# coding=utf-8
# Copyright 2021 Google AI and The HuggingFace Inc. team. All rights reserved.
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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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# distributed under the License is distributed on an "AS IS" BASIS,
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""" FNet model configuration """

from ...configuration_utils import PretrainedConfig
from ...utils import logging


logger = logging.get_logger(__name__)

FNET_PRETRAINED_CONFIG_ARCHIVE_MAP = {
    "google/fnet-base": "https://huggingface.co/google/fnet-base/resolve/main/config.json",
    "google/fnet-large": "https://huggingface.co/google/fnet-large/resolve/main/config.json"
    # See all FNet models at https://huggingface.co/models?filter=fnet
}


class FNetConfig(PretrainedConfig):
    r"""
    This is the configuration class to store the configuration of a :class:`~transformers.FNetModel`. It is used to
    instantiate an FNet model according to the specified arguments, defining the model architecture. Instantiating a
    configuration with the defaults will yield a similar configuration to that of the FNet `fnet-base
    <https://huggingface.co/google/fnet-base>`__ architecture.

    Configuration objects inherit from :class:`~transformers.PretrainedConfig` and can be used to control the model
    outputs. Read the documentation from :class:`~transformers.PretrainedConfig` for more information.


    Args:
        vocab_size (:obj:`int`, `optional`, defaults to 32000):
            Vocabulary size of the FNet model. Defines the number of different tokens that can be represented by the
            :obj:`inputs_ids` passed when calling :class:`~transformers.FNetModel` or
            :class:`~transformers.TFFNetModel`.
        hidden_size (:obj:`int`, `optional`, defaults to 768):
            Dimension of the encoder layers and the pooler layer.
        num_hidden_layers (:obj:`int`, `optional`, defaults to 12):
            Number of hidden layers in the Transformer encoder.
        intermediate_size (:obj:`int`, `optional`, defaults to 3072):
            Dimension of the "intermediate" (i.e., feed-forward) layer in the Transformer encoder.
        hidden_act (:obj:`str` or :obj:`function`, `optional`, defaults to :obj:`"gelu_new"`):
            The non-linear activation function (function or string) in the encoder and pooler. If string,
            :obj:`"gelu"`, :obj:`"relu"`, :obj:`"selu"` and :obj:`"gelu_new"` are supported.
        hidden_dropout_prob (:obj:`float`, `optional`, defaults to 0.1):
            The dropout probabilitiy for all fully connected layers in the embeddings, encoder, and pooler.
        max_position_embeddings (:obj:`int`, `optional`, defaults to 512):
            The maximum sequence length that this model might ever be used with. Typically set this to something large
            just in case (e.g., 512 or 1024 or 2048).
        type_vocab_size (:obj:`int`, `optional`, defaults to 4):
            The vocabulary size of the :obj:`token_type_ids` passed when calling :class:`~transformers.FNetModel` or
            :class:`~transformers.TFFNetModel`.
        initializer_range (:obj:`float`, `optional`, defaults to 0.02):
            The standard deviation of the truncated_normal_initializer for initializing all weight matrices.
        layer_norm_eps (:obj:`float`, `optional`, defaults to 1e-12):
            The epsilon used by the layer normalization layers.
        gradient_checkpointing (:obj:`bool`, `optional`, defaults to :obj:`False`):
            If :obj:`True`, use gradient checkpointing to save memory at the expense of slower backward pass.
        use_tpu_fourier_optimizations (:obj:`bool`, `optional`, defaults to :obj:`False`):
            Determines whether to use TPU optimized FFTs. If :obj:`True`, the model will favor axis-wise FFTs
            transforms. Set to :obj:`False` for GPU/CPU hardware, in which case n-dimensional FFTs are used.
        tpu_short_seq_length (:obj:`int`, `optional`, defaults to 512):
            The sequence length that is expected by the model when using TPUs. This will be used to initialize the DFT
            matrix only when `use_tpu_fourier_optimizations` is set to :obj:`True` and the input sequence is shorter
            than or equal to 4096 tokens.

    Example::


        >>> from transformers import FNetModel, FNetConfig

        >>> # Initializing a FNet fnet-base style configuration
        >>> configuration = FNetConfig()

        >>> # Initializing a model from the fnet-base style configuration
        >>> model = FNetModel(configuration)

        >>> # Accessing the model configuration
        >>> configuration = model.config
    """
    model_type = "fnet"

    def __init__(
        self,
        vocab_size=32000,
        hidden_size=768,
        num_hidden_layers=12,
        intermediate_size=3072,
        hidden_act="gelu_new",
        hidden_dropout_prob=0.1,
        max_position_embeddings=512,
        type_vocab_size=4,
        initializer_range=0.02,
        layer_norm_eps=1e-12,
        use_tpu_fourier_optimizations=False,
        tpu_short_seq_length=512,
        pad_token_id=3,
        bos_token_id=1,
        eos_token_id=2,
        **kwargs
    ):
        super().__init__(pad_token_id=pad_token_id, bos_token_id=bos_token_id, eos_token_id=eos_token_id, **kwargs)

        self.vocab_size = vocab_size
        self.max_position_embeddings = max_position_embeddings
        self.hidden_size = hidden_size
        self.num_hidden_layers = num_hidden_layers
        self.intermediate_size = intermediate_size
        self.hidden_act = hidden_act
        self.hidden_dropout_prob = hidden_dropout_prob
        self.initializer_range = initializer_range
        self.type_vocab_size = type_vocab_size
        self.layer_norm_eps = layer_norm_eps
        self.use_tpu_fourier_optimizations = use_tpu_fourier_optimizations
        self.tpu_short_seq_length = tpu_short_seq_length
