Blame for app.py

from __future__ import annotations
import os

# Disable Gradio SSR mode to prevent port 7860 collisions on HF Spaces
os.environ["GRADIO_SSR_MODE"] = "0"

# ---------------------------------------------------------------------------
# ZeroGPU compatibility (must run BEFORE torch is imported anywhere).
#
# Free HF accounts can no longer create CPU Gradio Spaces, and an existing
# ZeroGPU Space cannot be downgraded to CPU without PRO. ZeroGPU refuses to
# start ("No @spaces.GPU function detected during startup") unless:
#   1. at least one @spaces.GPU function is registered, and
#   2. `spaces.zero.startup()` reports it - normally triggered by
#      `gr.Blocks.launch()`, which we don't use because we serve FastAPI
#      directly with uvicorn. So we call it ourselves.
# The judge runs entirely on CPU; the GPU placeholder is never called.
# On CPU hardware / local dev `spaces` is absent and this block is skipped.
# ---------------------------------------------------------------------------
try:
    import spaces  # type: ignore

    @spaces.GPU
    def _zerogpu_placeholder() -> str:
        return "ok"

    _zero = getattr(spaces, "zero", None)
    _startup = getattr(_zero, "startup", None) if _zero is not None else None
    if callable(_startup):
        _startup()
        print("[codestar] ZeroGPU startup report sent", flush=True)
except ImportError:
    pass
except Exception as exc:  # never block the API from starting
    print(f"[codestar] ZeroGPU init warning: {exc!r}", flush=True)

import os
import sys
from pathlib import Path
import uvicorn

# Ensure repository root is on sys.path
ROOT = Path(__file__).resolve().parent
if str(ROOT) not in sys.path:
    sys.path.insert(0, str(ROOT))

from codestar.server.app import app as fastapi_app

# NOTE: We intentionally do NOT mount a Gradio UI. On HF Spaces Gradio enables
# SSR mode by default, whose startup hook spawns a Node server that grabs port
# 7860 before uvicorn can bind it ("address already in use"). The frontend
# lives on Netlify; the Space only needs to serve the JSON API.
app = fastapi_app


# Hugging Face Gradio Spaces start the app with `python app.py`, so we must
# launch the server ourselves on port 7860.
if __name__ == "__main__":
    port = int(os.environ.get("PORT", 7860))
    uvicorn.run(app, host="0.0.0.0", port=port)