from pathlib import Path

import pytest

from app.fit.rewriter import FitFormatError, is_fit_file
from tests.fit.builders import make_fit


def test_valid_12_and_14_byte_headers(tmp_path: Path) -> None:
    for size in (12, 14):
        path = tmp_path / f"valid-{size}.fit"
        path.write_bytes(make_fit(b"", header_size=size))
        assert is_fit_file(path) is True


def test_bad_file_crc_is_rejected(tmp_path: Path) -> None:
    payload = bytearray(make_fit(b""))
    payload[-1] ^= 0xFF
    path = tmp_path / "bad.fit"
    path.write_bytes(payload)
    assert is_fit_file(path) is False