? AND platform = ?
-    """, (video_id, platform))
+    try:
+        conn = get_connection()
+        cursor = conn.cursor()
+        cursor.execute("""
+            DELETE FROM video_tasks
+            WHERE video_id = ? AND platform = ?
+        """, (video_id, platform))
 
-    conn.commit()
-    conn.close()
+        conn.commit()
+        conn.close()
+        logger.info(f"Task deleted for video_id: {video_id} and platform: {platform}")
+    except Exception as e:
+        logger.error(f"Failed to delete task by video: {e}")