from __future__ import annotations

import shutil
import subprocess
from pathlib import Path


def build_gdc_command(manifest_path: Path, out_dir: Path, processes: int, retries: int) -> list[str]:
    return [
        "gdc-client",
        "download",
        "-m",
        str(manifest_path),
        "-d",
        str(out_dir),
        "--n-processes",
        str(processes),
        "--retry-count",
        str(retries),
        "--checksum",
    ]


def run_gdc_download(manifest_path: Path, out_dir: Path, processes: int = 4, retries: int = 3) -> None:
    if not shutil.which("gdc-client"):
        raise RuntimeError("gdc-client not found in PATH")
    cmd = build_gdc_command(manifest_path, out_dir, processes, retries)
    subprocess.run(cmd, check=True)