# Copyright (c) 2021, NVIDIA CORPORATION.  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.

import pynini
from pynini.lib import pynutil

from nemo_text_processing.text_normalization.en.graph_utils import NEMO_NOT_QUOTE, GraphFst


class TelephoneFst(GraphFst):
    """
    Finite state transducer for verbalizing telephone, e.g.
        telephone { number_part: "123-123-5678" }
        -> 123-123-5678 
    """

    def __init__(self):
        super().__init__(name="telephone", kind="verbalize")

        number_part = pynutil.delete("number_part: \"") + pynini.closure(NEMO_NOT_QUOTE, 1) + pynutil.delete("\"")
        optional_country_code = pynini.closure(
            pynutil.delete("country_code: \"")
            + pynini.closure(NEMO_NOT_QUOTE, 1)
            + pynutil.delete("\"")
            + pynini.accep(" "),
            0,
            1,
        )
        delete_tokens = self.delete_tokens(optional_country_code + number_part)
        self.fst = delete_tokens.optimize()