# Copyright 2025 The 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.
"""Fast Image processor class for ZoeDepth."""

from typing import (
    Optional,
    Union,
)

import numpy as np
import torch
from torchvision.transforms.v2 import functional as F

from ...image_processing_utils import (
    BatchFeature,
)
from ...image_processing_utils_fast import (
    BaseImageProcessorFast,
    group_images_by_shape,
    reorder_images,
)
from ...image_utils import (
    IMAGENET_STANDARD_MEAN,
    IMAGENET_STANDARD_STD,
    ChannelDimension,
    ImageInput,
    PILImageResampling,
    SizeDict,
    get_image_size,
)
from ...processing_utils import Unpack
from ...utils import (
    TensorType,
    auto_docstring,
    logging,
    requires_backends,
)
from .image_processing_zoedepth import ZoeDepthImageProcessorKwargs, get_resize_output_image_size
from .modeling_zoedepth import ZoeDepthDepthEstimatorOutput


logger = logging.get_logger(__name__)


@auto_docstring
class ZoeDepthImageProcessorFast(BaseImageProcessorFast):
    do_pad = True
    do_rescale = True
    do_normalize = True
    image_mean = IMAGENET_STANDARD_MEAN
    image_std = IMAGENET_STANDARD_STD
    do_resize = True
    size = {"height": 384, "width": 512}
    resample = PILImageResampling.BILINEAR
    keep_aspect_ratio = True
    ensure_multiple_of = 1 / 32
    valid_kwargs = ZoeDepthImageProcessorKwargs

    def __init__(self, **kwargs: Unpack[ZoeDepthImageProcessorKwargs]) -> None:
        super().__init__(**kwargs)

    @auto_docstring
    def preprocess(
        self,
        images: ImageInput,
        **kwargs: Unpack[ZoeDepthImageProcessorKwargs],
    ) -> BatchFeature:
        return super().preprocess(images, **kwargs)

    def resize(
        self,
        images: "torch.Tensor",
        size: SizeDict,
        keep_aspect_ratio: bool = False,
        ensure_multiple_of: int = 1,
        interpolation: Optional["F.InterpolationMode"] = None,
    ) -> "torch.Tensor":
        """
        Resize an image or batchd images to target size `(size["height"], size["width"])`. If `keep_aspect_ratio` is `True`, the image
        is resized to the largest possible size such that the aspect ratio is preserved. If `ensure_multiple_of` is
        set, the image is resized to a size that is a multiple of this value.

        Args:
            images (`torch.Tensor`):
                Images to resize.
            size (`dict[str, int]`):
                Target size of the output image.
            keep_aspect_ratio (`bool`, *optional*, defaults to `False`):
                If `True`, the image is resized to the largest possible size such that the aspect ratio is preserved.
            ensure_multiple_of (`int`, *optional*, defaults to 1):
                The image is resized to a size that is a multiple of this value.
            interpolation (`F.InterpolationMode`, *optional*, defaults to `InterpolationMode.BILINEAR`):
                Defines the resampling filter to use if resizing the image. Otherwise, the image is resized to size
                specified in `size`.
        """
        if not size.height or not size.width:
            raise ValueError(f"The size dictionary must contain the keys 'height' and 'width'. Got {size}")
        output_size = get_resize_output_image_size(
            images,
            output_size=(size.height, size.width),
            keep_aspect_ratio=keep_aspect_ratio,
            multiple=ensure_multiple_of,
            input_data_format=ChannelDimension.FIRST,
        )
        height, width = output_size

        resized_images = torch.nn.functional.interpolate(
            images, (int(height), int(width)), mode=interpolation.value, align_corners=True
        )

        return resized_images

    def _pad_images(
        self,
        images: "torch.Tensor",
    ):
        """
        Args:
            image (`torch.Tensor`):
                Image to pad.
        """
        height, width = get_image_size(images, channel_dim=ChannelDimension.FIRST)

        pad_height = int(np.sqrt(height / 2) * 3)
        pad_width = int(np.sqrt(width / 2) * 3)

        return F.pad(images, padding=(pad_width, pad_height), padding_mode="reflect")

    def _preprocess(
        self,
        images: list["torch.Tensor"],
        do_resize: bool,
        size: SizeDict,
        keep_aspect_ratio: bool | None,
        ensure_multiple_of: int | None,
        interpolation: Optional["F.InterpolationMode"],
        do_pad: bool,
        do_rescale: bool,
        rescale_factor: float | None,
        do_normalize: bool,
        image_mean: float | list[float] | None,
        image_std: float | list[float] | None,
        disable_grouping: bool | None,
        return_tensors: str | TensorType | None = None,
        **kwargs,
    ) -> BatchFeature:
        # Group images by size for batched resizing
        grouped_images, grouped_images_index = group_images_by_shape(images, disable_grouping=disable_grouping)
        resized_images_grouped = {}
        for shape, stacked_images in grouped_images.items():
            if do_rescale:
                stacked_images = self.rescale(stacked_images, rescale_factor)
            if do_pad:
                stacked_images = self._pad_images(images=stacked_images)
            if do_resize:
                stacked_images = self.resize(
                    stacked_images, size, keep_aspect_ratio, ensure_multiple_of, interpolation
                )
            if do_normalize:
                stacked_images = self.normalize(stacked_images, image_mean, image_std)
            resized_images_grouped[shape] = stacked_images
        processed_images = reorder_images(resized_images_grouped, grouped_images_index)

        return BatchFeature(data={"pixel_values": processed_images}, tensor_type=return_tensors)

    def post_process_depth_estimation(
        self,
        outputs: "ZoeDepthDepthEstimatorOutput",
        source_sizes: TensorType | list[tuple[int, int]] | None | None = None,
        target_sizes: TensorType | list[tuple[int, int]] | None | None = None,
        outputs_flipped: Union["ZoeDepthDepthEstimatorOutput", None] | None = None,
        do_remove_padding: bool | None | None = None,
    ) -> list[dict[str, TensorType]]:
        """
        Converts the raw output of [`ZoeDepthDepthEstimatorOutput`] into final depth predictions and depth PIL images.
        Only supports PyTorch.

        Args:
            outputs ([`ZoeDepthDepthEstimatorOutput`]):
                Raw outputs of the model.
            source_sizes (`TensorType` or `list[tuple[int, int]]`, *optional*):
                Tensor of shape `(batch_size, 2)` or list of tuples (`tuple[int, int]`) containing the source size
                (height, width) of each image in the batch before preprocessing. This argument should be dealt as
                "required" unless the user passes `do_remove_padding=False` as input to this function.
            target_sizes (`TensorType` or `list[tuple[int, int]]`, *optional*):
                Tensor of shape `(batch_size, 2)` or list of tuples (`tuple[int, int]`) containing the target size
                (height, width) of each image in the batch. If left to None, predictions will not be resized.
            outputs_flipped ([`ZoeDepthDepthEstimatorOutput`], *optional*):
                Raw outputs of the model from flipped input (averaged out in the end).
            do_remove_padding (`bool`, *optional*):
                By default ZoeDepth adds padding equal to `int(√(height / 2) * 3)` (and similarly for width) to fix the
                boundary artifacts in the output depth map, so we need remove this padding during post_processing. The
                parameter exists here in case the user changed the image preprocessing to not include padding.

        Returns:
            `list[dict[str, TensorType]]`: A list of dictionaries of tensors representing the processed depth
            predictions.
        """
        requires_backends(self, "torch")

        predicted_depth = outputs.predicted_depth

        if (outputs_flipped is not None) and (predicted_depth.shape != outputs_flipped.predicted_depth.shape):
            raise ValueError("Make sure that `outputs` and `outputs_flipped` have the same shape")

        if (target_sizes is not None) and (len(predicted_depth) != len(target_sizes)):
            raise ValueError(
                "Make sure that you pass in as many target sizes as the batch dimension of the predicted depth"
            )

        if do_remove_padding is None:
            do_remove_padding = self.do_pad

        if source_sizes is None and do_remove_padding:
            raise ValueError(
                "Either `source_sizes` should be passed in, or `do_remove_padding` should be set to False"
            )

        if (source_sizes is not None) and (len(predicted_depth) != len(source_sizes)):
            raise ValueError(
                "Make sure that you pass in as many source image sizes as the batch dimension of the logits"
            )

        if outputs_flipped is not None:
            predicted_depth = (predicted_depth + torch.flip(outputs_flipped.predicted_depth, dims=[-1])) / 2

        predicted_depth = predicted_depth.unsqueeze(1)

        # Zoe Depth model adds padding around the images to fix the boundary artifacts in the output depth map
        # The padding length is `int(np.sqrt(img_h/2) * fh)` for the height and similar for the width
        # fh (and fw respectively) are equal to '3' by default
        # Check [here](https://github.com/isl-org/ZoeDepth/blob/edb6daf45458569e24f50250ef1ed08c015f17a7/zoedepth/models/depth_model.py#L57)
        # for the original implementation.
        # In this section, we remove this padding to get the final depth image and depth prediction
        padding_factor_h = padding_factor_w = 3

        results = []
        target_sizes = [None] * len(predicted_depth) if target_sizes is None else target_sizes
        source_sizes = [None] * len(predicted_depth) if source_sizes is None else source_sizes
        for depth, target_size, source_size in zip(predicted_depth, target_sizes, source_sizes):
            # depth.shape = [1, H, W]
            if source_size is not None:
                pad_h = pad_w = 0

                if do_remove_padding:
                    pad_h = int(np.sqrt(source_size[0] / 2) * padding_factor_h)
                    pad_w = int(np.sqrt(source_size[1] / 2) * padding_factor_w)

                depth = F.resize(
                    depth,
                    size=[source_size[0] + 2 * pad_h, source_size[1] + 2 * pad_w],
                    interpolation=F.InterpolationMode.BICUBIC,
                    antialias=False,
                )

                if pad_h > 0:
                    depth = depth[:, pad_h:-pad_h, :]
                if pad_w > 0:
                    depth = depth[:, :, pad_w:-pad_w]

            if target_size is not None:
                target_size = [target_size[0], target_size[1]]
                depth = F.resize(
                    depth,
                    size=target_size,
                    interpolation=F.InterpolationMode.BICUBIC,
                    antialias=False,
                )
            depth = depth.squeeze(0)
            # depth.shape = [H, W]
            results.append({"predicted_depth": depth})

        return results


__all__ = ["ZoeDepthImageProcessorFast"]
