""" from https://github.com/keithito/tacotron """

import inflect
import re


_inflect = inflect.engine()
_comma_number_re = re.compile(r'([0-9][0-9\,]+[0-9])')
_decimal_number_re = re.compile(r'([0-9]+\.[0-9]+)')
_pounds_re = re.compile(r'£([0-9\,]*[0-9]+)')
_dollars_re = re.compile(r'\$([0-9\.\,]*[0-9]+)')
_ordinal_re = re.compile(r'[0-9]+(st|nd|rd|th)')
_number_re = re.compile(r'[0-9]+')
_magnitudes = ['trillion', 'billion', 'million', 'thousand', 'hundred', 'm', 'b', 't']
_currency_re = re.compile(r'([\$€£₩])([0-9\.\,]*[0-9]+)(?:[ ]?({})(?=[^a-zA-Z]))?'.format("|".join(_magnitudes)), re.IGNORECASE)
_currency_key = {'$': 'dollar', '£': 'pound', '€': 'euro', '₩': 'won'}
_magnitudes_key = {'m': 'million', 'b': 'billion', 't': 'trillion'}


def _remove_commas(m):
  return m.group(1).replace(',', '')


def _expand_decimal_point(m):
  return m.group(1).replace('.', ' point ')

def _expand_currency(m):
    currency = _currency_key[m.group(1)]
    quantity = m.group(2)
    magnitude = m.group(3)

    # remove commas from quantity to be able to convert to numerical
    quantity = quantity.replace(',', '')

    # check for million, billion, etc...
    if magnitude is not None and magnitude.lower() in _magnitudes:
        if len(magnitude) == 1:
            magnitude = _magnitudes_key[magnitude.lower()]
        return "{} {} {}".format(_expand_hundreds(quantity), magnitude, currency+'s')

    parts = quantity.split('.')
    if len(parts) > 2:
        return quantity + " " + currency + "s"    # Unexpected format

    dollars = int(parts[0]) if parts[0] else 0

    cents = int(parts[1]) if len(parts) > 1 and parts[1] else 0
    if dollars and cents:
        dollar_unit = currency if dollars == 1 else currency+'s'
        cent_unit = 'cent' if cents == 1 else 'cents'
        return "{} {}, {} {}".format(
            _expand_hundreds(dollars), dollar_unit,
            _inflect.number_to_words(cents), cent_unit)
    elif dollars:
        dollar_unit = currency if dollars == 1 else currency+'s'
        return "{} {}".format(_expand_hundreds(dollars), dollar_unit)
    elif cents:
        cent_unit = 'cent' if cents == 1 else 'cents'
        return "{} {}".format(_inflect.number_to_words(cents), cent_unit)
    else:
        return 'zero' + ' ' + currency + 's'
def _expand_hundreds(text):
    number = float(text)
    if 1000 < number < 10000 and (number % 100 == 0) and (number % 1000 != 0):
        return _inflect.number_to_words(int(number / 100)) + " hundred"
    else:
        return _inflect.number_to_words(text)


def _expand_dollars(m):
  match = m.group(1)
  parts = match.split('.')
  if len(parts) > 2:
    return match + ' dollars'  # Unexpected format
  dollars = int(parts[0]) if parts[0] else 0
  cents = int(parts[1]) if len(parts) > 1 and parts[1] else 0
  if dollars and cents:
    dollar_unit = 'dollar' if dollars == 1 else 'dollars'
    cent_unit = 'cent' if cents == 1 else 'cents'
    return '%s %s, %s %s' % (dollars, dollar_unit, cents, cent_unit)
  elif dollars:
    dollar_unit = 'dollar' if dollars == 1 else 'dollars'
    return '%s %s' % (dollars, dollar_unit)
  elif cents:
    cent_unit = 'cent' if cents == 1 else 'cents'
    return '%s %s' % (cents, cent_unit)
  else:
    return 'zero dollars'


def _expand_ordinal(m):
  return _inflect.number_to_words(m.group(0))


def _expand_number(m):
  num = int(m.group(0))
  if num > 1000 and num < 3000:
    if num == 2000:
      return 'two thousand'
    elif num > 2000 and num < 2010:
      return 'two thousand ' + _inflect.number_to_words(num % 100)
    elif num % 100 == 0:
      return _inflect.number_to_words(num // 100) + ' hundred'
    else:
      return _inflect.number_to_words(num, andword='', zero='oh', group=2).replace(', ', ' ')
  else:
    return _inflect.number_to_words(num, andword='')


def normalize_numbers(text):
  text = re.sub(_comma_number_re, _remove_commas, text)
  text = re.sub(_pounds_re, r'\1 pounds', text)
  text = re.sub(_dollars_re, _expand_dollars, text)
  text = re.sub(_decimal_number_re, _expand_decimal_point, text)
  text = re.sub(_ordinal_re, _expand_ordinal, text)
  text = re.sub(_number_re, _expand_number, text)
  return text