#!/usr/bin/env python3
"""Создаёт и проверяет HDD-fixture рекурсивного F5 одного каталога."""

from __future__ import annotations

import pathlib
import sys


def payload(size: int, seed: int) -> bytes:
    return bytes(((index * 53 + seed) & 0xFF) for index in range(size))


def create(root: pathlib.Path) -> None:
    tree = root / "SRC" / "TREE"
    (root / "DST").mkdir(parents=True)
    (tree / "EMPTY").mkdir(parents=True)
    (tree / "ROOT.TXT").write_bytes(b"recursive root\r\n")
    sub = tree / "SUB"
    sub.mkdir()
    (sub / "A.BIN").write_bytes(payload(4097, 7))
    (sub / "ZERO.DAT").write_bytes(b"")

    deep = sub
    for level in range(1, 17):
        deep = deep / f"L{level:02d}"
        deep.mkdir()
    (deep / "BOTTOM.TXT").write_bytes(b"depth sixteen\r\n")


def tree_snapshot(root: pathlib.Path) -> dict[str, bytes | None]:
    result: dict[str, bytes | None] = {}
    for path in sorted(root.rglob("*")):
        relative = path.relative_to(root).as_posix().upper()
        result[relative] = None if path.is_dir() else path.read_bytes()
    return result


def verify(root: pathlib.Path) -> None:
    source = root / "SRC" / "TREE"
    target = root / "DST" / "TREE"
    failures: list[str] = []

    if not source.is_dir() or not target.is_dir():
        failures.append("source или target TREE отсутствует")
    elif tree_snapshot(source) != tree_snapshot(target):
        failures.append("рекурсивное дерево target не совпадает с source")

    temporary = [path.as_posix() for path in (root / "DST").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: recursive tree copied exactly; depth=16; no temp.")


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()