#  ___________________________________________________________________________
#
#  Pyomo: Python Optimization Modeling Objects
#  Copyright 2017 National Technology and Engineering Solutions of Sandia, LLC
#  Under the terms of Contract DE-NA0003525 with National Technology and 
#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain 
#  rights in this software.
#  This software is distributed under the 3-clause BSD License.
#  ___________________________________________________________________________

__all__ = ['add_subparser', 'get_parser', 'subparsers']

import argparse
import sys

#
# Sort sub_parser names, since these are inserted throughout Pyomo
#
# NOTE: This may not be robust to different versions of argparse.  We're
# mucking with a non-public API here ...
#
class CustomHelpFormatter(argparse.RawDescriptionHelpFormatter):

    def _metavar_formatter(self, action, default_metavar):
        if action.metavar is not None:
            result = action.metavar
        elif action.choices is not None:
            choice_strs = sorted(str(choice) for choice in action.choices)
            result = '{%s}' % ','.join(choice_strs)
        else:
            result = default_metavar

        def format(tuple_size):
            if isinstance(result, tuple):
                return result
            else:
                return (result, ) * tuple_size
        return format

    def _iter_indented_subactions(self, action):
        try:
            get_subactions = action._get_subactions
        except AttributeError:
            pass
        else:
            self._indent()
            if isinstance(action, argparse._SubParsersAction):
                for subaction in sorted(get_subactions(), key=lambda x: x.dest):
                    yield subaction
            else:
                for subaction in get_subactions():
                    yield subaction
            self._dedent()


def get_version():
    from pyomo.version import version
    import platform
    return "Pyomo %s (%s %s on %s %s)" % (
            version,
            platform.python_implementation(),
            '.'.join( str(x) for x in sys.version_info[:3] ),
            platform.system(),
            platform.release() )

#
# Create the argparse parser for Pyomo
#
doc="This is the main driver for the Pyomo optimization software."
epilog="""
-------------------------------------------------------------------------
Pyomo supports a variety of modeling and optimization capabilities,
which are executed either as subcommands of 'pyomo' or as separate
commands.  Use the 'help' subcommand to get information about the
capabilities installed with Pyomo.  Additionally, each subcommand
supports independent command-line options.  Use the -h option to
print details for a subcommand.  For example, type

   pyomo solve -h

to print information about the `solve` subcommand.
"""
_pyomo_parser = argparse.ArgumentParser(
    description=doc, epilog=epilog, formatter_class=CustomHelpFormatter )
_pyomo_parser.add_argument("--version", action="version", version=get_version())
_pyomo_subparsers = _pyomo_parser.add_subparsers(
    dest='subparser_name', title='subcommands' )

subparsers = []

def add_subparser(name, **args):
    """
    Add a subparser to the 'pyomo' command.
    """
    global subparsers
    func = args.pop('func', None)
    parser = _pyomo_subparsers.add_parser(name, **args)
    subparsers.append(name)
    if func is not None:
        parser.set_defaults(func=func)
    return parser

def get_parser():
    """
    Return the parser used by the 'pyomo' commmand.
    """
    return _pyomo_parser