# Copyright 2024 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.


import torch
from huggingface_hub.dataclasses import strict

from transformers.models.instructblip.configuration_instructblip import (
    InstructBlipConfig,
    InstructBlipQFormerConfig,
    InstructBlipVisionConfig,
)
from transformers.models.instructblip.modeling_instructblip import (
    BaseModelOutputWithVisionQformerOutputs,
    InstructBlipForConditionalGeneration,
    InstructBlipForConditionalGenerationModelOutput,
    InstructBlipModel,
    InstructBlipPreTrainedModel,
    InstructBlipQFormerModel,
    InstructBlipVisionModel,
    TransformersKwargs,
)

from ...modeling_outputs import BaseModelOutputWithPooling
from ...processing_utils import Unpack
from ...utils import auto_docstring, can_return_tuple


@auto_docstring(checkpoint="Salesforce/instructblip-flan-t5-xl")
@strict
class InstructBlipVideoVisionConfig(InstructBlipVisionConfig):
    r"""
    Example:

    ```python
    >>> from transformers import InstructBlipVideoVisionConfig, InstructBlipVideoVisionModel

    >>> # Initializing a InstructBlipVideoVisionConfig with Salesforce/instructblip-flan-t5-xl style configuration
    >>> configuration = InstructBlipVideoVisionConfig()

    >>> # Initializing a InstructBlipVideoVisionModel (with random weights) from the Salesforce/instructblip-flan-t5-xl style configuration
    >>> model = InstructBlipVideoVisionModel(configuration)

    >>> # Accessing the model configuration
    >>> configuration = model.config
    ```"""


@auto_docstring(checkpoint="Salesforce/instructblip-flan-t5-xl")
@strict
class InstructBlipVideoQFormerConfig(InstructBlipQFormerConfig):
    r"""
    cross_attention_frequency (`int`, *optional*, defaults to 2):
        The frequency of adding cross-attention to the Transformer layers.
    encoder_hidden_size (`int`, *optional*, defaults to 1408):
        The hidden size of the hidden states for cross-attention.

    Examples:

    ```python
    >>> from transformers import InstructBlipVideoQFormerConfig, InstructBlipVideoQFormerModel

    >>> # Initializing a InstructBlipVideo Salesforce/instructblip-flan-t5-xl style configuration
    >>> configuration = InstructBlipVideoQFormerConfig()

    >>> # Initializing a model (with random weights) from the Salesforce/instructblip-flan-t5-xl style configuration
    >>> model = InstructBlipVideoQFormerModel(configuration)
    >>> # Accessing the model configuration
    >>> configuration = model.config
    ```"""


@auto_docstring(checkpoint="Salesforce/instructblip-flan-t5-xl")
@strict
class InstructBlipVideoConfig(InstructBlipConfig):
    r"""
    qformer_config (`dict`, *optional*):
        Dictionary of configuration options used to initialize [`InstructBlipVideoQFormerConfig`].
    num_query_tokens (`int`, *optional*, defaults to 32):
        The number of query tokens passed through the Transformer.

    Example:

    ```python
    >>> from transformers import (
    ...     InstructBlipVideoVisionConfig,
    ...     InstructBlipVideoQFormerConfig,
    ...     OPTConfig,
    ...     InstructBlipVideoConfig,
    ...     InstructBlipVideoForConditionalGeneration,
    ... )

    >>> # Initializing a InstructBlipVideoConfig with Salesforce/instructblip-flan-t5-xl style configuration
    >>> configuration = InstructBlipVideoConfig()

    >>> # Initializing a InstructBlipVideoForConditionalGeneration (with random weights) from the Salesforce/instructblip-flan-t5-xl style configuration
    >>> model = InstructBlipVideoForConditionalGeneration(configuration)

    >>> # Accessing the model configuration
    >>> configuration = model.config

    >>> # We can also initialize a InstructBlipVideoConfig from a InstructBlipVideoVisionConfig, InstructBlipVideoQFormerConfig and any PreTrainedConfig

    >>> # Initializing Instructblipvideo vision, Instructblipvideo Q-Former and language model configurations
    >>> vision_config = InstructBlipVideoVisionConfig()
    >>> qformer_config = InstructBlipVideoQFormerConfig()
    >>> text_config = OPTConfig()

    >>> config = InstructBlipVideoConfig(vision_config=vision_config, qformer_config=qformer_config, text_config=text_config)
    ```"""

    attribute_map = {"video_token_id": "video_token_index"}
    video_token_index: int | None = None
    image_token_index = AttributeError()


class InstructBlipVideoPreTrainedModel(InstructBlipPreTrainedModel):
    input_modalities = ("video", "text")


class InstructBlipVideoVisionModel(InstructBlipVisionModel):
    input_modalities = "video"


class InstructBlipVideoQFormerModel(InstructBlipQFormerModel):
    pass


class InstructBlipVideoForConditionalGenerationModelOutput(InstructBlipForConditionalGenerationModelOutput):
    pass


class InstructBlipVideoModel(InstructBlipModel):
    @can_return_tuple
    @auto_docstring
    def forward(
        self,
        pixel_values: torch.FloatTensor,
        qformer_input_ids: torch.FloatTensor,
        qformer_attention_mask: torch.LongTensor | None = None,
        input_ids: torch.FloatTensor | None = None,
        attention_mask: torch.LongTensor | None = None,
        decoder_input_ids: torch.LongTensor | None = None,
        decoder_attention_mask: torch.LongTensor | None = None,
        inputs_embeds: torch.Tensor | None = None,
        interpolate_pos_encoding: bool = False,
        use_cache: bool | None = None,
        **kwargs: Unpack[TransformersKwargs],
    ) -> tuple | InstructBlipVideoForConditionalGenerationModelOutput:
        # step 1: forward the images through the vision encoder,
        # we process in a batched way, later unbatch it back (video has frames=4 always)
        batch_size, frames, channel, height, width = pixel_values.shape
        pixel_values = pixel_values.reshape(batch_size * frames, channel, height, width)

        vision_outputs = self.vision_model(
            pixel_values=pixel_values,
            interpolate_pos_encoding=interpolate_pos_encoding,
            **kwargs,
        )
        image_embeds = vision_outputs[0]

        # step 2: forward the query tokens through the QFormer, using the image embeddings for cross-attention
        image_attention_mask = torch.ones(image_embeds.size()[:-1], dtype=torch.long, device=image_embeds.device)

        # difference with BLIP-2 here: we also feed the instruction prompt to the Q-Former
        query_tokens = self.query_tokens.expand(image_embeds.shape[0], -1, -1)
        query_attention_mask = torch.ones(query_tokens.size()[:-1], dtype=torch.long, device=image_embeds.device)

        if qformer_attention_mask is None:
            qformer_attention_mask = torch.ones_like(qformer_input_ids)

        qformer_input_ids = qformer_input_ids.repeat_interleave(frames, dim=0)
        qformer_attention_mask = qformer_attention_mask.repeat_interleave(frames, dim=0)
        qformer_attention_mask = torch.cat([query_attention_mask, qformer_attention_mask], dim=1)
        query_outputs = self.qformer(
            input_ids=qformer_input_ids,
            attention_mask=qformer_attention_mask,
            query_embeds=query_tokens,
            encoder_hidden_states=image_embeds,
            encoder_attention_mask=image_attention_mask,
            **kwargs,
        )
        query_output = query_outputs[0][:, : query_tokens.size(1), :]

        # step 3: use the language model, conditioned on the query outputs and the prompt
        language_model_inputs = self.language_projection(query_output)

        # unbatch inputs back, each video-frame gets `num_query_tokens` seq length
        language_model_inputs = language_model_inputs.reshape(batch_size, self.config.num_query_tokens * frames, -1)
        if inputs_embeds is None:
            inputs_embeds = self.language_model.get_input_embeddings()(input_ids)
            special_image_mask = input_ids == self.config.video_token_id
            if attention_mask is None:
                attention_mask = torch.ones_like(input_ids)
        else:
            special_image_mask = inputs_embeds == self.get_input_embeddings()(
                torch.tensor(self.config.video_token_id, dtype=torch.long, device=inputs_embeds.device)
            )
            special_image_mask = special_image_mask.all(-1)

        special_image_mask = special_image_mask.unsqueeze(-1).expand_as(inputs_embeds).to(inputs_embeds.device)
        language_model_inputs = language_model_inputs.to(inputs_embeds.device, inputs_embeds.dtype)
        inputs_embeds = inputs_embeds.masked_scatter(special_image_mask, language_model_inputs)

        if self.config.use_decoder_only_language_model:
            outputs = self.language_model(
                inputs_embeds=inputs_embeds,
                attention_mask=attention_mask,
                use_cache=use_cache,
                **kwargs,
            )
        else:
            outputs = self.language_model(
                inputs_embeds=inputs_embeds,
                attention_mask=attention_mask,
                decoder_input_ids=decoder_input_ids,
                decoder_attention_mask=decoder_attention_mask,
                use_cache=use_cache,
                **kwargs,
            )

        return InstructBlipVideoForConditionalGenerationModelOutput(
            vision_outputs=vision_outputs,
            qformer_outputs=query_outputs,
            language_model_outputs=outputs,
        )


class InstructBlipVideoForConditionalGeneration(InstructBlipForConditionalGeneration):
    @can_return_tuple
    @auto_docstring
    def get_video_features(
        self,
        pixel_values: torch.FloatTensor,
        qformer_input_ids: torch.LongTensor,
        qformer_attention_mask: torch.LongTensor | None = None,
        interpolate_pos_encoding: bool | None = False,
        **kwargs: Unpack[TransformersKwargs],
    ) -> tuple | BaseModelOutputWithVisionQformerOutputs:
        r"""
        pixel_values (`torch.FloatTensor` of shape `(batch_size, num_channels, image_size, image_size)`):
            The tensors corresponding to the input images.
        qformer_input_ids (`torch.LongTensor` of shape (batch_size, sequence_length)):
            The sequence used as a prompt to be fed to the Q-Former module.
        qformer_attention_mask (`torch.LongTensor` of shape (batch_size, sequence_length), *optional*):
            Mask to avoid performing attention on padding token indices.
        """
        # step 1: forward the images through the vision encoder,
        # we process in a batched way, later unbatch it back (video has frames=4 always)
        batch_size, frames, channel, height, width = pixel_values.shape
        pixel_values = pixel_values.reshape(batch_size * frames, channel, height, width)

        vision_outputs: BaseModelOutputWithPooling = self.vision_model(
            pixel_values=pixel_values,
            interpolate_pos_encoding=interpolate_pos_encoding,
            **kwargs,
        )
        vision_outputs = BaseModelOutputWithVisionQformerOutputs(
            last_hidden_state=vision_outputs.last_hidden_state,
            pooler_output=vision_outputs.pooler_output,
            hidden_states=vision_outputs.hidden_states,
            attentions=vision_outputs.attentions,
            vision_outputs=vision_outputs,
            qformer_outputs=None,
        )
        image_embeds = vision_outputs[0]

        # step 2: forward the query tokens through the QFormer, using the image embeddings for cross-attention
        image_attention_mask = torch.ones(image_embeds.size()[:-1], dtype=torch.long, device=image_embeds.device)

        # difference with BLIP-2 here: we also feed the instruction prompt to the Q-Former
        query_tokens = self.query_tokens.expand(image_embeds.shape[0], -1, -1)
        query_attention_mask = torch.ones(query_tokens.size()[:-1], dtype=torch.long, device=image_embeds.device)

        if qformer_attention_mask is None:
            qformer_attention_mask = torch.ones_like(qformer_input_ids)

        qformer_input_ids = qformer_input_ids.repeat_interleave(frames, dim=0)
        qformer_attention_mask = qformer_attention_mask.repeat_interleave(frames, dim=0)
        qformer_attention_mask = torch.cat([query_attention_mask, qformer_attention_mask], dim=1)
        qformer_outputs = self.qformer(
            input_ids=qformer_input_ids,
            attention_mask=qformer_attention_mask,
            query_embeds=query_tokens,
            encoder_hidden_states=image_embeds,
            encoder_attention_mask=image_attention_mask,
            **kwargs,
        )
        vision_outputs.qformer_outputs = qformer_outputs
        query_output = qformer_outputs[0][:, : query_tokens.size(1), :]

        # step 3: use the language model, conditioned on the query outputs and the prompt
        video_features = self.language_projection(query_output)

        # unbatch inputs back, each video-frame gets `num_query_tokens` seq length
        video_features = video_features.reshape(batch_size, self.config.num_query_tokens * frames, -1)
        vision_outputs.pooler_output = video_features

        return vision_outputs

    def get_image_features(**super_kwargs):
        raise AttributeError("No need to inherit as this architecture only supports videos.")

    def get_placeholder_mask(self, input_ids: torch.LongTensor, inputs_embeds: torch.FloatTensor):
        """
        Obtains multimodal placeholder mask from `input_ids` or `inputs_embeds`.
        """
        if input_ids is None:
            special_image_mask = inputs_embeds == self.get_input_embeddings()(
                torch.tensor(self.config.video_token_id, dtype=torch.long, device=inputs_embeds.device)
            )
            special_image_mask = special_image_mask.all(-1)
        else:
            special_image_mask = input_ids == self.config.video_token_id

        special_image_mask = special_image_mask.unsqueeze(-1).expand_as(inputs_embeds).to(inputs_embeds.device)
        return special_image_mask

    @can_return_tuple
    @auto_docstring
    def forward(
        self,
        pixel_values: torch.FloatTensor,
        qformer_input_ids: torch.FloatTensor,
        qformer_attention_mask: torch.LongTensor | None = None,
        input_ids: torch.FloatTensor | None = None,
        attention_mask: torch.LongTensor | None = None,
        decoder_input_ids: torch.LongTensor | None = None,
        decoder_attention_mask: torch.LongTensor | None = None,
        inputs_embeds: torch.FloatTensor | None = None,
        labels: torch.LongTensor | None = None,
        interpolate_pos_encoding: bool = False,
        use_cache: bool | None = None,
        **kwargs: Unpack[TransformersKwargs],
    ) -> tuple | InstructBlipVideoForConditionalGenerationModelOutput:
        r"""
        qformer_input_ids (`torch.LongTensor` of shape (batch_size, sequence_length)):
            The sequence used as a prompt to be fed to the Q-Former module.
        qformer_attention_mask (`torch.LongTensor` of shape (batch_size, sequence_length), *optional*):
            Mask to avoid performing attention on padding token indices.

        Examples:

        ```python
        >>> from transformers import InstructBlipVideoProcessor, InstructBlipVideoForConditionalGeneration
        >>> import torch
        >>> from huggingface_hub import hf_hub_download
        >>> import av
        >>> import numpy as np

        >>> def read_video_pyav(container, indices):
        ...     '''
        ...     Decode the video with PyAV decoder.
        ...     Args:
        ...         container (`av.container.input.InputContainer`): PyAV container.
        ...         indices (`list[int]`): List of frame indices to decode.
        ...     Returns:
        ...         result (np.ndarray): np array of decoded frames of shape (num_frames, height, width, 3).
        ...     '''
        ...     frames = []
        ...     container.seek(0)
        ...     start_index = indices[0]
        ...     end_index = indices[-1]
        ...     for i, frame in enumerate(container.decode(video=0)):
        ...         if i > end_index:
        ...             break
        ...         if i >= start_index and i in indices:
        ...             frames.append(frame)
        ...     return np.stack([x.to_ndarray(format="rgb24") for x in frames])

        >>> model = InstructBlipVideoForConditionalGeneration.from_pretrained("Salesforce/instructblip-vicuna-7b", device_map="auto")
        >>> processor = InstructBlipVideoProcessor.from_pretrained("Salesforce/instructblip-vicuna-7b")

        >>> file_path = hf_hub_download(
        ...       repo_id="nielsr/video-demo", filename="eating_spaghetti.mp4", repo_type="dataset"
        ... )
        >>> container = av.open(file_path)

        >>> # sample uniformly 4 frames from the videWhy is this video funny?o
        >>> total_frames = container.streams.video[0].frames
        >>> indices = np.arange(0, total_frames, total_frames / 4).astype(int)
        >>> clip = read_video_pyav(container, indices)

        >>> prompt = "What is happening in the video?"
        >>> inputs = processor(text=prompt, images=clip, return_tensors="pt").to(model.device)

        >>> outputs = model.generate(
        ...     **inputs,
        ...     do_sample=False,
        ...     num_beams=5,
        ...     max_length=256,
        ...     repetition_penalty=1.5,
        ...     length_penalty=1.0,
        ... )
        >>> generated_text = processor.batch_decode(outputs, skip_special_tokens=True)[0].strip()
        >>> print(generated_text)
        "A person is eating a bowl of pasta, and they are using a fork to eat it. The person is sitting at a table, and the plate of pasta is on the table in front"
        ```"""
        video_features: BaseModelOutputWithVisionQformerOutputs = self.get_video_features(
            pixel_values,
            qformer_input_ids=qformer_input_ids,
            qformer_attention_mask=qformer_attention_mask,
            interpolate_pos_encoding=interpolate_pos_encoding,
            **kwargs,
        )
        language_model_inputs = video_features.pooler_output
        qformer_outputs = video_features.qformer_outputs
        vision_outputs = video_features.vision_outputs

        if inputs_embeds is None:
            inputs_embeds = self.get_input_embeddings()(input_ids)

        if attention_mask is None:
            attention_mask = torch.ones_like(input_ids)

        language_model_inputs = language_model_inputs.to(inputs_embeds.device, inputs_embeds.dtype)
        special_image_mask = self.get_placeholder_mask(input_ids, inputs_embeds=inputs_embeds)
        inputs_embeds = inputs_embeds.masked_scatter(special_image_mask, language_model_inputs)

        if self.config.use_decoder_only_language_model:
            outputs = self.language_model(
                inputs_embeds=inputs_embeds,
                attention_mask=attention_mask,
                use_cache=use_cache,
                **kwargs,
            )
            logits = outputs[0]
            loss = None
            if labels is not None:
                loss = self.loss_function(
                    logits=logits, labels=labels, vocab_size=self.config.text_config.vocab_size, **kwargs
                )

        else:
            outputs = self.language_model(
                inputs_embeds=inputs_embeds,
                attention_mask=attention_mask,
                decoder_input_ids=decoder_input_ids,
                decoder_attention_mask=decoder_attention_mask,
                labels=labels,
                use_cache=use_cache,
                **kwargs,
            )
            loss = outputs.loss
            logits = outputs.logits

        return InstructBlipVideoForConditionalGenerationModelOutput(
            loss=loss,
            logits=logits,
            vision_outputs=vision_outputs,
            qformer_outputs=qformer_outputs,
            language_model_outputs=outputs,
        )

    @torch.no_grad()
    def generate(
        self,
        pixel_values: torch.FloatTensor,
        qformer_input_ids: torch.LongTensor | None = None,
        qformer_attention_mask: torch.LongTensor | None = None,
        input_ids: torch.LongTensor | None = None,
        attention_mask: torch.LongTensor | None = None,
        inputs_embeds: torch.FloatTensor | None = None,
        interpolate_pos_encoding: bool = False,
        **generate_kwargs,
    ) -> torch.LongTensor:
        r"""
        Overrides `generate` function to be able to use the model as a conditional generator.

        Args:
            pixel_values (`torch.FloatTensor` of shape (batch_size, num_channels, height, width) or
                (batch_size, num_frames, num_channels, height, width)): Input images or videos to be processed.
            qformer_input_ids (`torch.LongTensor` of shape (batch_size, sequence_length), *optional*):
                The sequence used as a prompt to be fed to the Q-Former module.
            qformer_attention_mask (`torch.LongTensor` of shape (batch_size, sequence_length), *optional*):
                Mask to avoid performing attention on padding token indices.
            input_ids (`torch.LongTensor` of shape (batch_size, sequence_length), *optional*):
                The sequence used as a prompt for the generation.
            attention_mask (`torch.LongTensor` of shape (batch_size, sequence_length), *optional*):
                Mask to avoid performing attention on padding token indices.
            inputs_embeds (`torch.FloatTensor` of shape `(batch_size, sequence_length, hidden_size)`):
                Embedded representation of the inputs. Should be float, not int tokens.
            interpolate_pos_encoding (`bool`, *optional*, defaults to `False`):
                Whether to interpolate the positional encoding of the image embeddings.

        Returns:
            captions (list): A list of strings of length batch_size * num_captions.
        """
        if hasattr(self, "hf_device_map"):
            # preprocess for `accelerate`
            self._preprocess_accelerate()

        batch_size = pixel_values.shape[0]
        video_features: BaseModelOutputWithVisionQformerOutputs = self.get_video_features(
            pixel_values,
            qformer_input_ids=qformer_input_ids,
            qformer_attention_mask=qformer_attention_mask,
            interpolate_pos_encoding=interpolate_pos_encoding,
        )
        language_model_inputs = video_features.pooler_output

        if inputs_embeds is None:
            if input_ids is None:
                video_tokens = [self.config.video_token_index] * self.config.num_query_tokens * 4
                start_tokens = video_tokens + [self.config.text_config.bos_token_id]
                input_ids = torch.tensor([start_tokens], dtype=torch.long, device=pixel_values.device)
                input_ids = input_ids.repeat(batch_size, 1)
            inputs_embeds = self.get_input_embeddings()(input_ids)

        if attention_mask is None:
            attention_mask = torch.ones_like(input_ids)

        language_model_inputs = language_model_inputs.to(inputs_embeds.device, inputs_embeds.dtype)
        special_image_mask = self.get_placeholder_mask(input_ids, inputs_embeds=inputs_embeds)
        inputs_embeds = inputs_embeds.masked_scatter(special_image_mask, language_model_inputs)

        inputs = {"inputs_embeds": inputs_embeds, "attention_mask": attention_mask}
        if not self.language_model.config.is_encoder_decoder:
            inputs["input_ids"] = input_ids

        outputs = self.language_model.generate(**inputs, **generate_kwargs)

        return outputs


__all__ = [
    "InstructBlipVideoConfig",
    "InstructBlipVideoQFormerConfig",
    "InstructBlipVideoVisionConfig",
    "InstructBlipVideoVisionModel",
    "InstructBlipVideoPreTrainedModel",
    "InstructBlipVideoQFormerModel",
    "InstructBlipVideoModel",
    "InstructBlipVideoForConditionalGeneration",
]
