#!/usr/bin/env python3
"""Make a temporary TTree copy for legacy Uproot versions."""

from __future__ import annotations

import argparse
from pathlib import Path

import awkward as ak
import uproot


def main() -> int:
    parser = argparse.ArgumentParser()
    parser.add_argument("source", type=Path)
    parser.add_argument("output", type=Path)
    args = parser.parse_args()
    with uproot.open(args.source) as root_file:
        tree = root_file["output"]
        arrays = tree.arrays(list(tree.keys()), library="ak")
    branch_types = {
        name: str(ak.type(arrays[name])).split("* ", 1)[1] for name in arrays.fields
    }
    with uproot.recreate(args.output) as root_file:
        root_file.mktree("output", branch_types)
        root_file["output"].extend(arrays)
    return 0


if __name__ == "__main__":
    raise SystemExit(main())