#!/usr/bin/env python3
"""Write deterministic SHA-256 checksums for release files."""

from __future__ import annotations

import hashlib
from pathlib import Path


ROOT = Path(__file__).resolve().parents[1]
EXCLUDED = {"checksums.sha256"}


def digest(path: Path) -> str:
    hasher = hashlib.sha256()
    with path.open("rb") as handle:
        for block in iter(lambda: handle.read(1024 * 1024), b""):
            hasher.update(block)
    return hasher.hexdigest()


def main() -> None:
    files = [
        path for path in ROOT.rglob("*")
        if path.is_file() and path.name not in EXCLUDED and "__pycache__" not in path.parts
    ]
    lines = [f"{digest(path)}  {path.relative_to(ROOT).as_posix()}" for path in sorted(files)]
    (ROOT / "checksums.sha256").write_text("\n".join(lines) + "\n", encoding="utf-8")
    print(f"Wrote checksums for {len(files)} files")


if __name__ == "__main__":
    main()