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#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
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#
#     http://www.apache.org/licenses/LICENSE-2.0
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import pynini
from pynini.lib import pynutil

from nemo_text_processing.text_normalization.ar.graph_utils import NEMO_CHAR, NEMO_SIGMA, GraphFst, delete_space


class WordFst(GraphFst):
    """
    Finite state transducer for verbalizing word
        e.g. tokens { name: "sleep" } -> sleep

    Args:
        deterministic: if True will provide a single transduction option,
            for False multiple transduction are generated (used for audio-based normalization)
    """

    def __init__(self, deterministic: bool = True):
        super().__init__(name="word", kind="verbalize", deterministic=deterministic)
        chars = pynini.closure(NEMO_CHAR - " ", 1)
        char = pynutil.delete("name:") + delete_space + pynutil.delete("\"") + chars + pynutil.delete("\"")
        graph = char @ pynini.cdrewrite(pynini.cross(u"\u00A0", " "), "", "", NEMO_SIGMA)

        self.fst = graph.optimize()