Mini Shell

import contextlib
import errno
import logging
import logging.handlers
import os
import sys
from logging import Filter
from typing import IO, Any, Callable, Iterator, Optional, TextIO, Type, cast

from pip._internal.utils._log import VERBOSE, getLogger
from pip._internal.utils.compat import WINDOWS
from pip._internal.utils.deprecation import DEPRECATION_MSG_PREFIX
from pip._internal.utils.misc import ensure_dir

try:
    import threading
except ImportError:
    import dummy_threading as threading  # type: ignore


try:
    from pip._vendor import colorama
# Lots of different errors can come from this, including SystemError and
# ImportError.
except Exception:
    colorama = None


_log_state = threading.local()
subprocess_logger = getLogger("pip.subprocessor")


class BrokenStdoutLoggingError(Exception):
    """
    Raised if BrokenPipeError occurs for the stdout stream while logging.
    """


def _is_broken_pipe_error(exc_class: Type[BaseException], exc: BaseException) -> bool:
    if exc_class is BrokenPipeError:
        return True

    # On Windows, a broken pipe can show up as EINVAL rather than EPIPE:
    # https://bugs.python.org/issue19612
    # https://bugs.python.org/issue30418
    if not WINDOWS:
        return False

    return isinstance(exc, OSError) and exc.errno in (errno.EINVAL, errno.EPIPE)


@contextlib.contextmanager
def indent_log(num: int = 2) -> Iterator[None]:
    """
    A context manager which will cause the log output to be indented for any
    log messages emitted inside it.
    """
    # For thread-safety
    _log_state.indentation = get_indentation()
    _log_state.indentation += num
    try:
        yield
    finally:
        _log_state.indentation -= num


def get_indentation() -> int:
    return getattr(_log_state, "indentation", 0)


class IndentingFormatter(logging.Formatter):
    default_time_format = "%Y-%m-%dT%H:%M:%S"

    def __init__(
        self,
        *args: Any,
        add_timestamp: bool = False,
        **kwargs: Any,
    ) -> None:
        """
        A logging.Formatter that obeys the indent_log() context manager.

        :param add_timestamp: A bool indicating output lines should be prefixed
            with their record's timestamp.
        """
        self.add_timestamp = add_timestamp
        super().__init__(*args, **kwargs)

    def get_message_start(self, formatted: str, levelno: int) -> str:
        """
        Return the start of the formatted log message (not counting the
        prefix to add to each line).
        """
        if levelno < logging.WARNING:
            return ""
        if formatted.startswith(DEPRECATION_MSG_PREFIX):
            # Then the message already has a prefix.  We don't want it to
            # look like "WARNING: DEPRECATION: ...."
            return ""
        if levelno < logging.ERROR:
            return "WARNING: "

        return "ERROR: "

    def format(self, record: logging.LogRecord) -> str:
        """
        Calls the standard formatter, but will indent all of the log message
        lines by our current indentation level.
        """
        formatted = super().format(record)
        message_start = self.get_message_start(formatted, record.levelno)
        formatted = message_start + formatted

        prefix = ""
        if self.add_timestamp:
            prefix = f"{self.formatTime(record)} "
        prefix += " " * get_indentation()
        formatted = "".join([prefix + line for line in formatted.splitlines(True)])
        return formatted


def _color_wrap(*colors: str) -> Callable[[str], str]:
    def wrapped(inp: str) -> str:
        return "".join(list(colors) + [inp, colorama.Style.RESET_ALL])

    return wrapped


class ColorizedStreamHandler(logging.StreamHandler):

    # Don't build up a list of colors if we don't have colorama
    if colorama:
        COLORS = [
            # This needs to be in order from highest logging level to lowest.
            (logging.ERROR, _color_wrap(colorama.Fore.RED)),
            (logging.WARNING, _color_wrap(colorama.Fore.YELLOW)),
        ]
    else:
        COLORS = []

    def __init__(self, stream: Optional[TextIO] = None, no_color: bool = None) -> None:
        super().__init__(stream)
        self._no_color = no_color

        if WINDOWS and colorama:
            self.stream = colorama.AnsiToWin32(self.stream)

    def _using_stdout(self) -> bool:
        """
        Return whether the handler is using sys.stdout.
        """
        if WINDOWS and colorama:
            # Then self.stream is an AnsiToWin32 object.
            stream = cast(colorama.AnsiToWin32, self.stream)
            return stream.wrapped is sys.stdout

        return self.stream is sys.stdout

    def should_color(self) -> bool:
        # Don't colorize things if we do not have colorama or if told not to
        if not colorama or self._no_color:
            return False

        real_stream = (
            self.stream
            if not isinstance(self.stream, colorama.AnsiToWin32)
            else self.stream.wrapped
        )

        # If the stream is a tty we should color it
        if hasattr(real_stream, "isatty") and real_stream.isatty():
            return True

        # If we have an ANSI term we should color it
        if os.environ.get("TERM") == "ANSI":
            return True

        # If anything else we should not color it
        return False

    def format(self, record: logging.LogRecord) -> str:
        msg = super().format(record)

        if self.should_color():
            for level, color in self.COLORS:
                if record.levelno >= level:
                    msg = color(msg)
                    break

        return msg

    # The logging module says handleError() can be customized.
    def handleError(self, record: logging.LogRecord) -> None:
        exc_class, exc = sys.exc_info()[:2]
        # If a broken pipe occurred while calling write() or flush() on the
        # stdout stream in logging's Handler.emit(), then raise our special
        # exception so we can handle it in main() instead of logging the
        # broken pipe error and continuing.
        if (
            exc_class
            and exc
            and self._using_stdout()
            and _is_broken_pipe_error(exc_class, exc)
        ):
            raise BrokenStdoutLoggingError()

        return super().handleError(record)


class BetterRotatingFileHandler(logging.handlers.RotatingFileHandler):
    def _open(self) -> IO[Any]:
        ensure_dir(os.path.dirname(self.baseFilename))
        return super()._open()


class MaxLevelFilter(Filter):
    def __init__(self, level: int) -> None:
        self.level = level

    def filter(self, record: logging.LogRecord) -> bool:
        return record.levelno < self.level


class ExcludeLoggerFilter(Filter):

    """
    A logging Filter that excludes records from a logger (or its children).
    """

    def filter(self, record: logging.LogRecord) -> bool:
        # The base Filter class allows only records from a logger (or its
        # children).
        return not super().filter(record)


def setup_logging(verbosity: int, no_color: bool, user_log_file: Optional[str]) -> int:
    """Configures and sets up all of the logging

    Returns the requested logging level, as its integer value.
    """

    # Determine the level to be logging at.
    if verbosity >= 2:
        level_number = logging.DEBUG
    elif verbosity == 1:
        level_number = VERBOSE
    elif verbosity == -1:
        level_number = logging.WARNING
    elif verbosity == -2:
        level_number = logging.ERROR
    elif verbosity <= -3:
        level_number = logging.CRITICAL
    else:
        level_number = logging.INFO

    level = logging.getLevelName(level_number)

    # The "root" logger should match the "console" level *unless* we also need
    # to log to a user log file.
    include_user_log = user_log_file is not None
    if include_user_log:
        additional_log_file = user_log_file
        root_level = "DEBUG"
    else:
        additional_log_file = "/dev/null"
        root_level = level

    # Disable any logging besides WARNING unless we have DEBUG level logging
    # enabled for vendored libraries.
    vendored_log_level = "WARNING" if level in ["INFO", "ERROR"] else "DEBUG"

    # Shorthands for clarity
    log_streams = {
        "stdout": "ext://sys.stdout",
        "stderr": "ext://sys.stderr",
    }
    handler_classes = {
        "stream": "pip._internal.utils.logging.ColorizedStreamHandler",
        "file": "pip._internal.utils.logging.BetterRotatingFileHandler",
    }
    handlers = ["console", "console_errors", "console_subprocess"] + (
        ["user_log"] if include_user_log else []
    )

    logging.config.dictConfig(
        {
            "version": 1,
            "disable_existing_loggers": False,
            "filters": {
                "exclude_warnings": {
                    "()": "pip._internal.utils.logging.MaxLevelFilter",
                    "level": logging.WARNING,
                },
                "restrict_to_subprocess": {
                    "()": "logging.Filter",
                    "name": subprocess_logger.name,
                },
                "exclude_subprocess": {
                    "()": "pip._internal.utils.logging.ExcludeLoggerFilter",
                    "name": subprocess_logger.name,
                },
            },
            "formatters": {
                "indent": {
                    "()": IndentingFormatter,
                    "format": "%(message)s",
                },
                "indent_with_timestamp": {
                    "()": IndentingFormatter,
                    "format": "%(message)s",
                    "add_timestamp": True,
                },
            },
            "handlers": {
                "console": {
                    "level": level,
                    "class": handler_classes["stream"],
                    "no_color": no_color,
                    "stream": log_streams["stdout"],
                    "filters": ["exclude_subprocess", "exclude_warnings"],
                    "formatter": "indent",
                },
                "console_errors": {
                    "level": "WARNING",
                    "class": handler_classes["stream"],
                    "no_color": no_color,
                    "stream": log_streams["stderr"],
                    "filters": ["exclude_subprocess"],
                    "formatter": "indent",
                },
                # A handler responsible for logging to the console messages
                # from the "subprocessor" logger.
                "console_subprocess": {
                    "level": level,
                    "class": handler_classes["stream"],
                    "no_color": no_color,
                    "stream": log_streams["stderr"],
                    "filters": ["restrict_to_subprocess"],
                    "formatter": "indent",
                },
                "user_log": {
                    "level": "DEBUG",
                    "class": handler_classes["file"],
                    "filename": additional_log_file,
                    "encoding": "utf-8",
                    "delay": True,
                    "formatter": "indent_with_timestamp",
                },
            },
            "root": {
                "level": root_level,
                "handlers": handlers,
            },
            "loggers": {"pip._vendor": {"level": vendored_log_level}},
        }
    )

    return level_number