#!/usr/bin/env python3
"""Verify deterministic web generation and the checked-in generated assets."""

from __future__ import annotations

import gzip
import hashlib
import tempfile
from pathlib import Path

from generate_web_assets import generate_assets


PROJECT_DIRECTORY = Path(__file__).resolve().parent.parent


def tree_digest(directory: Path) -> str:
    digest = hashlib.sha256()
    for path in sorted(item for item in directory.rglob("*") if item.is_file()):
        digest.update(path.relative_to(directory).as_posix().encode("utf-8"))
        digest.update(b"\0")
        digest.update(path.read_bytes())
    return digest.hexdigest()


def main() -> int:
    source_directory = PROJECT_DIRECTORY / "web"
    checked_in_directory = PROJECT_DIRECTORY / "data"
    with tempfile.TemporaryDirectory(prefix="maze32-assets-") as temporary:
        temporary_directory = Path(temporary)
        first = temporary_directory / "first"
        second = temporary_directory / "second"
        generate_assets(source_directory, first)
        generate_assets(source_directory, second)

        first_digest = tree_digest(first)
        second_digest = tree_digest(second)
        checked_in_digest = tree_digest(checked_in_directory)
        if first_digest != second_digest:
            raise AssertionError("Repeated web-asset generation produced different output")
        if first_digest != checked_in_digest:
            raise AssertionError("Generated web assets are stale; regenerate the data directory")

        index_source = (source_directory / "index.html").read_bytes()
        index_compressed = (first / "index.html.gz").read_bytes()
        if gzip.decompress(index_compressed) != index_source:
            raise AssertionError("Compressed index does not reproduce its source")

        provision_source = (source_directory / "provision.html").read_bytes()
        provision_compressed = (first / "provision.html.gz").read_bytes()
        if gzip.decompress(provision_compressed) != provision_source:
            raise AssertionError("Compressed provisioning page does not reproduce its source")

    print(f"web asset reproducibility: PASS ({first_digest})")
    return 0


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