_arguments.py

#!/usr/bin/env python

# ===============================================================================
# Copyright (c)  2014 Geoscience Australia
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"""
Created on 12/03/2015

@author: Alex Ip
"""
from __future__ import absolute_import

import sys
import os
import logging
import argparse

from ._gdfutils import log_multiline

logger = logging.getLogger(__name__)


# logger.setLevel(logging.DEBUG) # Logging level for this module

def _parse_args(arg_descriptors):
    """Virtual function to parse command line arguments.

    Parameters:
        arg_descriptors: dict keyed by dest variable name containing sub-dicts as follows:
            'short_flag': '-d',
            'long_flag': '--debug',
            'default': <Boolean>,
            'action': 'store_const',
            'const': <Boolean>,
            'help': <help string>

    Returns:
        argparse namespace object
    """
    logger.debug('Calling _parse_args()')
    log_multiline(logger.debug, arg_descriptors, 'arg_descriptors', '\t')

    _arg_parser = argparse.ArgumentParser(description=os.path.basename(sys.argv[0]))

    for arg_dest in sorted(arg_descriptors.keys()):
        arg_descriptor = arg_descriptors[arg_dest]
        log_multiline(logger.debug, arg_descriptor, 'arg_descriptor for %s' % arg_dest, '\t')

        _arg_parser.add_argument(arg_descriptor['short_flag'],
                                 arg_descriptor['long_flag'],
                                 dest=arg_dest,
                                 default=arg_descriptor['default'],
                                 action=arg_descriptor['action'],
                                 const=arg_descriptor['const'],
                                 help=arg_descriptor['help']
                                 )

    args, _unknown_args = _arg_parser.parse_known_args()

    return args.__dict__


class CommandLineArgs(object):
    DEFAULT_ARG_DESCRIPTORS = {'debug': {'short_flag': '-d',
                                         'long_flag': '--debug',
                                         'default': False,
                                         'action': 'store_const',
                                         'const': True,
                                         'help': 'Debug mode flag'
                                         },
                               'config_files': {'short_flag': '-C',
                                                'long_flag': '--config',
                                                'default': None,
                                                'action': 'store',
                                                'const': None,
                                                'help': 'Comma-delimited list of configuration files'
                                                }
                               }

    def __init__(self, arg_descriptors=None):
        """
        Constructor for class CommandLineArgs

        Parameters:
            arg_descriptors: dict keyed by dest variable name containing sub-dicts as follows:
                'short_flag': '-d',
                'long_flag': '--debug',
                'default': <Boolean>,
                'action': 'store_const',
                'const': <Boolean>,
                'help': <help string>
        """
        if not arg_descriptors:
            arg_descriptors = {}
        log_multiline(logger.debug, arg_descriptors, 'arg_descriptors', '\t')
        #        # Replace defaults with supplied dict
        #        arg_descriptors = arg_descriptors or CommandLineArgs.DEFAULT_ARG_DESCRIPTORS

        # Merge defaults with supplied dict (overwriting defaults)
        temp_arg_descriptors = CommandLineArgs.DEFAULT_ARG_DESCRIPTORS.copy()
        temp_arg_descriptors.update(arg_descriptors)
        arg_descriptors = temp_arg_descriptors
        log_multiline(logger.debug, arg_descriptors, 'arg_descriptors', '\t')

        self._arguments = _parse_args(arg_descriptors)

        log_multiline(logger.debug, self.__dict__, 'CommandLineArgs.__dict__', '\t')

    @property
    def arguments(self):
        return self._arguments.copy()