from __future__ import annotations

import shutil
import subprocess
from pathlib import Path

from tcga_downloader.logger import get_logger

logger = get_logger("download")


def build_gdc_command(
    manifest_path: Path, out_dir: Path, processes: int, retries: int, token: str | None = None
) -> list[str]:
    cmd = [
        "gdc-client",
        "download",
        "-m",
        str(manifest_path),
        "-d",
        str(out_dir),
        "--n-processes",
        str(processes),
        "--retry-amount",
        str(retries),
    ]
    if token:
        cmd.extend(["--token", token])
    return cmd


def run_gdc_download(
    manifest_path: Path,
    out_dir: Path,
    processes: int = 4,
    retries: int = 3,
    token: str | None = None,
) -> None:
    if not manifest_path.exists():
        raise FileNotFoundError(f"Manifest file not found: {manifest_path}")

    if not shutil.which("gdc-client"):
        raise RuntimeError(
            "gdc-client not found in PATH. Install from https://gdc.cancer.gov/access-data/gdc-data-transfer-tool"
        )

    cmd = build_gdc_command(manifest_path, out_dir, processes, retries, token)
    logger.info("Starting download: manifest=%s, out_dir=%s", manifest_path, out_dir)
    logger.debug("Running command: %s", " ".join(cmd))

    try:
        result = subprocess.run(cmd, check=True, capture_output=True, text=True)
        if result.stdout:
            logger.debug("gdc-client output: %s", result.stdout)
    except subprocess.CalledProcessError as e:
        logger.error("Download failed with exit code %d", e.returncode)
        if e.stdout:
            logger.info("gdc-client output:\n%s", e.stdout)
        if e.stderr:
            logger.error("gdc-client error:\n%s", e.stderr)
        raise RuntimeError(f"gdc-client download failed with exit code {e.returncode}") from e

    logger.info("Download completed successfully")