better timeout handling

src/main.py

@@ -159,16 +159,20 @@ async def generate(
     }
 
     start_time = time.monotonic()
-
-    async with aiohttp.ClientSession() as session:
-        async with session.post(
-            "https://image.novelai.net/ai/generate-image",
-            json=payload,
-            headers=headers,
-            timeout=aiohttp.ClientTimeout(total=120),
-        ) as response:
-            response_bytes = await response.read()
-            status_code = response.status
+    try:
+        async with aiohttp.ClientSession() as session:
+            async with session.post(
+                "https://image.novelai.net/ai/generate-image",
+                json=payload,
+                headers=headers,
+                timeout=aiohttp.ClientTimeout(total=120),
+            ) as response:
+                response_bytes = await response.read()
+                status_code = response.status
+    except aiohttp.TimeoutError:
+        await interaction.followup.send("Error: the request timed out.")
+    except aiohttp.ClientError as e:
+        await interaction.followup.send(f"Error: {e}")
 
     duration = time.monotonic() - start_time
     logger.info("Image creation took %.2f seconds", duration)
@@ -214,9 +218,9 @@ async def generate(
     except Exception:  # pylint: disable=W0718
         error_data = "error message unreadable"
 
-    error_message = f"Error {status_code} at API-request.\n" f"Answer: {error_data}\n"
+        error_message = f"Error {status_code} at API-request.\n" f"Answer: {error_data}\n"
 
-    await interaction.followup.send(error_message)
+        await interaction.followup.send(error_message)
 
 
 bot.run(BOT_TOKEN)