scripts/convert_name

#!/usr/bin/env python
#
# Copyright 2016-present the Material Components for iOS authors. All Rights Reserved.
#
# Licensed 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
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

from __future__ import print_function  # Print as function not keyword.

import argparse
import re
import string
import sys

def create_arg_parser():
  """Create a command-line argument parser."""
  description='Convert a name between conventions.'
  parser = argparse.ArgumentParser(description=description)
  parser.add_argument('-c', '--check', action='store_true',
                      help='exit with a status of 0 if the name matches mode.')
  parser.add_argument('-p', '--print', action='store_true',
                      help='print the mode and exit.')
  parser.add_argument('-m', '--mode',
                      choices=['camel', 'hyphen', 'period', 'underscore'],
                      help=('the mode to convert to: '
                            'FooBar, foo-bar, foo.bar, foo_bar')) 
  parser.add_argument('name', help='the name to convert (in any mode)')
  return parser


def detect_mode(name):
  """Detect the mode of a name."""
  if '-' in name:
    return 'hyphen'
  elif '.' in name:
    return 'period'
  elif '_' in name:
    return 'underscore'
  else:
    return 'camel'


def split_name(name, mode):
  """Split a name into its pieces based on mode."""
  if mode == 'hyphen':
    return string.split(name, '-')
  elif mode == 'period':
    return string.split(name, '.')
  elif mode == 'underscore':
    return string.split(name, '_')
  else:
    return camel_split(name)
    

def camel_split(name):
  """Split a camel case name into pieces.

  For example, 'fooBarBazX' should become ['foo', 'Bar', 'Baz, 'X']."""
  pieces = []
  index = 0
  # Find transitions between lowercase and uppercase, or the same and the
  # beginning/end of the string.
  regex = r'([a-z]|\A)([A-Z]+|\Z)'
  for i in re.finditer(regex, name):
    if i.end(1) > 0: 
      pieces.append(name[index:i.end(1)])
    index = i.start(2)
  if index < len(name):
    pieces.append(name[index:])
  return pieces


def convert_name_to_mode(name, cur_mode, mode):
  """Convert a name from cur_mode to mode."""
  pieces = split_name(name, cur_mode)
  if mode == 'hyphen':
    return '-'.join(pieces).lower()
  elif mode == 'period':
    return '.'.join(pieces).lower()
  elif mode == 'underscore':
    return '_'.join(pieces).lower()
  else:
    return ''.join([s.capitalize() for s in pieces])


def main():
  parser = create_arg_parser()
  args = parser.parse_args()

  cur_mode = detect_mode(args.name)
  exit_status = 0
  if args.print:
    print(cur_mode)
  elif args.check:
    exit_status = 0 if cur_mode == args.mode else 1
  else:
    print(convert_name_to_mode(args.name, cur_mode, args.mode))

  sys.exit(exit_status)


if __name__ == '__main__':
  main()