#!/usr/bin/env python3
"""Создаёт и проверяет fixture запрета target внутри source."""

from __future__ import annotations

import pathlib
import sys


CONTENT = b"self-target guard\r\n"


def create(root: pathlib.Path) -> None:
    tree = root / "SRC" / "TREE"
    (tree / "INNER").mkdir(parents=True)
    (tree / "FILE.TXT").write_bytes(CONTENT)


def verify(root: pathlib.Path) -> None:
    tree = root / "SRC" / "TREE"
    failures: list[str] = []
    if (tree / "FILE.TXT").read_bytes() != CONTENT:
        failures.append("source FILE.TXT изменён")
    inner = tree / "INNER"
    if not inner.is_dir() or any(inner.iterdir()):
        failures.append("внутри source появился рекурсивный target")
    temporary = [path.as_posix() for path in tree.rglob("*")
                 if path.name.upper().endswith(".TMP")]
    if temporary:
        failures.append(f"остались temp: {temporary}")
    if failures:
        for failure in failures:
            print(f"FAIL: {failure}")
        raise SystemExit(1)
    print("PASS: target-inside-source refused before mutation.")


def main() -> None:
    if len(sys.argv) != 3 or sys.argv[1] not in {"create", "verify"}:
        raise SystemExit(f"usage: {sys.argv[0]} create|verify DIR")
    root = pathlib.Path(sys.argv[2])
    if sys.argv[1] == "create":
        create(root)
    else:
        verify(root)


if __name__ == "__main__":
    main()