Better download (#628)

* fix: rfc for get_workdir_files was failing

* fix: make downloads chunked with progress

---------

Co-authored-by: Rafael Uzarowski <uzarowski.rafael@proton.me>

python/api/download_work_dir_file.py

@@ -1,10 +1,77 @@
 import base64
 from io import BytesIO
+import mimetypes
+import os
 
-from python.helpers.api import ApiHandler, Input, Output, Request, Response, send_file
+from flask import Response
+from python.helpers.api import ApiHandler, Input, Output, Request
 from python.helpers import files, runtime
 from python.api import file_info
-import os
+
+
+def stream_file_download(file_source, download_name, chunk_size=8192):
+    """
+    Create a streaming response for file downloads that shows progress in browser.
+
+    Args:
+        file_source: Either a file path (str) or BytesIO object
+        download_name: Name for the downloaded file
+        chunk_size: Size of chunks to stream (default 8192 bytes)
+
+    Returns:
+        Flask Response object with streaming content
+    """
+    # Calculate file size for Content-Length header
+    if isinstance(file_source, str):
+        # File path - get size from filesystem
+        file_size = os.path.getsize(file_source)
+    elif isinstance(file_source, BytesIO):
+        # BytesIO object - get size from buffer
+        current_pos = file_source.tell()
+        file_source.seek(0, 2)  # Seek to end
+        file_size = file_source.tell()
+        file_source.seek(current_pos)  # Restore original position
+    else:
+        raise ValueError(f"Unsupported file source type: {type(file_source)}")
+
+    def generate():
+        if isinstance(file_source, str):
+            # File path - open and stream from disk
+            with open(file_source, 'rb') as f:
+                while True:
+                    chunk = f.read(chunk_size)
+                    if not chunk:
+                        break
+                    yield chunk
+        elif isinstance(file_source, BytesIO):
+            # BytesIO object - stream from memory
+            file_source.seek(0)  # Ensure we're at the beginning
+            while True:
+                chunk = file_source.read(chunk_size)
+                if not chunk:
+                    break
+                yield chunk
+
+    # Detect content type based on file extension
+    content_type, _ = mimetypes.guess_type(download_name)
+    if not content_type:
+        content_type = 'application/octet-stream'
+
+    # Create streaming response with proper headers for immediate streaming
+    response = Response(
+        generate(),
+        content_type=content_type,
+        direct_passthrough=True,  # Prevent Flask from buffering the response
+        headers={
+            'Content-Disposition': f'attachment; filename="{download_name}"',
+            'Content-Length': str(file_size),  # Critical for browser progress bars
+            'Cache-Control': 'no-cache',
+            'X-Accel-Buffering': 'no',  # Disable nginx buffering
+            'Accept-Ranges': 'bytes'  # Allow browser to resume downloads
+        }
+    )
+
+    return response
 
 
 class DownloadFile(ApiHandler):
@@ -32,31 +99,27 @@ class DownloadFile(ApiHandler):
             if runtime.is_development():
                 b64 = await runtime.call_development_function(fetch_file, zip_file)
                 file_data = BytesIO(base64.b64decode(b64))
-                return send_file(
+                return stream_file_download(
                     file_data,
-                    as_attachment=True,
-                    download_name=os.path.basename(zip_file),
+                    download_name=os.path.basename(zip_file)
                 )
             else:
-                return send_file(
+                return stream_file_download(
                     zip_file,
-                    as_attachment=True,
-                    download_name=f"{os.path.basename(file_path)}.zip",
+                    download_name=f"{os.path.basename(file_path)}.zip"
                 )
         elif file["is_file"]:
             if runtime.is_development():
                 b64 = await runtime.call_development_function(fetch_file, file["abs_path"])
                 file_data = BytesIO(base64.b64decode(b64))
-                return send_file(
+                return stream_file_download(
                     file_data,
-                    as_attachment=True,
-                    download_name=os.path.basename(file_path),
+                    download_name=os.path.basename(file_path)
                 )
             else:
-                return send_file(
+                return stream_file_download(
                     file["abs_path"],
-                    as_attachment=True,
-                    download_name=os.path.basename(file["file_name"]),
+                    download_name=os.path.basename(file["file_name"])
                 )
         raise Exception(f"File {file_path} not found")
 

python/api/get_work_dir_files.py

@@ -1,6 +1,7 @@
 from python.helpers.api import ApiHandler, Request, Response
 from python.helpers.file_browser import FileBrowser
 from python.helpers import runtime
+import python.api.get_work_dir_files as get_work_dir_files_module
 
 
 class GetWorkDirFiles(ApiHandler):
@@ -20,7 +21,7 @@ class GetWorkDirFiles(ApiHandler):
 
         # browser = FileBrowser()
         # result = browser.get_files(current_path)
-        result = await runtime.call_development_function(get_files, current_path)
+        result = await runtime.call_development_function(get_work_dir_files_module.get_files, current_path)
 
         return {"data": result}