# Copyright 2021 The Fairseq Authors and the HuggingFace Inc. team. 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.
"""PyTorch Hubert model."""

import torch
import torch.nn as nn

from ... import initialization as init
from ...activations import ACT2FN
from ...integrations.deepspeed import is_deepspeed_zero3_enabled
from ...modeling_outputs import BaseModelOutput
from ...modeling_utils import PreTrainedModel
from ...utils import auto_docstring
from ..wav2vec2.modeling_wav2vec2 import (
    Wav2Vec2Encoder,
    Wav2Vec2EncoderStableLayerNorm,
    Wav2Vec2FeatureEncoder,
    Wav2Vec2ForCTC,
    Wav2Vec2ForSequenceClassification,
    Wav2Vec2Model,
    Wav2Vec2SamePadLayer,
)
from .configuration_hubert import HubertConfig


_HIDDEN_STATES_START_POSITION = 1


class HubertPositionalConvEmbedding(nn.Module):
    def __init__(self, config):
        super().__init__()
        self.conv = nn.Conv1d(
            config.hidden_size,
            config.hidden_size,
            kernel_size=config.num_conv_pos_embeddings,
            padding=config.num_conv_pos_embeddings // 2,
            groups=config.num_conv_pos_embedding_groups,
        )

        self.batch_norm = None
        if config.conv_pos_batch_norm:
            self.batch_norm = nn.BatchNorm1d(config.hidden_size)
        else:
            weight_norm = nn.utils.weight_norm
            if hasattr(nn.utils.parametrizations, "weight_norm"):
                weight_norm = nn.utils.parametrizations.weight_norm

            if is_deepspeed_zero3_enabled():
                import deepspeed

                with deepspeed.zero.GatheredParameters(self.conv.weight, modifier_rank=0):
                    self.conv = weight_norm(self.conv, name="weight", dim=2)
                if hasattr(self.conv, "parametrizations"):
                    weight_g = self.conv.parametrizations.weight.original0
                    weight_v = self.conv.parametrizations.weight.original1
                else:
                    weight_g = self.conv.weight_g
                    weight_v = self.conv.weight_v
                deepspeed.zero.register_external_parameter(self, weight_v)
                deepspeed.zero.register_external_parameter(self, weight_g)
            else:
                self.conv = weight_norm(self.conv, name="weight", dim=2)

        self.padding = HubertSamePadLayer(config.num_conv_pos_embeddings)
        self.activation = ACT2FN[config.feat_extract_activation]

    def forward(self, hidden_states):
        hidden_states = hidden_states.transpose(1, 2)
        if self.batch_norm is not None:
            hidden_states = self.batch_norm(hidden_states)
        hidden_states = self.conv(hidden_states)
        hidden_states = self.padding(hidden_states)
        hidden_states = self.activation(hidden_states)

        hidden_states = hidden_states.transpose(1, 2)
        return hidden_states


class HubertSamePadLayer(Wav2Vec2SamePadLayer):
    pass


class HubertFeatureEncoder(Wav2Vec2FeatureEncoder):
    pass


class HubertFeatureProjection(nn.Module):
    def __init__(self, config):
        super().__init__()
        self.feat_proj_layer_norm = config.feat_proj_layer_norm
        if self.feat_proj_layer_norm:
            self.layer_norm = nn.LayerNorm(config.conv_dim[-1], eps=config.layer_norm_eps)
        self.projection = nn.Linear(config.conv_dim[-1], config.hidden_size)
        self.dropout = nn.Dropout(config.feat_proj_dropout)

    def forward(self, hidden_states):
        # non-projected hidden states are needed for quantization
        if self.feat_proj_layer_norm:
            hidden_states = self.layer_norm(hidden_states)
        hidden_states = self.projection(hidden_states)
        hidden_states = self.dropout(hidden_states)
        return hidden_states


class HubertEncoder(Wav2Vec2Encoder):
    pass


class HubertEncoderStableLayerNorm(Wav2Vec2EncoderStableLayerNorm):
    pass


@auto_docstring
class HubertPreTrainedModel(PreTrainedModel):
    config: HubertConfig
    base_model_prefix = "hubert"
    main_input_name = "input_values"
    input_modalities = "audio"
    supports_gradient_checkpointing = True
    _supports_flash_attn = True
    _supports_sdpa = True
    _supports_flex_attn = True

    @torch.no_grad()
    def _init_weights(self, module):
        """Initialize the weights"""
        if isinstance(module, nn.Linear):
            init.normal_(module.weight, mean=0.0, std=self.config.initializer_range)
            if module.bias is not None:
                init.zeros_(module.bias)
        elif isinstance(module, (nn.LayerNorm, nn.GroupNorm, nn.BatchNorm1d)):
            init.zeros_(module.bias)
            init.ones_(module.weight)
            if getattr(module, "running_mean", None) is not None:
                init.zeros_(module.running_mean)
                init.ones_(module.running_var)
                init.zeros_(module.num_batches_tracked)
        elif isinstance(module, nn.Conv1d):
            if is_deepspeed_zero3_enabled():
                import deepspeed

                if hasattr(module, "weight_v") and hasattr(module, "weight_g"):
                    with deepspeed.zero.GatheredParameters([module.weight_v, module.weight_g], modifier_rank=0):
                        init.kaiming_normal_(module.weight)
                else:
                    with deepspeed.zero.GatheredParameters(module.weight, modifier_rank=0):
                        init.kaiming_normal_(module.weight)
            else:
                init.kaiming_normal_(module.weight)

            if module.bias is not None:
                init.zeros_(module.bias)
        elif isinstance(module, HubertModel):
            if hasattr(module, "masked_spec_embed"):
                init.uniform_(module.masked_spec_embed)
        elif isinstance(module, HubertForSequenceClassification):
            if hasattr(module, "layer_weights"):
                init.constant_(module.layer_weights, 1.0 / (self.config.num_hidden_layers + 1))

    def _get_feat_extract_output_lengths(self, input_lengths: torch.LongTensor | int):
        """
        Computes the output length of the convolutional layers
        """

        def _conv_out_length(input_length, kernel_size, stride):
            # 1D convolutional layer output length formula taken
            # from https://pytorch.org/docs/stable/generated/torch.nn.Conv1d.html
            return torch.div(input_length - kernel_size, stride, rounding_mode="floor") + 1

        for kernel_size, stride in zip(self.config.conv_kernel, self.config.conv_stride):
            input_lengths = _conv_out_length(input_lengths, kernel_size, stride)

        return input_lengths

    def _get_feature_vector_attention_mask(self, feature_vector_length: int, attention_mask: torch.LongTensor):
        output_lengths = self._get_feat_extract_output_lengths(attention_mask.sum(-1)).to(torch.long)
        batch_size = attention_mask.shape[0]

        attention_mask = torch.zeros(
            (batch_size, feature_vector_length), dtype=attention_mask.dtype, device=attention_mask.device
        )
        # these two operations makes sure that all values before the output lengths idxs are attended to
        attention_mask[(torch.arange(attention_mask.shape[0], device=attention_mask.device), output_lengths - 1)] = 1
        attention_mask = attention_mask.flip([-1]).cumsum(-1).flip([-1]).bool()
        return attention_mask


class HubertModel(Wav2Vec2Model, HubertPreTrainedModel):
    def __init__(self, config: HubertConfig):
        super().__init__(config)
        self.config = config
        self.feature_extractor = HubertFeatureEncoder(config)
        self.feature_projection = HubertFeatureProjection(config)

        if config.mask_time_prob > 0.0 or config.mask_feature_prob > 0.0:
            self.masked_spec_embed = nn.Parameter(torch.Tensor(config.hidden_size).uniform_())

        if config.do_stable_layer_norm:
            self.encoder = HubertEncoderStableLayerNorm(config)
        else:
            self.encoder = HubertEncoder(config)

        # Initialize weights and apply final processing
        self.post_init()

        del self.adapter

    def freeze_feature_encoder(self):
        raise AttributeError("Not needed for Hubert")

    def forward(
        self,
        input_values: torch.Tensor | None,
        attention_mask: torch.Tensor | None = None,
        mask_time_indices: torch.FloatTensor | None = None,
        output_attentions: bool | None = None,
        output_hidden_states: bool | None = None,
        return_dict: bool | None = None,
        **kwargs,
    ) -> tuple | BaseModelOutput:
        r"""
        mask_time_indices (`torch.BoolTensor` of shape `(batch_size, sequence_length)`, *optional*):
            Indices to mask extracted features for contrastive loss. When in training mode, model learns to predict
            masked extracted features in *config.proj_codevector_dim* space.

        Example:

        ```python
        >>> from transformers import AutoProcessor, HubertModel
        >>> from datasets import load_dataset

        >>> processor = AutoProcessor.from_pretrained("facebook/hubert-large-ls960-ft")
        >>> model = HubertModel.from_pretrained("facebook/hubert-large-ls960-ft")


        >>> def map_to_array(example):
        ...     example["speech"] = example["audio"]["array"]
        ...     return example


        >>> ds = load_dataset("hf-internal-testing/librispeech_asr_dummy", "clean", split="validation")
        >>> ds = ds.map(map_to_array)

        >>> input_values = processor(ds["speech"][0], return_tensors="pt").input_values  # Batch size 1
        >>> hidden_states = model(input_values).last_hidden_state
        ```"""
        output_attentions = output_attentions if output_attentions is not None else self.config.output_attentions
        output_hidden_states = (
            output_hidden_states if output_hidden_states is not None else self.config.output_hidden_states
        )
        return_dict = return_dict if return_dict is not None else self.config.use_return_dict

        extract_features = self.feature_extractor(input_values)
        extract_features = extract_features.transpose(1, 2)

        if attention_mask is not None:
            # compute reduced attention_mask corresponding to feature vectors
            attention_mask = self._get_feature_vector_attention_mask(extract_features.shape[1], attention_mask)

        hidden_states = self.feature_projection(extract_features)
        hidden_states = self._mask_hidden_states(hidden_states, mask_time_indices=mask_time_indices)

        encoder_outputs = self.encoder(
            hidden_states,
            attention_mask=attention_mask,
            output_attentions=output_attentions,
            output_hidden_states=output_hidden_states,
            return_dict=return_dict,
        )

        hidden_states = encoder_outputs[0]

        if not return_dict:
            return (hidden_states,) + encoder_outputs[1:]

        return BaseModelOutput(
            last_hidden_state=hidden_states,
            hidden_states=encoder_outputs.hidden_states,
            attentions=encoder_outputs.attentions,
        )


class HubertForCTC(Wav2Vec2ForCTC):
    pass


class HubertForSequenceClassification(Wav2Vec2ForSequenceClassification):
    pass


__all__ = ["HubertForCTC", "HubertForSequenceClassification", "HubertModel", "HubertPreTrainedModel"]
