"""Python dependencies used by the helper; optional cover tagging is excluded."""
from __future__ import annotations

import importlib.metadata
import re
from pathlib import Path


def requirements(yt_dlp="yt-dlp>=2026.8.19", ejs="yt-dlp-ejs"):
    return [yt_dlp, ejs, "brotli", "certifi", "pycryptodomex",
            "requests>=2.32.2,<3", "urllib3>=2,<3", "websockets>=13"]


def validate_metadata(records):
    """Reject strong copyleft Python libraries before activating a bundle.

    FFmpeg is a separately executed program, so this policy concerns Python
    libraries loaded into the helper process, not the FFmpeg distribution.
    """
    for metadata in records:
        name = re.sub(r"[-_.]+", "-", metadata.get("name", "").lower())
        licenses = [metadata.get("license_expression") or "", metadata.get("license") or "",
                    *metadata.get("classifier", [])]
        incompatible = name == "mutagen" or any(
            re.search(r"(?<![A-Z])(?:A?GPL)(?:[-\s\dv]|$)|GNU (?:Affero )?General Public License",
                      license, re.IGNORECASE) for license in licenses)
        if incompatible:
            raise ValueError(f"Python-пакет {name} требует отдельной проверки совместимости лицензии; комплект не изменён.")


def validate_installed(directory: Path):
    records = []
    for distribution in importlib.metadata.distributions(path=[str(directory)]):
        metadata = distribution.metadata
        records.append({"name": metadata.get("Name", ""),
                        "license_expression": metadata.get("License-Expression", ""),
                        "license": metadata.get("License", ""),
                        "classifier": metadata.get_all("Classifier") or []})
    validate_metadata(records)
    return {distribution.metadata["Name"]: distribution.version
            for distribution in importlib.metadata.distributions(path=[str(directory)])}