feat: Control features with build arg

src/api/src/main.py

@@ -17,6 +17,7 @@ from fastapi.responses import (
     StreamingResponse,
 )
 from fastapi.staticfiles import StaticFiles
+from os import getenv
 
 from create_book import (
     EPUBGenerator,
@@ -36,6 +37,8 @@ from create_book.parser import clean_tree, fetch_tree_images
 app = FastAPI()
 BUILD_PATH = Path(__file__).parent / "build"
 
+feature_flag = True if getenv("VITE_FEATURE_FLAG") == "true" else False
+
 
 class RequestCancelledMiddleware:
     # Thanks https://github.com/fastapi/fastapi/discussions/11360#discussion-6427734
@@ -192,6 +195,12 @@ async def handle_download(
                 book = EPUBGenerator(metadata, part_trees, cover_data, images)
                 media_type = "application/epub+zip"
             case DownloadFormat.pdf:
+                if not feature_flag:
+                    logger.error("PDF downloads not enabled.")
+                    return HTMLResponse(
+                        status_code=403,
+                        content='PDF downloads have been disabled by the server administrator. Support is available on the <a href="https://discord.gg/P9RHC4KCwd" target="_blank">Discord</a>',
+                    )
                 author_image = await fetch_image(
                     metadata["user"]["avatar"].replace("-256-", "-512-")
                 )
@@ -215,7 +224,7 @@ async def handle_download(
                 yield chunk
 
         return StreamingResponse(
-            iterfile(),
+            book_buffer if feature_flag else iterfile(),
             media_type=media_type,
             headers={
                 "Content-Disposition": f'attachment; filename="{slugify(metadata["title"])}_{story_id}{"_images" if download_images else ""}.{format.value}"',  # Thanks https://stackoverflow.com/a/72729058