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# 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.
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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.en.graph_utils import (
    NEMO_CHAR,
    NEMO_SPACE,
    GraphFst,
    delete_space,
    insert_space,
)


class MoneyFst(GraphFst):
    """
    Finite state transducer for verbalizing money, e.g.
        money { integer_part: "20000" currency: "֏" } -> 20000 ֏

    Args:
        decimal: DecimalFst
    """

    def __init__(self, decimal: GraphFst):
        super().__init__(name="money", kind="verbalize")
        unit = (
            pynutil.delete("currency:")
            + delete_space
            + pynutil.delete("\"")
            + pynini.closure(NEMO_CHAR - NEMO_SPACE, 1)
            + pynutil.delete("\"")
        )
        graph = decimal.numbers + delete_space + insert_space + unit
        delete_tokens = self.delete_tokens(graph)
        self.fst = delete_tokens.optimize()