"""
A tox python environment runner that uses the virtualenv project.
"""
from __future__ import annotations

from pathlib import Path

from tox.plugin import impl
from tox.tox_env.register import ToxEnvRegister

from ..runner import PythonRun
from .api import VirtualEnv


class VirtualEnvRunner(VirtualEnv, PythonRun):
    """local file system python virtual environment via the virtualenv package"""

    @staticmethod
    def id() -> str:
        return "virtualenv"

    @property
    def _package_tox_env_type(self) -> str:
        return "virtualenv-pep-517"

    @property
    def _external_pkg_tox_env_type(self) -> str:
        return "virtualenv-cmd-builder"

    @property
    def default_pkg_type(self) -> str:
        tox_root: Path = self.core["tox_root"]
        if not (any((tox_root / i).exists() for i in ("pyproject.toml", "setup.py", "setup.cfg"))):
            return "skip"
        return super().default_pkg_type


@impl
def tox_register_tox_env(register: ToxEnvRegister) -> None:
    register.add_run_env(VirtualEnvRunner)