#!/usr/bin/env python3
from __future__ import annotations

import argparse
from pathlib import Path
import shutil
import subprocess
from urllib.parse import urlparse


def download_s3_source(source_uri: str, destination: Path) -> None:
    aws_path = shutil.which("aws")
    if aws_path:
        subprocess.run(
            [
                aws_path,
                "s3",
                "cp",
                source_uri,
                str(destination),
                "--only-show-errors",
            ],
            check=True,
        )
        return

    parsed = urlparse(source_uri)
    if parsed.scheme != "s3" or not parsed.netloc or not parsed.path.lstrip("/"):
        raise SystemExit(f"invalid S3 source URI: {source_uri}")

    import boto3

    boto3.client("s3").download_file(
        parsed.netloc,
        parsed.path.lstrip("/"),
        str(destination),
    )


def main() -> None:
    parser = argparse.ArgumentParser(
        description="Download a frozen Salesforce migration source from S3."
    )
    parser.add_argument("source_uri")
    parser.add_argument("destination", type=Path)
    args = parser.parse_args()

    download_s3_source(args.source_uri, args.destination)


if __name__ == "__main__":
    main()