Mini Shell

"""Base Command class, and related routines"""

import functools
import logging
import logging.config
import optparse
import os
import sys
import traceback
from optparse import Values
from typing import Any, Callable, List, Optional, Tuple

from pip._internal.cli import cmdoptions
from pip._internal.cli.command_context import CommandContextMixIn
from pip._internal.cli.parser import ConfigOptionParser, UpdatingDefaultsHelpFormatter
from pip._internal.cli.status_codes import (
    ERROR,
    PREVIOUS_BUILD_DIR_ERROR,
    UNKNOWN_ERROR,
    VIRTUALENV_NOT_FOUND,
)
from pip._internal.exceptions import (
    BadCommand,
    CommandError,
    InstallationError,
    NetworkConnectionError,
    PreviousBuildDirError,
    UninstallationError,
)
from pip._internal.utils.filesystem import check_path_owner
from pip._internal.utils.logging import BrokenStdoutLoggingError, setup_logging
from pip._internal.utils.misc import get_prog, normalize_path
from pip._internal.utils.temp_dir import TempDirectoryTypeRegistry as TempDirRegistry
from pip._internal.utils.temp_dir import global_tempdir_manager, tempdir_registry
from pip._internal.utils.virtualenv import running_under_virtualenv

__all__ = ["Command"]

logger = logging.getLogger(__name__)


class Command(CommandContextMixIn):
    usage: str = ""
    ignore_require_venv: bool = False

    def __init__(self, name: str, summary: str, isolated: bool = False) -> None:
        super().__init__()

        self.name = name
        self.summary = summary
        self.parser = ConfigOptionParser(
            usage=self.usage,
            prog=f"{get_prog()} {name}",
            formatter=UpdatingDefaultsHelpFormatter(),
            add_help_option=False,
            name=name,
            description=self.__doc__,
            isolated=isolated,
        )

        self.tempdir_registry: Optional[TempDirRegistry] = None

        # Commands should add options to this option group
        optgroup_name = f"{self.name.capitalize()} Options"
        self.cmd_opts = optparse.OptionGroup(self.parser, optgroup_name)

        # Add the general options
        gen_opts = cmdoptions.make_option_group(
            cmdoptions.general_group,
            self.parser,
        )
        self.parser.add_option_group(gen_opts)

        self.add_options()

    def add_options(self) -> None:
        pass

    def handle_pip_version_check(self, options: Values) -> None:
        """
        This is a no-op so that commands by default do not do the pip version
        check.
        """
        # Make sure we do the pip version check if the index_group options
        # are present.
        assert not hasattr(options, "no_index")

    def run(self, options: Values, args: List[str]) -> int:
        raise NotImplementedError

    def parse_args(self, args: List[str]) -> Tuple[Values, List[str]]:
        # factored out for testability
        return self.parser.parse_args(args)

    def main(self, args: List[str]) -> int:
        try:
            with self.main_context():
                return self._main(args)
        finally:
            logging.shutdown()

    def _main(self, args: List[str]) -> int:
        # We must initialize this before the tempdir manager, otherwise the
        # configuration would not be accessible by the time we clean up the
        # tempdir manager.
        self.tempdir_registry = self.enter_context(tempdir_registry())
        # Intentionally set as early as possible so globally-managed temporary
        # directories are available to the rest of the code.
        self.enter_context(global_tempdir_manager())

        options, args = self.parse_args(args)

        # Set verbosity so that it can be used elsewhere.
        self.verbosity = options.verbose - options.quiet

        level_number = setup_logging(
            verbosity=self.verbosity,
            no_color=options.no_color,
            user_log_file=options.log,
        )

        # TODO: Try to get these passing down from the command?
        #       without resorting to os.environ to hold these.
        #       This also affects isolated builds and it should.

        if options.no_input:
            os.environ["PIP_NO_INPUT"] = "1"

        if options.exists_action:
            os.environ["PIP_EXISTS_ACTION"] = " ".join(options.exists_action)

        if options.require_venv and not self.ignore_require_venv:
            # If a venv is required check if it can really be found
            if not running_under_virtualenv():
                logger.critical("Could not find an activated virtualenv (required).")
                sys.exit(VIRTUALENV_NOT_FOUND)

        if options.cache_dir:
            options.cache_dir = normalize_path(options.cache_dir)
            if not check_path_owner(options.cache_dir):
                logger.warning(
                    "The directory '%s' or its parent directory is not owned "
                    "or is not writable by the current user. The cache "
                    "has been disabled. Check the permissions and owner of "
                    "that directory. If executing pip with sudo, you should "
                    "use sudo's -H flag.",
                    options.cache_dir,
                )
                options.cache_dir = None

        if "2020-resolver" in options.features_enabled:
            logger.warning(
                "--use-feature=2020-resolver no longer has any effect, "
                "since it is now the default dependency resolver in pip. "
                "This will become an error in pip 21.0."
            )

        def intercepts_unhandled_exc(
            run_func: Callable[..., int]
        ) -> Callable[..., int]:
            @functools.wraps(run_func)
            def exc_logging_wrapper(*args: Any) -> int:
                try:
                    status = run_func(*args)
                    assert isinstance(status, int)
                    return status
                except PreviousBuildDirError as exc:
                    logger.critical(str(exc))
                    logger.debug("Exception information:", exc_info=True)

                    return PREVIOUS_BUILD_DIR_ERROR
                except (
                    InstallationError,
                    UninstallationError,
                    BadCommand,
                    NetworkConnectionError,
                ) as exc:
                    logger.critical(str(exc))
                    logger.debug("Exception information:", exc_info=True)

                    return ERROR
                except CommandError as exc:
                    logger.critical("%s", exc)
                    logger.debug("Exception information:", exc_info=True)

                    return ERROR
                except BrokenStdoutLoggingError:
                    # Bypass our logger and write any remaining messages to
                    # stderr because stdout no longer works.
                    print("ERROR: Pipe to stdout was broken", file=sys.stderr)
                    if level_number <= logging.DEBUG:
                        traceback.print_exc(file=sys.stderr)

                    return ERROR
                except KeyboardInterrupt:
                    logger.critical("Operation cancelled by user")
                    logger.debug("Exception information:", exc_info=True)

                    return ERROR
                except BaseException:
                    logger.critical("Exception:", exc_info=True)

                    return UNKNOWN_ERROR

            return exc_logging_wrapper

        try:
            if not options.debug_mode:
                run = intercepts_unhandled_exc(self.run)
            else:
                run = self.run
            return run(options, args)
        finally:
            self.handle_pip_version_check(options)