#!/usr/bin/env python3
"""Compare stronger compression candidates for Pixel Island asset JSON.

Usage:
  python server/compression_lab.py exported_world.json

This does not change production data. It reports approximate sizes for raw JSON,
minified JSON, gzip, zlib, and brotli if the optional `brotli` module is installed.
For browser/server interchange, prefer: compact JSON -> gzip/brotli at HTTP layer.
"""
from __future__ import annotations
import argparse, gzip, json, zlib
from pathlib import Path

try:
    import brotli  # type: ignore
except Exception:  # pragma: no cover
    brotli = None


def main() -> int:
    ap = argparse.ArgumentParser()
    ap.add_argument('json_file', type=Path)
    args = ap.parse_args()
    data = json.loads(args.json_file.read_text(encoding='utf-8'))
    pretty = json.dumps(data, ensure_ascii=False, indent=2).encode('utf-8')
    mini = json.dumps(data, ensure_ascii=False, separators=(',', ':')).encode('utf-8')
    rows = [
        ('pretty_json', len(pretty)),
        ('minified_json', len(mini)),
        ('gzip_9', len(gzip.compress(mini, compresslevel=9))),
        ('zlib_9', len(zlib.compress(mini, level=9))),
    ]
    if brotli:
        rows.append(('brotli_11', len(brotli.compress(mini, quality=11))))
    base = len(pretty) or 1
    for name, size in rows:
        print(f'{name:14} {size:10d} bytes  {size/base:6.1%} of pretty JSON')
    return 0

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