Mini Shell

# coding=utf-8
#
# Copyright © Cloud Linux GmbH & Cloud Linux Software, Inc 2010-2019 All Rights Reserved
#
# Licensed under CLOUD LINUX LICENSE AGREEMENT
# http://cloudlinux.com/docs/LICENSE.TXT

"""
Extensions for validation and output formatting argparse
"""

import argparse
import pwd
import datetime

from prettytable import PrettyTable

from lvestats.lib.commons.dateutil import parse_date, parse_period2


class SmartFormatter(argparse.HelpFormatter):
    """
    Format argparse help in many line, to format many lines use "R|" at start line
    >>>import argparse
    >>>parser = argparse.ArgumentParser(formatter_class=SmartFormatter)
    >>>parser.add_argument('-a', '--argument', help="R| Descriptions: \\n first new line\\n second new line")
    """
    def _split_lines(self, text, width):
        if text.startswith('R|'):
            return text[2:].splitlines()
        return argparse.HelpFormatter._split_lines(self, text, width)  # pylint: disable=protected-access

    def _format_args(self, action, default_metavar):
        if isinstance(action, ParseDatetime):
            get_metavar = self._metavar_formatter(action, default_metavar)
            return str(get_metavar(1))
        return argparse.HelpFormatter._format_args(self, action, default_metavar)  # pylint: disable=protected-access


class ParseDatetime(argparse.Action):
    """
    Interprets a string ([YY]YY-MM-DD[ HH:MM]) as a datetime for argument parsing.
    return parsed data as <type 'datetime.datetime'>
    """
    def __call__(self, parser, namespace, values, option_string=None):
        datetime_str = ' '.join(values) if hasattr(values, '__iter__') else values
        try:
            result_datetime = parse_date(datetime_str)
        except ValueError as e:
            raise argparse.ArgumentError(
                self,
                f"{datetime_str} is an invalid; use [YY]YY-MM-DD[ HH:MM] format",
            ) from e
        setattr(namespace, self.dest, result_datetime)


def check_percentages(value):
    """
    Check if input argument between 0 and 100
    :param str value:
    :return int: percent
    :except argparse.ArgumentTypeError: generate exception for command line warning message
    """
    value = int(value)
    if value < 0 or value > 100:
        raise argparse.ArgumentTypeError(f"{value} is an invalid; this value can range from 0 to 100")
    return value


def check_non_negative_int(value):
    """
    Check if input argument greater than (or equal to) zero and not float
    :param str value:
    :return int:
    :except argparse.ArgumentTypeError: generate exception for command line warning message
    """
    try:
        non_negative_int = int(value)
    except ValueError as e:
        raise argparse.ArgumentTypeError(
            f'"{value}" is an invalid; must be a number greater than (or equal to) zero'
        ) from e
    if '.' in value or non_negative_int < 0:
        raise argparse.ArgumentTypeError(
            f'"{value}" is an invalid; must be a number greater than (or equal to) zero'
        )
    return non_negative_int


def check_positive_int(value):
    """
    Check if input argument is digest, greater than zero and not float
    :param str value: line to check
    :return int: positive integer
    :except argparse.ArgumentTypeError: generate exception for command line warning message
    """
    try:
        positive_int = int(value)
    except ValueError as e:
        raise argparse.ArgumentTypeError(
            f'"{value}" is an invalid; must be a number greater than zero'
        ) from e
    if '.' in value or positive_int <= 0:
        raise argparse.ArgumentTypeError(
            f'"{value}" is an invalid; must be a number greater than zero'
        )
    return positive_int


def check_timestamp(value):
    """
    Check if input argument is a correct timestamp
    253370754000.0 == time.mktime(datetime.datetime(year=datetime.MAXYEAR, month=1, day=1).timetuple())
    :param str value: line to check
    :return float: timestamp
    :except argparse.ArgumentTypeError: generate exception for command line warning message
    """
    try:
        positive_float = float(value)
    except ValueError as e:
        raise argparse.ArgumentTypeError(
            f'"{value}" is an invalid; timestamp must be a number between 0 and 253370754000'
        ) from e
    if not 0 < positive_float < 253370754000:
        raise argparse.ArgumentTypeError(
            f'"{value}" is an invalid; timestamp must be a number between 0 and 253370754000'
        )
    return positive_float


def check_from_zero_to_max_int(value):
    """
    Check if input argument less then maximum integer number
    PostgreSQL - 2147483647
    MySQL - 2147483647
    SQLite - 9223372036854775807
    :param str value:
    :return int:
    :except argparse.ArgumentTypeError: generate exception for command line warning message
    """
    max_int = 2147483647
    try:
        non_negative_int = int(value)
    except ValueError as e:
        raise argparse.ArgumentTypeError(
            f'"{value}" is an invalid; must be a number greater than (or equal to) zero '
            f'and less than {max_int}'
        ) from e
    if '.' in value or non_negative_int < 0 or non_negative_int > max_int:
        raise argparse.ArgumentTypeError(
            f'"{value}" is an invalid; must be a number greater than (or equal to) zero '
            f'and less than {max_int}'
        )
    return non_negative_int


def check_user_name(value):
    """
    Check if user present in system and convert user name to user id
    :param str value: user name (login)
    :return int: user id
    :except argparse.ArgumentTypeError: generate exception for command line warning message
    """
    try:
        user_id = pwd.getpwnam(value).pw_uid
    except KeyError as e:
        raise argparse.ArgumentTypeError(f'user "{value}" not present in system') from e
    return user_id


def period_type(value):
    """
    Parse multiple period line, and validate input data
    :param str value: line to parsing
    :return int: period in seconds
    :except argparse.ArgumentTypeError: generate exception for command line warning message
    """
    try:
        int_converted = int(value)
        if '.' in value or int_converted <= 0:
            raise argparse.ArgumentTypeError(
                f'"{value}" is an invalid; time period should be greater than (or equal to) '
                '1 minute (60 seconds); not negative'
            )
        value = str(int_converted) + 'm'  # if only digest convert to minutes
    except ValueError:
        pass

    try:
        seconds = parse_period2(value)
    except ValueError as e:
        raise argparse.ArgumentTypeError(str(e)) from e
    if seconds < 60:
        raise argparse.ArgumentTypeError(
            f'"{value}" is an invalid; time period should be greater than (or equal to) '
            '1 minute (60 seconds)'
        )
    return seconds


def period_type2(value, datetime_now=None, round_to_minutes=True):
    """
    Extented period_type function
    Added support 'yesterday' and 'today'
    :param bool round_to_minutes:
    :param str value: line to parsing
    :return tuple: period from to (<type 'datetime.datetime'>, <type 'datetime.datetime'>)
    :except argparse.ArgumentTypeError: generate exception for command line warning message
    """
    datetime_now = datetime_now or datetime.datetime.utcnow()
    value = value.lower()
    if value == 'yesterday':
        datetime_to = datetime_now.replace(hour=0, minute=0, second=0, microsecond=0)  # today midnight
        datetime_from = datetime_to - datetime.timedelta(days=1)  # yesterday midnight
    elif value == 'today':
        datetime_from = datetime_now.replace(hour=0, minute=0, second=0, microsecond=0)  # today midnight
        datetime_to = datetime_now
    else:
        if round_to_minutes:
            datetime_from = datetime_now.replace(second=0, microsecond=0)  # rounded to minutes
            datetime_to = datetime_now.replace(second=0, microsecond=0)  # rounded to minutes
        else:
            datetime_from = datetime_now
            datetime_to = datetime_now
        datetime_from -= datetime.timedelta(seconds=period_type(value))
    return datetime_from, datetime_to


def format_aliases(description):
    """
    Prepare aliases descriptions to table formatted
    :param tuple|list|iter description: massive of data
    :return str: ascii table
    """
    fields = description[0]
    description = description[1:]
    table = PrettyTable(fields, padding_width=0, left_padding=2)
    for field in fields:
        table.align[field] = "l"
    list(map(table.add_row, description))
    return table.get_string(border=False)


BY_USAGE_PERCENT = 90


def alias_action(alias_dscr):
    alias_dscr = alias_dscr[1:]  # first line is headers for descriptions in print tables
    aliases_func_dict = _alias_dscr_to_dict(alias_dscr)

    class AliasAction(argparse.Action):
        def __call__(self, parser, namespace, values, option_string=None):

            output_as_list = self.nargs in ('+', '*')

            if output_as_list:
                values_ = []
                for val_ in values:  # for using ',' as separator in options
                    values_.extend(filter(bool, val_.lower().split(',')))
                    # "filter(bool" for correct processing --show-columns=,ID,
            else:
                values_ = [values.strip('"').strip("'").lower()]

            # generate exception for not supported aliases
            not_supported_values = set(values_).difference(set(aliases_func_dict))
            if not_supported_values:
                supported_values = tuple(aliases_func_dict)
                unsupported_aliases = '", "'.join(not_supported_values)
                raise argparse.ArgumentError(
                    self,
                    f'alias(es) "{unsupported_aliases}" not valid; '
                    f'choice from: {", ".join(supported_values)}'
                )

            result = [aliases_func_dict[_] for _ in values_]  # replace aliases to main aliases
            if not output_as_list:
                result = result[0]
            setattr(namespace, self.dest, result)  # write result to namespace
    return AliasAction


def _alias_dscr_to_dict(alias_dscr):
    """
    preparation of the dictionary to extract the names of the aggregation function name (used in show_history)
    as aliases are used from the first to the penultimate elements alias_dscr
    as aggregation function name are used penultimate element

    >>> _alias_dscr_to_dict((('al_1', 'al_2', 'al_m1', 'description1'), ('al_3', 'al_4', 'al_m2', 'description1')))
    {'al_2': 'al_m1', 'al_1': 'al_m1', 'al_m1': 'al_m1', 'al_3': 'al_m2', 'al_m2': 'al_m2', 'al_4': 'al_m2'}
    :param tuple|list alias_dscr:
    :type return: dict
    """
    val_index_ = -2
    aliases_func_pairs = [(_[val_index_].lower(), _[val_index_])for _ in alias_dscr]
    for key_index_ in range(len(alias_dscr[0]) - 1):
        aliases_func_pairs.extend([(_[key_index_], _[val_index_]) for _ in alias_dscr])
    aliases_func_dict = dict(aliases_func_pairs)
    return aliases_func_dict


def argparse_process_period(namespace):
    # prepare period
    period_from, period_to = getattr(namespace, 'from'), namespace.to
    if namespace.period:
        period_from, period_to = namespace.period
    setattr(namespace, 'from', period_from)
    namespace.to = period_to
    return namespace