dev: add ADK agent with vector search tool and Google Cloud file storage implementation

rag_agent/file_storage/base.py

@@ -0,0 +1,56 @@
+"""Abstract base class for file storage providers."""
+
+from abc import ABC, abstractmethod
+from typing import BinaryIO
+
+
+class BaseFileStorage(ABC):
+    """Abstract base class for a remote file processor.
+
+    Defines the interface for listing and processing files from
+    a remote source.
+    """
+
+    @abstractmethod
+    def upload_file(
+        self,
+        file_path: str,
+        destination_blob_name: str,
+        content_type: str | None = None,
+    ) -> None:
+        """Upload a file to the remote source.
+
+        Args:
+            file_path: The local path to the file to upload.
+            destination_blob_name: Name of the file in remote storage.
+            content_type: The content type of the file.
+
+        """
+        ...
+
+    @abstractmethod
+    def list_files(self, path: str | None = None) -> list[str]:
+        """List files from a remote location.
+
+        Args:
+            path: Path to a specific file or directory. If None,
+                  recursively lists all files in the bucket.
+
+        Returns:
+            A list of file paths.
+
+        """
+        ...
+
+    @abstractmethod
+    def get_file_stream(self, file_name: str) -> BinaryIO:
+        """Get a file from the remote source as a file-like object.
+
+        Args:
+            file_name: The name of the file to retrieve.
+
+        Returns:
+            A file-like object containing the file data.
+
+        """
+        ...