# Copyright 2023 The HuggingFace Inc. & Google 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.
"""Pix2Struct modeling file"""

import math
from typing import Union

import torch
from torch import nn

from ... import initialization as init
from ...activations import ACT2FN
from ...cache_utils import Cache, DynamicCache, EncoderDecoderCache
from ...generation import GenerationMixin
from ...modeling_attn_mask_utils import AttentionMaskConverter
from ...modeling_layers import GradientCheckpointingLayer
from ...modeling_outputs import (
    BaseModelOutput,
    BaseModelOutputWithPooling,
    CausalLMOutputWithCrossAttentions,
    Seq2SeqLMOutput,
    Seq2SeqModelOutput,
)
from ...modeling_utils import PreTrainedModel
from ...utils import (
    DUMMY_INPUTS,
    DUMMY_MASK,
    auto_docstring,
    is_torch_flex_attn_available,
    is_torchdynamo_compiling,
    logging,
)
from .configuration_pix2struct import Pix2StructConfig, Pix2StructTextConfig, Pix2StructVisionConfig


if is_torch_flex_attn_available():
    from torch.nn.attention.flex_attention import BlockMask

    from ...integrations.flex_attention import make_flex_block_causal_mask


logger = logging.get_logger(__name__)

# General docstring


# Adapted from transformers.models.t5.modeling_t5.T5LayerNorm with T5->Pix2Struct
class Pix2StructLayerNorm(nn.Module):
    def __init__(self, hidden_size, eps=1e-6):
        """
        Construct a layernorm module in the T5 style. No bias and no subtraction of mean.
        """
        super().__init__()
        self.weight = nn.Parameter(torch.ones(hidden_size))
        self.variance_epsilon = eps

    def forward(self, hidden_states):
        # T5 uses a layer_norm which only scales and doesn't shift, which is also known as Root Mean
        # Square Layer Normalization https://huggingface.co/papers/1910.07467 thus variance is calculated
        # w/o mean and there is no bias. Additionally we want to make sure that the accumulation for
        # half-precision inputs is done in fp32

        variance = hidden_states.to(torch.float32).pow(2).mean(-1, keepdim=True)
        hidden_states = hidden_states * torch.rsqrt(variance + self.variance_epsilon)

        # convert into half-precision if necessary
        if self.weight.dtype in [torch.float16, torch.bfloat16]:
            hidden_states = hidden_states.to(self.weight.dtype)

        return self.weight * hidden_states


try:
    from apex.normalization import FusedRMSNorm

    Pix2StructLayerNorm = FusedRMSNorm

    logger.info("Discovered apex.normalization.FusedRMSNorm - will use it instead of Pix2StructLayerNorm")
except ImportError:
    # using the normal Pix2StructLayerNorm
    pass
except Exception:
    logger.warning("Discovered apex but it failed to load, falling back to Pix2StructLayerNorm")


class Pix2StructVisionEmbeddings(nn.Module):
    r"""
    Construct the embeddings from patch. In `Pix2Struct` the input is different from classic Vision-transformer models.
    Here the input is a sequence of `seq_len` flattened patches that also combines padding patches (tokens). Each patch
    is represented by a vector of `hidden_size` values.
    """

    def __init__(self, config: Pix2StructConfig) -> None:
        super().__init__()
        self.patch_projection = nn.Linear(config.patch_embed_hidden_size, config.hidden_size)

        self.row_embedder = nn.Embedding(config.seq_len, config.hidden_size)
        self.column_embedder = nn.Embedding(config.seq_len, config.hidden_size)

        self.dropout = nn.Dropout(config.dropout_rate)

    def forward(self, flattened_patches: torch.Tensor) -> torch.Tensor:
        # the row and column indices are stored in the first and second position of the flattened_patches
        # flattened_patches: `batch_size`, `seq_len`, `hidden_size` + 2
        row_indices = flattened_patches[:, :, 0].long()
        col_indices = flattened_patches[:, :, 1].long()

        flattened_patches = flattened_patches[:, :, 2:]

        embeddings = self.patch_projection(flattened_patches)
        row_embeddings = self.row_embedder(row_indices)
        col_embeddings = self.column_embedder(col_indices)

        # sum all embeddings together
        embeddings = embeddings + row_embeddings + col_embeddings

        embeddings = self.dropout(embeddings)

        return embeddings


class Pix2StructVisionAttention(nn.Module):
    def __init__(self, config):
        super().__init__()
        self.hidden_size = config.hidden_size
        self.key_value_proj_dim = config.d_kv
        self.n_heads = config.num_attention_heads
        self.dropout = config.attention_dropout
        self.inner_dim = self.n_heads * self.key_value_proj_dim

        self.query = nn.Linear(self.hidden_size, self.inner_dim, bias=False)
        self.key = nn.Linear(self.hidden_size, self.inner_dim, bias=False)
        self.value = nn.Linear(self.hidden_size, self.inner_dim, bias=False)
        self.output = nn.Linear(self.inner_dim, self.hidden_size, bias=False)

        self.gradient_checkpointing = False

    def forward(
        self,
        hidden_states,
        attention_mask=None,
        position_bias=None,
        output_attentions=False,
    ):
        """
        Self-attention block
        """
        # Input is (batch_size, seq_length, dim)
        # Mask is (batch_size, key_length) (non-causal) or (batch_size, key_length, key_length)
        batch_size, seq_length = hidden_states.shape[:2]

        def to_projection_shape(states):
            """projection"""
            return states.contiguous().view(batch_size, -1, self.n_heads, self.key_value_proj_dim).transpose(1, 2)

        # get query states
        # (batch_size, n_heads, seq_length, dim_per_head)
        query_states = to_projection_shape(self.query(hidden_states))

        # get key/value states
        key_states = to_projection_shape(self.key(hidden_states))
        value_states = to_projection_shape(self.value(hidden_states))

        # compute scores
        # equivalent of torch.einsum("bnqd,bnkd->bnqk", query_states, key_states), compatible with onnx op>9
        scores = torch.matmul(query_states, key_states.transpose(3, 2))

        if position_bias is None:
            position_bias = torch.zeros(
                (1, self.n_heads, seq_length, seq_length), device=scores.device, dtype=scores.dtype
            )
            if self.gradient_checkpointing and self.training:
                position_bias.requires_grad = True

            if attention_mask.dim() == 2:
                position_bias = position_bias + attention_mask[:, None, None, :].to(position_bias.device)
            elif attention_mask is not None:
                # (batch_size, n_heads, seq_length, key_length)
                position_bias = position_bias + attention_mask.to(position_bias.device)
            elif not is_torchdynamo_compiling():
                attention_mask = torch.ones(
                    (batch_size, seq_length), device=position_bias.device, dtype=position_bias.dtype
                )
                position_bias = position_bias + attention_mask.to(position_bias.device)

            position_bias = 1 - position_bias

        position_bias_masked = position_bias.masked_fill(position_bias == 1, torch.finfo(scores.dtype).min)
        scores += position_bias_masked
        scores = torch.max(scores, torch.tensor(torch.finfo(scores.dtype).min))

        # (batch_size, n_heads, seq_length, key_length)
        attn_weights = nn.functional.softmax(scores, dim=-1, dtype=torch.float32).type_as(scores)

        # (batch_size, n_heads, seq_length, key_length)
        attn_weights = nn.functional.dropout(attn_weights, p=self.dropout, training=self.training)

        attn_output = torch.matmul(attn_weights, value_states)

        # (batch_size, seq_length, dim)
        attn_output = attn_output.transpose(1, 2).contiguous().view(batch_size, -1, self.inner_dim)

        attn_output = self.output(attn_output)

        outputs = (attn_output,) + (position_bias,)

        if output_attentions:
            outputs = outputs + (attn_weights,)
        return outputs


# Copied from transformers.models.t5.modeling_t5.T5DenseGatedActDense with T5DenseGatedActDense->Pix2StructVisionMlp,T5Config->Pix2StructVisionConfig,config.d_model->config.hidden_size,dropout_rate->dropout_rate
class Pix2StructVisionMlp(nn.Module):
    def __init__(self, config: Pix2StructVisionConfig):
        super().__init__()
        self.wi_0 = nn.Linear(config.hidden_size, config.d_ff, bias=False)
        self.wi_1 = nn.Linear(config.hidden_size, config.d_ff, bias=False)
        self.wo = nn.Linear(config.d_ff, config.hidden_size, bias=False)
        self.dropout = nn.Dropout(config.dropout_rate)
        self.act = ACT2FN[config.dense_act_fn]

    def forward(self, hidden_states):
        hidden_gelu = self.act(self.wi_0(hidden_states))
        hidden_linear = self.wi_1(hidden_states)
        hidden_states = hidden_gelu * hidden_linear
        hidden_states = self.dropout(hidden_states)

        # To make 8bit quantization work for google/flan-t5-xxl, self.wo is kept in float32.
        # See https://github.com/huggingface/transformers/issues/20287
        # we also make sure the weights are not in `int8` in case users will force `_keep_in_fp32_modules` to be `None``
        if (
            isinstance(self.wo.weight, torch.Tensor)
            and hidden_states.dtype != self.wo.weight.dtype
            and self.wo.weight.dtype != torch.int8
        ):
            hidden_states = hidden_states.to(self.wo.weight.dtype)

        hidden_states = self.wo(hidden_states)
        return hidden_states


class Pix2StructVisionLayer(GradientCheckpointingLayer):
    def __init__(self, config: Pix2StructConfig) -> None:
        super().__init__()
        self.chunk_size_feed_forward = config.chunk_size_feed_forward
        self.seq_len_dim = 1
        self.attention = Pix2StructVisionAttention(config)
        self.mlp = Pix2StructVisionMlp(config)
        self.pre_mlp_layer_norm = Pix2StructLayerNorm(config.hidden_size, eps=config.layer_norm_eps)
        self.pre_attention_layer_norm = Pix2StructLayerNorm(config.hidden_size, eps=config.layer_norm_eps)

    def forward(
        self,
        hidden_states: torch.Tensor,
        attention_mask: torch.Tensor | None = None,
        output_attentions: bool = False,
    ) -> tuple[torch.Tensor, torch.Tensor] | tuple[torch.Tensor]:
        residual = hidden_states

        # in Pix2StructVision, layernorm is applied before self-attention
        hidden_states = self.pre_attention_layer_norm(hidden_states)

        self_attention_outputs = self.attention(
            hidden_states,
            attention_mask=attention_mask,
            output_attentions=output_attentions,
        )
        attention_output = self_attention_outputs[0]
        outputs = self_attention_outputs[1:]  # add self attentions if we output attention weights

        # first residual connection
        hidden_states = attention_output + residual

        # in Pix2StructVision, layernorm is also applied after self-attention
        layer_output = self.pre_mlp_layer_norm(hidden_states)
        layer_output = self.mlp(layer_output) + hidden_states  # second residual connection

        outputs = (layer_output,) + outputs

        return outputs


class Pix2StructVisionEncoder(nn.Module):
    def __init__(self, config: Pix2StructVisionConfig) -> None:
        super().__init__()
        self.config = config
        self.layer = nn.ModuleList([Pix2StructVisionLayer(config) for _ in range(config.num_hidden_layers)])
        self.gradient_checkpointing = False

    def forward(
        self,
        hidden_states: torch.Tensor,
        attention_mask: torch.Tensor | None = None,
        output_attentions: bool = False,
        output_hidden_states: bool = False,
        return_dict: bool = True,
    ) -> tuple | BaseModelOutput:
        all_hidden_states = () if output_hidden_states else None
        all_self_attentions = () if output_attentions else None

        for i, layer_module in enumerate(self.layer):
            if output_hidden_states:
                all_hidden_states = all_hidden_states + (hidden_states,)

            layer_outputs = layer_module(hidden_states, attention_mask, output_attentions)

            hidden_states = layer_outputs[0]

            if output_attentions:
                all_self_attentions = all_self_attentions + (layer_outputs[1],)

        if output_hidden_states:
            all_hidden_states = all_hidden_states + (hidden_states,)

        if not return_dict:
            return tuple(v for v in [hidden_states, all_hidden_states, all_self_attentions] if v is not None)
        return BaseModelOutput(
            last_hidden_state=hidden_states,
            hidden_states=all_hidden_states,
            attentions=all_self_attentions,
        )


@auto_docstring
class Pix2StructPreTrainedModel(PreTrainedModel):
    config: Pix2StructConfig
    input_modalities = ("image", "text")

    _can_compile_fullgraph = False

    @property
    def dummy_inputs(self):
        input_ids = torch.tensor(DUMMY_INPUTS)
        input_mask = torch.tensor(DUMMY_MASK)
        dummy_inputs = {
            "decoder_input_ids": input_ids,
            "input_ids": input_ids,
            "decoder_attention_mask": input_mask,
        }
        return dummy_inputs

    @torch.no_grad()
    def _init_weights(self, module):
        """Initialize the weights"""
        factor = self.config.initializer_factor  # Used for testing weights initialization
        if isinstance(module, Pix2StructLayerNorm):
            init.constant_(module.weight, factor * 1.0)
        elif isinstance(module, Pix2StructTextDenseGatedActDense):
            hidden_size = (
                self.config.text_config.hidden_size
                if isinstance(self.config, Pix2StructConfig)
                else self.config.hidden_size
            )
            d_ff = self.config.text_config.d_ff if isinstance(self.config, Pix2StructConfig) else self.config.d_ff

            init.normal_(module.wi_0.weight, mean=0.0, std=factor * ((hidden_size) ** -0.5))
            if hasattr(module.wi_0, "bias") and module.wi_0.bias is not None:
                init.zeros_(module.wi_0.bias)
            init.normal_(module.wi_1.weight, mean=0.0, std=factor * ((hidden_size) ** -0.5))
            if hasattr(module.wi_1, "bias") and module.wi_1.bias is not None:
                init.zeros_(module.wi_1.bias)
            init.normal_(module.wo.weight, mean=0.0, std=factor * ((d_ff) ** -0.5))
            if hasattr(module.wo, "bias") and module.wo.bias is not None:
                init.zeros_(module.wo.bias)
        elif isinstance(module, Pix2StructTextAttention):
            hidden_size = (
                self.config.text_config.hidden_size
                if isinstance(self.config, Pix2StructConfig)
                else self.config.hidden_size
            )
            key_value_proj_dim = (
                self.config.text_config.d_kv if isinstance(self.config, Pix2StructConfig) else self.config.hidden_size
            )
            n_heads = (
                self.config.text_config.num_heads
                if isinstance(self.config, Pix2StructConfig)
                else self.config.num_heads
            )

            init.normal_(module.query.weight, mean=0.0, std=factor * ((hidden_size * key_value_proj_dim) ** -0.5))
            init.normal_(module.key.weight, mean=0.0, std=factor * (hidden_size**-0.5))
            init.normal_(module.value.weight, mean=0.0, std=factor * (hidden_size**-0.5))
            init.normal_(module.output.weight, mean=0.0, std=factor * ((n_heads * key_value_proj_dim) ** -0.5))
            if module.has_relative_attention_bias:
                init.normal_(module.relative_attention_bias.weight, mean=0.0, std=factor * ((hidden_size) ** -0.5))
        elif isinstance(module, nn.Embedding):
            hidden_size = (
                self.config.text_config.hidden_size
                if isinstance(self.config, Pix2StructConfig)
                else self.config.hidden_size
            )

            init.normal_(module.weight, mean=0.0, std=factor * ((hidden_size) ** -0.5))
            # Here we need the check explicitly, as we slice the weight in the `zeros_` call, so it looses the flag
            if module.padding_idx is not None and not getattr(module.weight, "_is_hf_initialized", False):
                init.zeros_(module.weight[module.padding_idx])
        elif isinstance(module, Pix2StructTextModel):
            hidden_size = (
                self.config.text_config.hidden_size
                if isinstance(self.config, Pix2StructConfig)
                else self.config.hidden_size
            )

            init.normal_(module.lm_head.weight, mean=0.0, std=factor * ((hidden_size) ** -0.5))
        elif isinstance(module, (nn.Linear, nn.Conv2d)):
            init.trunc_normal_(module.weight, mean=0.0, std=self.config.initializer_range)
            if module.bias is not None:
                init.zeros_(module.bias)
        elif isinstance(module, Pix2StructLayerNorm):
            if module.weight is not None:
                init.ones_(module.weight)
        elif isinstance(module, nn.Embedding):
            init.normal_(module.weight, mean=0.0, std=self.config.initializer_range)
            # Here we need the check explicitly, as we slice the weight in the `zeros_` call, so it looses the flag
            if module.padding_idx is not None and not getattr(module.weight, "_is_hf_initialized", False):
                init.zeros_(module.weight[module.padding_idx])

    # Copied from transformers.models.t5.modeling_t5.T5PreTrainedModel._shift_right with T5->Pix2Struct
    def _shift_right(self, input_ids):
        decoder_start_token_id = self.config.decoder_start_token_id
        pad_token_id = self.config.pad_token_id

        if decoder_start_token_id is None:
            raise ValueError(
                "self.model.config.decoder_start_token_id has to be defined. In Pix2Struct it is usually set to the pad_token_id. "
                "See Pix2Struct docs for more information."
            )

        shifted_input_ids = input_ids.new_zeros(input_ids.shape)
        shifted_input_ids[..., 1:] = input_ids[..., :-1].clone()
        shifted_input_ids[..., 0] = decoder_start_token_id

        if pad_token_id is None:
            raise ValueError("self.model.config.pad_token_id has to be defined.")
        # replace possible -100 values in labels by `pad_token_id`
        shifted_input_ids.masked_fill_(shifted_input_ids == -100, pad_token_id)

        return shifted_input_ids


@auto_docstring
class Pix2StructVisionModel(Pix2StructPreTrainedModel):
    config: Pix2StructVisionConfig
    main_input_name = "flattened_patches"
    input_modalities = ("image",)
    supports_gradient_checkpointing = True
    _no_split_modules = ["Pix2StructVisionLayer"]

    def __init__(self, config: Pix2StructVisionConfig):
        super().__init__(config)
        self.config = config

        self.embeddings = Pix2StructVisionEmbeddings(config)
        self.encoder = Pix2StructVisionEncoder(config)

        self.layernorm = Pix2StructLayerNorm(config.hidden_size, eps=config.layer_norm_eps)

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

    def get_input_embeddings(self):
        return self.embeddings.patch_projection

    @auto_docstring
    def forward(
        self,
        flattened_patches: torch.Tensor | None = None,
        attention_mask: torch.Tensor | None = None,
        output_attentions: bool | None = None,
        output_hidden_states: bool | None = None,
        return_dict: bool | None = None,
        **kwargs,
    ) -> tuple | BaseModelOutputWithPooling:
        r"""
        flattened_patches (`torch.FloatTensor` of shape `(batch_size, sequence_length, num_channels x patch_height x patch_width)`):
            Flattened and padded pixel values. These values can be obtained using [`AutoImageProcessor`]. See
            [`Pix2StructVisionImageProcessor.__call__`] for details. Check the [original
            paper](https://huggingface.co/papers/2210.03347) (figure 5) for more details.

        Example:

        ```python
        >>> import requests
        >>> from PIL import Image
        >>> from transformers import AutoProcessor, Pix2StructVisionModel

        >>> image_processor = AutoProcessor.from_pretrained("google/pix2struct-textcaps-base")
        >>> model = Pix2StructVisionModel.from_pretrained("google/pix2struct-textcaps-base")

        >>> url = "https://www.ilankelman.org/stopsigns/australia.jpg"
        >>> image = Image.open(requests.get(url, stream=True).raw)

        >>> inputs = image_processor(images=image, return_tensors="pt")
        >>> with torch.no_grad():
        ...     outputs = model(**inputs)

        >>> last_hidden_states = outputs.last_hidden_state
        >>> list(last_hidden_states.shape)
        [1, 2048, 768]
        ```
        """
        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

        if flattened_patches is None:
            raise ValueError("You have to specify flattened_patches")

        if attention_mask is None:
            # check where `flattened_patches` is not 0
            attention_mask = (flattened_patches.sum(dim=-1) != 0).float()

        embedding_output = self.embeddings(flattened_patches)

        encoder_outputs = self.encoder(
            embedding_output,
            attention_mask=attention_mask,
            output_attentions=output_attentions,
            output_hidden_states=output_hidden_states,
            return_dict=return_dict,
        )
        sequence_output = encoder_outputs[0]
        sequence_output = self.layernorm(sequence_output)

        if not return_dict:
            head_outputs = (sequence_output,)
            return head_outputs + encoder_outputs[1:]

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


# Copied from transformers.models.t5.modeling_t5.T5DenseGatedActDense with T5->Pix2StructText,d_model->hidden_size
class Pix2StructTextDenseGatedActDense(nn.Module):
    def __init__(self, config: Pix2StructTextConfig):
        super().__init__()
        self.wi_0 = nn.Linear(config.hidden_size, config.d_ff, bias=False)
        self.wi_1 = nn.Linear(config.hidden_size, config.d_ff, bias=False)
        self.wo = nn.Linear(config.d_ff, config.hidden_size, bias=False)
        self.dropout = nn.Dropout(config.dropout_rate)
        self.act = ACT2FN[config.dense_act_fn]

    def forward(self, hidden_states):
        hidden_gelu = self.act(self.wi_0(hidden_states))
        hidden_linear = self.wi_1(hidden_states)
        hidden_states = hidden_gelu * hidden_linear
        hidden_states = self.dropout(hidden_states)

        # To make 8bit quantization work for google/flan-t5-xxl, self.wo is kept in float32.
        # See https://github.com/huggingface/transformers/issues/20287
        # we also make sure the weights are not in `int8` in case users will force `_keep_in_fp32_modules` to be `None``
        if (
            isinstance(self.wo.weight, torch.Tensor)
            and hidden_states.dtype != self.wo.weight.dtype
            and self.wo.weight.dtype != torch.int8
        ):
            hidden_states = hidden_states.to(self.wo.weight.dtype)

        hidden_states = self.wo(hidden_states)
        return hidden_states


class Pix2StructTextLayerFF(nn.Module):
    def __init__(self, config: Pix2StructTextConfig):
        super().__init__()
        self.DenseReluDense = Pix2StructTextDenseGatedActDense(config)

        self.layer_norm = Pix2StructLayerNorm(config.hidden_size, eps=config.layer_norm_epsilon)
        self.dropout = nn.Dropout(config.dropout_rate)

    # Copied from transformers.models.t5.modeling_t5.T5LayerFF.forward
    def forward(self, hidden_states):
        forwarded_states = self.layer_norm(hidden_states)
        forwarded_states = self.DenseReluDense(forwarded_states)
        hidden_states = hidden_states + self.dropout(forwarded_states)
        return hidden_states


class Pix2StructTextAttention(nn.Module):
    def __init__(self, config: Pix2StructTextConfig, has_relative_attention_bias=False, layer_idx: int | None = None):
        super().__init__()
        self.has_relative_attention_bias = has_relative_attention_bias
        self.relative_attention_num_buckets = config.relative_attention_num_buckets
        self.relative_attention_max_distance = config.relative_attention_max_distance
        self.hidden_size = config.hidden_size
        self.key_value_proj_dim = config.d_kv
        self.n_heads = config.num_heads
        self.dropout = config.dropout_rate
        self.inner_dim = self.n_heads * self.key_value_proj_dim
        self.layer_idx = layer_idx
        if layer_idx is None:
            logger.warning_once(
                f"Instantiating a decoder {self.__class__.__name__} without passing `layer_idx` is not recommended and "
                "will to errors during the forward call, if caching is used. Please make sure to provide a `layer_idx` "
                "when creating this class."
            )

        self.query = nn.Linear(self.hidden_size, self.hidden_size, bias=False)
        self.key = nn.Linear(self.hidden_size, self.hidden_size, bias=False)
        self.value = nn.Linear(self.hidden_size, self.hidden_size, bias=False)
        self.output = nn.Linear(self.hidden_size, self.hidden_size, bias=False)

        if self.has_relative_attention_bias:
            self.relative_attention_bias = nn.Embedding(self.relative_attention_num_buckets, self.n_heads)

        self.gradient_checkpointing = False

    @staticmethod
    # Copied from transformers.models.t5.modeling_t5.T5Attention._relative_position_bucket
    def _relative_position_bucket(relative_position, bidirectional=True, num_buckets=32, max_distance=128):
        """
        Adapted from Mesh Tensorflow:
        https://github.com/tensorflow/mesh/blob/0cb87fe07da627bf0b7e60475d59f95ed6b5be3d/mesh_tensorflow/transformer/transformer_layers.py#L593

        Translate relative position to a bucket number for relative attention. The relative position is defined as
        memory_position - query_position, i.e. the distance in tokens from the attending position to the attended-to
        position. If bidirectional=False, then positive relative positions are invalid. We use smaller buckets for
        small absolute relative_position and larger buckets for larger absolute relative_positions. All relative
        positions >=max_distance map to the same bucket. All relative positions <=-max_distance map to the same bucket.
        This should allow for more graceful generalization to longer sequences than the model has been trained on

        Args:
            relative_position: an int32 Tensor
            bidirectional: a boolean - whether the attention is bidirectional
            num_buckets: an integer
            max_distance: an integer

        Returns:
            a Tensor with the same shape as relative_position, containing int32 values in the range [0, num_buckets)
        """
        relative_buckets = 0
        if bidirectional:
            num_buckets //= 2
            relative_buckets += (relative_position > 0).to(torch.long) * num_buckets
            relative_position = torch.abs(relative_position)
        else:
            relative_position = -torch.min(relative_position, torch.zeros_like(relative_position))
        # now relative_position is in the range [0, inf)

        # half of the buckets are for exact increments in positions
        max_exact = num_buckets // 2
        is_small = relative_position < max_exact

        # The other half of the buckets are for logarithmically bigger bins in positions up to max_distance
        relative_position_if_large = max_exact + (
            torch.log(relative_position.float() / max_exact)
            / math.log(max_distance / max_exact)
            * (num_buckets - max_exact)
        ).to(torch.long)
        relative_position_if_large = torch.min(
            relative_position_if_large, torch.full_like(relative_position_if_large, num_buckets - 1)
        )

        relative_buckets += torch.where(is_small, relative_position, relative_position_if_large)
        return relative_buckets

    # Adapted from transformers.models.t5.modeling_t5.T5Attention.compute_bias
    def compute_bias(self, query_length, key_length, device=None, cache_position=None):
        """Compute binned relative position bias"""
        if device is None:
            device = self.relative_attention_bias.weight.device
        if cache_position is None:
            context_position = torch.arange(query_length, dtype=torch.long, device=device)[:, None]
        else:
            context_position = cache_position[:, None].to(device)
        memory_position = torch.arange(key_length, dtype=torch.long, device=device)[None, :]
        relative_position = memory_position - context_position  # shape (query_length, key_length)
        relative_position_bucket = self._relative_position_bucket(
            relative_position,  # shape (query_length, key_length)
            bidirectional=False,
            num_buckets=self.relative_attention_num_buckets,
            max_distance=self.relative_attention_max_distance,
        )
        values = self.relative_attention_bias(relative_position_bucket)  # shape (query_length, key_length, num_heads)
        values = values.permute([2, 0, 1]).unsqueeze(0)  # shape (1, num_heads, query_length, key_length)
        return values

    # Adapted from transformers.models.t5.modeling_t5.T5Attention.forward
    def forward(
        self,
        hidden_states,
        mask=None,
        key_value_states=None,
        position_bias=None,
        past_key_values=None,
        query_length=None,
        use_cache=False,
        output_attentions=False,
        cache_position=None,
    ):
        """
        Self-attention (if key_value_states is None) or attention over source sentence (provided by key_value_states).
        """
        # Input is (batch_size, seq_length, dim)
        # Mask is (batch_size, 1, 1, key_length) (non-causal) or (batch_size, 1, seq_length, key_length) (causal decoder)
        batch_size, seq_length = hidden_states.shape[:2]

        # if key_value_states are provided this layer is used as a cross-attention layer for the decoder
        is_cross_attention = key_value_states is not None

        query_states = self.query(hidden_states)
        query_states = query_states.view(batch_size, -1, self.n_heads, self.key_value_proj_dim).transpose(1, 2)

        # Check is encoder-decoder model is being used. Otherwise we'll get `DynamicCache`
        if past_key_values is not None and isinstance(past_key_values, EncoderDecoderCache):
            is_updated = past_key_values.is_updated.get(self.layer_idx)
            if is_cross_attention:
                # after the first generated id, we can subsequently re-use all key/value_states from cache
                curr_past_key_values = past_key_values.cross_attention_cache
            else:
                curr_past_key_values = past_key_values.self_attention_cache
        else:
            curr_past_key_values = past_key_values

        current_states = key_value_states if is_cross_attention else hidden_states
        if is_cross_attention and past_key_values and is_updated:
            # reuse k,v, cross_attentions
            key_states = curr_past_key_values.layers[self.layer_idx].keys
            value_states = curr_past_key_values.layers[self.layer_idx].values
        else:
            key_states = self.key(current_states)
            value_states = self.value(current_states)
            key_states = key_states.view(batch_size, -1, self.n_heads, self.key_value_proj_dim).transpose(1, 2)
            value_states = value_states.view(batch_size, -1, self.n_heads, self.key_value_proj_dim).transpose(1, 2)

            if past_key_values is not None:
                # save all key/value_states to cache to be re-used for fast auto-regressive generation
                cache_position = cache_position if not is_cross_attention else None
                key_states, value_states = curr_past_key_values.update(
                    key_states, value_states, self.layer_idx, {"cache_position": cache_position}
                )
                # set flag that curr layer for cross-attn is already updated so we can re-use in subsequent calls
                if is_cross_attention:
                    past_key_values.is_updated[self.layer_idx] = True

        # compute scores, equivalent of torch.einsum("bnqd,bnkd->bnqk", query_states, key_states), compatible with onnx op>9
        scores = torch.matmul(query_states, key_states.transpose(3, 2))

        if position_bias is None:
            key_length = key_states.shape[-2]
            # cache position is 0-indexed so we add 1 to get the real length of queries (aka with past)
            real_seq_length = query_length if query_length is not None else cache_position[-1] + 1
            if not self.has_relative_attention_bias:
                position_bias = torch.zeros(
                    (1, self.n_heads, seq_length, key_length), device=scores.device, dtype=scores.dtype
                )
                if self.gradient_checkpointing and self.training:
                    position_bias.requires_grad = True
            else:
                position_bias = self.compute_bias(
                    real_seq_length, key_length, device=scores.device, cache_position=cache_position
                )
                position_bias = position_bias[:, :, -seq_length:, :]

            if mask is not None:
                causal_mask = mask[:, :, :, : key_states.shape[-2]]
                position_bias = position_bias + causal_mask

        position_bias_masked = position_bias
        scores += position_bias_masked

        # (batch_size, n_heads, seq_length, key_length)
        attn_weights = nn.functional.softmax(scores.float(), dim=-1).type_as(scores)
        attn_weights = nn.functional.dropout(attn_weights, p=self.dropout, training=self.training)

        attn_output = torch.matmul(attn_weights, value_states)

        attn_output = attn_output.transpose(1, 2).contiguous()
        attn_output = attn_output.view(batch_size, -1, self.inner_dim)
        attn_output = self.output(attn_output)

        outputs = (attn_output, position_bias)

        if output_attentions:
            outputs = outputs + (attn_weights,)
        return outputs


# Copied from transformers.models.t5.modeling_t5.T5LayerSelfAttention with T5LayerNorm->Pix2StructLayerNorm,T5Attention->Pix2StructTextAttention,T5LayerSelfAttention->Pix2StructTextLayerSelfAttention,self.SelfAttention->self.attention,config.d_model->config.hidden_size
class Pix2StructTextLayerSelfAttention(nn.Module):
    def __init__(self, config, has_relative_attention_bias=False, layer_idx: int | None = None):
        super().__init__()
        self.attention = Pix2StructTextAttention(
            config, has_relative_attention_bias=has_relative_attention_bias, layer_idx=layer_idx
        )
        self.layer_norm = Pix2StructLayerNorm(config.hidden_size, eps=config.layer_norm_epsilon)
        self.dropout = nn.Dropout(config.dropout_rate)

    def forward(
        self,
        hidden_states,
        attention_mask=None,
        position_bias=None,
        past_key_values=None,
        use_cache=False,
        output_attentions=False,
        cache_position=None,
    ):
        normed_hidden_states = self.layer_norm(hidden_states)
        attention_output = self.attention(
            normed_hidden_states,
            mask=attention_mask,
            position_bias=position_bias,
            past_key_values=past_key_values,
            use_cache=use_cache,
            output_attentions=output_attentions,
            cache_position=cache_position,
        )
        hidden_states = hidden_states + self.dropout(attention_output[0])
        outputs = (hidden_states,) + attention_output[1:]  # add attentions if we output them
        return outputs


# Copied from transformers.models.t5.modeling_t5.T5LayerCrossAttention with T5LayerNorm->Pix2StructLayerNorm,T5Attention->Pix2StructTextAttention,T5LayerCrossAttention->Pix2StructTextLayerCrossAttention,self.EncDecAttention->self.attention,config.d_model->config.hidden_size
class Pix2StructTextLayerCrossAttention(nn.Module):
    def __init__(self, config, layer_idx: int | None = None):
        super().__init__()
        self.attention = Pix2StructTextAttention(config, has_relative_attention_bias=False, layer_idx=layer_idx)
        self.layer_norm = Pix2StructLayerNorm(config.hidden_size, eps=config.layer_norm_epsilon)
        self.dropout = nn.Dropout(config.dropout_rate)

    def forward(
        self,
        hidden_states,
        key_value_states,
        attention_mask=None,
        position_bias=None,
        past_key_values=None,
        use_cache=False,
        query_length=None,
        output_attentions=False,
        cache_position=None,
    ):
        normed_hidden_states = self.layer_norm(hidden_states)
        attention_output = self.attention(
            normed_hidden_states,
            mask=attention_mask,
            key_value_states=key_value_states,
            position_bias=position_bias,
            past_key_values=past_key_values,
            use_cache=use_cache,
            query_length=query_length,
            output_attentions=output_attentions,
            cache_position=cache_position,
        )
        layer_output = hidden_states + self.dropout(attention_output[0])
        outputs = (layer_output,) + attention_output[1:]  # add attentions if we output them
        return outputs


class Pix2StructTextBlock(GradientCheckpointingLayer):
    def __init__(self, config, has_relative_attention_bias=False, layer_idx: int | None = None):
        super().__init__()

        self.self_attention = Pix2StructTextLayerSelfAttention(
            config,
            has_relative_attention_bias=has_relative_attention_bias,
            layer_idx=layer_idx,
        )

        self.encoder_decoder_attention = Pix2StructTextLayerCrossAttention(
            config,
            layer_idx=layer_idx,
        )

        self.mlp = Pix2StructTextLayerFF(config)

    def forward(
        self,
        hidden_states,
        attention_mask=None,
        position_bias=None,
        encoder_hidden_states=None,
        encoder_attention_mask=None,
        encoder_decoder_position_bias=None,
        past_key_values=None,
        use_cache=False,
        output_attentions=False,
        return_dict=True,
        cache_position=None,
    ):
        self_attention_outputs = self.self_attention(
            hidden_states,
            attention_mask=attention_mask,
            position_bias=position_bias,
            past_key_values=past_key_values,
            use_cache=use_cache,
            output_attentions=output_attentions,
            cache_position=cache_position,
        )
        hidden_states = self_attention_outputs[0]
        attention_outputs = self_attention_outputs[1:]  # Keep self-attention outputs and relative position weights

        # clamp inf values to enable fp16 training
        if hidden_states.dtype == torch.float16 and torch.isinf(hidden_states).any():
            clamp_value = torch.finfo(hidden_states.dtype).max - 1000
            hidden_states = torch.clamp(hidden_states, min=-clamp_value, max=clamp_value)

        do_cross_attention = encoder_hidden_states is not None
        if do_cross_attention:
            cross_attention_outputs = self.encoder_decoder_attention(
                hidden_states,
                key_value_states=encoder_hidden_states,
                attention_mask=encoder_attention_mask,
                position_bias=encoder_decoder_position_bias,
                past_key_values=past_key_values,
                query_length=cache_position[-1] + 1,
                use_cache=use_cache,
                output_attentions=output_attentions,
            )
            hidden_states = cross_attention_outputs[0]

            # clamp inf values to enable fp16 training
            if hidden_states.dtype == torch.float16 and torch.isinf(hidden_states).any():
                clamp_value = torch.finfo(hidden_states.dtype).max - 1000
                hidden_states = torch.clamp(hidden_states, min=-clamp_value, max=clamp_value)

            # Keep cross-attention outputs and relative position weights
            attention_outputs = attention_outputs + cross_attention_outputs[1:]

        # Apply Feed Forward layer
        hidden_states = self.mlp(hidden_states)

        # clamp inf values to enable fp16 training
        if hidden_states.dtype == torch.float16 and torch.isinf(hidden_states).any():
            clamp_value = torch.finfo(hidden_states.dtype).max - 1000
            hidden_states = torch.clamp(hidden_states, min=-clamp_value, max=clamp_value)

        outputs = (hidden_states,)

        return outputs + attention_outputs


@auto_docstring(
    custom_intro="""
    The standalone text decoder of Pix2Struct
    """
)
class Pix2StructTextModel(Pix2StructPreTrainedModel):
    config: Pix2StructTextConfig
    input_modalities = ("text",)
    _no_split_modules = ["Pix2StructTextBlock"]
    _tied_weights_keys = {"lm_head.weight": "embed_tokens.weight"}
    supports_gradient_checkpointing = True

    def __init__(self, config):
        super().__init__(config)
        self.embed_tokens = nn.Embedding(config.vocab_size, config.hidden_size)

        self.layer = nn.ModuleList(
            [
                Pix2StructTextBlock(config, has_relative_attention_bias=bool(i == 0), layer_idx=i)
                for i in range(config.num_layers)
            ]
        )
        self.final_layer_norm = Pix2StructLayerNorm(config.hidden_size, eps=config.layer_norm_epsilon)
        self.dropout = nn.Dropout(config.dropout_rate)

        self.lm_head = nn.Linear(config.hidden_size, config.vocab_size, bias=False)

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

    def set_input_embeddings(self, new_embeddings):
        self.embed_tokens = new_embeddings

    @auto_docstring
    def forward(
        self,
        input_ids: torch.LongTensor | None = None,
        attention_mask: torch.FloatTensor | None = None,
        encoder_hidden_states: torch.FloatTensor | None = None,
        encoder_attention_mask: torch.FloatTensor | None = None,
        inputs_embeds: torch.LongTensor | None = None,
        past_key_values: Cache | None = None,
        use_cache: bool | None = None,
        output_attentions: bool | None = None,
        output_hidden_states: bool | None = None,
        labels: torch.LongTensor | None = None,
        return_dict: bool | None = None,
        cache_position: torch.LongTensor | None = None,
        **kwargs,
    ) -> tuple[torch.FloatTensor, ...] | CausalLMOutputWithCrossAttentions:
        r"""
        input_ids (`torch.LongTensor` of shape `(batch_size, sequence_length)`):
            Indices of input sequence tokens in the vocabulary. Pix2StructText is a model with relative position
            embeddings so you should be able to pad the inputs on both the right and the left.

            Indices can be obtained using [`AutoTokenizer`]. See [`PreTrainedTokenizer.encode`] and
            [`PreTrainedTokenizer.__call__`] for detail.

            [What are input IDs?](../glossary#input-ids)

            To know more on how to prepare `input_ids` for pretraining take a look a [Pix2StructText
            Training](./t5#training).

        Example:

        ```python
        >>> from transformers import AutoProcessor, Pix2StructTextModel

        >>> processor = AutoProcessor.from_pretrained("google/pix2struct-textcaps-base")
        >>> model = Pix2StructTextModel.from_pretrained("google/pix2struct-textcaps-base")

        >>> inputs = processor(text="Hello, my dog is cute", return_tensors="pt")
        >>> outputs = model(**inputs)
        >>> loss = outputs.loss
        ```
        """
        use_cache = use_cache if use_cache is not None else self.config.use_cache
        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

        if self.gradient_checkpointing and self.training and use_cache:
            logger.warning(
                "`use_cache=True` is incompatible with gradient checkpointing. Setting `use_cache=False`..."
            )
            use_cache = False

        if input_ids is not None and inputs_embeds is not None:
            raise ValueError("You cannot specify both decoder_input_ids and decoder_inputs_embeds at the same time")
        elif input_ids is not None:
            input_shape = input_ids.size()
            input_ids = input_ids.view(-1, input_shape[-1])
        elif inputs_embeds is not None:
            input_shape = inputs_embeds.size()[:-1]
        else:
            raise ValueError("You have to specify either decoder_input_ids or decoder_inputs_embeds")

        if inputs_embeds is None:
            assert self.embed_tokens is not None, "You have to initialize the model with valid token embeddings"
            inputs_embeds = self.embed_tokens(input_ids)

        batch_size, seq_length = input_shape

        if use_cache and past_key_values is None:
            if self.config.is_encoder_decoder:
                past_key_values = EncoderDecoderCache(
                    DynamicCache(config=self.config), DynamicCache(config=self.config)
                )
            else:
                past_key_values = DynamicCache(config=self.config)

        past_key_values_length = 0
        if cache_position is not None:
            past_key_values_length = cache_position[0]
        elif past_key_values is not None:
            past_key_values_length = past_key_values.get_seq_length()

        if cache_position is None:
            cache_position = torch.arange(
                past_key_values_length, past_key_values_length + seq_length, device=inputs_embeds.device
            )

        if attention_mask is None:
            # required mask seq length can be calculated via length of past
            mask_seq_length = (
                past_key_values.get_seq_length() + seq_length if past_key_values is not None else seq_length
            )
            attention_mask = torch.ones(batch_size, mask_seq_length, device=inputs_embeds.device)

        if self.config.is_decoder:
            causal_mask = self._update_causal_mask(
                attention_mask,
                inputs_embeds,
                cache_position,
                past_key_values.self_attention_cache
                if isinstance(past_key_values, EncoderDecoderCache)
                else past_key_values,
                output_attentions,
            )
        else:
            causal_mask = attention_mask[:, None, None, :]
            causal_mask = causal_mask.to(dtype=inputs_embeds.dtype)
            causal_mask = (1.0 - causal_mask) * torch.finfo(inputs_embeds.dtype).min

        # If a 2D or 3D attention mask is provided for the cross-attention
        # we need to make broadcastable to [batch_size, num_heads, seq_length, seq_length]
        if encoder_hidden_states is not None:
            encoder_batch_size, encoder_sequence_length, _ = encoder_hidden_states.size()
            encoder_hidden_shape = (encoder_batch_size, encoder_sequence_length)
            if encoder_attention_mask is None:
                encoder_attention_mask = torch.ones(encoder_hidden_shape, device=inputs_embeds.device)
            encoder_extended_attention_mask = self.invert_attention_mask(encoder_attention_mask)
        else:
            encoder_extended_attention_mask = None

        all_hidden_states = () if output_hidden_states else None
        all_attentions = () if output_attentions else None
        all_cross_attentions = () if (output_attentions) else None
        position_bias = None
        encoder_decoder_position_bias = None

        hidden_states = self.dropout(inputs_embeds)

        for i, layer_module in enumerate(self.layer):
            if output_hidden_states:
                all_hidden_states = all_hidden_states + (hidden_states,)

            layer_outputs = layer_module(
                hidden_states,
                causal_mask,
                position_bias,
                encoder_hidden_states,
                encoder_extended_attention_mask,
                encoder_decoder_position_bias,  # as a positional argument for gradient checkpointing
                past_key_values=past_key_values,
                use_cache=use_cache,
                output_attentions=output_attentions,
                cache_position=cache_position,
            )

            hidden_states = layer_outputs[0]

            # We share the position biases between the layers - the first layer store them
            # layer_outputs = hidden-states, key-value-states (self-attention position bias), (self-attention weights),
            # (cross-attention position bias), (cross-attention weights)
            position_bias = layer_outputs[1]
            if encoder_hidden_states is not None:
                encoder_decoder_position_bias = layer_outputs[3 if output_attentions else 2]

            if output_attentions:
                all_attentions = all_attentions + (layer_outputs[2],)
                if encoder_hidden_states is not None:
                    all_cross_attentions = all_cross_attentions + (layer_outputs[4],)

        hidden_states = self.final_layer_norm(hidden_states)
        hidden_states = self.dropout(hidden_states)

        logits = self.lm_head(hidden_states)

        # Add last layer
        if output_hidden_states:
            all_hidden_states = all_hidden_states + (hidden_states,)

        loss = None
        if labels is not None:
            # move labels to correct device
            labels = labels.to(logits.device)
            loss_fct = nn.CrossEntropyLoss(ignore_index=-100, reduction="mean")

            loss = loss_fct(logits.contiguous().view(-1, logits.size(-1)), labels.contiguous().view(-1))

        if not return_dict:
            return tuple(
                v
                for v in [
                    loss,
                    logits,
                    past_key_values,
                    all_hidden_states,
                    all_attentions,
                    all_cross_attentions,
                ]
                if v is not None
            )
        return CausalLMOutputWithCrossAttentions(
            loss=loss,
            logits=logits,
            past_key_values=past_key_values,
            hidden_states=all_hidden_states,
            attentions=all_attentions,
            cross_attentions=all_cross_attentions,
        )

    # Copied from transformers.models.gptj.modeling_gptj.GPTJModel._update_causal_mask
    def _update_causal_mask(
        self,
        attention_mask: Union[torch.Tensor, "BlockMask"],
        input_tensor: torch.Tensor,
        cache_position: torch.Tensor,
        past_key_values: Cache,
        output_attentions: bool = False,
    ):
        if self.config._attn_implementation == "flash_attention_2":
            if attention_mask is not None and (attention_mask == 0.0).any():
                return attention_mask
            return None
        if self.config._attn_implementation == "flex_attention":
            if isinstance(attention_mask, torch.Tensor):
                attention_mask = make_flex_block_causal_mask(attention_mask)
            return attention_mask

        # For SDPA, when possible, we will rely on its `is_causal` argument instead of its `attn_mask` argument, in
        # order to dispatch on Flash Attention 2. This feature is not compatible with static cache, as SDPA will fail
        # to infer the attention mask.
        past_seen_tokens = past_key_values.get_seq_length() if past_key_values is not None else 0
        using_compilable_cache = past_key_values.is_compileable if past_key_values is not None else False

        # When output attentions is True, sdpa implementation's forward method calls the eager implementation's forward
        if self.config._attn_implementation == "sdpa" and not using_compilable_cache and not output_attentions:
            if AttentionMaskConverter._ignore_causal_mask_sdpa(
                attention_mask,
                inputs_embeds=input_tensor,
                past_key_values_length=past_seen_tokens,
                is_training=self.training,
            ):
                return None

        dtype = input_tensor.dtype
        sequence_length = input_tensor.shape[1]
        if using_compilable_cache:
            target_length = past_key_values.get_max_cache_shape()
        else:
            target_length = (
                attention_mask.shape[-1]
                if isinstance(attention_mask, torch.Tensor)
                else past_seen_tokens + sequence_length + 1
            )

        # In case the provided `attention` mask is 2D, we generate a causal mask here (4D).
        causal_mask = self._prepare_4d_causal_attention_mask_with_cache_position(
            attention_mask,
            sequence_length=sequence_length,
            target_length=target_length,
            dtype=dtype,
            cache_position=cache_position,
            batch_size=input_tensor.shape[0],
        )

        if (
            self.config._attn_implementation == "sdpa"
            and attention_mask is not None
            and attention_mask.device.type in ["cuda", "xpu", "npu"]
            and not output_attentions
        ):
            # Attend to all tokens in fully masked rows in the causal_mask, for example the relevant first rows when
            # using left padding. This is required by F.scaled_dot_product_attention memory-efficient attention path.
            # Details: https://github.com/pytorch/pytorch/issues/110213
            min_dtype = torch.finfo(dtype).min
            causal_mask = AttentionMaskConverter._unmask_unattended(causal_mask, min_dtype)

        return causal_mask

    @staticmethod
    # Copied from transformers.models.gptj.modeling_gptj.GPTJModel._prepare_4d_causal_attention_mask_with_cache_position
    def _prepare_4d_causal_attention_mask_with_cache_position(
        attention_mask: torch.Tensor,
        sequence_length: int,
        target_length: int,
        dtype: torch.dtype,
        cache_position: torch.Tensor,
        batch_size: int,
        **kwargs,
    ):
        """
        Creates a causal 4D mask of shape `(batch_size, 1, query_length, key_value_length)` from a 2D mask of shape
        `(batch_size, key_value_length)`, or if the input `attention_mask` is already 4D, do nothing.

        Args:
            attention_mask (`torch.Tensor`):
                A 2D attention mask of shape `(batch_size, key_value_length)` or a 4D attention mask of shape
                `(batch_size, 1, query_length, key_value_length)`.
            sequence_length (`int`):
                The sequence length being processed.
            target_length (`int`):
                The target length: when generating with static cache, the mask should be as long as the static cache,
                to account for the 0 padding, the part of the cache that is not filled yet.
            dtype (`torch.dtype`):
                The dtype to use for the 4D attention mask.
            cache_position (`torch.Tensor`):
                Indices depicting the position of the input sequence tokens in the sequence.
            batch_size (`torch.Tensor`):
                Batch size.
        """
        if attention_mask is not None and attention_mask.dim() == 4:
            # In this case we assume that the mask comes already in inverted form and requires no inversion or slicing.
            causal_mask = attention_mask
        else:
            min_dtype = torch.finfo(dtype).min
            causal_mask = torch.full(
                (sequence_length, target_length), fill_value=min_dtype, dtype=dtype, device=cache_position.device
            )
            if sequence_length != 1:
                causal_mask = torch.triu(causal_mask, diagonal=1)
            causal_mask *= torch.arange(target_length, device=cache_position.device) > cache_position.reshape(-1, 1)
            causal_mask = causal_mask[None, None, :, :].expand(batch_size, 1, -1, -1)
            if attention_mask is not None:
                causal_mask = causal_mask.clone()  # copy to contiguous memory for in-place edit
                mask_length = attention_mask.shape[-1]
                padding_mask = causal_mask[:, :, :, :mask_length] + attention_mask[:, None, None, :].to(
                    causal_mask.device
                )
                padding_mask = padding_mask == 0
                causal_mask[:, :, :, :mask_length] = causal_mask[:, :, :, :mask_length].masked_fill(
                    padding_mask, min_dtype
                )

        return causal_mask


@auto_docstring(
    custom_intro="""
    A conditional generation model with a language modeling head. Can be used for sequence generation tasks.
    """
)
class Pix2StructForConditionalGeneration(Pix2StructPreTrainedModel, GenerationMixin):
    config: Pix2StructConfig
    main_input_name = "flattened_patches"

    def __init__(self, config: Pix2StructConfig):
        super().__init__(config)

        self.encoder = Pix2StructVisionModel(config.vision_config)
        self.decoder = Pix2StructTextModel(config.text_config)

        self.is_vqa = config.is_vqa

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

    def get_input_embeddings(self):
        return self.decoder.get_input_embeddings()

    def set_input_embeddings(self, new_embeddings):
        self.decoder.set_input_embeddings(new_embeddings)

    def get_output_embeddings(self) -> nn.Module:
        return self.decoder.get_output_embeddings()

    def set_output_embeddings(self, new_embeddings):
        self.decoder.set_output_embeddings(new_embeddings)

    @auto_docstring
    def forward(
        self,
        flattened_patches: torch.FloatTensor | None = None,
        attention_mask: torch.FloatTensor | None = None,
        decoder_input_ids: torch.LongTensor | None = None,
        decoder_attention_mask: torch.BoolTensor | None = None,
        encoder_outputs: tuple[tuple[torch.FloatTensor]] | None = None,
        past_key_values: Cache | None = None,
        labels: torch.LongTensor | None = None,
        decoder_inputs_embeds: torch.Tensor | None = None,
        use_cache: bool | None = None,
        output_attentions: bool | None = None,
        output_hidden_states: bool | None = None,
        return_dict: bool | None = None,
        cache_position: torch.LongTensor | None = None,
        **kwargs,
    ) -> tuple[torch.FloatTensor] | Seq2SeqModelOutput:
        r"""
        flattened_patches (`torch.FloatTensor` of shape `(batch_size, seq_length, hidden_size)`):
            Flattened pixel patches. the `hidden_size` is obtained by the following formula: `hidden_size` =
            `num_channels` * `patch_size` * `patch_size`

            The process of flattening the pixel patches is done by `Pix2StructProcessor`.
        decoder_input_ids (`torch.LongTensor` of shape `(batch_size, target_sequence_length)`, *optional*):
            Indices of decoder input sequence tokens in the vocabulary.

            Indices can be obtained using [`AutoTokenizer`]. See [`PreTrainedTokenizer.encode`] and
            [`PreTrainedTokenizer.__call__`] for details.

            [What are decoder input IDs?](../glossary#decoder-input-ids)

            Pix2StructText uses the `pad_token_id` as the starting token for `decoder_input_ids` generation. If
            `past_key_values` is used, optionally only the last `decoder_input_ids` have to be input (see
            `past_key_values`).

            To know more on how to prepare `decoder_input_ids` for pretraining take a look at [Pix2StructText
            Training](./t5#training).
        decoder_attention_mask (`torch.BoolTensor` of shape `(batch_size, target_sequence_length)`, *optional*):
            Default behavior: generate a tensor that ignores pad tokens in `decoder_input_ids`. Causal mask will also
            be used by default.
        labels (`torch.LongTensor` of shape `(batch_size, sequence_length)`, *optional*):
            Labels for computing the masked language modeling loss for the decoder.

        Example:

        Inference:

        ```python
        >>> from PIL import Image
        >>> import requests
        >>> from transformers import AutoProcessor, Pix2StructForConditionalGeneration

        >>> processor = AutoProcessor.from_pretrained("google/pix2struct-textcaps-base")
        >>> model = Pix2StructForConditionalGeneration.from_pretrained("google/pix2struct-textcaps-base")

        >>> url = "https://www.ilankelman.org/stopsigns/australia.jpg"
        >>> image = Image.open(requests.get(url, stream=True).raw)

        >>> inputs = processor(images=image, return_tensors="pt")

        >>> # autoregressive generation
        >>> generated_ids = model.generate(**inputs, max_new_tokens=50)
        >>> generated_text = processor.batch_decode(generated_ids, skip_special_tokens=True)[0]
        >>> print(generated_text)
        A stop sign is on a street corner.

        >>> # conditional generation
        >>> text = "A picture of"
        >>> inputs = processor(text=text, images=image, return_tensors="pt", add_special_tokens=False)

        >>> generated_ids = model.generate(**inputs, max_new_tokens=50)
        >>> generated_text = processor.batch_decode(generated_ids, skip_special_tokens=True)[0]
        >>> print(generated_text)
        A picture of a stop sign with a red stop sign
        ```

        Training:

        ```python
        >>> from PIL import Image
        >>> import requests
        >>> from transformers import AutoProcessor, Pix2StructForConditionalGeneration

        >>> processor = AutoProcessor.from_pretrained("google/pix2struct-base")
        >>> model = Pix2StructForConditionalGeneration.from_pretrained("google/pix2struct-base")

        >>> url = "https://www.ilankelman.org/stopsigns/australia.jpg"
        >>> image = Image.open(requests.get(url, stream=True).raw)
        >>> text = "A stop sign is on the street corner."

        >>> inputs = processor(images=image, return_tensors="pt")
        >>> labels = processor(text=text, return_tensors="pt").input_ids

        >>> # forward pass
        >>> outputs = model(**inputs, labels=labels)
        >>> loss = outputs.loss
        >>> print(f"{loss.item():.5f}")
        5.94282
        ```"""
        use_cache = use_cache if use_cache is not None else self.config.text_config.use_cache
        return_dict = return_dict if return_dict is not None else self.config.use_return_dict

        # Encode if needed (training, first prediction pass)
        if encoder_outputs is None:
            encoder_outputs = self.encoder(
                flattened_patches=flattened_patches,
                attention_mask=attention_mask,
                output_attentions=output_attentions,
                output_hidden_states=output_hidden_states,
                return_dict=return_dict,
            )
        elif return_dict and not isinstance(encoder_outputs, BaseModelOutput):
            encoder_outputs = BaseModelOutput(
                last_hidden_state=encoder_outputs[0],
                hidden_states=encoder_outputs[1] if len(encoder_outputs) > 1 else None,
                attentions=encoder_outputs[2] if len(encoder_outputs) > 2 else None,
            )

        hidden_states = encoder_outputs[0]

        if labels is not None and decoder_input_ids is None and decoder_inputs_embeds is None:
            # get decoder inputs from shifting lm labels to the right
            decoder_input_ids = self._shift_right(labels)
            decoder_attention_mask = (
                decoder_attention_mask
                if decoder_attention_mask is not None
                else decoder_input_ids.ne(self.config.pad_token_id).float()
            )
            # Always attend to the first token
            decoder_attention_mask[:, 0] = 1

        # Decode
        decoder_outputs = self.decoder(
            input_ids=decoder_input_ids,
            attention_mask=decoder_attention_mask,
            inputs_embeds=decoder_inputs_embeds,
            past_key_values=past_key_values,
            encoder_hidden_states=hidden_states,
            encoder_attention_mask=attention_mask,
            use_cache=use_cache,
            output_attentions=output_attentions,
            output_hidden_states=output_hidden_states,
            labels=labels,
            return_dict=return_dict,
            cache_position=cache_position,
        )

        if not return_dict:
            return decoder_outputs + encoder_outputs

        return Seq2SeqLMOutput(
            loss=decoder_outputs.loss,
            logits=decoder_outputs.logits,
            past_key_values=decoder_outputs.past_key_values,
            decoder_hidden_states=decoder_outputs.hidden_states,
            decoder_attentions=decoder_outputs.attentions,
            cross_attentions=decoder_outputs.cross_attentions,
            encoder_last_hidden_state=encoder_outputs.last_hidden_state,
            encoder_hidden_states=encoder_outputs.hidden_states,
            encoder_attentions=encoder_outputs.attentions,
        )


__all__ = [
    "Pix2StructPreTrainedModel",
    "Pix2StructForConditionalGeneration",
    "Pix2StructVisionModel",
    "Pix2StructTextModel",
]
