# coding=utf-8
# Copyright 2025 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 gc
import unittest

import numpy as np
import torch
from transformers import CLIPTextConfig, CLIPTextModelWithProjection, CLIPTokenizer

from diffusers import PriorTransformer, UnCLIPPipeline, UnCLIPScheduler, UNet2DConditionModel, UNet2DModel
from diffusers.pipelines.unclip.text_proj import UnCLIPTextProjModel
from diffusers.utils.testing_utils import (
    backend_empty_cache,
    backend_max_memory_allocated,
    backend_reset_max_memory_allocated,
    backend_reset_peak_memory_stats,
    enable_full_determinism,
    load_numpy,
    nightly,
    require_torch_accelerator,
    skip_mps,
    torch_device,
)

from ..pipeline_params import TEXT_TO_IMAGE_BATCH_PARAMS, TEXT_TO_IMAGE_PARAMS
from ..test_pipelines_common import PipelineTesterMixin, assert_mean_pixel_difference


enable_full_determinism()


class UnCLIPPipelineFastTests(PipelineTesterMixin, unittest.TestCase):
    pipeline_class = UnCLIPPipeline
    params = TEXT_TO_IMAGE_PARAMS - {
        "negative_prompt",
        "height",
        "width",
        "negative_prompt_embeds",
        "guidance_scale",
        "prompt_embeds",
        "cross_attention_kwargs",
    }
    batch_params = TEXT_TO_IMAGE_BATCH_PARAMS
    required_optional_params = [
        "generator",
        "return_dict",
        "prior_num_inference_steps",
        "decoder_num_inference_steps",
        "super_res_num_inference_steps",
    ]
    test_xformers_attention = False

    @property
    def text_embedder_hidden_size(self):
        return 32

    @property
    def time_input_dim(self):
        return 32

    @property
    def block_out_channels_0(self):
        return self.time_input_dim

    @property
    def time_embed_dim(self):
        return self.time_input_dim * 4

    @property
    def cross_attention_dim(self):
        return 100

    @property
    def dummy_tokenizer(self):
        tokenizer = CLIPTokenizer.from_pretrained("hf-internal-testing/tiny-random-clip")
        return tokenizer

    @property
    def dummy_text_encoder(self):
        torch.manual_seed(0)
        config = CLIPTextConfig(
            bos_token_id=0,
            eos_token_id=2,
            hidden_size=self.text_embedder_hidden_size,
            projection_dim=self.text_embedder_hidden_size,
            intermediate_size=37,
            layer_norm_eps=1e-05,
            num_attention_heads=4,
            num_hidden_layers=5,
            pad_token_id=1,
            vocab_size=1000,
        )
        return CLIPTextModelWithProjection(config)

    @property
    def dummy_prior(self):
        torch.manual_seed(0)

        model_kwargs = {
            "num_attention_heads": 2,
            "attention_head_dim": 12,
            "embedding_dim": self.text_embedder_hidden_size,
            "num_layers": 1,
        }

        model = PriorTransformer(**model_kwargs)
        return model

    @property
    def dummy_text_proj(self):
        torch.manual_seed(0)

        model_kwargs = {
            "clip_embeddings_dim": self.text_embedder_hidden_size,
            "time_embed_dim": self.time_embed_dim,
            "cross_attention_dim": self.cross_attention_dim,
        }

        model = UnCLIPTextProjModel(**model_kwargs)
        return model

    @property
    def dummy_decoder(self):
        torch.manual_seed(0)

        model_kwargs = {
            "sample_size": 32,
            # RGB in channels
            "in_channels": 3,
            # Out channels is double in channels because predicts mean and variance
            "out_channels": 6,
            "down_block_types": ("ResnetDownsampleBlock2D", "SimpleCrossAttnDownBlock2D"),
            "up_block_types": ("SimpleCrossAttnUpBlock2D", "ResnetUpsampleBlock2D"),
            "mid_block_type": "UNetMidBlock2DSimpleCrossAttn",
            "block_out_channels": (self.block_out_channels_0, self.block_out_channels_0 * 2),
            "layers_per_block": 1,
            "cross_attention_dim": self.cross_attention_dim,
            "attention_head_dim": 4,
            "resnet_time_scale_shift": "scale_shift",
            "class_embed_type": "identity",
        }

        model = UNet2DConditionModel(**model_kwargs)
        return model

    @property
    def dummy_super_res_kwargs(self):
        return {
            "sample_size": 64,
            "layers_per_block": 1,
            "down_block_types": ("ResnetDownsampleBlock2D", "ResnetDownsampleBlock2D"),
            "up_block_types": ("ResnetUpsampleBlock2D", "ResnetUpsampleBlock2D"),
            "block_out_channels": (self.block_out_channels_0, self.block_out_channels_0 * 2),
            "in_channels": 6,
            "out_channels": 3,
        }

    @property
    def dummy_super_res_first(self):
        torch.manual_seed(0)

        model = UNet2DModel(**self.dummy_super_res_kwargs)
        return model

    @property
    def dummy_super_res_last(self):
        # seeded differently to get different unet than `self.dummy_super_res_first`
        torch.manual_seed(1)

        model = UNet2DModel(**self.dummy_super_res_kwargs)
        return model

    def get_dummy_components(self):
        prior = self.dummy_prior
        decoder = self.dummy_decoder
        text_proj = self.dummy_text_proj
        text_encoder = self.dummy_text_encoder
        tokenizer = self.dummy_tokenizer
        super_res_first = self.dummy_super_res_first
        super_res_last = self.dummy_super_res_last

        prior_scheduler = UnCLIPScheduler(
            variance_type="fixed_small_log",
            prediction_type="sample",
            num_train_timesteps=1000,
            clip_sample_range=5.0,
        )

        decoder_scheduler = UnCLIPScheduler(
            variance_type="learned_range",
            prediction_type="epsilon",
            num_train_timesteps=1000,
        )

        super_res_scheduler = UnCLIPScheduler(
            variance_type="fixed_small_log",
            prediction_type="epsilon",
            num_train_timesteps=1000,
        )

        components = {
            "prior": prior,
            "decoder": decoder,
            "text_proj": text_proj,
            "text_encoder": text_encoder,
            "tokenizer": tokenizer,
            "super_res_first": super_res_first,
            "super_res_last": super_res_last,
            "prior_scheduler": prior_scheduler,
            "decoder_scheduler": decoder_scheduler,
            "super_res_scheduler": super_res_scheduler,
        }

        return components

    def get_dummy_inputs(self, device, seed=0):
        if str(device).startswith("mps"):
            generator = torch.manual_seed(seed)
        else:
            generator = torch.Generator(device=device).manual_seed(seed)
        inputs = {
            "prompt": "horse",
            "generator": generator,
            "prior_num_inference_steps": 2,
            "decoder_num_inference_steps": 2,
            "super_res_num_inference_steps": 2,
            "output_type": "np",
        }
        return inputs

    def test_unclip(self):
        device = "cpu"

        components = self.get_dummy_components()

        pipe = self.pipeline_class(**components)
        pipe = pipe.to(device)

        pipe.set_progress_bar_config(disable=None)

        output = pipe(**self.get_dummy_inputs(device))
        image = output.images

        image_from_tuple = pipe(
            **self.get_dummy_inputs(device),
            return_dict=False,
        )[0]

        image_slice = image[0, -3:, -3:, -1]
        image_from_tuple_slice = image_from_tuple[0, -3:, -3:, -1]

        assert image.shape == (1, 64, 64, 3)

        expected_slice = np.array(
            [
                0.9997,
                0.9988,
                0.0028,
                0.9997,
                0.9984,
                0.9965,
                0.0029,
                0.9986,
                0.0025,
            ]
        )

        assert np.abs(image_slice.flatten() - expected_slice).max() < 1e-2
        assert np.abs(image_from_tuple_slice.flatten() - expected_slice).max() < 1e-2

    def test_unclip_passed_text_embed(self):
        device = torch.device("cpu")

        class DummyScheduler:
            init_noise_sigma = 1

        components = self.get_dummy_components()

        pipe = self.pipeline_class(**components)
        pipe = pipe.to(device)

        prior = components["prior"]
        decoder = components["decoder"]
        super_res_first = components["super_res_first"]
        tokenizer = components["tokenizer"]
        text_encoder = components["text_encoder"]

        generator = torch.Generator(device=device).manual_seed(0)
        dtype = prior.dtype
        batch_size = 1

        shape = (batch_size, prior.config.embedding_dim)
        prior_latents = pipe.prepare_latents(
            shape, dtype=dtype, device=device, generator=generator, latents=None, scheduler=DummyScheduler()
        )
        shape = (batch_size, decoder.config.in_channels, decoder.config.sample_size, decoder.config.sample_size)
        generator = torch.Generator(device=device).manual_seed(0)
        decoder_latents = pipe.prepare_latents(
            shape, dtype=dtype, device=device, generator=generator, latents=None, scheduler=DummyScheduler()
        )

        shape = (
            batch_size,
            super_res_first.config.in_channels // 2,
            super_res_first.config.sample_size,
            super_res_first.config.sample_size,
        )
        super_res_latents = pipe.prepare_latents(
            shape, dtype=dtype, device=device, generator=generator, latents=None, scheduler=DummyScheduler()
        )

        pipe.set_progress_bar_config(disable=None)

        prompt = "this is a prompt example"

        generator = torch.Generator(device=device).manual_seed(0)
        output = pipe(
            [prompt],
            generator=generator,
            prior_num_inference_steps=2,
            decoder_num_inference_steps=2,
            super_res_num_inference_steps=2,
            prior_latents=prior_latents,
            decoder_latents=decoder_latents,
            super_res_latents=super_res_latents,
            output_type="np",
        )
        image = output.images

        text_inputs = tokenizer(
            prompt,
            padding="max_length",
            max_length=tokenizer.model_max_length,
            return_tensors="pt",
        )
        text_model_output = text_encoder(text_inputs.input_ids)
        text_attention_mask = text_inputs.attention_mask

        generator = torch.Generator(device=device).manual_seed(0)
        image_from_text = pipe(
            generator=generator,
            prior_num_inference_steps=2,
            decoder_num_inference_steps=2,
            super_res_num_inference_steps=2,
            prior_latents=prior_latents,
            decoder_latents=decoder_latents,
            super_res_latents=super_res_latents,
            text_model_output=text_model_output,
            text_attention_mask=text_attention_mask,
            output_type="np",
        )[0]

        # make sure passing text embeddings manually is identical
        assert np.abs(image - image_from_text).max() < 1e-4

    # Overriding PipelineTesterMixin::test_attention_slicing_forward_pass
    # because UnCLIP GPU undeterminism requires a looser check.
    @skip_mps
    def test_attention_slicing_forward_pass(self):
        test_max_difference = torch_device == "cpu"

        self._test_attention_slicing_forward_pass(test_max_difference=test_max_difference, expected_max_diff=0.01)

    # Overriding PipelineTesterMixin::test_inference_batch_single_identical
    # because UnCLIP undeterminism requires a looser check.
    @skip_mps
    def test_inference_batch_single_identical(self):
        additional_params_copy_to_batched_inputs = [
            "prior_num_inference_steps",
            "decoder_num_inference_steps",
            "super_res_num_inference_steps",
        ]

        self._test_inference_batch_single_identical(
            additional_params_copy_to_batched_inputs=additional_params_copy_to_batched_inputs, expected_max_diff=9.8e-3
        )

    def test_inference_batch_consistent(self):
        additional_params_copy_to_batched_inputs = [
            "prior_num_inference_steps",
            "decoder_num_inference_steps",
            "super_res_num_inference_steps",
        ]

        if torch_device == "mps":
            # TODO: MPS errors with larger batch sizes
            batch_sizes = [2, 3]
            self._test_inference_batch_consistent(
                batch_sizes=batch_sizes,
                additional_params_copy_to_batched_inputs=additional_params_copy_to_batched_inputs,
            )
        else:
            self._test_inference_batch_consistent(
                additional_params_copy_to_batched_inputs=additional_params_copy_to_batched_inputs
            )

    @skip_mps
    def test_dict_tuple_outputs_equivalent(self):
        return super().test_dict_tuple_outputs_equivalent()

    @skip_mps
    def test_save_load_local(self):
        return super().test_save_load_local(expected_max_difference=5e-3)

    @skip_mps
    def test_save_load_optional_components(self):
        return super().test_save_load_optional_components()

    @unittest.skip("UnCLIP produces very large differences in fp16 vs fp32. Test is not useful.")
    def test_float16_inference(self):
        super().test_float16_inference(expected_max_diff=1.0)


@nightly
class UnCLIPPipelineCPUIntegrationTests(unittest.TestCase):
    def setUp(self):
        # clean up the VRAM before each test
        super().setUp()
        gc.collect()
        backend_empty_cache(torch_device)

    def tearDown(self):
        # clean up the VRAM after each test
        super().tearDown()
        gc.collect()
        backend_empty_cache(torch_device)

    def test_unclip_karlo_cpu_fp32(self):
        expected_image = load_numpy(
            "https://huggingface.co/datasets/hf-internal-testing/diffusers-images/resolve/main"
            "/unclip/karlo_v1_alpha_horse_cpu.npy"
        )

        pipeline = UnCLIPPipeline.from_pretrained("kakaobrain/karlo-v1-alpha")
        pipeline.set_progress_bar_config(disable=None)

        generator = torch.manual_seed(0)
        output = pipeline(
            "horse",
            num_images_per_prompt=1,
            generator=generator,
            output_type="np",
        )

        image = output.images[0]

        assert image.shape == (256, 256, 3)
        assert np.abs(expected_image - image).max() < 1e-1


@nightly
@require_torch_accelerator
class UnCLIPPipelineIntegrationTests(unittest.TestCase):
    def setUp(self):
        # clean up the VRAM before each test
        super().setUp()
        gc.collect()
        backend_empty_cache(torch_device)

    def tearDown(self):
        # clean up the VRAM after each test
        super().tearDown()
        gc.collect()
        backend_empty_cache(torch_device)

    def test_unclip_karlo(self):
        expected_image = load_numpy(
            "https://huggingface.co/datasets/hf-internal-testing/diffusers-images/resolve/main"
            "/unclip/karlo_v1_alpha_horse_fp16.npy"
        )

        pipeline = UnCLIPPipeline.from_pretrained("kakaobrain/karlo-v1-alpha", torch_dtype=torch.float16)
        pipeline = pipeline.to(torch_device)
        pipeline.set_progress_bar_config(disable=None)

        generator = torch.Generator(device="cpu").manual_seed(0)
        output = pipeline(
            "horse",
            generator=generator,
            output_type="np",
        )

        image = output.images[0]

        assert image.shape == (256, 256, 3)

        assert_mean_pixel_difference(image, expected_image)

    def test_unclip_pipeline_with_sequential_cpu_offloading(self):
        backend_empty_cache(torch_device)
        backend_reset_max_memory_allocated(torch_device)
        backend_reset_peak_memory_stats(torch_device)

        pipe = UnCLIPPipeline.from_pretrained("kakaobrain/karlo-v1-alpha", torch_dtype=torch.float16)
        pipe.set_progress_bar_config(disable=None)
        pipe.enable_attention_slicing()
        pipe.enable_sequential_cpu_offload()

        _ = pipe(
            "horse",
            num_images_per_prompt=1,
            prior_num_inference_steps=2,
            decoder_num_inference_steps=2,
            super_res_num_inference_steps=2,
            output_type="np",
        )

        mem_bytes = backend_max_memory_allocated(torch_device)
        # make sure that less than 7 GB is allocated
        assert mem_bytes < 7 * 10**9
