text: # Copyright (c) 2021, NVIDIA CORPORATION & AFFILIATES.  All rights reserved.
  # Copyright 2015 and onwards Google, Inc.
  #
  # 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 nemo_text_processing.text_normalization.en.graph_utils import NEMO_DIGIT, GraphFst, delete_space, insert_space
  from nemo_text_processing.text_normalization.ru.alphabet import RU_ALPHA_OR_SPACE
  
  try:
      import pynini
      from pynini.lib import pynutil
  
      PYNINI_AVAILABLE = True
  except (ModuleNotFoundError, ImportError):
      PYNINI_AVAILABLE = False
  
  
  class TelephoneFst(GraphFst):
      """
      Finite state transducer for classifying telephone, which includes country code, number part and extension 
  
      E.g 
      "8-913-983-56-01" -> telephone { number_part: "восемь девятьсот тринадцать девятьсот восемьдесят три пятьдесят шесть ноль один" }
  
      Args:
          number_names: number_names for cardinal and ordinal numbers
          deterministic: if True will provide a single transduction option,
              for False multiple transduction are generated (used for audio-based normalization)
      """
  
      def __init__(self, number_names: dict, deterministic: bool = True):
          super().__init__(name="telephone", kind="classify", deterministic=deterministic)
  
          separator = pynini.cross("-", " ")  # between components
          number = number_names['nominative_up_to_thousand_names']
  
          country_code = (
              pynutil.insert("country_code: \"")
              + pynini.closure(pynutil.add_weight(pynutil.delete("+"), 0.1), 0, 1)
              + number
              + separator
              + pynutil.insert("\"")
          )
          optional_country_code = pynini.closure(country_code + insert_space, 0, 1)
  
          number_part = (
              NEMO_DIGIT ** 3 @ number
              + separator
              + NEMO_DIGIT ** 3 @ number
              + separator
              + NEMO_DIGIT ** 2 @ number
              + separator
              + NEMO_DIGIT ** 2 @ (pynini.closure(pynini.cross("0", "ноль ")) + number)
          )
          number_part = pynutil.insert("number_part: \"") + number_part + pynutil.insert("\"")
          tagger_graph = (optional_country_code + number_part).optimize()
  
          # verbalizer
          verbalizer_graph = pynini.closure(
              pynutil.delete("country_code: \"")
              + pynini.closure(RU_ALPHA_OR_SPACE, 1)
              + pynutil.delete("\"")
              + delete_space,
              0,
              1,
          )
          verbalizer_graph += (
              pynutil.delete("number_part: \"") + pynini.closure(RU_ALPHA_OR_SPACE, 1) + pynutil.delete("\"")
          )
          verbalizer_graph = verbalizer_graph.optimize()
  
          self.final_graph = (tagger_graph @ verbalizer_graph).optimize()
          self.fst = self.add_tokens(
              pynutil.insert("number_part: ") + self.final_graph + pynutil.insert("\"")
          ).optimize()
  