Issue #1: ADD check if there any files to zip

app/proxy.py

@@ -57,17 +57,31 @@ def create_zip(files, collection_id):
 @app.route('/<collection_id>', methods=['GET'])
 def download_zip(collection_id):
     try:
-        if os.path.exists(f"colecao_{collection_id}.zip"):
-            zip_path = os.path.abspath(f"colecao_{collection_id}.zip")
+        zip_filename = f"colecao_{collection_id}.zip"
+        if os.path.exists(zip_filename):
+            # Check if zip file is empty
+            with ZipFile(zip_filename, 'r') as zip:
+                if not zip.namelist():  # If namelist() returns an empty list, the zip is empty
+                    return "Zip is empty", 200
+            
+            # Zip file exists and is not empty, send it
+            zip_path = os.path.abspath(zip_filename)
             return send_file(zip_path, as_attachment=True), 200
+        
         ids = get_collection_ids(collection_id)
         downloaded_files = download_files(ids)
+        
+        # Check if downloaded_files is empty
+        if not downloaded_files:
+            return "No files to zip", 200
+        
         create_zip(downloaded_files, collection_id)
-        zip_path = os.path.abspath(f"colecao_{collection_id}.zip")
+        zip_path = os.path.abspath(zip_filename)
         response = send_file(zip_path, as_attachment=True)
         return response, 200
     except Exception as e:
         return str(e), 500
 
+
 if __name__ == "__main__":
     app.run(port=3333)