#!/usr/bin/env python3

"""Minimal xargs replacement for environments where /usr/bin/xargs is unavailable.

Supports the subset of functionality exercised by Verilator's generated makefiles:
optional -0 (NUL-delimited input) and -t (echo command) flags, followed by a command
invocation constructed from stdin tokens.
"""

from __future__ import annotations

import subprocess
import sys


def main() -> int:
    args = sys.argv[1:]
    show_cmd = False
    null_delimited = False

    while args and args[0].startswith("-") and args[0] != "-":
        opt = args.pop(0)
        if opt == "-0":
            null_delimited = True
        elif opt == "-t":
            show_cmd = True
        else:
            sys.stderr.write(f"xargs shim: unsupported option {opt}\n")
            return 1

    if not args:
        args = ["echo"]

    data = sys.stdin.buffer.read()
    if not data.strip():
        return 0

    if null_delimited:
        items = [chunk.decode() for chunk in data.split(b"\0") if chunk]
    else:
        items = data.decode().split()

    if not items:
        return 0

    cmd = args + items
    if show_cmd:
        print(" ".join(cmd))

    try:
        subprocess.check_call(cmd)
    except FileNotFoundError:
        return 127
    except subprocess.CalledProcessError as exc:
        return exc.returncode

    return 0


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