Refactor useGenerationForm to streamline model download handling

- Removed unnecessary isDownloading variable and related logic.
- Consolidated model download state reset to the finally block for improved clarity and reliability.
- Enhanced error handling by ensuring model download state is reset in case of failure.

app/src/lib/hooks/useGenerationForm.ts

@@ -70,7 +70,6 @@ export function useGenerationForm(options: UseGenerationFormOptions = {}) {
       const modelName = `qwen-tts-${data.modelSize}`;
       const displayName = data.modelSize === '1.7B' ? 'Qwen TTS 1.7B' : 'Qwen TTS 0.6B';
 
-      let isDownloading = false;
       try {
         const modelStatus = await apiClient.getModelStatus();
         const model = modelStatus.models.find((m) => m.model_name === modelName);
@@ -78,7 +77,6 @@ export function useGenerationForm(options: UseGenerationFormOptions = {}) {
         if (model && !model.downloaded) {
           setDownloadingModelName(modelName);
           setDownloadingDisplayName(displayName);
-          isDownloading = true;
         }
       } catch (error) {
         console.error('Failed to check model status:', error);
@@ -103,21 +101,16 @@ export function useGenerationForm(options: UseGenerationFormOptions = {}) {
 
       form.reset();
       options.onSuccess?.(result.id);
-
-      if (isDownloading) {
-        setDownloadingModelName(null);
-        setDownloadingDisplayName(null);
-      }
     } catch (error) {
       toast({
         title: 'Generation failed',
         description: error instanceof Error ? error.message : 'Failed to generate audio',
         variant: 'destructive',
       });
-      setDownloadingModelName(null);
-      setDownloadingDisplayName(null);
     } finally {
       setIsGenerating(false);
+      setDownloadingModelName(null);
+      setDownloadingDisplayName(null);
     }
   }