"""Verify the public format through an independent Python implementation."""

import importlib.util
import math
from pathlib import Path
import struct
import subprocess
import sys
import tempfile


def main():
    """Check native/text equality and CSV output using files produced by C++."""
    sys.dont_write_bytecode = True
    writer, reader_path = sys.argv[1:]
    spec = importlib.util.spec_from_file_location("serif_archive", reader_path)
    module = importlib.util.module_from_spec(spec)
    spec.loader.exec_module(module)
    with tempfile.TemporaryDirectory(prefix="serif-python-reader-") as directory:
        subprocess.run([writer, directory], check=True)
        representations = []
        for encoding in ("binary", "text"):
            path = Path(directory) / f"{encoding}.serif"
            with module.Archive(path) as archive:
                values = archive.read("values")
                assert len(values) == 5
                assert math.copysign(1.0, values[0]) < 0
                assert values[1] == 1.2345678901234567
                assert values[2] == float.fromhex("0x0.0000000000001p-1022")
                assert values[3] == math.inf
                assert struct.pack("<d", values[4]).hex() == "bc9a78563412f87f"
                assert archive.read("integers") == [-(1 << 63), (1 << 63) - 1]
                assert archive.read("label") == 'ξ\n"quote"\\end'
                assert archive.read("empty") == []
                assert archive.read("provenance/author") == "Cross-language regression"
                representations.append(struct.pack("<5d", *values))
            csv = subprocess.run([sys.executable, reader_path, str(path), "--read", "values", "--csv"], check=True, capture_output=True, text=True).stdout
            assert csv.startswith("index,value\n0,-0.0\n")
            damaged = bytearray(path.read_bytes())
            damaged[550] ^= 1
            path.write_bytes(damaged)
            try:
                module.Archive(path)
            except ValueError as error:
                assert "ledger" in str(error)
            else:
                raise AssertionError("Corrupted ledger was accepted")
        assert representations[0] == representations[1]
    print("Python reader: binary/text exact values, provenance, CSV and corruption checks passed")


if __name__ == "__main__":
    main()