# coding=utf-8
# Copyright 2022 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.
""" Testing suite for the PyTorch MaskFormer model. """

import inspect
import unittest

import numpy as np

from tests.test_modeling_common import floats_tensor
from transformers import DetrConfig, MaskFormerConfig, SwinConfig, is_torch_available, is_vision_available
from transformers.testing_utils import require_torch, require_vision, slow, torch_device
from transformers.utils import cached_property

from ...test_configuration_common import ConfigTester
from ...test_modeling_common import ModelTesterMixin


if is_torch_available():
    import torch

    from transformers import MaskFormerForInstanceSegmentation, MaskFormerModel

    if is_vision_available():
        from transformers import MaskFormerFeatureExtractor

if is_vision_available():
    from PIL import Image


class MaskFormerModelTester:
    def __init__(
        self,
        parent,
        batch_size=2,
        is_training=True,
        use_auxiliary_loss=False,
        num_queries=10,
        num_channels=3,
        min_size=32 * 4,
        max_size=32 * 6,
        num_labels=4,
        mask_feature_size=32,
    ):
        self.parent = parent
        self.batch_size = batch_size
        self.is_training = is_training
        self.use_auxiliary_loss = use_auxiliary_loss
        self.num_queries = num_queries
        self.num_channels = num_channels
        self.min_size = min_size
        self.max_size = max_size
        self.num_labels = num_labels
        self.mask_feature_size = mask_feature_size

    def prepare_config_and_inputs(self):
        pixel_values = floats_tensor([self.batch_size, self.num_channels, self.min_size, self.max_size]).to(
            torch_device
        )

        pixel_mask = torch.ones([self.batch_size, self.min_size, self.max_size], device=torch_device)

        mask_labels = (
            torch.rand([self.batch_size, self.num_labels, self.min_size, self.max_size], device=torch_device) > 0.5
        ).float()
        class_labels = (torch.rand((self.batch_size, self.num_labels), device=torch_device) > 0.5).long()

        config = self.get_config()
        return config, pixel_values, pixel_mask, mask_labels, class_labels

    def get_config(self):
        return MaskFormerConfig.from_backbone_and_decoder_configs(
            backbone_config=SwinConfig(
                depths=[1, 1, 1, 1],
            ),
            decoder_config=DetrConfig(
                decoder_ffn_dim=128,
                num_queries=self.num_queries,
                decoder_attention_heads=2,
                d_model=self.mask_feature_size,
            ),
            mask_feature_size=self.mask_feature_size,
            fpn_feature_size=self.mask_feature_size,
            num_channels=self.num_channels,
            num_labels=self.num_labels,
        )

    def prepare_config_and_inputs_for_common(self):
        config, pixel_values, pixel_mask, _, _ = self.prepare_config_and_inputs()
        inputs_dict = {"pixel_values": pixel_values, "pixel_mask": pixel_mask}
        return config, inputs_dict

    def check_output_hidden_state(self, output, config):
        encoder_hidden_states = output.encoder_hidden_states
        pixel_decoder_hidden_states = output.pixel_decoder_hidden_states
        transformer_decoder_hidden_states = output.transformer_decoder_hidden_states

        self.parent.assertTrue(len(encoder_hidden_states), len(config.backbone_config.depths))
        self.parent.assertTrue(len(pixel_decoder_hidden_states), len(config.backbone_config.depths))
        self.parent.assertTrue(len(transformer_decoder_hidden_states), config.decoder_config.decoder_layers)

    def create_and_check_maskformer_model(self, config, pixel_values, pixel_mask, output_hidden_states=False):
        with torch.no_grad():
            model = MaskFormerModel(config=config)
            model.to(torch_device)
            model.eval()

            output = model(pixel_values=pixel_values, pixel_mask=pixel_mask)
            output = model(pixel_values, output_hidden_states=True)
        # the correct shape of output.transformer_decoder_hidden_states ensure the correcteness of the
        # encoder and pixel decoder
        self.parent.assertEqual(
            output.transformer_decoder_last_hidden_state.shape,
            (self.batch_size, self.num_queries, self.mask_feature_size),
        )
        # let's ensure the other two hidden state exists
        self.parent.assertTrue(output.pixel_decoder_last_hidden_state is not None)
        self.parent.assertTrue(output.encoder_last_hidden_state is not None)

        if output_hidden_states:
            self.check_output_hidden_state(output, config)

    def create_and_check_maskformer_instance_segmentation_head_model(
        self, config, pixel_values, pixel_mask, mask_labels, class_labels
    ):
        model = MaskFormerForInstanceSegmentation(config=config)
        model.to(torch_device)
        model.eval()

        def comm_check_on_output(result):
            # let's still check that all the required stuff is there
            self.parent.assertTrue(result.transformer_decoder_last_hidden_state is not None)
            self.parent.assertTrue(result.pixel_decoder_last_hidden_state is not None)
            self.parent.assertTrue(result.encoder_last_hidden_state is not None)
            # okay, now we need to check the logits shape
            # due to the encoder compression, masks have a //4 spatial size
            self.parent.assertEqual(
                result.masks_queries_logits.shape,
                (self.batch_size, self.num_queries, self.min_size // 4, self.max_size // 4),
            )
            # + 1 for null class
            self.parent.assertEqual(
                result.class_queries_logits.shape, (self.batch_size, self.num_queries, self.num_labels + 1)
            )

        with torch.no_grad():
            result = model(pixel_values=pixel_values, pixel_mask=pixel_mask)
            result = model(pixel_values)

            comm_check_on_output(result)

            result = model(
                pixel_values=pixel_values, pixel_mask=pixel_mask, mask_labels=mask_labels, class_labels=class_labels
            )

        comm_check_on_output(result)

        self.parent.assertTrue(result.loss is not None)
        self.parent.assertEqual(result.loss.shape, torch.Size([1]))


@require_torch
class MaskFormerModelTest(ModelTesterMixin, unittest.TestCase):

    all_model_classes = (MaskFormerModel, MaskFormerForInstanceSegmentation) if is_torch_available() else ()

    is_encoder_decoder = False
    test_pruning = False
    test_head_masking = False
    test_missing_keys = False

    def setUp(self):
        self.model_tester = MaskFormerModelTester(self)
        self.config_tester = ConfigTester(self, config_class=MaskFormerConfig, has_text_modality=False)

    def test_config(self):
        self.config_tester.run_common_tests()

    def test_maskformer_model(self):
        config, inputs = self.model_tester.prepare_config_and_inputs_for_common()
        self.model_tester.create_and_check_maskformer_model(config, **inputs, output_hidden_states=False)

    def test_maskformer_instance_segmentation_head_model(self):
        config_and_inputs = self.model_tester.prepare_config_and_inputs()
        self.model_tester.create_and_check_maskformer_instance_segmentation_head_model(*config_and_inputs)

    @unittest.skip(reason="MaskFormer does not use inputs_embeds")
    def test_inputs_embeds(self):
        pass

    @unittest.skip(reason="MaskFormer does not have a get_input_embeddings method")
    def test_model_common_attributes(self):
        pass

    @unittest.skip(reason="MaskFormer is not a generative model")
    def test_generate_without_input_ids(self):
        pass

    @unittest.skip(reason="MaskFormer does not use token embeddings")
    def test_resize_tokens_embeddings(self):
        pass

    def test_forward_signature(self):
        config, _ = self.model_tester.prepare_config_and_inputs_for_common()

        for model_class in self.all_model_classes:
            model = model_class(config)
            signature = inspect.signature(model.forward)
            # signature.parameters is an OrderedDict => so arg_names order is deterministic
            arg_names = [*signature.parameters.keys()]

            expected_arg_names = ["pixel_values"]
            self.assertListEqual(arg_names[:1], expected_arg_names)

    @slow
    def test_model_from_pretrained(self):
        for model_name in ["facebook/maskformer-swin-small-coco"]:
            model = MaskFormerModel.from_pretrained(model_name)
            self.assertIsNotNone(model)

    def test_model_with_labels(self):
        size = (self.model_tester.min_size,) * 2
        inputs = {
            "pixel_values": torch.randn((2, 3, *size), device=torch_device),
            "mask_labels": torch.randn((2, 10, *size), device=torch_device),
            "class_labels": torch.zeros(2, 10, device=torch_device).long(),
        }

        model = MaskFormerForInstanceSegmentation(MaskFormerConfig()).to(torch_device)
        outputs = model(**inputs)
        self.assertTrue(outputs.loss is not None)

    def test_hidden_states_output(self):
        config, inputs = self.model_tester.prepare_config_and_inputs_for_common()
        self.model_tester.create_and_check_maskformer_model(config, **inputs, output_hidden_states=True)

    def test_attention_outputs(self):
        config, inputs = self.model_tester.prepare_config_and_inputs_for_common()

        for model_class in self.all_model_classes:
            model = model_class(config).to(torch_device)
            outputs = model(**inputs, output_attentions=True)
            self.assertTrue(outputs.attentions is not None)

    def test_training(self):
        if not self.model_tester.is_training:
            return
        # only MaskFormerForInstanceSegmentation has the loss
        model_class = self.all_model_classes[1]
        config, pixel_values, pixel_mask, mask_labels, class_labels = self.model_tester.prepare_config_and_inputs()

        model = model_class(config)
        model.to(torch_device)
        model.train()

        loss = model(pixel_values, mask_labels=mask_labels, class_labels=class_labels).loss
        loss.backward()

    def test_retain_grad_hidden_states_attentions(self):
        # only MaskFormerForInstanceSegmentation has the loss
        model_class = self.all_model_classes[1]
        config, pixel_values, pixel_mask, mask_labels, class_labels = self.model_tester.prepare_config_and_inputs()
        config.output_hidden_states = True
        config.output_attentions = True

        model = model_class(config)
        model.to(torch_device)
        model.train()

        outputs = model(pixel_values, mask_labels=mask_labels, class_labels=class_labels)

        encoder_hidden_states = outputs.encoder_hidden_states[0]
        encoder_hidden_states.retain_grad()

        pixel_decoder_hidden_states = outputs.pixel_decoder_hidden_states[0]
        pixel_decoder_hidden_states.retain_grad()
        # we requires_grad=True in inputs_embeds (line 2152), the original implementation don't
        transformer_decoder_hidden_states = outputs.transformer_decoder_hidden_states[0]
        transformer_decoder_hidden_states.retain_grad()

        attentions = outputs.attentions[0]
        attentions.retain_grad()

        outputs.loss.backward(retain_graph=True)

        self.assertIsNotNone(encoder_hidden_states.grad)
        self.assertIsNotNone(pixel_decoder_hidden_states.grad)
        self.assertIsNotNone(transformer_decoder_hidden_states.grad)
        self.assertIsNotNone(attentions.grad)


TOLERANCE = 1e-4


# We will verify our results on an image of cute cats
def prepare_img():
    image = Image.open("./tests/fixtures/tests_samples/COCO/000000039769.png")
    return image


@require_vision
@slow
class MaskFormerModelIntegrationTest(unittest.TestCase):
    @cached_property
    def model_checkpoints(self):
        return "facebook/maskformer-swin-small-coco"

    @cached_property
    def default_feature_extractor(self):
        return MaskFormerFeatureExtractor.from_pretrained(self.model_checkpoints) if is_vision_available() else None

    def test_inference_no_head(self):
        model = MaskFormerModel.from_pretrained(self.model_checkpoints).to(torch_device)
        feature_extractor = self.default_feature_extractor
        image = prepare_img()
        inputs = feature_extractor(image, return_tensors="pt").to(torch_device)
        inputs_shape = inputs["pixel_values"].shape
        # check size is divisible by 32
        self.assertTrue((inputs_shape[-1] % 32) == 0 and (inputs_shape[-2] % 32) == 0)
        # check size
        self.assertEqual(inputs_shape, (1, 3, 800, 1088))

        with torch.no_grad():
            outputs = model(**inputs)

        expected_slice_hidden_state = torch.tensor(
            [[-0.0482, 0.9228, 0.4951], [-0.2547, 0.8017, 0.8527], [-0.0069, 0.3385, -0.0089]]
        ).to(torch_device)
        self.assertTrue(
            torch.allclose(
                outputs.encoder_last_hidden_state[0, 0, :3, :3], expected_slice_hidden_state, atol=TOLERANCE
            )
        )

        expected_slice_hidden_state = torch.tensor(
            [[-0.8422, -0.8434, -0.9718], [-1.0144, -0.5565, -0.4195], [-1.0038, -0.4484, -0.1961]]
        ).to(torch_device)
        self.assertTrue(
            torch.allclose(
                outputs.pixel_decoder_last_hidden_state[0, 0, :3, :3], expected_slice_hidden_state, atol=TOLERANCE
            )
        )

        expected_slice_hidden_state = torch.tensor(
            [[0.2852, -0.0159, 0.9735], [0.6254, 0.1858, 0.8529], [-0.0680, -0.4116, 1.8413]]
        ).to(torch_device)
        self.assertTrue(
            torch.allclose(
                outputs.transformer_decoder_last_hidden_state[0, :3, :3], expected_slice_hidden_state, atol=TOLERANCE
            )
        )

    def test_inference_instance_segmentation_head(self):
        model = MaskFormerForInstanceSegmentation.from_pretrained(self.model_checkpoints).to(torch_device).eval()
        feature_extractor = self.default_feature_extractor
        image = prepare_img()
        inputs = feature_extractor(image, return_tensors="pt").to(torch_device)
        inputs_shape = inputs["pixel_values"].shape
        # check size is divisible by 32
        self.assertTrue((inputs_shape[-1] % 32) == 0 and (inputs_shape[-2] % 32) == 0)
        # check size
        self.assertEqual(inputs_shape, (1, 3, 800, 1088))

        with torch.no_grad():
            outputs = model(**inputs)
        # masks_queries_logits
        masks_queries_logits = outputs.masks_queries_logits
        self.assertEqual(
            masks_queries_logits.shape, (1, model.config.num_queries, inputs_shape[-2] // 4, inputs_shape[-1] // 4)
        )
        expected_slice = torch.tensor(
            [[-1.3738, -1.7725, -1.9365], [-1.5978, -1.9869, -2.1524], [-1.5796, -1.9271, -2.0940]]
        ).to(torch_device)
        self.assertTrue(torch.allclose(masks_queries_logits[0, 0, :3, :3], expected_slice, atol=TOLERANCE))
        # class_queries_logits
        class_queries_logits = outputs.class_queries_logits
        self.assertEqual(class_queries_logits.shape, (1, model.config.num_queries, model.config.num_labels + 1))
        expected_slice = torch.tensor(
            [
                [1.6512e00, -5.2572e00, -3.3519e00],
                [3.6169e-02, -5.9025e00, -2.9313e00],
                [1.0766e-04, -7.7630e00, -5.1263e00],
            ]
        ).to(torch_device)
        self.assertTrue(torch.allclose(outputs.class_queries_logits[0, :3, :3], expected_slice, atol=TOLERANCE))

    def test_with_segmentation_maps_and_loss(self):
        model = MaskFormerForInstanceSegmentation.from_pretrained(self.model_checkpoints).to(torch_device).eval()
        feature_extractor = self.default_feature_extractor

        inputs = feature_extractor(
            [np.zeros((3, 800, 1333)), np.zeros((3, 800, 1333))],
            segmentation_maps=[np.zeros((384, 384)).astype(np.float32), np.zeros((384, 384)).astype(np.float32)],
            return_tensors="pt",
        )

        inputs["pixel_values"] = inputs["pixel_values"].to(torch_device)
        inputs["mask_labels"] = [el.to(torch_device) for el in inputs["mask_labels"]]
        inputs["class_labels"] = [el.to(torch_device) for el in inputs["class_labels"]]

        with torch.no_grad():
            outputs = model(**inputs)

        self.assertTrue(outputs.loss is not None)
