import logging
import os
from functools import partial

from ..app_data import make_app_data
from ..config.cli.parser import VirtualEnvConfigParser
from ..report import LEVELS, setup_report
from ..run.session import Session
from ..seed.wheels.periodic_update import manual_upgrade
from ..version import __version__
from .plugin.activators import ActivationSelector
from .plugin.creators import CreatorSelector
from .plugin.discovery import get_discover
from .plugin.seeders import SeederSelector


def cli_run(args, options=None, setup_logging=True, env=None):
    """
    Create a virtual environment given some command line interface arguments.

    :param args: the command line arguments
    :param options: passing in a ``VirtualEnvOptions`` object allows return of the parsed options
    :param setup_logging: ``True`` if setup logging handlers, ``False`` to use handlers already registered
    :param env: environment variables to use
    :return: the session object of the creation (its structure for now is experimental and might change on short notice)
    """
    env = os.environ if env is None else env
    of_session = session_via_cli(args, options, setup_logging, env)
    with of_session:
        of_session.run()
    return of_session


def session_via_cli(args, options=None, setup_logging=True, env=None):
    """
    Create a virtualenv session (same as cli_run, but this does not perform the creation). Use this if you just want to
    query what the virtual environment would look like, but not actually create it.

    :param args: the command line arguments
    :param options: passing in a ``VirtualEnvOptions`` object allows return of the parsed options
    :param setup_logging: ``True`` if setup logging handlers, ``False`` to use handlers already registered
    :param env: environment variables to use
    :return: the session object of the creation (its structure for now is experimental and might change on short notice)
    """
    env = os.environ if env is None else env
    parser, elements = build_parser(args, options, setup_logging, env)
    options = parser.parse_args(args)
    options.py_version = parser._interpreter.version_info  # noqa: SLF001
    creator, seeder, activators = tuple(e.create(options) for e in elements)  # create types
    of_session = Session(options.verbosity, options.app_data, parser._interpreter, creator, seeder, activators)
    return of_session


def build_parser(args=None, options=None, setup_logging=True, env=None):
    parser = VirtualEnvConfigParser(options, os.environ if env is None else env)
    add_version_flag(parser)
    parser.add_argument(
        "--with-traceback",
        dest="with_traceback",
        action="store_true",
        default=False,
        help="on failure also display the stacktrace internals of virtualenv",
    )
    _do_report_setup(parser, args, setup_logging)
    options = load_app_data(args, parser, options)
    handle_extra_commands(options)

    discover = get_discover(parser, args)
    parser._interpreter = interpreter = discover.interpreter
    if interpreter is None:
        raise RuntimeError(f"failed to find interpreter for {discover}")
    elements = [
        CreatorSelector(interpreter, parser),
        SeederSelector(interpreter, parser),
        ActivationSelector(interpreter, parser),
    ]
    options, _ = parser.parse_known_args(args)
    for element in elements:
        element.handle_selected_arg_parse(options)
    parser.enable_help()
    return parser, elements


def build_parser_only(args=None):
    """Used to provide a parser for the doc generation"""
    return build_parser(args)[0]


def handle_extra_commands(options):
    if options.upgrade_embed_wheels:
        # result = manual_upgrade(options.app_data, options.env)
        logging.warning("virtualenv installed from the RPM package uses wheels from RPM packages as well. Updating them via virtualenv is not possible. The RPM packaged wheels are updated together with other RPM packages of the system.")
        raise SystemExit(1)


def load_app_data(args, parser, options):
    parser.add_argument(
        "--read-only-app-data",
        action="store_true",
        help="use app data folder in read-only mode (write operations will fail with error)",
    )
    options, _ = parser.parse_known_args(args, namespace=options)

    # here we need a write-able application data (e.g. the zipapp might need this for discovery cache)
    parser.add_argument(
        "--app-data",
        help="a data folder used as cache by the virtualenv",
        type=partial(make_app_data, read_only=options.read_only_app_data, env=options.env),
        default=make_app_data(None, read_only=options.read_only_app_data, env=options.env),
    )
    parser.add_argument(
        "--reset-app-data",
        action="store_true",
        help="start with empty app data folder",
    )
    parser.add_argument(
        "--upgrade-embed-wheels",
        action="store_true",
        help="trigger a manual update of the embedded wheels",
    )
    options, _ = parser.parse_known_args(args, namespace=options)
    if options.reset_app_data:
        options.app_data.reset()
    return options


def add_version_flag(parser):
    import virtualenv

    parser.add_argument(
        "--version",
        action="version",
        version=f"%(prog)s {__version__} from {virtualenv.__file__}",
        help="display the version of the virtualenv package and its location, then exit",
    )


def _do_report_setup(parser, args, setup_logging):
    level_map = ", ".join(f"{logging.getLevelName(l)}={c}" for c, l in sorted(LEVELS.items()))
    msg = "verbosity = verbose - quiet, default {}, mapping => {}"
    verbosity_group = parser.add_argument_group(
        title="verbosity",
        description=msg.format(logging.getLevelName(LEVELS[3]), level_map),
    )
    verbosity = verbosity_group.add_mutually_exclusive_group()
    verbosity.add_argument("-v", "--verbose", action="count", dest="verbose", help="increase verbosity", default=2)
    verbosity.add_argument("-q", "--quiet", action="count", dest="quiet", help="decrease verbosity", default=0)
    option, _ = parser.parse_known_args(args)
    if setup_logging:
        setup_report(option.verbosity)


__all__ = [
    "cli_run",
    "session_via_cli",
]