import os


HF_REPO_ID = "VAST-AI/AniGen"
CKPTS_DIR = "ckpts"


REQUIRED_FILES = [
    "ckpts/dinov2/hubconf.py",
    "ckpts/dinov2/dinov2/__init__.py",
    "ckpts/dsine/dsine.pt",
    "ckpts/vgg/vgg16-397923af.pth",
]


def ensure_ckpts(local_dir: str = ".") -> None:
    missing = [
        path for path in REQUIRED_FILES
        if not os.path.exists(os.path.join(local_dir, path))
    ]
    if not missing:
        return

    print(f"Missing checkpoint files: {missing}")
    print(f"Downloading checkpoints from Hugging Face ({HF_REPO_ID}) ...")

    from huggingface_hub import snapshot_download

    snapshot_download(
        repo_id=HF_REPO_ID,
        allow_patterns=[f"{CKPTS_DIR}/**"],
        local_dir=local_dir,
    )

    print("Checkpoint download complete.")