from transformers import Wav2Vec2Config, Wav2Vec2Model
from transformers.modeling_outputs import BaseModelOutput

from .torch_utils import linear_interpolation

# the implementation of Wav2Vec2Model is borrowed from
# https://github.com/huggingface/transformers/blob/HEAD/src/transformers/models/wav2vec2/modeling_wav2vec2.py
# initialize our encoder with the pre-trained wav2vec 2.0 weights.
class Wav2Vec2Model(Wav2Vec2Model):
    def __init__(self, config: Wav2Vec2Config):
        super().__init__(config)

    def forward(
        self,
        input_values,
        seq_len,
        attention_mask=None,
        mask_time_indices=None,
        output_attentions=None,
        output_hidden_states=None,
        return_dict=None,
    ):
        self.config.output_attentions = True

        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)
        extract_features = linear_interpolation(extract_features, seq_len=seq_len)

        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, add_adapter=False
            )

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

        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 self.adapter is not None:
            hidden_states = self.adapter(hidden_states)

        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,
        )


    def feature_extract(
        self,
        input_values,
        seq_len,
    ):
        extract_features = self.feature_extractor(input_values)
        extract_features = extract_features.transpose(1, 2)
        extract_features = linear_interpolation(extract_features, seq_len=seq_len)

        return extract_features

    def encode(
        self,
        extract_features,
        attention_mask=None,
        mask_time_indices=None,
        output_attentions=None,
        output_hidden_states=None,
        return_dict=None,
    ):
        self.config.output_attentions = True

        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

        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, add_adapter=False
            )
            

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

        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 self.adapter is not None:
            hidden_states = self.adapter(hidden_states)

        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,
        )
