Update app.py

app.py

@@ -1,18 +1,56 @@
-# app.py — wrapper used by Hugging Face Spaces to start the Chainlit UI
-# This simple script locates the packaged chainlit app and invokes the chainlit CLI.
+"""app.py — entrypoint used by Hugging Face Spaces
+
+Creates a writable files directory for Chainlit and starts the Chainlit app.
+This file is robust for both Docker and non-Docker runtimes:
+- If CHAINLIT_FILES_DIR is set (e.g. by the Dockerfile), it will use that.
+- Otherwise it tries /home/user/app/.files (the Docker image's path created at build-time).
+- If neither is writable it will fall back to /tmp/mini_transformer_files.
+
+It then runs the chainlit CLI against the packaged `mini_transformer.apps.chainlit_app`.
+"""
 
 import os
 import subprocess
-from pathlib import Path
 import sys
+from pathlib import Path
+
+# Prefer an externally provided writable directory
+files_dir = os.environ.get("CHAINLIT_FILES_DIR")
 
-# Optional: set a default model name here or use Space env vars to override
-# os.environ.setdefault("MINI_TRANSFORMER_MODEL_NAME", "small_model_v1")
+if files_dir:
+    files_path = Path(files_dir)
+else:
+    # prefer repo-level .files under /home/user/app (created by Dockerfile), else fallback to /tmp
+    candidate = Path("/home/user/app/.files")
+    if candidate.exists() and os.access(candidate, os.W_OK):
+        files_path = candidate
+    else:
+        files_path = Path(os.environ.get("TMPDIR", "/tmp")) / "mini_transformer_files"
 
-# Resolve path to packaged chainlit app inside the repository
+# Ensure directory exists and is writable
+try:
+    files_path.mkdir(parents=True, exist_ok=True)
+    # Try to set permissive access for the runtime user
+    try:
+        files_path.chmod(0o700)
+    except Exception:
+        pass
+except Exception as exc:  # pragma: no cover - permissive in container
+    print(f"Failed to create files dir {files_path}: {exc}", file=sys.stderr)
+    raise
+
+# Export helpful env vars for Chainlit and other libs
+os.environ.setdefault("CHAINLIT_FILES_DIR", str(files_path))
+os.environ.setdefault("TMPDIR", str(files_path))
+os.environ.setdefault("XDG_CACHE_HOME", str(files_path / "cache"))
+os.environ.setdefault("XDG_STATE_HOME", str(files_path / "state"))
+
+port = os.environ.get("PORT", os.environ.get("MINI_TRANSFORMER_UI_PORT", "7860"))
+host = os.environ.get("HOST", "0.0.0.0")
+
+# Resolve path to packaged chainlit app. If the source files aren't present, rely on installed package.
 app_path = Path(__file__).parent / "src" / "mini_transformer" / "apps" / "chainlit_app.py"
 if not app_path.exists():
-    # If package is installed into env, try to find installed module
     try:
         import mini_transformer.apps.chainlit_app as packed
 
@@ -21,13 +59,10 @@ if not app_path.exists():
         print("Could not locate mini_transformer.apps.chainlit_app. Make sure package files are present.", file=sys.stderr)
         raise SystemExit(1)
 
-port = os.environ.get("PORT", os.environ.get("MINI_TRANSFORMER_UI_PORT", "7860"))
-host = os.environ.get("HOST", "0.0.0.0")
-
 cmd = ["chainlit", "run", str(app_path), "--host", host, "--port", str(port)]
 print("Starting Chainlit with:\n", " ".join(cmd))
 
-# Use subprocess.run so Chainlit becomes the foreground process
+# Run Chainlit as foreground process
 try:
     subprocess.run(cmd, check=True)
 except FileNotFoundError: