"""Expose native helpers in a test-only COFF copy, without patching instructions."""
from pathlib import Path
import re
import struct
from check_card_exit_build import Coff

ROOT = Path(__file__).resolve().parents[2]
EXPOSE = {"engineMode", "deltaTime3D", "mouseClick3D", "mouseX3D", "mouseY3D",
          "keys3D", "pressedKeys3D", "tableCos", "tableSin", "screenBuffer",
          "cardExitButton3D", "unavailableText3D", "bankroll", "rngSeed3D"}


def main():
    folder = ROOT / "build/billiards"
    folder.mkdir(exist_ok=True)
    functions = set()
    for name in ("billiards", "pyramid_rules", "eightball", "pyramid_play", "billiards_prediction", "pyramid_render"):
        source = (ROOT / "src_graphics" / (name + ".inc")).read_text(encoding="cp1251")
        functions.update(re.findall(r"^(\w+) PROC", source, re.M))
    for name in ("pyramid_test", "billiards_choice_test", "eightball_regression"):
        source = (ROOT / "tools/tests" / (name + ".inc")).read_text(encoding="cp1251")
        functions.update(re.findall(r"^(\w+) PROC", source, re.M))
    coff = Coff(ROOT / "build/actions/actions-test.obj")
    original = coff.data
    data = bytearray(original)
    start = struct.unpack_from("<I", data, 8)[0]
    found, changes = set(), set()
    for index, name in coff.symbols.items():
        at = start + index * 18
        _, section, kind, storage, _ = struct.unpack_from("<IhHBB", data, at+8)
        target = None
        if name in EXPOSE:
            found.add(name)
            target = 2
        elif name.startswith("_") and name[1:].split("@")[0] in functions and kind == 0x20 and section > 0:
            target = 3
        if target is not None and target != storage:
            data[at+16] = target
            changes.add(at+16)
    assert found == EXPOSE, EXPOSE-found
    assert {i for i, (a, b) in enumerate(zip(original, data)) if a != b} == changes
    (folder / "helpers.obj").write_bytes(data)
    print("Prepared test-only native helpers; only COFF visibility bytes changed")


if __name__ == "__main__":
    main()