heron/tools/cli/src/python/help.py

#!/usr/bin/env python3
# -*- encoding: utf-8 -*-

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#  or more contributor license agreements.  See the NOTICE file
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#  to you under the Apache License, Version 2.0 (the
#  "License"); you may not use this file except in compliance
#  with the License.  You may obtain a copy of the License at
#
#    http://www.apache.org/licenses/LICENSE-2.0
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#  under the License.

''' help.py '''
from heron.common.src.python.utils.log import Log
from heron.tools.cli.src.python.result import SimpleResult, Status
import heron.tools.common.src.python.utils.config as config

def create_parser(subparsers):
  '''
  :param subparsers:
  :return:
  '''
  parser = subparsers.add_parser(
      'help',
      help='Prints help for commands',
      add_help=True)

  # pylint: disable=protected-access
  parser._positionals.title = "Required arguments"
  parser._optionals.title = "Optional arguments"

  parser.add_argument(
      'help-command',
      nargs='?',
      default='help',
      help='Provide help for a command')

  parser.set_defaults(subcommand='help')
  return parser


# pylint: disable=unused-argument,superfluous-parens
def run(command, parser, args, unknown_args):
  '''
  :param command:
  :param parser:
  :param args:
  :param unknown_args:
  :return:
  '''
  # get the command for detailed help
  command_help = args['help-command']

  # if no command is provided, just print main help
  if command_help == 'help':
    parser.print_help()
    return SimpleResult(Status.Ok)

  # get the subparser for the specific command
  subparser = config.get_subparser(parser, command_help)
  if subparser:
    print(subparser.format_help())
    return SimpleResult(Status.Ok)
  else:
    Log.error("Unknown subcommand \'%s\'", command_help)
    return SimpleResult(Status.InvocationError)