#!/usr/bin/env python3
"""Run mklittlefs with a fixed wall clock for reproducible images."""

from __future__ import annotations

import os
import shutil
import subprocess
import sys
from pathlib import Path


def build_time_override(output_path: Path) -> None:
    source_path = Path(__file__).with_name("reproducible_time.c")
    compiler = shutil.which("cc")
    if compiler is None:
        raise RuntimeError("A host C compiler named 'cc' is required")
    subprocess.run(
        [
            compiler,
            "-shared",
            "-fPIC",
            "-O2",
            str(source_path),
            "-o",
            str(output_path),
        ],
        check=True,
    )


def main() -> int:
    real_tool = os.environ.get("MAZE32_REAL_MKFSTOOL")
    build_directory = os.environ.get("MAZE32_BUILD_DIR")
    if not real_tool or not build_directory:
        raise RuntimeError("PlatformIO did not provide the filesystem tool environment")

    override_path = Path(build_directory) / "reproducible_time.so"
    override_path.parent.mkdir(parents=True, exist_ok=True)
    build_time_override(override_path)

    environment = os.environ.copy()
    existing_preload = environment.get("LD_PRELOAD")
    environment["LD_PRELOAD"] = (
        f"{override_path}:{existing_preload}" if existing_preload else str(override_path)
    )
    completed = subprocess.run([real_tool, *sys.argv[1:]], env=environment)
    return completed.returncode


if __name__ == "__main__":
    raise SystemExit(main())