import copy
import math
import os
from typing import Dict, List, Optional, Union

import numpy as np
import torch
from PIL import Image
from transformers.feature_extraction_utils import BatchFeature
from transformers.image_processing_utils import (
    BaseImageProcessor,
    get_size_dict,
)
from transformers.image_transforms import (
    convert_to_rgb,
    get_resize_output_image_size,
    resize,
    to_channel_dimension_format,
)
from transformers.image_utils import (
    OPENAI_CLIP_MEAN,
    OPENAI_CLIP_STD,
    ChannelDimension,
    ImageInput,
    PILImageResampling,
    get_image_size,
    infer_channel_dimension_format,
    is_scaled_image,
    make_list_of_images,
    to_numpy_array,
    valid_images,
)
from transformers.utils import TensorType, logging

logger = logging.get_logger(__name__)


class HCXImageProcessor(BaseImageProcessor):
    r"""
    Constructs a VLM image processor. Based on [`CLIPImageProcessor`] with incorporation of additional techniques for processing high resolution images.
    Args:
        anyres: (bool) anyres 기능을 사용할지 안할지
        unpad: (bool) anyres 사용시, unpad 기능 (순수 pad 영역에 해당하는 visual tokens 은 LLM input 에서 제거) 을 사용할지 안할지
        num_queries_vis_abstractor: (int) 각 grid 에 대해서 resampler 를 사용하는 경우, visual query 수
        possible_resolutions: (List) anyres 기능 사용시, 가능한 resolution 조합, 예: [[336, 336], [336, 672], [672, 336]]
        patch_size: (int) ViT patch size
        pad_to_square: (bool) 정사각형으로 padding 을 수행할지, 안할지를 결정. False 이면 정사각형이 아니기 때문에 center crop 을 거쳐 ViT 의 입력으로 들어감
    """

    model_input_names = ["pixel_values"]

    def __init__(
        self,
        do_resize: bool = True,
        size: Dict[str, int] = None,
        anyres: bool = False,
        unpad: bool = False,
        num_queries_vis_abstractor_image: int = 81,
        num_queries_vis_abstractor_video_slow: int = 81,
        num_queries_vis_abstractor_video_fast: int = 9,
        first_last_frames_slow_video: bool = False,
        possible_resolutions: List = [],
        patch_size: int = 14,
        pad_to_square: bool = True,
        resample: PILImageResampling = PILImageResampling.BICUBIC,
        do_center_crop: bool = True,
        crop_size: Dict[str, int] = None,
        do_rescale: bool = True,
        rescale_factor: Union[int, float] = 1 / 255,
        do_normalize: bool = True,
        image_mean: Optional[Union[float, List[float]]] = None,
        image_std: Optional[Union[float, List[float]]] = None,
        do_convert_rgb: bool = True,
        **kwargs,
    ) -> None:
        super().__init__(**kwargs)
        size = size if size is not None else {"shortest_edge": 336}
        size = get_size_dict(size, default_to_square=False)
        crop_size = crop_size if crop_size is not None else {"height": 336, "width": 336}
        crop_size = get_size_dict(crop_size, default_to_square=True, param_name="crop_size")

        self.do_resize = do_resize
        self.size = size
        self.anyres = anyres
        self.unpad = unpad
        self.num_queries_vis_abstractor_image = num_queries_vis_abstractor_image
        self.num_queries_vis_abstractor_video_slow = num_queries_vis_abstractor_video_slow
        self.num_queries_vis_abstractor_video_fast = num_queries_vis_abstractor_video_fast
        self.first_last_frames_slow_video = first_last_frames_slow_video
        self.possible_resolutions = [_resolution for _resolution in possible_resolutions]
        self.patch_size = patch_size
        self.pad_to_square = pad_to_square
        self.resample = resample
        self.do_center_crop = do_center_crop
        self.crop_size = crop_size
        self.do_rescale = do_rescale
        self.rescale_factor = rescale_factor
        self.do_normalize = do_normalize
        self.image_mean = image_mean if image_mean is not None else OPENAI_CLIP_MEAN
        self.image_std = image_std if image_std is not None else OPENAI_CLIP_STD
        self.do_convert_rgb = do_convert_rgb

    def resize(
        self,
        image: np.ndarray,
        size: Dict[str, int],
        resample: PILImageResampling = PILImageResampling.BICUBIC,
        data_format: Optional[Union[str, ChannelDimension]] = None,
        input_data_format: Optional[Union[str, ChannelDimension]] = None,
        **kwargs,
    ) -> np.ndarray:
        default_to_square = True
        if "shortest_edge" in size:
            size = size["shortest_edge"]
            default_to_square = False
        elif "height" in size and "width" in size:
            size = (size["height"], size["width"])
        else:
            raise ValueError("Size must contain either 'shortest_edge' or 'height' and 'width'.")

        output_size = get_resize_output_image_size(
            image,
            size=size,
            default_to_square=default_to_square,
            input_data_format=input_data_format,
        )

        return resize(
            image,
            size=output_size,
            resample=resample,
            data_format=data_format,
            input_data_format=input_data_format,
            **kwargs,
        )

    def _preprocess(
        self,
        images: ImageInput,
        do_resize: bool = None,
        size: Dict[str, int] = None,
        resample: PILImageResampling = None,
        do_center_crop: bool = None,
        crop_size: int = None,
        do_rescale: bool = None,
        rescale_factor: float = None,
        do_normalize: bool = None,
        image_mean: Optional[Union[float, List[float]]] = None,
        image_std: Optional[Union[float, List[float]]] = None,
        data_format: Optional[ChannelDimension] = ChannelDimension.FIRST,
        input_data_format: Optional[Union[str, ChannelDimension]] = None,
    ) -> Image.Image:
        images = make_list_of_images(images)

        if do_resize:
            images = [
                self.resize(image=image, size=size, resample=resample, input_data_format=input_data_format)
                for image in images
            ]

        if do_center_crop:
            images = [
                self.center_crop(image=image, size=crop_size, input_data_format=input_data_format) for image in images
            ]

        if do_rescale:
            images = [
                self.rescale(image=image, scale=rescale_factor, input_data_format=input_data_format) for image in images
            ]

        if do_normalize:
            images = [
                self.normalize(image=image, mean=image_mean, std=image_std, input_data_format=input_data_format)
                for image in images
            ]

        images = [
            to_channel_dimension_format(image, data_format, input_channel_dim=input_data_format) for image in images
        ]

        return images

    def _resize_for_local_grids(
        self, image: np.array, target_resolution: tuple, resample, input_data_format: ChannelDimension
    ) -> np.array:
        new_height, new_width = _get_local_grids_output_size(image, target_resolution, input_data_format)

        # Resize the image
        resized_image = resize(image, (new_height, new_width), resample=resample, input_data_format=input_data_format)

        return resized_image

    def _pad_for_patching(
        self, image: np.array, target_resolution: tuple, input_data_format: ChannelDimension
    ) -> np.array:
        """
        Pad an image to a target resolution while maintaining aspect ratio.
        """
        target_height, target_width = target_resolution

        background_color = tuple(int(x * 255) for x in self.image_mean)
        padded_image = pad(
            image,
            target_size=(target_height, target_width),
            background_color=background_color,
            input_data_format=input_data_format,
        )

        return padded_image

    def get_image_grids(
        self,
        image: np.array,
        possible_resolutions,
        grid_size: int,
        resample: PILImageResampling,
        data_format: ChannelDimension,
        input_data_format: ChannelDimension,
    ) -> List[np.array]:
        if not isinstance(possible_resolutions, list):
            raise ValueError("possible_resolutions must be a list of possible resolutions.")

        image_size = get_image_size(image, channel_dim=input_data_format)
        best_resolution = select_best_resolution(image_size, possible_resolutions)
        resized_image = self._resize_for_local_grids(
            image, best_resolution, resample=resample, input_data_format=input_data_format
        )
        padded_image = self._pad_for_patching(resized_image, best_resolution, input_data_format=input_data_format)
        local_grids = divide_to_grids(padded_image, grid_size=grid_size, input_data_format=input_data_format)

        # make sure that all patches are in the input data format
        local_grids = [
            to_channel_dimension_format(grid, channel_dim=data_format, input_channel_dim=input_data_format)
            for grid in local_grids
        ]

        return local_grids

    def preprocess(
        self,
        images: ImageInput,
        do_resize: bool = None,
        size: Dict[str, int] = None,
        anyres: bool = None,
        unpad: bool = None,
        is_video: bool = False,
        num_queries_vis_abstractor_image: int = None,
        num_queries_vis_abstractor_video_slow: int = None,
        num_queries_vis_abstractor_video_fast: int = None,
        first_last_frames_slow_video: bool = None,
        possible_resolutions: List = None,
        patch_size: int = None,
        pad_to_square: bool = None,
        resample: PILImageResampling = None,
        do_center_crop: bool = None,
        crop_size: int = None,
        do_rescale: bool = None,
        rescale_factor: float = None,
        do_normalize: bool = None,
        image_mean: Optional[Union[float, List[float]]] = None,
        image_std: Optional[Union[float, List[float]]] = None,
        do_convert_rgb: bool = None,
        return_tensors: Optional[Union[str, TensorType]] = None,
        data_format: Optional[ChannelDimension] = ChannelDimension.FIRST,
        input_data_format: Optional[Union[str, ChannelDimension]] = None,
        return_dummy_image: bool = False,
        first_last_frames_slow: bool = False,
        is_first_or_last_frames: bool = False,
        **kwargs,
    ):
        """
        HCXVisionImageProcessor 로 image tensor, original image size (width, height), visual tokens
        :return pixel_values: List of 4D tensor 로 image tensor
        :return image_sizes: List of Dict 로 image width, height [{"width": image 1 의 width, "height": image 1 의 height}, {"width": image 2 의 width, "height": image 2 의 height}, ...]
        :return vision_query_lengths: List of int 로 각 image 가 LLM 입력으로 전달될때 변환되는 visual token 수
        """

        do_resize = do_resize if do_resize is not None else self.do_resize
        size = size if size is not None else self.size
        size = get_size_dict(size, param_name="size", default_to_square=False)
        anyres = anyres if anyres is not None else self.anyres
        unpad = unpad if unpad is not None else self.unpad
        num_queries_vis_abstractor_image = (
            num_queries_vis_abstractor_image
            if num_queries_vis_abstractor_image is not None
            else self.num_queries_vis_abstractor_image
        )
        num_queries_vis_abstractor_video_slow = (
            num_queries_vis_abstractor_video_slow
            if num_queries_vis_abstractor_video_slow is not None
            else self.num_queries_vis_abstractor_video_slow
        )
        num_queries_vis_abstractor_video_fast = (
            num_queries_vis_abstractor_video_fast
            if num_queries_vis_abstractor_video_fast is not None
            else self.num_queries_vis_abstractor_video_fast
        )
        first_last_frames_slow_video = (
            first_last_frames_slow_video
            if first_last_frames_slow_video is not None
            else self.first_last_frames_slow_video
        )
        possible_resolutions = possible_resolutions if possible_resolutions is not None else self.possible_resolutions
        patch_size = patch_size if patch_size is not None else self.patch_size
        pad_to_square = pad_to_square if pad_to_square is not None else self.pad_to_square
        resample = resample if resample is not None else self.resample
        do_center_crop = do_center_crop if do_center_crop is not None else self.do_center_crop
        crop_size = crop_size if crop_size is not None else self.crop_size
        crop_size = get_size_dict(crop_size, param_name="crop_size", default_to_square=True)
        do_rescale = do_rescale if do_rescale is not None else self.do_rescale
        rescale_factor = rescale_factor if rescale_factor is not None else self.rescale_factor
        do_normalize = do_normalize if do_normalize is not None else self.do_normalize
        image_mean = image_mean if image_mean is not None else self.image_mean
        image_std = image_std if image_std is not None else self.image_std
        do_convert_rgb = do_convert_rgb if do_convert_rgb is not None else self.do_convert_rgb

        if is_video:
            num_queries_vis_abstractor = num_queries_vis_abstractor_video_fast
            num_queries_vis_abstractor_slow = num_queries_vis_abstractor_video_slow
            unpad = False
        else:
            num_queries_vis_abstractor = num_queries_vis_abstractor_image
            num_queries_vis_abstractor_slow = 0

        if return_dummy_image:
            images = Image.new("RGB", (224, 224), (0, 0, 0))

        images = make_list_of_images(images)

        if not valid_images(images):
            raise ValueError(
                "Invalid image type. Must be of type PIL.Image.Image, numpy.ndarray, "
                "torch.Tensor, tf.Tensor or jax.ndarray."
            )

        if do_convert_rgb:
            images = [convert_to_rgb(image) for image in images]

        # All transformations expect numpy arrays.
        images = [to_numpy_array(image) for image in images]

        if is_scaled_image(images[0]) and do_rescale:
            logger.warning_once(
                "It looks like you are trying to rescale already rescaled images. If the input"
                " images have pixel values between 0 and 1, set `do_rescale=False` to avoid rescaling them again."
            )

        if input_data_format is None:
            # We assume that all images have the same channel dimension format.
            input_data_format = infer_channel_dimension_format(images[0])

        new_images = []
        image_sizes = [get_image_size(image, channel_dim=input_data_format) for image in images]
        vision_query_lengths = []

        assert crop_size["height"] == crop_size["width"]

        # global image 의 padding 연산은, image original width, height 가 클 때 bottleneck 이 될 수 있음
        # 장축의 길이를 size["shortest_edge"] 로 resize 를 먼저 한 뒤에, padding
        if anyres:
            anyres_global_images = copy.deepcopy(images)
            if pad_to_square:
                background_color = tuple(int(x * 255) for x in self.image_mean)
                anyres_global_images = [
                    resize_longside(copy.deepcopy(image), size["shortest_edge"], resample, input_data_format)
                    for image in anyres_global_images
                ]
                anyres_global_images = [
                    expand2square(image, background_color=background_color, input_data_format=input_data_format)[0]
                    for image in anyres_global_images
                ]
            else:
                anyres_global_images = [
                    self.resize(
                        image=image,
                        size={"height": size["shortest_edge"], "width": size["shortest_edge"]},
                        resample=resample,
                        input_data_format=input_data_format,
                    )
                    for image in anyres_global_images
                ]
        else:
            anyres_global_images = [None for _ in range(len(images))]
            if pad_to_square:
                background_color = tuple(int(x * 255) for x in self.image_mean)
                images = [
                    resize_longside(image, size["shortest_edge"], resample, input_data_format) for image in images
                ]
                images = [
                    expand2square(image, background_color=background_color, input_data_format=input_data_format)[0]
                    for image in images
                ]

        for image, anyres_global_image, image_size in zip(images, anyres_global_images, image_sizes):
            if anyres:
                # convert image into a list of grids
                # we intentially use the same data format as the input data format
                image_grids = self.get_image_grids(
                    image,
                    possible_resolutions,
                    grid_size=crop_size["height"],
                    resample=resample,
                    data_format=input_data_format,
                    input_data_format=input_data_format,
                )
                # video 에 대해서는 global image (thumbnail) 를 사용하지 않음
                if not is_video:
                    image_grids = [anyres_global_image] + image_grids
            else:
                image_grids = [image]

            pixel_values = self._preprocess(
                image_grids,
                do_resize=do_resize,
                size=size,
                resample=resample,
                do_center_crop=do_center_crop,
                crop_size=crop_size,
                do_rescale=do_rescale,
                rescale_factor=rescale_factor,
                do_normalize=do_normalize,
                image_mean=image_mean,
                image_std=image_std,
                data_format=data_format,
                input_data_format=input_data_format,
            )

            pixel_values = np.array(pixel_values)
            new_images.append(pixel_values)

            vision_query_length = determine_anyres_num_vision_patches(
                image_size=image_size,
                grid_size=crop_size["height"],
                patch_size=patch_size,
                possible_resolutions=possible_resolutions,
                anyres=anyres,
                unpad=unpad,
                num_queries_vis_abstractor=num_queries_vis_abstractor,
                num_queries_vis_abstractor_slow=num_queries_vis_abstractor_slow,
                is_video=is_video,
                first_last_frames_slow=first_last_frames_slow,
                is_first_or_last_frames=is_first_or_last_frames,
            )

            vision_query_lengths.append(vision_query_length)

        if return_dummy_image:
            vision_query_lengths = []

        data = {
            "pixel_values": [torch.tensor(new_image) for new_image in new_images],
            "image_sizes": [{"width": image_size[1], "height": image_size[0]} for image_size in image_sizes],
            "vision_query_lengths": vision_query_lengths,
        }

        return BatchFeature(data=data, tensor_type=return_tensors)

    def save_pretrained(
        self,
        save_directory: Union[str, os.PathLike],
        *args,
        **kwargs,
    ):
        self.register_for_auto_class()
        super().save_pretrained(save_directory, *args, **kwargs)


def determine_anyres_num_vision_patches(
    image_size,
    grid_size,
    patch_size,
    possible_resolutions,
    anyres=False,
    unpad=True,
    num_queries_vis_abstractor=0,
    num_queries_vis_abstractor_slow=0,
    is_video=False,
    first_last_frames_slow=False,  # sample-wise option
    is_first_or_last_frames=False,  # grid-wise option
):
    """
    Computes the number of visual tokens (patches) based on image resolution, grid configuration, and patch size.

    This function supports both fixed-size and any-resolution settings, as well as video-specific configurations
    such as handling slow frames and frame position flags.

    Args:
        num_grids (int): Number of grids per image (e.g., 1 for 1x1, 4 for 2x2, etc.).
        image_size (tuple): The original image size as (height, width).
        grid_size (int): Size of each grid in pixels (e.g., 336).
        patch_size (int): Size of each vision patch (e.g., 14 for ViT models).
        possible_resolutions (list): List of possible resolution tuples [(h1, w1), (h2, w2), ...].
        anyres (bool, optional): Whether to use any-resolution mode. Defaults to False.
        unpad (bool, optional): Whether to unpad the image before computing patches. Defaults to True.
        num_queries_vis_abstractor (int, optional): Number of query tokens for vision abstractor (fast path).
        num_queries_vis_abstractor_slow (int, optional): Number of query tokens for vision abstractor (slow path).
        is_video (bool, optional): Whether the input is a video. Defaults to False.
        first_last_frames_slow (bool, optional): Whether to treat first/last video frames as "slow". Defaults to False.
        is_first_or_last_frames (bool, optional): Whether current grid corresponds to first/last frame. Defaults to False.

    Returns:
        int: Total number of visual tokens (patches) after processing.
    """

    if not anyres:
        return num_queries_vis_abstractor if num_queries_vis_abstractor > 0 else (grid_size // patch_size) ** 2

    if num_queries_vis_abstractor > 0:
        num_patch_per_grid = int(num_queries_vis_abstractor**0.5)
    else:
        num_patch_per_grid = grid_size // patch_size

    num_global_per_grid = num_patch_per_grid

    # In anyres mode, a global image is included, so there are always at least 2 grids.
    # However, for video inputs, there is no global image, so it's possible to have only 1 grid.
    # Therefore, the assertion below is commented out:
    # assert num_grids > 1

    # Compute the number of vision patches.
    height, width = select_best_resolution(image_size, possible_resolutions)

    num_patch_height = (height // grid_size) * num_patch_per_grid
    num_patch_width = (width // grid_size) * num_patch_per_grid

    # local images
    if unpad:
        original_height, original_width = image_size

        original_aspect_ratio = original_width / original_height
        current_aspect_ratio = num_patch_width / num_patch_height

        if original_aspect_ratio > current_aspect_ratio:
            scale_factor = num_patch_width / original_width
            new_height = int(original_height * scale_factor)
            padding = (num_patch_height - new_height) // 2
            num_patch_height = num_patch_height - padding * 2
        else:
            scale_factor = num_patch_height / original_height
            new_width = int(original_width * scale_factor)
            padding = (num_patch_width - new_width) // 2
            num_patch_width = num_patch_width - padding * 2

        num_patches = num_patch_width * num_patch_height + num_patch_height
    else:
        num_patches = num_patch_width * num_patch_height

    # In the "slow" strategy, when applying to first and last frames only, it is applied exclusively to those two frames.
    if num_queries_vis_abstractor_slow > 0:
        if first_last_frames_slow:
            if is_first_or_last_frames:
                num_patches += num_queries_vis_abstractor_slow - num_queries_vis_abstractor
        else:
            num_patches += num_queries_vis_abstractor_slow - num_queries_vis_abstractor
        # The slowfast feature is only applicable when unpad is set to False.
        assert unpad is False

    # Global image is not included for video inputs.
    if not is_video:
        num_patches += num_global_per_grid**2

    return num_patches


def divide_to_grids(image: np.array, grid_size: int, input_data_format=None) -> List[np.array]:
    """
    Divides a local image into grids of size (grid_size x grid_size).

    Args:
        image (np.array): Input image as a NumPy array.
        grid_size (int): The size (in pixels) of each square grid.
        input_data_format (optional): Optional format specifier (e.g., "channels_first" or "channels_last").

    Returns:
        List[np.array]: A list of image patches, each of size (grid_size x grid_size).
    """
    grids = []
    height, width = get_image_size(image, channel_dim=input_data_format)
    for i in range(0, height, grid_size):
        for j in range(0, width, grid_size):
            if input_data_format == ChannelDimension.LAST:
                grid = image[i : i + grid_size, j : j + grid_size]
            else:
                grid = image[:, i : i + grid_size, j : j + grid_size]
            grids.append(grid)

    return grids


def pad(
    image: np.array,
    target_size: tuple,
    background_color=(127, 127, 127),
    input_data_format=None,
) -> np.array:
    """
    Pads the input image on the sides (top/bottom and left/right) to match the target height and width.

    Args:
        image (np.array): Input image as a NumPy array.
        target_size (tuple): Target size as (target_height, target_width).
        background_color (tuple, optional): RGB color value used for padding. Defaults to (127, 127, 127).
        input_data_format (optional): Optional format specifier (e.g., "channels_first" or "channels_last").

    Returns:
        np.array: The padded image with the specified target size.
    """
    target_height, target_width = target_size
    height, width = get_image_size(image, channel_dim=input_data_format)

    # result = np.ones((target_height, target_width, image.shape[2]), dtype=image.dtype) * background_color
    result = np.empty((target_height, target_width, image.shape[2]), dtype=image.dtype)
    for i in range(image.shape[2]):
        result[..., i].fill(background_color[i])

    paste_x = (target_width - width) // 2
    paste_y = (target_height - height) // 2

    result[paste_y : paste_y + height, paste_x : paste_x + width, :] = image

    return result


def expand2square(
    image: np.array,
    bboxes_dict=None,
    background_color=(127, 127, 127),
    input_data_format=None,
) -> np.array:
    """
    Expands the input image to a square shape by placing it at the center of a new square canvas,
    with padding added to the shorter side (either top/bottom or left/right).

    The image is always centered on the new canvas, and padding is applied symmetrically.

    Args:
        image (np.array): Input image as a NumPy array.
        bboxes_dict (dict, optional): A dictionary of bounding boxes, where each value is an NDArray of shape (N, 4, 2)
            with box coordinates in the format [[xtl, ytl], [xtr, ytr], [xbr, ybr], [xbl, ybl]].
            Supports multiple categories (e.g., "ocr", "html") simultaneously.
        background_color (tuple, optional): RGB color to fill the padding area. Defaults to (127, 127, 127).
        input_data_format (optional): Optional format specifier for image data (e.g., "channels_first" or "channels_last").

    Returns:
        np.array: A square-shaped image with the original image centered and padded as needed.

    Example:
        >>> _img = np.ones((80, 100), dtype=np.uint8) * 100
        >>> _bboxes_dict = {"words": np.array([[[10, 10], [20, 10], [20, 20], [10, 20]],
        ...                                    [[30, 30], [40, 30], [40, 40], [30, 40]]])}
        >>> _img, _bboxes_dict = expand2square(_img, _bboxes_dict, (255, 255, 255))
        >>> _img.shape
        (100, 100)
        >>> guessed_ocr_bboxes = np.array([[[20, 10], [30, 10], [30, 20], [20, 20]],
        ...                                [[40, 30], [50, 30], [50, 40], [40, 40]]])
        >>> np.testing.assert_array_almost_equal(_bboxes_dict["words"], guessed_ocr_bboxes) is None
        True
    """
    height, width = get_image_size(image, channel_dim=input_data_format)
    if width == height:
        return image, bboxes_dict
    elif width > height:
        # result = np.ones((width, width, image.shape[2]), dtype=image.dtype) * background_color
        result = np.empty((width, width, image.shape[2]), dtype=image.dtype)
        for i in range(image.shape[2]):
            result[..., i].fill(background_color[i])

        result[(width - height) // 2 : (width - height) // 2 + height, :] = image
        if bboxes_dict is not None:
            for key in bboxes_dict:
                bboxes_dict[key][:, :, 1] += (width - height) // 2
        return result, bboxes_dict
    else:
        # result = np.ones((height, height, image.shape[2]), dtype=image.dtype) * background_color
        result = np.empty((height, height, image.shape[2]), dtype=image.dtype)
        for i in range(image.shape[2]):
            result[..., i].fill(background_color[i])

        result[:, (height - width) // 2 : (height - width) // 2 + width] = image
        if bboxes_dict is not None:
            for key in bboxes_dict:
                bboxes_dict[key][:, :, 0] += (height - width) // 2
        return result, bboxes_dict


def resize_longside(
    image: np.array,
    size: int,
    resample: PILImageResampling = PILImageResampling.BICUBIC,  # type: ignore
    data_format: Optional[Union[str, ChannelDimension]] = None,
    input_data_format: Optional[Union[str, ChannelDimension]] = None,
):
    """
    Resizes the image so that its longer side matches the specified size, maintaining the original aspect ratio.

    Args:
        image (np.array): Input image as a NumPy array.
        size (int): Target size for the longer side of the image.
        resample (PILImageResampling, optional): Resampling method to use during resizing. Defaults to BICUBIC.
        data_format (str or ChannelDimension, optional): Output data format (e.g., "channels_first" or "channels_last").
        input_data_format (str or ChannelDimension, optional): Input data format of the image.

    Returns:
        np.array: The resized image with its aspect ratio preserved.
    """
    height, width = get_image_size(image, channel_dim=input_data_format)

    if width == height:
        target_height, target_width = size, size
    elif width > height:
        target_width = size
        target_height = math.ceil(height / width * size)
    else:
        target_width = math.ceil(width / height * size)
        target_height = size

    return resize(
        image,
        size=(target_height, target_width),
        resample=resample,
        data_format=data_format,
        input_data_format=input_data_format,
    )


def _get_local_grids_output_size(image: np.array, target_resolution: tuple, input_data_format=None):
    """
    Computes the number of local grids (patches) along the height and width when resizing an image
    to the target resolution.

    Args:
        image (np.array): Input image as a NumPy array.
        target_resolution (tuple): Target resolution in the format (target_height, target_width).
        input_data_format (optional): Optional format specifier (e.g., "channels_first" or "channels_last").

    Returns:
        tuple: A tuple (grid_h, grid_w) representing the number of grids along the height and width.
    """
    original_height, original_width = get_image_size(image, channel_dim=input_data_format)
    target_height, target_width = target_resolution

    scale_w = target_width / original_width
    scale_h = target_height / original_height

    if scale_w < scale_h:
        new_width = target_width
        new_height = min(math.ceil(original_height * scale_w), target_height)
    else:
        new_height = target_height
        new_width = min(math.ceil(original_width * scale_h), target_width)

    return new_height, new_width


def select_best_resolution(original_size: tuple, possible_resolutions: list) -> tuple:
    """
    Selects the best-fit resolution from a list of possible resolutions based on the original image size.

    This function, adapted from LLaVA-Next
    (https://github.com/huggingface/transformers/blob/v4.40.2/src/transformers/models/llava_next/image_processing_llava_next.py),
    evaluates each resolution by computing its effective and wasted area compared to the original size.
    The optimal resolution is the one that maximizes the effective area while minimizing unused (wasted) space.

    Args:
        original_size (tuple): The original image size in the format (height, width).
        possible_resolutions (list): A list of candidate resolutions in the format [(height1, width1), (height2, width2), ...].

    Returns:
        tuple: The best-fit resolution in the format (height, width).
    """
    original_height, original_width = original_size
    best_fit = None
    max_effective_resolution = 0
    min_wasted_resolution = float("inf")

    for height, width in possible_resolutions:
        scale = min(width / original_width, height / original_height)
        downscaled_width, downscaled_height = int(original_width * scale), int(original_height * scale)
        effective_resolution = min(downscaled_width * downscaled_height, original_width * original_height)
        wasted_resolution = (width * height) - effective_resolution

        if effective_resolution > max_effective_resolution or (
            effective_resolution == max_effective_resolution and wasted_resolution < min_wasted_resolution
        ):
            max_effective_resolution = effective_resolution
            min_wasted_resolution = wasted_resolution
            best_fit = (height, width)

    return best_fit
