Feat/create result storage class

gateway/api/services/result_storage.py

@@ -0,0 +1,70 @@
+
+import os
+import logging
+import mimetypes
+from typing import Optional, Tuple
+from wsgiref.util import FileWrapper
+from django.conf import settings
+from django.core.files import File
+
+logger = logging.getLogger("gateway")
+
+
+class ResultStorage:
+    """Handles the storage and retrieval of user job results."""
+
+    RESULT_FILE_EXTENSION = ".json"
+    ENCODING = "utf-8"
+
+    def __init__(self, username: str):
+        """Initialize the storage path for a given user."""
+        self.user_results_directory = os.path.join(
+            settings.MEDIA_ROOT, username, "results")
+        os.makedirs(self.user_results_directory, exist_ok=True)
+
+    def __build_result_path(self, job_id: str) -> str:
+        """Construct the full path for a result file."""
+        return os.path.join(self.user_results_directory, f"{job_id}{self.RESULT_FILE_EXTENSION}")
+
+    def get(self, job_id: str) -> Optional[Tuple[FileWrapper, str, int]]:
+        """
+        Retrieve a result file for the given job ID.
+
+        Returns:
+            Tuple containing:
+            - FileWrapper for the file
+            - File MIME type
+            - File size in bytes
+        """
+        result_path = self.__build_result_path(job_id)
+
+        if not os.path.exists(result_path):
+            logger.warning(
+                "Result file for job ID '%s' not found in directory '%s'.",
+                job_id,
+                self.user_results_directory,
+            )
+            return None
+
+        with open(result_path, "rb") as result_file:
+            file_wrapper = FileWrapper(result_file)
+            file_type = mimetypes.guess_type(
+                result_path)[0] or "application/octet-stream"
+            file_size = os.path.getsize(result_path)
+            return file_wrapper, file_type, file_size
+
+    def save(self, job_id: str, result: str) -> None:
+        """
+        Save the result content to a file associated with the given job ID.
+
+        Args:
+            job_id (str): The unique identifier for the job. This will be used as the base 
+                        name for the result file.
+            result (str): The job result content to be saved in the file.
+        """
+        result_path = self.__build_result_path(job_id)
+
+        with open(result_path, "w", encoding=self.ENCODING) as result_file:
+            result_file.write(result)
+            logger.info(
+                "Result for job ID '%s' successfully saved at '%s'.", job_id, result_path)