feat: enhance error handling for file downloads

Introduce `DownloadException` to improve error reporting and handling when file downloads fail. Modified `download_file` method to accept a `raise_error` flag, which, when set, raises `DownloadException` upon a download error instead of just logging it. This enables the bot to respond with a specific error message to the room if a download fails during processing of speech-to-text, file messages, and image messages, enhancing user feedback on download failures.

src/gptbot/classes/bot.py

@@ -54,6 +54,7 @@ from ..callbacks import RESPONSE_CALLBACKS, EVENT_CALLBACKS
 from ..commands import COMMANDS
 from ..tools import TOOLS, Handover, StopProcessing
 from .ai.base import BaseAI
+from .exceptions import DownloadException
 
 
 class GPTBot:
@@ -1192,7 +1193,9 @@ class GPTBot:
                 if message == event or (not message.event_id == event.event_id):
                     if self.room_uses_stt(room):
                         try:
-                            download = await self.download_file(message.url)
+                            download = await self.download_file(
+                                message.url, raise_error=True
+                            )
                             message_text = await self.stt_api.speech_to_text(
                                 download.body
                             )
@@ -1213,7 +1216,7 @@ class GPTBot:
 
             elif isinstance(message, RoomMessageFile):
                 try:
-                    download = await self.download_file(message.url)
+                    download = await self.download_file(message.url, raise_error=True)
                     if download:
                         try:
                             text = download.body.decode("utf-8")
@@ -1252,7 +1255,7 @@ class GPTBot:
             ):
                 try:
                     image_url = message.url
-                    download = await self.download_file(image_url)
+                    download = await self.download_file(image_url, raise_error=True)
 
                     if download:
                         pil_image = Image.open(BytesIO(download.body))
@@ -1306,6 +1309,13 @@ class GPTBot:
                         )
 
                 except Exception as e:
+                    if isinstance(e, DownloadException):
+                        self.send_message(
+                            room,
+                            f"Could not process image due to download error: {e.args[0]}",
+                            True,
+                        )
+
                     self.logger.log(f"Error generating image from file: {e}", "error")
                     message_body = (
                         message.body
@@ -1369,7 +1379,7 @@ class GPTBot:
         await self.matrix_client.room_typing(room.room_id, False)
 
     async def download_file(
-        self, mxc
+        self, mxc: str, raise_error: bool = False
     ) -> Union[DiskDownloadResponse, MemoryDownloadResponse]:
         """Download a file from the homeserver.
 
@@ -1384,6 +1394,8 @@ class GPTBot:
 
         if isinstance(download, DownloadError):
             self.logger.log(f"Error downloading file: {download.message}", "error")
+            if raise_error:
+                raise DownloadException(download.message)
             return
 
         return download

src/gptbot/classes/exceptions.py

@@ -0,0 +1,2 @@
+class DownloadException(Exception):
+    pass