from optparse import IndentedHelpFormatter
from optparse import OptionParser

import Configuration.Defaults


def default_option_parser(usage=None):
    # Use a VerbatimFormatter instead of the default
    # IndentedHelpFormatter.    
    fmtr = VerbatimHelpFormatter()
    
    # -h (help) Conflicts with -h HOSTNAME
    parser = OptionParser(usage = usage,
                          add_help_option = False,
                          formatter = fmtr)

    parser.add_option('-h',
                      '--host',
                      help='The hostname/address where the database is located.',
                      default=Configuration.Defaults.DATABASE_HOST)

    parser.add_option('-d',
                      '--database',
                      help='The database in which the population data are stored.',
                      default=Configuration.Defaults.DATABASE_NAME)

    parser.add_option('-U',
                      '--username',
                      help='The username who has access to the database.',
                      default=Configuration.Defaults.DATABASE_USERNAME)

    return parser



class VerbatimHelpFormatter(IndentedHelpFormatter):
    """
    The two HelpFormatters supplied with OptParse like to mangle their
    descriptions during print_help(). This subclassed formatter
    overrides the format_description() method with an implementation
    that simply returns the description unmodified.
    """
    def format_description(self, description):
        return description