# Copyright (c) 2023, NVIDIA CORPORATION & AFFILIATES.  All rights reserved.
#
# 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 nemo_text_processing.inverse_text_normalization.zh.graph_utils import (
    NEMO_DIGIT,
    NEMO_SIGMA,
    GraphFst,
    delete_space,
)
from pynini.lib import pynutil


class OrdinalFst(GraphFst):
    def __init__(self):
        super().__init__(name="ordinal", kind="verbalize")
        graph_integer = (
            pynutil.delete("integer:")
            + delete_space
            + pynutil.delete('"')
            + pynini.accep("第")
            + pynini.closure(NEMO_DIGIT)
            + pynini.closure(NEMO_SIGMA)
            + pynutil.delete('"')
        )

        delete_tokens = self.delete_tokens(graph_integer)
        self.fst = delete_tokens.optimize()
