#!/usr/bin/env python3
"""Detect frozen-Python packers and locate the embedded archive.

Scans an executable for PyInstaller, py2exe, and cx_Freeze markers, locates the PyInstaller
CArchive magic cookie, and extracts embedded Python version strings. Reads bytes statically;
executes nothing.
"""
from __future__ import annotations

import argparse
import json
import re
import sys
from pathlib import Path

PYI_COOKIE = b"MEI\014\013\012\013\016"
PYI_MARKERS = [b"pyi-windows-manifest-filename", b"PYZ-00.pyz", b"pyiboot01_bootstrap",
               b"_MEIPASS"]
PY2EXE_MARKERS = [b"PYTHONSCRIPT", b"py2exe"]
CXFREEZE_MARKERS = [b"cx_Freeze", b"cx_freeze__init__"]
RE_PYVER = re.compile(rb"python(\d)\.?(\d{1,2})")
RE_PYDLL = re.compile(rb"python(\d)(\d{1,2})\.dll", re.I)


def detect(path: str) -> dict:
    data = Path(path).read_bytes()
    pyi = any(m in data for m in PYI_MARKERS) or PYI_COOKIE in data
    py2exe = any(m in data for m in PY2EXE_MARKERS)
    cxfreeze = any(m in data for m in CXFREEZE_MARKERS)
    cookie_off = data.rfind(PYI_COOKIE)
    versions = sorted({f"{m.group(1).decode()}.{m.group(2).decode()}"
                       for m in RE_PYVER.finditer(data)})
    dll_versions = sorted({f"{m.group(1).decode()}.{m.group(2).decode()}"
                           for m in RE_PYDLL.finditer(data)})
    packer = "PyInstaller" if pyi else "py2exe" if py2exe else \
        "cx_Freeze" if cxfreeze else "unknown"
    return {
        "is_frozen_python": pyi or py2exe or cxfreeze,
        "packer": packer,
        "pyinstaller_cookie_offset": cookie_off if cookie_off != -1 else None,
        "python_versions": versions[:5],
        "python_dll_versions": dll_versions[:5],
        "next_step": "extract the archive (e.g. pyinstxtractor) then decompile matching .pyc",
    }


def main(argv: list[str] | None = None) -> int:
    parser = argparse.ArgumentParser(description="Detect frozen-Python packers")
    sub = parser.add_subparsers(dest="cmd", required=True)
    p = sub.add_parser("detect")
    p.add_argument("file")
    args = parser.parse_args(argv)
    print(json.dumps(detect(args.file), indent=2))
    return 0


if __name__ == "__main__":
    sys.exit(main())