Fix: Add graceful download cancellation on Ctrl+C

- Add cancellation flag to AniworldLoader with request_cancel/reset_cancel/is_cancelled methods
- Update base_provider.Loader interface with cancellation abstract methods
- Integrate cancellation check in YT-DLP progress hooks
- Add request_download_cancel method to SeriesApp and AnimeService
- Update DownloadService.stop() to request cancellation before shutdown
- Clean up temp files on cancellation

src/core/providers/aniworld_provider.py

@@ -4,6 +4,7 @@ import logging
 import os
 import re
 import shutil
+import threading
 from pathlib import Path
 from urllib.parse import quote
 
@@ -70,6 +71,9 @@ class AniworldLoader(Loader):
         }
         self.ANIWORLD_TO = "https://aniworld.to"
         self.session = requests.Session()
+        
+        # Cancellation flag for graceful shutdown
+        self._cancel_flag = threading.Event()
 
         # Configure retries with backoff
         retries = Retry(
@@ -198,6 +202,30 @@ class AniworldLoader(Loader):
         logging.debug(f"Available languages for S{season:02}E{episode:03}: {languages}, requested: {language_code}, available: {is_available}")
         return is_available
 
+    def request_cancel(self) -> None:
+        """Request cancellation of any ongoing download.
+        
+        Sets the internal cancellation flag. Downloads will check this
+        flag periodically and abort if set.
+        """
+        logging.info("Download cancellation requested")
+        self._cancel_flag.set()
+    
+    def reset_cancel(self) -> None:
+        """Reset the cancellation flag.
+        
+        Should be called before starting a new download.
+        """
+        self._cancel_flag.clear()
+    
+    def is_cancelled(self) -> bool:
+        """Check if cancellation has been requested.
+        
+        Returns:
+            bool: True if cancellation was requested
+        """
+        return self._cancel_flag.is_set()
+
     def download(
         self,
         base_directory: str,
@@ -223,7 +251,15 @@ class AniworldLoader(Loader):
             
         Returns:
             bool: True if download succeeded, False otherwise
+            
+        Raises:
+            asyncio.CancelledError: If download was cancelled via request_cancel()
         """
+        # Check cancellation before starting
+        if self.is_cancelled():
+            logging.info("Download cancelled before starting")
+            raise InterruptedError("Download cancelled")
+            
         logging.info(
             f"Starting download for S{season:02}E{episode:03} "
             f"({key}) in {language}"
@@ -261,11 +297,26 @@ class AniworldLoader(Loader):
         logging.debug(f"Temporary path: {temp_path}")
 
         for provider in self.SUPPORTED_PROVIDERS:
+            # Check cancellation before each provider attempt
+            if self.is_cancelled():
+                logging.info("Download cancelled during provider selection")
+                raise InterruptedError("Download cancelled")
+                
             logging.debug(f"Attempting download with provider: {provider}")
             link, header = self._get_direct_link_from_provider(
                 season, episode, key, language
             )
             logging.debug("Direct link obtained from provider")
+            
+            # Create a cancellation-aware progress hook
+            cancel_flag = self._cancel_flag
+            
+            def cancellation_check_hook(d):
+                """Progress hook that checks for cancellation."""
+                if cancel_flag.is_set():
+                    logging.info("Cancellation detected in progress hook")
+                    raise InterruptedError("Download cancelled")
+            
             ydl_opts = {
                 'fragment_retries': float('inf'),
                 'outtmpl': temp_path,
@@ -273,14 +324,20 @@ class AniworldLoader(Loader):
                 'no_warnings': True,
                 'progress_with_newline': False,
                 'nocheckcertificate': True,
+                # Add cancellation check as a progress hook
+                'progress_hooks': [cancellation_check_hook],
             }
 
             if header:
                 ydl_opts['http_headers'] = header
                 logging.debug("Using custom headers for download")
             if progress_callback:
-                # Wrap the callback to add logging
+                # Wrap the callback to add logging and keep cancellation check
                 def logged_progress_callback(d):
+                    # Check cancellation first
+                    if cancel_flag.is_set():
+                        logging.info("Cancellation detected in progress callback")
+                        raise InterruptedError("Download cancelled")
                     logging.debug(
                         f"YT-DLP progress: status={d.get('status')}, "
                         f"downloaded={d.get('downloaded_bytes')}, "
@@ -305,6 +362,14 @@ class AniworldLoader(Loader):
                         f"filesize={info.get('filesize')}"
                     )
 
+                # Check cancellation after download completes
+                if self.is_cancelled():
+                    logging.info("Download cancelled after completion")
+                    # Clean up temp file if exists
+                    if os.path.exists(temp_path):
+                        os.remove(temp_path)
+                    raise InterruptedError("Download cancelled")
+
                 if os.path.exists(temp_path):
                     logging.debug("Moving file from temp to final destination")
                     shutil.copy(temp_path, output_path)
@@ -320,6 +385,16 @@ class AniworldLoader(Loader):
                     )
                     self.clear_cache()
                     return False
+            except InterruptedError:
+                # Re-raise cancellation errors
+                logging.info("Download interrupted, propagating cancellation")
+                # Clean up temp file if exists
+                if os.path.exists(temp_path):
+                    try:
+                        os.remove(temp_path)
+                    except OSError:
+                        pass
+                raise
             except BrokenPipeError as e:
                 logging.error(
                     f"Broken pipe error with provider {provider}: {e}. "

src/core/providers/base_provider.py

@@ -5,6 +5,30 @@ from typing import Any, Callable, Dict, List, Optional
 class Loader(ABC):
     """Abstract base class for anime data loaders/providers."""
 
+    @abstractmethod
+    def request_cancel(self) -> None:
+        """Request cancellation of any ongoing download.
+        
+        Sets an internal flag that downloads should check periodically
+        and abort if set. This enables graceful shutdown.
+        """
+
+    @abstractmethod
+    def reset_cancel(self) -> None:
+        """Reset the cancellation flag.
+        
+        Should be called before starting a new download to ensure
+        it's not immediately cancelled.
+        """
+
+    @abstractmethod
+    def is_cancelled(self) -> bool:
+        """Check if cancellation has been requested.
+        
+        Returns:
+            bool: True if cancellation was requested
+        """
+
     @abstractmethod
     def search(self, word: str) -> List[Dict[str, Any]]:
         """Search for anime series by name.