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"""Utilities for creating a virtual environment"""
from __future__ import annotations

import os
import sys
import warnings

import jinja2

from airflow.utils.decorators import remove_task_decorator as _remove_task_decorator
from airflow.utils.process_utils import execute_in_subprocess


def _generate_virtualenv_cmd(tmp_dir: str, python_bin: str, system_site_packages: bool) -> list[str]:
    cmd = [sys.executable, '-m', 'virtualenv', tmp_dir]
    if system_site_packages:
        cmd.append('--system-site-packages')
    if python_bin is not None:
        cmd.append(f'--python={python_bin}')
    return cmd


def _generate_pip_install_cmd_from_file(
    tmp_dir: str, requirements_file_path: str, pip_install_options: list[str]
) -> list[str]:
    cmd = [f'{tmp_dir}/bin/pip', 'install'] + pip_install_options + ['-r']
    return cmd + [requirements_file_path]


def _generate_pip_install_cmd_from_list(
    tmp_dir: str, requirements: list[str], pip_install_options: list[str]
) -> list[str]:
    cmd = [f'{tmp_dir}/bin/pip', 'install'] + pip_install_options
    return cmd + requirements


def remove_task_decorator(python_source: str, task_decorator_name: str) -> str:
    warnings.warn(
        "Import remove_task_decorator from airflow.utils.decorators instead",
        DeprecationWarning,
        stacklevel=2,
    )
    return _remove_task_decorator(python_source, task_decorator_name)


def prepare_virtualenv(
    venv_directory: str,
    python_bin: str,
    system_site_packages: bool,
    requirements: list[str] | None = None,
    requirements_file_path: str | None = None,
    pip_install_options: list[str] | None = None,
) -> str:
    """Creates a virtual environment and installs the additional python packages.

    :param venv_directory: The path for directory where the environment will be created.
    :param python_bin: Path to the Python executable.
    :param system_site_packages: Whether to include system_site_packages in your virtualenv.
        See virtualenv documentation for more information.
    :param requirements: List of additional python packages.
    :param requirements_file_path: Path to the ``requirements.txt`` file.
    :return: Path to a binary file with Python in a virtual environment.
    :rtype: str
    """
    if pip_install_options is None:
        pip_install_options = []

    virtualenv_cmd = _generate_virtualenv_cmd(venv_directory, python_bin, system_site_packages)
    execute_in_subprocess(virtualenv_cmd)

    if requirements is not None and requirements_file_path is not None:
        raise Exception("Either requirements OR requirements_file_path has to be passed, but not both")

    pip_cmd = None
    if requirements is not None and len(requirements) != 0:
        pip_cmd = _generate_pip_install_cmd_from_list(venv_directory, requirements, pip_install_options)
    if requirements_file_path is not None and requirements_file_path:
        pip_cmd = _generate_pip_install_cmd_from_file(
            venv_directory, requirements_file_path, pip_install_options
        )

    if pip_cmd:
        execute_in_subprocess(pip_cmd)

    return f'{venv_directory}/bin/python'


def write_python_script(
    jinja_context: dict,
    filename: str,
    render_template_as_native_obj: bool = False,
):
    """
    Renders the python script to a file to execute in the virtual environment.

    :param jinja_context: The jinja context variables to unpack and replace with its placeholders in the
        template file.
    :param filename: The name of the file to dump the rendered script to.
    :param render_template_as_native_obj: If ``True``, rendered Jinja template would be converted
        to a native Python object
    """
    template_loader = jinja2.FileSystemLoader(searchpath=os.path.dirname(__file__))
    template_env: jinja2.Environment
    if render_template_as_native_obj:
        template_env = jinja2.nativetypes.NativeEnvironment(
            loader=template_loader, undefined=jinja2.StrictUndefined
        )
    else:
        template_env = jinja2.Environment(loader=template_loader, undefined=jinja2.StrictUndefined)
    template = template_env.get_template('python_virtualenv_script.jinja2')
    template.stream(**jinja_context).dump(filename)
