# Copyright 2024 HuggingFace Inc.
#
# 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 unittest
from dataclasses import dataclass

import numpy as np

from transformers.testing_utils import require_torch, require_vision
from transformers.utils import is_torch_available

from ...test_image_processing_common import ImageProcessingTester, ImageProcessingTestMixin, prepare_image_inputs


if is_torch_available():
    import torch


@dataclass
class ZoeDepthDepthOutputProxy:
    predicted_depth: torch.FloatTensor = None


class ZoeDepthImageProcessingTester(ImageProcessingTester):
    def __init__(self, **kwargs):
        # Image processor init kwargs
        kwargs.setdefault("size", {"height": 18, "width": 18})
        kwargs.setdefault("ensure_multiple_of", 32)
        kwargs.setdefault("keep_aspect_ratio", False)

        super().__init__(**kwargs)

    def expected_output_image_shape(self, images):
        return self.num_channels, self.ensure_multiple_of, self.ensure_multiple_of

    def prepare_depth_outputs(self):
        depth_tensors = prepare_image_inputs(
            batch_size=self.batch_size,
            num_channels=1,
            min_resolution=self.min_resolution,
            max_resolution=self.max_resolution,
            equal_resolution=True,
            torchify=True,
        )
        depth_tensors = [depth_tensor.squeeze(0) for depth_tensor in depth_tensors]
        stacked_depth_tensors = torch.stack(depth_tensors, dim=0)
        return ZoeDepthDepthOutputProxy(predicted_depth=stacked_depth_tensors)


@require_torch
@require_vision
class ZoeDepthImageProcessingTest(ImageProcessingTestMixin, unittest.TestCase):
    image_processor_tester_class = ZoeDepthImageProcessingTester

    def test_ensure_multiple_of(self):
        # Test variable by turning off all other variables which affect the size, size which is not multiple of 32
        image = np.zeros((489, 640, 3))

        size = {"height": 380, "width": 513}
        multiple = 32
        for image_processor_class in self.image_processing_classes.values():
            image_processor = image_processor_class(
                do_pad=False, ensure_multiple_of=multiple, size=size, keep_aspect_ratio=False
            )
            pixel_values = image_processor(image, return_tensors="pt").pixel_values

            self.assertEqual(list(pixel_values.shape), [1, 3, 384, 512])
            self.assertTrue(pixel_values.shape[2] % multiple == 0)
            self.assertTrue(pixel_values.shape[3] % multiple == 0)

        # Test variable by turning off all other variables which affect the size, size which is already multiple of 32
        image = np.zeros((511, 511, 3))

        height, width = 512, 512
        size = {"height": height, "width": width}
        multiple = 32
        for image_processing_class in self.image_processing_classes.values():
            image_processor = image_processing_class(
                do_pad=False, ensure_multiple_of=multiple, size=size, keep_aspect_ratio=False
            )
            pixel_values = image_processor(image, return_tensors="pt").pixel_values

            self.assertEqual(list(pixel_values.shape), [1, 3, height, width])
            self.assertTrue(pixel_values.shape[2] % multiple == 0)
            self.assertTrue(pixel_values.shape[3] % multiple == 0)

    def test_keep_aspect_ratio(self):
        # Test `keep_aspect_ratio=True` by turning off all other variables which affect the size
        height, width = 489, 640
        image = np.zeros((height, width, 3))

        size = {"height": 512, "width": 512}
        for image_processing_class in self.image_processing_classes.values():
            image_processor = image_processing_class(
                do_pad=False, keep_aspect_ratio=True, size=size, ensure_multiple_of=1
            )
            pixel_values = image_processor(image, return_tensors="pt").pixel_values

            # As can be seen, the image is resized to the maximum size that fits in the specified size
            self.assertEqual(list(pixel_values.shape), [1, 3, 512, 670])

        # Test `keep_aspect_ratio=False` by turning off all other variables which affect the size
        for image_processing_class in self.image_processing_classes.values():
            image_processor = image_processing_class(
                do_pad=False, keep_aspect_ratio=False, size=size, ensure_multiple_of=1
            )
            pixel_values = image_processor(image, return_tensors="pt").pixel_values

            # As can be seen, the size is respected
            self.assertEqual(list(pixel_values.shape), [1, 3, size["height"], size["width"]])

        # Test `keep_aspect_ratio=True` with `ensure_multiple_of` set
        image = np.zeros((489, 640, 3))

        size = {"height": 511, "width": 511}
        multiple = 32
        for image_processing_class in self.image_processing_classes.values():
            image_processor = image_processing_class(size=size, keep_aspect_ratio=True, ensure_multiple_of=multiple)

            pixel_values = image_processor(image, return_tensors="pt").pixel_values

            self.assertEqual(list(pixel_values.shape), [1, 3, 512, 672])
            self.assertTrue(pixel_values.shape[2] % multiple == 0)
            self.assertTrue(pixel_values.shape[3] % multiple == 0)

    # extend this test to check if removal of padding works fine!
    def test_post_processing_equivalence(self):
        if len(self.image_processing_classes) < 2:
            self.skipTest(reason="Skipping post-processing equivalence test as there are less than 2 backends")

        outputs = self.image_processor_tester.prepare_depth_outputs()
        list(self.image_processing_classes.keys())
        image_processor_torchvision = self.image_processing_classes["torchvision"](**self.image_processor_dict)
        image_processor_pil = self.image_processing_classes["pil"](**self.image_processor_dict)

        source_sizes = [outputs.predicted_depth.shape[1:]] * self.image_processor_tester.batch_size
        target_sizes = [
            torch.Size([outputs.predicted_depth.shape[1] // 2, *(outputs.predicted_depth.shape[2:])])
        ] * self.image_processor_tester.batch_size

        processed_torchvision = image_processor_torchvision.post_process_depth_estimation(
            outputs,
            source_sizes=source_sizes,
            target_sizes=target_sizes,
        )
        processed_pil = image_processor_pil.post_process_depth_estimation(
            outputs,
            source_sizes=source_sizes,
            target_sizes=target_sizes,
        )
        for pred_torchvision, pred_pil in zip(processed_torchvision, processed_pil):
            depth_torchvision = pred_torchvision["predicted_depth"]
            depth_pil = pred_pil["predicted_depth"]

            torch.testing.assert_close(depth_torchvision, depth_pil, atol=1e-1, rtol=1e-3)
            self.assertLessEqual(torch.mean(torch.abs(depth_torchvision.float() - depth_pil.float())).item(), 5e-3)
