# 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.

from inverse_text_normalization.ml.graph_utils import NEMO_CHAR, GraphFst, delete_space
from inverse_text_normalization.ml.verbalizers.decimal import DecimalFst

try:
    import pynini
    from pynini.lib import pynutil

    decimal = DecimalFst()

    PYNINI_AVAILABLE = True
except (ModuleNotFoundError, ImportError):
    # Add placeholders
    decimal = None

    PYNINI_AVAILABLE = False


class MoneyFst(GraphFst):
    """
    Finite state transducer for verbalizing money
        e.g. tokens { money { integer_part: "12" fractional_part: 05 currency: "$" } } -> $12.05
    """

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