# coding=utf-8
# Copyright 2024 The HuggingFace Inc. team.
#
# 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
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"""
Processor class for LLaVa-NeXT.
"""

from typing import Optional, Union

import numpy as np

from ...feature_extraction_utils import BatchFeature
from ...image_processing_utils import select_best_resolution
from ...image_utils import ImageInput, get_image_size, to_numpy_array
from ...processing_utils import (
    MultiModalData,
    ProcessingKwargs,
    ProcessorMixin,
    Unpack,
)
from ...tokenization_utils_base import PreTokenizedInput, TextInput
from ...utils import logging


logger = logging.get_logger(__name__)


class LlavaNextProcessorKwargs(ProcessingKwargs, total=False):
    _defaults = {
        "text_kwargs": {
            "padding": False,
            "return_mm_token_type_ids": False,
        },
        "images_kwargs": {
            "do_pad": True,
        },
    }


class LlavaNextProcessor(ProcessorMixin):
    r"""
    Constructs a LLaVa-NeXT processor which wraps a LLaVa-NeXT image processor and a LLaMa tokenizer into a single processor.

    [`LlavaNextProcessor`] offers all the functionalities of [`LlavaNextImageProcessor`] and [`LlamaTokenizerFast`]. See the
    [`~LlavaNextProcessor.__call__`] and [`~LlavaNextProcessor.decode`] for more information.

    Args:
        image_processor ([`LlavaNextImageProcessor`], *optional*):
            The image processor is a required input.
        tokenizer ([`LlamaTokenizerFast`], *optional*):
            The tokenizer is a required input.
        patch_size (`int`, *optional*):
            Patch size from the vision tower.
        vision_feature_select_strategy (`str`, *optional*):
            The feature selection strategy used to select the vision feature from the vision backbone.
            Should be same as in model's config
        chat_template (`str`, *optional*): A Jinja template which will be used to convert lists of messages
            in a chat into a tokenizable string.
        image_token (`str`, *optional*, defaults to `"<image>"`):
            Special token used to denote image location.
        num_additional_image_tokens (`int`, *optional*, defaults to 0):
            Number of additional tokens added to the image embeddings, such as CLS (+1). If the backbone has no CLS or other
            extra tokens appended, no need to set this arg.
    """

    attributes = ["image_processor", "tokenizer"]
    image_processor_class = "AutoImageProcessor"
    tokenizer_class = "AutoTokenizer"

    def __init__(
        self,
        image_processor=None,
        tokenizer=None,
        patch_size=None,
        vision_feature_select_strategy=None,
        chat_template=None,
        image_token="<image>",  # set the default and let users change if they have peculiar special tokens in rare cases
        num_additional_image_tokens=0,
        **kwargs,
    ):
        self.patch_size = patch_size
        self.num_additional_image_tokens = num_additional_image_tokens
        self.vision_feature_select_strategy = vision_feature_select_strategy
        self.image_token = tokenizer.image_token if hasattr(tokenizer, "image_token") else image_token
        self.image_token_id = (
            tokenizer.image_token_id
            if getattr(tokenizer, "image_token_id", None)
            else tokenizer.convert_tokens_to_ids(self.image_token)
        )
        super().__init__(image_processor, tokenizer, chat_template=chat_template)

    def __call__(
        self,
        images: Optional[ImageInput] = None,
        text: Union[TextInput, PreTokenizedInput, list[TextInput], list[PreTokenizedInput]] = None,
        **kwargs: Unpack[LlavaNextProcessorKwargs],
    ) -> BatchFeature:
        """
        Main method to prepare for the model one or several sequences(s) and image(s). This method forwards the `text`
        and `kwargs` arguments to LlamaTokenizerFast's [`~LlamaTokenizerFast.__call__`] if `text` is not `None` to encode
        the text. To prepare the image(s), this method forwards the `images` and `kwargs` arguments to
        LlavaNextImageProcessor's [`~LlavaNextImageProcessor.__call__`] if `images` is not `None`. Please refer to the docstring
        of the above two methods for more information.

        Args:
            images (`PIL.Image.Image`, `np.ndarray`, `torch.Tensor`, `list[PIL.Image.Image]`, `list[np.ndarray]`, `list[torch.Tensor]`):
                The image or batch of images to be prepared. Each image can be a PIL image, NumPy array or PyTorch
                tensor. Both channels-first and channels-last formats are supported.
            text (`str`, `list[str]`, `list[list[str]]`):
                The sequence or batch of sequences to be encoded. Each sequence can be a string or a list of strings
                (pretokenized string). If the sequences are provided as list of strings (pretokenized), you must set
                `is_split_into_words=True` (to lift the ambiguity with a batch of sequences).

        Returns:
            [`BatchFeature`]: A [`BatchFeature`] with the following fields:

            - **input_ids** -- List of token ids to be fed to a model. Returned when `text` is not `None`.
            - **attention_mask** -- List of indices specifying which tokens should be attended to by the model (when
              `return_attention_mask=True` or if *"attention_mask"* is in `self.model_input_names` and if `text` is not
              `None`).
            - **pixel_values** -- Pixel values to be fed to a model. Returned when `images` is not `None`.
        """
        if images is None and text is None:
            raise ValueError("You have to specify at least images or text.")

        output_kwargs = self._merge_kwargs(
            LlavaNextProcessorKwargs,
            tokenizer_init_kwargs=self.tokenizer.init_kwargs,
            **kwargs,
        )
        if images is not None:
            image_inputs = self.image_processor(images, **output_kwargs["images_kwargs"])
        else:
            image_inputs = {}

        if isinstance(text, str):
            text = [text]
        elif not isinstance(text, list) and not isinstance(text[0], str):
            raise TypeError("Invalid input text. Please provide a string, or a list of strings")

        prompt_strings = text
        if image_inputs:
            image_sizes = iter(image_inputs["image_sizes"])
            height, width = get_image_size(to_numpy_array(image_inputs["pixel_values"][0][0]))
            prompt_strings = []
            for sample in text:
                while self.image_token in sample:
                    image_size = next(image_sizes)
                    if not isinstance(image_size, (list, tuple)):
                        # cast to list to avoid numerical precision errors when calculating unpadding
                        image_size = image_size.tolist()
                    orig_height, orig_width = image_size
                    num_image_tokens = self._get_number_of_features(orig_height, orig_width, height, width)
                    if self.vision_feature_select_strategy == "default":
                        num_image_tokens -= 1
                    sample = sample.replace(self.image_token, "<placeholder>" * num_image_tokens, 1)
                prompt_strings.append(sample)
            prompt_strings = [sample.replace("<placeholder>", self.image_token) for sample in prompt_strings]

        return_tensors = output_kwargs["text_kwargs"].pop("return_tensors", None)
        return_mm_token_type_ids = output_kwargs["text_kwargs"].pop("return_mm_token_type_ids", None)
        text_inputs = self.tokenizer(prompt_strings, **output_kwargs["text_kwargs"])
        self._check_special_mm_tokens(prompt_strings, text_inputs, modalities=["image"])

        if return_mm_token_type_ids:
            array_ids = np.array(text_inputs["input_ids"])
            mm_token_type_ids = np.zeros_like(text_inputs["input_ids"])
            mm_token_type_ids[array_ids == self.image_token_id] = 1
            text_inputs["mm_token_type_ids"] = mm_token_type_ids.tolist()

        return BatchFeature(data={**text_inputs, **image_inputs}, tensor_type=return_tensors)

    def _get_number_of_features(self, orig_height: int, orig_width: int, height: int, width: int) -> int:
        image_grid_pinpoints = self.image_processor.image_grid_pinpoints

        height_best_resolution, width_best_resolution = select_best_resolution(
            [orig_height, orig_width], image_grid_pinpoints
        )
        scale_height, scale_width = height_best_resolution // height, width_best_resolution // width

        patches_height = height // self.patch_size
        patches_width = width // self.patch_size
        unpadded_features, newline_features = self._get_unpadded_features(
            orig_height, orig_width, patches_height, patches_width, scale_height, scale_width
        )
        # The base patch covers the entire image (+1 for the CLS)
        base_features = patches_height * patches_width + self.num_additional_image_tokens
        num_image_tokens = unpadded_features + newline_features + base_features
        return num_image_tokens

    def _get_unpadded_features(self, height, width, patches_height, patches_width, scale_height, scale_width):
        """
        Get number of features for a given image with height/width. LLaVA-NeXT is different from LLaVA
        because it divided each image into patches depending on its resolution. Therefore we need to calculate how many
        patches an image is divided into and get the number of features from that.
        """
        current_height = patches_height * scale_height
        current_width = patches_width * scale_width

        original_aspect_ratio = width / height
        current_aspect_ratio = current_width / current_height
        if original_aspect_ratio > current_aspect_ratio:
            new_height = int(round(height * (current_width / width), 7))
            padding = (current_height - new_height) // 2
            current_height -= padding * 2
        else:
            new_width = int(round(width * (current_height / height), 7))
            padding = (current_width - new_width) // 2
            current_width -= padding * 2

        unpadded_features = current_height * current_width
        newline_features = current_height
        return (unpadded_features, newline_features)

    def _get_num_multimodal_tokens(self, image_sizes=None, **kwargs):
        """
        Computes the number of placeholder tokens needed for multimodal inputs with the given sizes.
        Args:
            image_sizes (list[list[str]], *optional*):
                The input sizes formatted as (height, width) per each image.
        Returns:
            `MultiModalData`: A `MultiModalData` object holding number of tokens per each of the provided
            input modalities, along with other useful data.
        """
        vision_data = {}
        if image_sizes is not None:
            images_kwargs = LlavaNextProcessorKwargs._defaults.get("images_kwargs", {})
            images_kwargs.update(kwargs)

            size = images_kwargs.get("size", None) or self.image_processor.size
            size = (
                (size["shortest_edge"], size["shortest_edge"])
                if "shortest_edge" in size
                else (min(size["height"], size["width"]), min(size["height"], size["width"]))
            )
            processed_height, processed_width = size

            batch_num_image_tokens = []
            num_image_patches = [1] * len(image_sizes)  # llava-next doesn't batch pixels as Idefics, thus `1` patch`
            for image_size in image_sizes:
                orig_height, orig_width = image_size
                num_image_tokens = self._get_number_of_features(
                    orig_height, orig_width, processed_height, processed_width
                )
                if self.vision_feature_select_strategy == "default":
                    num_image_tokens -= 1
                batch_num_image_tokens.append(num_image_tokens)
            vision_data.update({"num_image_tokens": batch_num_image_tokens, "num_image_patches": num_image_patches})

        return MultiModalData(**vision_data)


__all__ = ["LlavaNextProcessor"]
