# coding=utf-8
# Copyright 2023 The HuggingFace Inc. team.
# Copyright (c) 2022, NVIDIA CORPORATION.  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.

import fnmatch
import importlib
import inspect
import os
import re
import warnings
from dataclasses import dataclass
from pathlib import Path
from typing import Any, Callable, Dict, List, Optional, Union

import numpy as np
import PIL
import torch
from huggingface_hub import hf_hub_download, model_info, snapshot_download
from packaging import version
from PIL import Image
from tqdm.auto import tqdm

import diffusers

from .. import __version__
from ..configuration_utils import ConfigMixin
from ..models.modeling_utils import _LOW_CPU_MEM_USAGE_DEFAULT
from ..schedulers.scheduling_utils import SCHEDULER_CONFIG_NAME
from ..utils import (
    CONFIG_NAME,
    DEPRECATED_REVISION_ARGS,
    DIFFUSERS_CACHE,
    HF_HUB_OFFLINE,
    SAFETENSORS_WEIGHTS_NAME,
    WEIGHTS_NAME,
    BaseOutput,
    deprecate,
    get_class_from_dynamic_module,
    is_accelerate_available,
    is_accelerate_version,
    is_safetensors_available,
    is_torch_version,
    is_transformers_available,
    logging,
)


if is_transformers_available():
    import transformers
    from transformers import PreTrainedModel
    from transformers.utils import FLAX_WEIGHTS_NAME as TRANSFORMERS_FLAX_WEIGHTS_NAME
    from transformers.utils import SAFE_WEIGHTS_NAME as TRANSFORMERS_SAFE_WEIGHTS_NAME
    from transformers.utils import WEIGHTS_NAME as TRANSFORMERS_WEIGHTS_NAME

from ..utils import FLAX_WEIGHTS_NAME, ONNX_EXTERNAL_WEIGHTS_NAME, ONNX_WEIGHTS_NAME


if is_accelerate_available():
    import accelerate


INDEX_FILE = "diffusion_pytorch_model.bin"
CUSTOM_PIPELINE_FILE_NAME = "pipeline.py"
DUMMY_MODULES_FOLDER = "diffusers.utils"
TRANSFORMERS_DUMMY_MODULES_FOLDER = "transformers.utils"


logger = logging.get_logger(__name__)


LOADABLE_CLASSES = {
    "diffusers": {
        "ModelMixin": ["save_pretrained", "from_pretrained"],
        "SchedulerMixin": ["save_pretrained", "from_pretrained"],
        "DiffusionPipeline": ["save_pretrained", "from_pretrained"],
        "OnnxRuntimeModel": ["save_pretrained", "from_pretrained"],
    },
    "transformers": {
        "PreTrainedTokenizer": ["save_pretrained", "from_pretrained"],
        "PreTrainedTokenizerFast": ["save_pretrained", "from_pretrained"],
        "PreTrainedModel": ["save_pretrained", "from_pretrained"],
        "FeatureExtractionMixin": ["save_pretrained", "from_pretrained"],
        "ProcessorMixin": ["save_pretrained", "from_pretrained"],
        "ImageProcessingMixin": ["save_pretrained", "from_pretrained"],
    },
    "onnxruntime.training": {
        "ORTModule": ["save_pretrained", "from_pretrained"],
    },
}

ALL_IMPORTABLE_CLASSES = {}
for library in LOADABLE_CLASSES:
    ALL_IMPORTABLE_CLASSES.update(LOADABLE_CLASSES[library])


@dataclass
class ImagePipelineOutput(BaseOutput):
    """
    Output class for image pipelines.

    Args:
        images (`List[PIL.Image.Image]` or `np.ndarray`)
            List of denoised PIL images of length `batch_size` or numpy array of shape `(batch_size, height, width,
            num_channels)`. PIL images or numpy array present the denoised images of the diffusion pipeline.
    """

    images: Union[List[PIL.Image.Image], np.ndarray]


@dataclass
class AudioPipelineOutput(BaseOutput):
    """
    Output class for audio pipelines.

    Args:
        audios (`np.ndarray`)
            List of denoised samples of shape `(batch_size, num_channels, sample_rate)`. Numpy array present the
            denoised audio samples of the diffusion pipeline.
    """

    audios: np.ndarray


def is_safetensors_compatible(filenames, variant=None) -> bool:
    """
    Checking for safetensors compatibility:
    - By default, all models are saved with the default pytorch serialization, so we use the list of default pytorch
      files to know which safetensors files are needed.
    - The model is safetensors compatible only if there is a matching safetensors file for every default pytorch file.

    Converting default pytorch serialized filenames to safetensors serialized filenames:
    - For models from the diffusers library, just replace the ".bin" extension with ".safetensors"
    - For models from the transformers library, the filename changes from "pytorch_model" to "model", and the ".bin"
      extension is replaced with ".safetensors"
    """
    pt_filenames = []

    sf_filenames = set()

    for filename in filenames:
        _, extension = os.path.splitext(filename)

        if extension == ".bin":
            pt_filenames.append(filename)
        elif extension == ".safetensors":
            sf_filenames.add(filename)

    for filename in pt_filenames:
        #  filename = 'foo/bar/baz.bam' -> path = 'foo/bar', filename = 'baz', extention = '.bam'
        path, filename = os.path.split(filename)
        filename, extension = os.path.splitext(filename)

        if filename == "pytorch_model":
            filename = "model"
        elif filename == f"pytorch_model.{variant}":
            filename = f"model.{variant}"
        else:
            filename = filename

        expected_sf_filename = os.path.join(path, filename)
        expected_sf_filename = f"{expected_sf_filename}.safetensors"

        if expected_sf_filename not in sf_filenames:
            logger.warning(f"{expected_sf_filename} not found")
            return False

    return True


def variant_compatible_siblings(filenames, variant=None) -> Union[List[os.PathLike], str]:
    weight_names = [
        WEIGHTS_NAME,
        SAFETENSORS_WEIGHTS_NAME,
        FLAX_WEIGHTS_NAME,
        ONNX_WEIGHTS_NAME,
        ONNX_EXTERNAL_WEIGHTS_NAME,
    ]

    if is_transformers_available():
        weight_names += [TRANSFORMERS_WEIGHTS_NAME, TRANSFORMERS_SAFE_WEIGHTS_NAME, TRANSFORMERS_FLAX_WEIGHTS_NAME]

    # model_pytorch, diffusion_model_pytorch, ...
    weight_prefixes = [w.split(".")[0] for w in weight_names]
    # .bin, .safetensors, ...
    weight_suffixs = [w.split(".")[-1] for w in weight_names]

    variant_file_regex = (
        re.compile(f"({'|'.join(weight_prefixes)})(.{variant}.)({'|'.join(weight_suffixs)})")
        if variant is not None
        else None
    )
    non_variant_file_regex = re.compile(f"{'|'.join(weight_names)}")

    if variant is not None:
        variant_filenames = {f for f in filenames if variant_file_regex.match(f.split("/")[-1]) is not None}
    else:
        variant_filenames = set()

    non_variant_filenames = {f for f in filenames if non_variant_file_regex.match(f.split("/")[-1]) is not None}

    usable_filenames = set(variant_filenames)
    for f in non_variant_filenames:
        variant_filename = f"{f.split('.')[0]}.{variant}.{f.split('.')[1]}"
        if variant_filename not in usable_filenames:
            usable_filenames.add(f)

    return usable_filenames, variant_filenames


def warn_deprecated_model_variant(pretrained_model_name_or_path, use_auth_token, variant, revision, model_filenames):
    info = model_info(
        pretrained_model_name_or_path,
        use_auth_token=use_auth_token,
        revision=None,
    )
    filenames = {sibling.rfilename for sibling in info.siblings}
    comp_model_filenames, _ = variant_compatible_siblings(filenames, variant=revision)
    comp_model_filenames = [".".join(f.split(".")[:1] + f.split(".")[2:]) for f in comp_model_filenames]

    if set(comp_model_filenames) == set(model_filenames):
        warnings.warn(
            f"You are loading the variant {revision} from {pretrained_model_name_or_path} via `revision='{revision}'` even though you can load it via `variant=`{revision}`. Loading model variants via `revision='{revision}'` is deprecated and will be removed in diffusers v1. Please use `variant='{revision}'` instead.",
            FutureWarning,
        )
    else:
        warnings.warn(
            f"You are loading the variant {revision} from {pretrained_model_name_or_path} via `revision='{revision}'`. This behavior is deprecated and will be removed in diffusers v1. One should use `variant='{revision}'` instead. However, it appears that {pretrained_model_name_or_path} currently does not have the required variant filenames in the 'main' branch. \n The Diffusers team and community would be very grateful if you could open an issue: https://github.com/huggingface/diffusers/issues/new with the title '{pretrained_model_name_or_path} is missing {revision} files' so that the correct variant file can be added.",
            FutureWarning,
        )


def maybe_raise_or_warn(
    library_name, library, class_name, importable_classes, passed_class_obj, name, is_pipeline_module
):
    """Simple helper method to raise or warn in case incorrect module has been passed"""
    if not is_pipeline_module:
        library = importlib.import_module(library_name)
        class_obj = getattr(library, class_name)
        class_candidates = {c: getattr(library, c, None) for c in importable_classes.keys()}

        expected_class_obj = None
        for class_name, class_candidate in class_candidates.items():
            if class_candidate is not None and issubclass(class_obj, class_candidate):
                expected_class_obj = class_candidate

        if not issubclass(passed_class_obj[name].__class__, expected_class_obj):
            raise ValueError(
                f"{passed_class_obj[name]} is of type: {type(passed_class_obj[name])}, but should be"
                f" {expected_class_obj}"
            )
    else:
        logger.warning(
            f"You have passed a non-standard module {passed_class_obj[name]}. We cannot verify whether it"
            " has the correct type"
        )


def get_class_obj_and_candidates(library_name, class_name, importable_classes, pipelines, is_pipeline_module):
    """Simple helper method to retrieve class object of module as well as potential parent class objects"""
    if is_pipeline_module:
        pipeline_module = getattr(pipelines, library_name)

        class_obj = getattr(pipeline_module, class_name)
        class_candidates = {c: class_obj for c in importable_classes.keys()}
    else:
        # else we just import it from the library.
        library = importlib.import_module(library_name)

        class_obj = getattr(library, class_name)
        class_candidates = {c: getattr(library, c, None) for c in importable_classes.keys()}

    return class_obj, class_candidates


def load_sub_model(
    library_name: str,
    class_name: str,
    importable_classes: List[Any],
    pipelines: Any,
    is_pipeline_module: bool,
    pipeline_class: Any,
    torch_dtype: torch.dtype,
    provider: Any,
    sess_options: Any,
    device_map: Optional[Union[Dict[str, torch.device], str]],
    model_variants: Dict[str, str],
    name: str,
    from_flax: bool,
    variant: str,
    low_cpu_mem_usage: bool,
    cached_folder: Union[str, os.PathLike],
):
    """Helper method to load the module `name` from `library_name` and `class_name`"""
    # retrieve class candidates
    class_obj, class_candidates = get_class_obj_and_candidates(
        library_name, class_name, importable_classes, pipelines, is_pipeline_module
    )

    load_method_name = None
    # retrive load method name
    for class_name, class_candidate in class_candidates.items():
        if class_candidate is not None and issubclass(class_obj, class_candidate):
            load_method_name = importable_classes[class_name][1]

    # if load method name is None, then we have a dummy module -> raise Error
    if load_method_name is None:
        none_module = class_obj.__module__
        is_dummy_path = none_module.startswith(DUMMY_MODULES_FOLDER) or none_module.startswith(
            TRANSFORMERS_DUMMY_MODULES_FOLDER
        )
        if is_dummy_path and "dummy" in none_module:
            # call class_obj for nice error message of missing requirements
            class_obj()

        raise ValueError(
            f"The component {class_obj} of {pipeline_class} cannot be loaded as it does not seem to have"
            f" any of the loading methods defined in {ALL_IMPORTABLE_CLASSES}."
        )

    load_method = getattr(class_obj, load_method_name)

    # add kwargs to loading method
    loading_kwargs = {}
    if issubclass(class_obj, torch.nn.Module):
        loading_kwargs["torch_dtype"] = torch_dtype
    if issubclass(class_obj, diffusers.OnnxRuntimeModel):
        loading_kwargs["provider"] = provider
        loading_kwargs["sess_options"] = sess_options

    is_diffusers_model = issubclass(class_obj, diffusers.ModelMixin)

    if is_transformers_available():
        transformers_version = version.parse(version.parse(transformers.__version__).base_version)
    else:
        transformers_version = "N/A"

    is_transformers_model = (
        is_transformers_available()
        and issubclass(class_obj, PreTrainedModel)
        and transformers_version >= version.parse("4.20.0")
    )

    # When loading a transformers model, if the device_map is None, the weights will be initialized as opposed to diffusers.
    # To make default loading faster we set the `low_cpu_mem_usage=low_cpu_mem_usage` flag which is `True` by default.
    # This makes sure that the weights won't be initialized which significantly speeds up loading.
    if is_diffusers_model or is_transformers_model:
        loading_kwargs["device_map"] = device_map
        loading_kwargs["variant"] = model_variants.pop(name, None)
        if from_flax:
            loading_kwargs["from_flax"] = True

        # the following can be deleted once the minimum required `transformers` version
        # is higher than 4.27
        if (
            is_transformers_model
            and loading_kwargs["variant"] is not None
            and transformers_version < version.parse("4.27.0")
        ):
            raise ImportError(
                f"When passing `variant='{variant}'`, please make sure to upgrade your `transformers` version to at least 4.27.0.dev0"
            )
        elif is_transformers_model and loading_kwargs["variant"] is None:
            loading_kwargs.pop("variant")

        # if `from_flax` and model is transformer model, can currently not load with `low_cpu_mem_usage`
        if not (from_flax and is_transformers_model):
            loading_kwargs["low_cpu_mem_usage"] = low_cpu_mem_usage
        else:
            loading_kwargs["low_cpu_mem_usage"] = False

    # check if the module is in a subdirectory
    if os.path.isdir(os.path.join(cached_folder, name)):
        loaded_sub_model = load_method(os.path.join(cached_folder, name), **loading_kwargs)
    else:
        # else load from the root directory
        loaded_sub_model = load_method(cached_folder, **loading_kwargs)

    return loaded_sub_model


class DiffusionPipeline(ConfigMixin):
    r"""
    Base class for all models.

    [`DiffusionPipeline`] takes care of storing all components (models, schedulers, processors) for diffusion pipelines
    and handles methods for loading, downloading and saving models as well as a few methods common to all pipelines to:

        - move all PyTorch modules to the device of your choice
        - enabling/disabling the progress bar for the denoising iteration

    Class attributes:

        - **config_name** (`str`) -- name of the config file that will store the class and module names of all
          components of the diffusion pipeline.
        - **_optional_components** (List[`str`]) -- list of all components that are optional so they don't have to be
          passed for the pipeline to function (should be overridden by subclasses).
    """
    config_name = "model_index.json"
    _optional_components = []

    def register_modules(self, **kwargs):
        # import it here to avoid circular import
        from diffusers import pipelines

        for name, module in kwargs.items():
            # retrieve library
            if module is None:
                register_dict = {name: (None, None)}
            else:
                library = module.__module__.split(".")[0]

                # check if the module is a pipeline module
                pipeline_dir = module.__module__.split(".")[-2] if len(module.__module__.split(".")) > 2 else None
                path = module.__module__.split(".")
                is_pipeline_module = pipeline_dir in path and hasattr(pipelines, pipeline_dir)

                # if library is not in LOADABLE_CLASSES, then it is a custom module.
                # Or if it's a pipeline module, then the module is inside the pipeline
                # folder so we set the library to module name.
                if library not in LOADABLE_CLASSES or is_pipeline_module:
                    library = pipeline_dir

                # retrieve class_name
                class_name = module.__class__.__name__

                register_dict = {name: (library, class_name)}

            # save model index config
            self.register_to_config(**register_dict)

            # set models
            setattr(self, name, module)

    def save_pretrained(
        self,
        save_directory: Union[str, os.PathLike],
        safe_serialization: bool = False,
        variant: Optional[str] = None,
    ):
        """
        Save all variables of the pipeline that can be saved and loaded as well as the pipelines configuration file to
        a directory. A pipeline variable can be saved and loaded if its class implements both a save and loading
        method. The pipeline can easily be re-loaded using the `[`~DiffusionPipeline.from_pretrained`]` class method.

        Arguments:
            save_directory (`str` or `os.PathLike`):
                Directory to which to save. Will be created if it doesn't exist.
            safe_serialization (`bool`, *optional*, defaults to `False`):
                Whether to save the model using `safetensors` or the traditional PyTorch way (that uses `pickle`).
            variant (`str`, *optional*):
                If specified, weights are saved in the format pytorch_model.<variant>.bin.
        """
        self.save_config(save_directory)

        model_index_dict = dict(self.config)
        model_index_dict.pop("_class_name")
        model_index_dict.pop("_diffusers_version")
        model_index_dict.pop("_module", None)

        expected_modules, optional_kwargs = self._get_signature_keys(self)

        def is_saveable_module(name, value):
            if name not in expected_modules:
                return False
            if name in self._optional_components and value[0] is None:
                return False
            return True

        model_index_dict = {k: v for k, v in model_index_dict.items() if is_saveable_module(k, v)}

        for pipeline_component_name in model_index_dict.keys():
            sub_model = getattr(self, pipeline_component_name)
            model_cls = sub_model.__class__

            save_method_name = None
            # search for the model's base class in LOADABLE_CLASSES
            for library_name, library_classes in LOADABLE_CLASSES.items():
                library = importlib.import_module(library_name)
                for base_class, save_load_methods in library_classes.items():
                    class_candidate = getattr(library, base_class, None)
                    if class_candidate is not None and issubclass(model_cls, class_candidate):
                        # if we found a suitable base class in LOADABLE_CLASSES then grab its save method
                        save_method_name = save_load_methods[0]
                        break
                if save_method_name is not None:
                    break

            save_method = getattr(sub_model, save_method_name)

            # Call the save method with the argument safe_serialization only if it's supported
            save_method_signature = inspect.signature(save_method)
            save_method_accept_safe = "safe_serialization" in save_method_signature.parameters
            save_method_accept_variant = "variant" in save_method_signature.parameters

            save_kwargs = {}
            if save_method_accept_safe:
                save_kwargs["safe_serialization"] = safe_serialization
            if save_method_accept_variant:
                save_kwargs["variant"] = variant

            save_method(os.path.join(save_directory, pipeline_component_name), **save_kwargs)

    def to(
        self,
        torch_device: Optional[Union[str, torch.device]] = None,
        torch_dtype: Optional[torch.dtype] = None,
        silence_dtype_warnings: bool = False,
    ):
        if torch_device is None and torch_dtype is None:
            return self

        # throw warning if pipeline is in "offloaded"-mode but user tries to manually set to GPU.
        def module_is_sequentially_offloaded(module):
            if not is_accelerate_available() or is_accelerate_version("<", "0.14.0"):
                return False

            return hasattr(module, "_hf_hook") and not isinstance(module._hf_hook, accelerate.hooks.CpuOffload)

        def module_is_offloaded(module):
            if not is_accelerate_available() or is_accelerate_version("<", "0.17.0.dev0"):
                return False

            return hasattr(module, "_hf_hook") and isinstance(module._hf_hook, accelerate.hooks.CpuOffload)

        # .to("cuda") would raise an error if the pipeline is sequentially offloaded, so we raise our own to make it clearer
        pipeline_is_sequentially_offloaded = any(
            module_is_sequentially_offloaded(module) for _, module in self.components.items()
        )
        if pipeline_is_sequentially_offloaded and torch.device(torch_device).type == "cuda":
            raise ValueError(
                "It seems like you have activated sequential model offloading by calling `enable_sequential_cpu_offload`, but are now attempting to move the pipeline to GPU. This is not compatible with offloading. Please, move your pipeline `.to('cpu')` or consider removing the move altogether if you use sequential offloading."
            )

        # Display a warning in this case (the operation succeeds but the benefits are lost)
        pipeline_is_offloaded = any(module_is_offloaded(module) for _, module in self.components.items())
        if pipeline_is_offloaded and torch.device(torch_device).type == "cuda":
            logger.warning(
                f"It seems like you have activated model offloading by calling `enable_model_cpu_offload`, but are now manually moving the pipeline to GPU. It is strongly recommended against doing so as memory gains from offloading are likely to be lost. Offloading automatically takes care of moving the individual components {', '.join(self.components.keys())} to GPU when needed. To make sure offloading works as expected, you should consider moving the pipeline back to CPU: `pipeline.to('cpu')` or removing the move altogether if you use offloading."
            )

        module_names, _, _ = self.extract_init_dict(dict(self.config))
        is_offloaded = pipeline_is_offloaded or pipeline_is_sequentially_offloaded
        for name in module_names.keys():
            module = getattr(self, name)
            if isinstance(module, torch.nn.Module):
                module.to(torch_device, torch_dtype)
                if (
                    module.dtype == torch.float16
                    and str(torch_device) in ["cpu"]
                    and not silence_dtype_warnings
                    and not is_offloaded
                ):
                    logger.warning(
                        "Pipelines loaded with `torch_dtype=torch.float16` cannot run with `cpu` device. It"
                        " is not recommended to move them to `cpu` as running them will fail. Please make"
                        " sure to use an accelerator to run the pipeline in inference, due to the lack of"
                        " support for`float16` operations on this device in PyTorch. Please, remove the"
                        " `torch_dtype=torch.float16` argument, or use another device for inference."
                    )
        return self

    @property
    def device(self) -> torch.device:
        r"""
        Returns:
            `torch.device`: The torch device on which the pipeline is located.
        """
        module_names, _, _ = self.extract_init_dict(dict(self.config))
        for name in module_names.keys():
            module = getattr(self, name)
            if isinstance(module, torch.nn.Module):
                return module.device
        return torch.device("cpu")

    @classmethod
    def from_pretrained(cls, pretrained_model_name_or_path: Optional[Union[str, os.PathLike]], **kwargs):
        r"""
        Instantiate a PyTorch diffusion pipeline from pre-trained pipeline weights.

        The pipeline is set in evaluation mode by default using `model.eval()` (Dropout modules are deactivated).

        The warning *Weights from XXX not initialized from pretrained model* means that the weights of XXX do not come
        pretrained with the rest of the model. It is up to you to train those weights with a downstream fine-tuning
        task.

        The warning *Weights from XXX not used in YYY* means that the layer XXX is not used by YYY, therefore those
        weights are discarded.

        Parameters:
            pretrained_model_name_or_path (`str` or `os.PathLike`, *optional*):
                Can be either:

                    - A string, the *repo id* of a pretrained pipeline hosted inside a model repo on
                      https://huggingface.co/ Valid repo ids have to be located under a user or organization name, like
                      `CompVis/ldm-text2im-large-256`.
                    - A path to a *directory* containing pipeline weights saved using
                      [`~DiffusionPipeline.save_pretrained`], e.g., `./my_pipeline_directory/`.
            torch_dtype (`str` or `torch.dtype`, *optional*):
                Override the default `torch.dtype` and load the model under this dtype. If `"auto"` is passed the dtype
                will be automatically derived from the model's weights.
            custom_pipeline (`str`, *optional*):

                <Tip warning={true}>

                    This is an experimental feature and is likely to change in the future.

                </Tip>

                Can be either:

                    - A string, the *repo id* of a custom pipeline hosted inside a model repo on
                      https://huggingface.co/. Valid repo ids have to be located under a user or organization name,
                      like `hf-internal-testing/diffusers-dummy-pipeline`.

                        <Tip>

                         It is required that the model repo has a file, called `pipeline.py` that defines the custom
                         pipeline.

                        </Tip>

                    - A string, the *file name* of a community pipeline hosted on GitHub under
                      https://github.com/huggingface/diffusers/tree/main/examples/community. Valid file names have to
                      match exactly the file name without `.py` located under the above link, *e.g.*
                      `clip_guided_stable_diffusion`.

                        <Tip>

                         Community pipelines are always loaded from the current `main` branch of GitHub.

                        </Tip>

                    - A path to a *directory* containing a custom pipeline, e.g., `./my_pipeline_directory/`.

                        <Tip>

                         It is required that the directory has a file, called `pipeline.py` that defines the custom
                         pipeline.

                        </Tip>

                For more information on how to load and create custom pipelines, please have a look at [Loading and
                Adding Custom
                Pipelines](https://huggingface.co/docs/diffusers/using-diffusers/custom_pipeline_overview)

            force_download (`bool`, *optional*, defaults to `False`):
                Whether or not to force the (re-)download of the model weights and configuration files, overriding the
                cached versions if they exist.
            cache_dir (`Union[str, os.PathLike]`, *optional*):
                Path to a directory in which a downloaded pretrained model configuration should be cached if the
                standard cache should not be used.
            resume_download (`bool`, *optional*, defaults to `False`):
                Whether or not to delete incompletely received files. Will attempt to resume the download if such a
                file exists.
            proxies (`Dict[str, str]`, *optional*):
                A dictionary of proxy servers to use by protocol or endpoint, e.g., `{'http': 'foo.bar:3128',
                'http://hostname': 'foo.bar:4012'}`. The proxies are used on each request.
            output_loading_info(`bool`, *optional*, defaults to `False`):
                Whether or not to also return a dictionary containing missing keys, unexpected keys and error messages.
            local_files_only(`bool`, *optional*, defaults to `False`):
                Whether or not to only look at local files (i.e., do not try to download the model).
            use_auth_token (`str` or *bool*, *optional*):
                The token to use as HTTP bearer authorization for remote files. If `True`, will use the token generated
                when running `huggingface-cli login` (stored in `~/.huggingface`).
            revision (`str`, *optional*, defaults to `"main"`):
                The specific model version to use. It can be a branch name, a tag name, or a commit id, since we use a
                git-based system for storing models and other artifacts on huggingface.co, so `revision` can be any
                identifier allowed by git.
            custom_revision (`str`, *optional*, defaults to `"main"` when loading from the Hub and to local version of `diffusers` when loading from GitHub):
                The specific model version to use. It can be a branch name, a tag name, or a commit id similar to
                `revision` when loading a custom pipeline from the Hub. It can be a diffusers version when loading a
                custom pipeline from GitHub.
            mirror (`str`, *optional*):
                Mirror source to accelerate downloads in China. If you are from China and have an accessibility
                problem, you can set this option to resolve it. Note that we do not guarantee the timeliness or safety.
                Please refer to the mirror site for more information. specify the folder name here.
            device_map (`str` or `Dict[str, Union[int, str, torch.device]]`, *optional*):
                A map that specifies where each submodule should go. It doesn't need to be refined to each
                parameter/buffer name, once a given module name is inside, every submodule of it will be sent to the
                same device.

                To have Accelerate compute the most optimized `device_map` automatically, set `device_map="auto"`. For
                more information about each option see [designing a device
                map](https://hf.co/docs/accelerate/main/en/usage_guides/big_modeling#designing-a-device-map).
            low_cpu_mem_usage (`bool`, *optional*, defaults to `True` if torch version >= 1.9.0 else `False`):
                Speed up model loading by not initializing the weights and only loading the pre-trained weights. This
                also tries to not use more than 1x model size in CPU memory (including peak memory) while loading the
                model. This is only supported when torch version >= 1.9.0. If you are using an older version of torch,
                setting this argument to `True` will raise an error.
            use_safetensors (`bool`, *optional* ):
                If set to `True`, the pipeline will be loaded from `safetensors` weights. If set to `None` (the
                default). The pipeline will load using `safetensors` if the safetensors weights are available *and* if
                `safetensors` is installed. If the to `False` the pipeline will *not* use `safetensors`.
            kwargs (remaining dictionary of keyword arguments, *optional*):
                Can be used to overwrite load - and saveable variables - *i.e.* the pipeline components - of the
                specific pipeline class. The overwritten components are then directly passed to the pipelines
                `__init__` method. See example below for more information.
            variant (`str`, *optional*):
                If specified load weights from `variant` filename, *e.g.* pytorch_model.<variant>.bin. `variant` is
                ignored when using `from_flax`.

        <Tip>

         It is required to be logged in (`huggingface-cli login`) when you want to use private or [gated
         models](https://huggingface.co/docs/hub/models-gated#gated-models), *e.g.* `"runwayml/stable-diffusion-v1-5"`

        </Tip>

        <Tip>

        Activate the special ["offline-mode"](https://huggingface.co/diffusers/installation.html#offline-mode) to use
        this method in a firewalled environment.

        </Tip>

        Examples:

        ```py
        >>> from diffusers import DiffusionPipeline

        >>> # Download pipeline from huggingface.co and cache.
        >>> pipeline = DiffusionPipeline.from_pretrained("CompVis/ldm-text2im-large-256")

        >>> # Download pipeline that requires an authorization token
        >>> # For more information on access tokens, please refer to this section
        >>> # of the documentation](https://huggingface.co/docs/hub/security-tokens)
        >>> pipeline = DiffusionPipeline.from_pretrained("runwayml/stable-diffusion-v1-5")

        >>> # Use a different scheduler
        >>> from diffusers import LMSDiscreteScheduler

        >>> scheduler = LMSDiscreteScheduler.from_config(pipeline.scheduler.config)
        >>> pipeline.scheduler = scheduler
        ```
        """
        cache_dir = kwargs.pop("cache_dir", DIFFUSERS_CACHE)
        resume_download = kwargs.pop("resume_download", False)
        force_download = kwargs.pop("force_download", False)
        proxies = kwargs.pop("proxies", None)
        local_files_only = kwargs.pop("local_files_only", HF_HUB_OFFLINE)
        use_auth_token = kwargs.pop("use_auth_token", None)
        revision = kwargs.pop("revision", None)
        from_flax = kwargs.pop("from_flax", False)
        torch_dtype = kwargs.pop("torch_dtype", None)
        custom_pipeline = kwargs.pop("custom_pipeline", None)
        custom_revision = kwargs.pop("custom_revision", None)
        provider = kwargs.pop("provider", None)
        sess_options = kwargs.pop("sess_options", None)
        device_map = kwargs.pop("device_map", None)
        low_cpu_mem_usage = kwargs.pop("low_cpu_mem_usage", _LOW_CPU_MEM_USAGE_DEFAULT)
        variant = kwargs.pop("variant", None)
        kwargs.pop("use_safetensors", None if is_safetensors_available() else False)

        # 1. Download the checkpoints and configs
        # use snapshot download here to get it working from from_pretrained
        if not os.path.isdir(pretrained_model_name_or_path):
            cached_folder = cls.download(
                pretrained_model_name_or_path,
                cache_dir=cache_dir,
                resume_download=resume_download,
                force_download=force_download,
                proxies=proxies,
                local_files_only=local_files_only,
                use_auth_token=use_auth_token,
                revision=revision,
                from_flax=from_flax,
                custom_pipeline=custom_pipeline,
                variant=variant,
            )
        else:
            cached_folder = pretrained_model_name_or_path

        config_dict = cls.load_config(cached_folder)

        # 2. Define which model components should load variants
        # We retrieve the information by matching whether variant
        # model checkpoints exist in the subfolders
        model_variants = {}
        if variant is not None:
            for folder in os.listdir(cached_folder):
                folder_path = os.path.join(cached_folder, folder)
                is_folder = os.path.isdir(folder_path) and folder in config_dict
                variant_exists = is_folder and any(path.split(".")[1] == variant for path in os.listdir(folder_path))
                if variant_exists:
                    model_variants[folder] = variant

        # 3. Load the pipeline class, if using custom module then load it from the hub
        # if we load from explicit class, let's use it
        if custom_pipeline is not None:
            if custom_pipeline.endswith(".py"):
                path = Path(custom_pipeline)
                # decompose into folder & file
                file_name = path.name
                custom_pipeline = path.parent.absolute()
            else:
                file_name = CUSTOM_PIPELINE_FILE_NAME

            pipeline_class = get_class_from_dynamic_module(
                custom_pipeline, module_file=file_name, cache_dir=cache_dir, revision=custom_revision
            )
        elif cls != DiffusionPipeline:
            pipeline_class = cls
        else:
            diffusers_module = importlib.import_module(cls.__module__.split(".")[0])
            pipeline_class = getattr(diffusers_module, config_dict["_class_name"])

        # DEPRECATED: To be removed in 1.0.0
        if pipeline_class.__name__ == "StableDiffusionInpaintPipeline" and version.parse(
            version.parse(config_dict["_diffusers_version"]).base_version
        ) <= version.parse("0.5.1"):
            from diffusers import StableDiffusionInpaintPipeline, StableDiffusionInpaintPipelineLegacy

            pipeline_class = StableDiffusionInpaintPipelineLegacy

            deprecation_message = (
                "You are using a legacy checkpoint for inpainting with Stable Diffusion, therefore we are loading the"
                f" {StableDiffusionInpaintPipelineLegacy} class instead of {StableDiffusionInpaintPipeline}. For"
                " better inpainting results, we strongly suggest using Stable Diffusion's official inpainting"
                " checkpoint: https://huggingface.co/runwayml/stable-diffusion-inpainting instead or adapting your"
                f" checkpoint {pretrained_model_name_or_path} to the format of"
                " https://huggingface.co/runwayml/stable-diffusion-inpainting. Note that we do not actively maintain"
                " the {StableDiffusionInpaintPipelineLegacy} class and will likely remove it in version 1.0.0."
            )
            deprecate("StableDiffusionInpaintPipelineLegacy", "1.0.0", deprecation_message, standard_warn=False)

        # 4. Define expected modules given pipeline signature
        # and define non-None initialized modules (=`init_kwargs`)

        # some modules can be passed directly to the init
        # in this case they are already instantiated in `kwargs`
        # extract them here
        expected_modules, optional_kwargs = cls._get_signature_keys(pipeline_class)
        passed_class_obj = {k: kwargs.pop(k) for k in expected_modules if k in kwargs}
        passed_pipe_kwargs = {k: kwargs.pop(k) for k in optional_kwargs if k in kwargs}

        init_dict, unused_kwargs, _ = pipeline_class.extract_init_dict(config_dict, **kwargs)

        # define init kwargs
        init_kwargs = {k: init_dict.pop(k) for k in optional_kwargs if k in init_dict}
        init_kwargs = {**init_kwargs, **passed_pipe_kwargs}

        # remove `null` components
        def load_module(name, value):
            if value[0] is None:
                return False
            if name in passed_class_obj and passed_class_obj[name] is None:
                return False
            return True

        init_dict = {k: v for k, v in init_dict.items() if load_module(k, v)}

        # Special case: safety_checker must be loaded separately when using `from_flax`
        if from_flax and "safety_checker" in init_dict and "safety_checker" not in passed_class_obj:
            raise NotImplementedError(
                "The safety checker cannot be automatically loaded when loading weights `from_flax`."
                " Please, pass `safety_checker=None` to `from_pretrained`, and load the safety checker"
                " separately if you need it."
            )

        # 5. Throw nice warnings / errors for fast accelerate loading
        if len(unused_kwargs) > 0:
            logger.warning(
                f"Keyword arguments {unused_kwargs} are not expected by {pipeline_class.__name__} and will be ignored."
            )

        if low_cpu_mem_usage and not is_accelerate_available():
            low_cpu_mem_usage = False
            logger.warning(
                "Cannot initialize model with low cpu memory usage because `accelerate` was not found in the"
                " environment. Defaulting to `low_cpu_mem_usage=False`. It is strongly recommended to install"
                " `accelerate` for faster and less memory-intense model loading. You can do so with: \n```\npip"
                " install accelerate\n```\n."
            )

        if device_map is not None and not is_torch_version(">=", "1.9.0"):
            raise NotImplementedError(
                "Loading and dispatching requires torch >= 1.9.0. Please either update your PyTorch version or set"
                " `device_map=None`."
            )

        if low_cpu_mem_usage is True and not is_torch_version(">=", "1.9.0"):
            raise NotImplementedError(
                "Low memory initialization requires torch >= 1.9.0. Please either update your PyTorch version or set"
                " `low_cpu_mem_usage=False`."
            )

        if low_cpu_mem_usage is False and device_map is not None:
            raise ValueError(
                f"You cannot set `low_cpu_mem_usage` to False while using device_map={device_map} for loading and"
                " dispatching. Please make sure to set `low_cpu_mem_usage=True`."
            )

        # import it here to avoid circular import
        from diffusers import pipelines

        # 6. Load each module in the pipeline
        for name, (library_name, class_name) in init_dict.items():
            # 6.1 - now that JAX/Flax is an official framework of the library, we might load from Flax names
            if class_name.startswith("Flax"):
                class_name = class_name[4:]

            # 6.2 Define all importable classes
            is_pipeline_module = hasattr(pipelines, library_name)
            importable_classes = ALL_IMPORTABLE_CLASSES if is_pipeline_module else LOADABLE_CLASSES[library_name]
            loaded_sub_model = None

            # 6.3 Use passed sub model or load class_name from library_name
            if name in passed_class_obj:
                # if the model is in a pipeline module, then we load it from the pipeline
                # check that passed_class_obj has correct parent class
                maybe_raise_or_warn(
                    library_name, library, class_name, importable_classes, passed_class_obj, name, is_pipeline_module
                )

                loaded_sub_model = passed_class_obj[name]
            else:
                # load sub model
                loaded_sub_model = load_sub_model(
                    library_name=library_name,
                    class_name=class_name,
                    importable_classes=importable_classes,
                    pipelines=pipelines,
                    is_pipeline_module=is_pipeline_module,
                    pipeline_class=pipeline_class,
                    torch_dtype=torch_dtype,
                    provider=provider,
                    sess_options=sess_options,
                    device_map=device_map,
                    model_variants=model_variants,
                    name=name,
                    from_flax=from_flax,
                    variant=variant,
                    low_cpu_mem_usage=low_cpu_mem_usage,
                    cached_folder=cached_folder,
                )

            init_kwargs[name] = loaded_sub_model  # UNet(...), # DiffusionSchedule(...)

        # 7. Potentially add passed objects if expected
        missing_modules = set(expected_modules) - set(init_kwargs.keys())
        passed_modules = list(passed_class_obj.keys())
        optional_modules = pipeline_class._optional_components
        if len(missing_modules) > 0 and missing_modules <= set(passed_modules + optional_modules):
            for module in missing_modules:
                init_kwargs[module] = passed_class_obj.get(module, None)
        elif len(missing_modules) > 0:
            passed_modules = set(list(init_kwargs.keys()) + list(passed_class_obj.keys())) - optional_kwargs
            raise ValueError(
                f"Pipeline {pipeline_class} expected {expected_modules}, but only {passed_modules} were passed."
            )

        # 8. Instantiate the pipeline
        model = pipeline_class(**init_kwargs)

        return_cached_folder = kwargs.pop("return_cached_folder", False)
        if return_cached_folder:
            message = f"Passing `return_cached_folder=True` is deprecated and will be removed in `diffusers=0.17.0`. Please do the following instead: \n 1. Load the cached_folder via `cached_folder={cls}.download({pretrained_model_name_or_path})`. \n 2. Load the pipeline by loading from the cached folder: `pipeline={cls}.from_pretrained(cached_folder)`."
            deprecate("return_cached_folder", "0.17.0", message, take_from=kwargs)
            return model, cached_folder

        return model

    @classmethod
    def download(cls, pretrained_model_name, **kwargs) -> Union[str, os.PathLike]:
        r"""
        Download and cache a PyTorch diffusion pipeline from pre-trained pipeline weights.

        Parameters:
             pretrained_model_name (`str` or `os.PathLike`, *optional*):
                Should be a string, the *repo id* of a pretrained pipeline hosted inside a model repo on
                https://huggingface.co/ Valid repo ids have to be located under a user or organization name, like
                `CompVis/ldm-text2im-large-256`.
            custom_pipeline (`str`, *optional*):

                <Tip warning={true}>

                    This is an experimental feature and is likely to change in the future.

                </Tip>

                Can be either:

                    - A string, the *repo id* of a custom pipeline hosted inside a model repo on
                      https://huggingface.co/. Valid repo ids have to be located under a user or organization name,
                      like `hf-internal-testing/diffusers-dummy-pipeline`.

                        <Tip>

                         It is required that the model repo has a file, called `pipeline.py` that defines the custom
                         pipeline.

                        </Tip>

                    - A string, the *file name* of a community pipeline hosted on GitHub under
                      https://github.com/huggingface/diffusers/tree/main/examples/community. Valid file names have to
                      match exactly the file name without `.py` located under the above link, *e.g.*
                      `clip_guided_stable_diffusion`.

                        <Tip>

                         Community pipelines are always loaded from the current `main` branch of GitHub.

                        </Tip>

                    - A path to a *directory* containing a custom pipeline, e.g., `./my_pipeline_directory/`.

                        <Tip>

                         It is required that the directory has a file, called `pipeline.py` that defines the custom
                         pipeline.

                        </Tip>

                For more information on how to load and create custom pipelines, please have a look at [Loading and
                Adding Custom
                Pipelines](https://huggingface.co/docs/diffusers/using-diffusers/custom_pipeline_overview)

            force_download (`bool`, *optional*, defaults to `False`):
                Whether or not to force the (re-)download of the model weights and configuration files, overriding the
                cached versions if they exist.
            resume_download (`bool`, *optional*, defaults to `False`):
                Whether or not to delete incompletely received files. Will attempt to resume the download if such a
                file exists.
            proxies (`Dict[str, str]`, *optional*):
                A dictionary of proxy servers to use by protocol or endpoint, e.g., `{'http': 'foo.bar:3128',
                'http://hostname': 'foo.bar:4012'}`. The proxies are used on each request.
            output_loading_info(`bool`, *optional*, defaults to `False`):
                Whether or not to also return a dictionary containing missing keys, unexpected keys and error messages.
            local_files_only(`bool`, *optional*, defaults to `False`):
                Whether or not to only look at local files (i.e., do not try to download the model).
            use_auth_token (`str` or *bool*, *optional*):
                The token to use as HTTP bearer authorization for remote files. If `True`, will use the token generated
                when running `huggingface-cli login` (stored in `~/.huggingface`).
            revision (`str`, *optional*, defaults to `"main"`):
                The specific model version to use. It can be a branch name, a tag name, or a commit id, since we use a
                git-based system for storing models and other artifacts on huggingface.co, so `revision` can be any
                identifier allowed by git.
            custom_revision (`str`, *optional*, defaults to `"main"` when loading from the Hub and to local version of
            `diffusers` when loading from GitHub):
                The specific model version to use. It can be a branch name, a tag name, or a commit id similar to
                `revision` when loading a custom pipeline from the Hub. It can be a diffusers version when loading a
                custom pipeline from GitHub.
            mirror (`str`, *optional*):
                Mirror source to accelerate downloads in China. If you are from China and have an accessibility
                problem, you can set this option to resolve it. Note that we do not guarantee the timeliness or safety.
                Please refer to the mirror site for more information. specify the folder name here.
            variant (`str`, *optional*):
                If specified load weights from `variant` filename, *e.g.* pytorch_model.<variant>.bin. `variant` is
                ignored when using `from_flax`.

        <Tip>

         It is required to be logged in (`huggingface-cli login`) when you want to use private or [gated
         models](https://huggingface.co/docs/hub/models-gated#gated-models)

        </Tip>

        """
        cache_dir = kwargs.pop("cache_dir", DIFFUSERS_CACHE)
        resume_download = kwargs.pop("resume_download", False)
        force_download = kwargs.pop("force_download", False)
        proxies = kwargs.pop("proxies", None)
        local_files_only = kwargs.pop("local_files_only", HF_HUB_OFFLINE)
        use_auth_token = kwargs.pop("use_auth_token", None)
        revision = kwargs.pop("revision", None)
        from_flax = kwargs.pop("from_flax", False)
        custom_pipeline = kwargs.pop("custom_pipeline", None)
        variant = kwargs.pop("variant", None)
        use_safetensors = kwargs.pop("use_safetensors", None)

        if use_safetensors and not is_safetensors_available():
            raise ValueError(
                "`use_safetensors`=True but safetensors is not installed. Please install safetensors with `pip install safetenstors"
            )

        allow_pickle = False
        if use_safetensors is None:
            use_safetensors = is_safetensors_available()
            allow_pickle = True

        pipeline_is_cached = False
        allow_patterns = None
        ignore_patterns = None

        if not local_files_only:
            config_file = hf_hub_download(
                pretrained_model_name,
                cls.config_name,
                cache_dir=cache_dir,
                revision=revision,
                proxies=proxies,
                force_download=force_download,
                resume_download=resume_download,
                use_auth_token=use_auth_token,
            )
            info = model_info(
                pretrained_model_name,
                use_auth_token=use_auth_token,
                revision=revision,
            )

            config_dict = cls._dict_from_json_file(config_file)
            # retrieve all folder_names that contain relevant files
            folder_names = [k for k, v in config_dict.items() if isinstance(v, list)]

            filenames = {sibling.rfilename for sibling in info.siblings}
            model_filenames, variant_filenames = variant_compatible_siblings(filenames, variant=variant)

            # if the whole pipeline is cached we don't have to ping the Hub
            if revision in DEPRECATED_REVISION_ARGS and version.parse(
                version.parse(__version__).base_version
            ) >= version.parse("0.17.0"):
                warn_deprecated_model_variant(
                    pretrained_model_name, use_auth_token, variant, revision, model_filenames
                )

            model_folder_names = {os.path.split(f)[0] for f in model_filenames}

            # all filenames compatible with variant will be added
            allow_patterns = list(model_filenames)

            # allow all patterns from non-model folders
            # this enables downloading schedulers, tokenizers, ...
            allow_patterns += [os.path.join(k, "*") for k in folder_names if k not in model_folder_names]
            # also allow downloading config.json files with the model
            allow_patterns += [os.path.join(k, "*.json") for k in model_folder_names]

            allow_patterns += [
                SCHEDULER_CONFIG_NAME,
                CONFIG_NAME,
                cls.config_name,
                CUSTOM_PIPELINE_FILE_NAME,
            ]

            if (
                use_safetensors
                and not allow_pickle
                and not is_safetensors_compatible(model_filenames, variant=variant)
            ):
                raise EnvironmentError(
                    f"Could not found the necessary `safetensors` weights in {model_filenames} (variant={variant})"
                )
            if from_flax:
                ignore_patterns = ["*.bin", "*.safetensors", "*.onnx", "*.pb"]
            elif use_safetensors and is_safetensors_compatible(model_filenames, variant=variant):
                ignore_patterns = ["*.bin", "*.msgpack"]

                safetensors_variant_filenames = {f for f in variant_filenames if f.endswith(".safetensors")}
                safetensors_model_filenames = {f for f in model_filenames if f.endswith(".safetensors")}
                if (
                    len(safetensors_variant_filenames) > 0
                    and safetensors_model_filenames != safetensors_variant_filenames
                ):
                    logger.warn(
                        f"\nA mixture of {variant} and non-{variant} filenames will be loaded.\nLoaded {variant} filenames:\n[{', '.join(safetensors_variant_filenames)}]\nLoaded non-{variant} filenames:\n[{', '.join(safetensors_model_filenames - safetensors_variant_filenames)}\nIf this behavior is not expected, please check your folder structure."
                    )
            else:
                ignore_patterns = ["*.safetensors", "*.msgpack"]

                bin_variant_filenames = {f for f in variant_filenames if f.endswith(".bin")}
                bin_model_filenames = {f for f in model_filenames if f.endswith(".bin")}
                if len(bin_variant_filenames) > 0 and bin_model_filenames != bin_variant_filenames:
                    logger.warn(
                        f"\nA mixture of {variant} and non-{variant} filenames will be loaded.\nLoaded {variant} filenames:\n[{', '.join(bin_variant_filenames)}]\nLoaded non-{variant} filenames:\n[{', '.join(bin_model_filenames - bin_variant_filenames)}\nIf this behavior is not expected, please check your folder structure."
                    )

            re_ignore_pattern = [re.compile(fnmatch.translate(p)) for p in ignore_patterns]
            re_allow_pattern = [re.compile(fnmatch.translate(p)) for p in allow_patterns]

            expected_files = [f for f in filenames if not any(p.match(f) for p in re_ignore_pattern)]
            expected_files = [f for f in expected_files if any(p.match(f) for p in re_allow_pattern)]

            snapshot_folder = Path(config_file).parent
            pipeline_is_cached = all((snapshot_folder / f).is_file() for f in expected_files)

            if pipeline_is_cached:
                # if the pipeline is cached, we can directly return it
                # else call snapshot_download
                return snapshot_folder

        user_agent = {"pipeline_class": cls.__name__}
        if custom_pipeline is not None and not custom_pipeline.endswith(".py"):
            user_agent["custom_pipeline"] = custom_pipeline

        # download all allow_patterns - ignore_patterns
        cached_folder = snapshot_download(
            pretrained_model_name,
            cache_dir=cache_dir,
            resume_download=resume_download,
            proxies=proxies,
            local_files_only=local_files_only,
            use_auth_token=use_auth_token,
            revision=revision,
            allow_patterns=allow_patterns,
            ignore_patterns=ignore_patterns,
            user_agent=user_agent,
        )

        return cached_folder

    @staticmethod
    def _get_signature_keys(obj):
        parameters = inspect.signature(obj.__init__).parameters
        required_parameters = {k: v for k, v in parameters.items() if v.default == inspect._empty}
        optional_parameters = set({k for k, v in parameters.items() if v.default != inspect._empty})
        expected_modules = set(required_parameters.keys()) - {"self"}
        return expected_modules, optional_parameters

    @property
    def components(self) -> Dict[str, Any]:
        r"""

        The `self.components` property can be useful to run different pipelines with the same weights and
        configurations to not have to re-allocate memory.

        Examples:

        ```py
        >>> from diffusers import (
        ...     StableDiffusionPipeline,
        ...     StableDiffusionImg2ImgPipeline,
        ...     StableDiffusionInpaintPipeline,
        ... )

        >>> text2img = StableDiffusionPipeline.from_pretrained("runwayml/stable-diffusion-v1-5")
        >>> img2img = StableDiffusionImg2ImgPipeline(**text2img.components)
        >>> inpaint = StableDiffusionInpaintPipeline(**text2img.components)
        ```

        Returns:
            A dictionary containing all the modules needed to initialize the pipeline.
        """
        expected_modules, optional_parameters = self._get_signature_keys(self)
        components = {
            k: getattr(self, k) for k in self.config.keys() if not k.startswith("_") and k not in optional_parameters
        }

        if set(components.keys()) != expected_modules:
            raise ValueError(
                f"{self} has been incorrectly initialized or {self.__class__} is incorrectly implemented. Expected"
                f" {expected_modules} to be defined, but {components.keys()} are defined."
            )

        return components

    @staticmethod
    def numpy_to_pil(images):
        """
        Convert a numpy image or a batch of images to a PIL image.
        """
        if images.ndim == 3:
            images = images[None, ...]
        images = (images * 255).round().astype("uint8")
        if images.shape[-1] == 1:
            # special case for grayscale (single channel) images
            pil_images = [Image.fromarray(image.squeeze(), mode="L") for image in images]
        else:
            pil_images = [Image.fromarray(image) for image in images]

        return pil_images

    def progress_bar(self, iterable=None, total=None):
        if not hasattr(self, "_progress_bar_config"):
            self._progress_bar_config = {}
        elif not isinstance(self._progress_bar_config, dict):
            raise ValueError(
                f"`self._progress_bar_config` should be of type `dict`, but is {type(self._progress_bar_config)}."
            )

        if iterable is not None:
            return tqdm(iterable, **self._progress_bar_config)
        elif total is not None:
            return tqdm(total=total, **self._progress_bar_config)
        else:
            raise ValueError("Either `total` or `iterable` has to be defined.")

    def set_progress_bar_config(self, **kwargs):
        self._progress_bar_config = kwargs

    def enable_xformers_memory_efficient_attention(self, attention_op: Optional[Callable] = None):
        r"""
        Enable memory efficient attention as implemented in xformers.

        When this option is enabled, you should observe lower GPU memory usage and a potential speed up at inference
        time. Speed up at training time is not guaranteed.

        Warning: When Memory Efficient Attention and Sliced attention are both enabled, the Memory Efficient Attention
        is used.

        Parameters:
            attention_op (`Callable`, *optional*):
                Override the default `None` operator for use as `op` argument to the
                [`memory_efficient_attention()`](https://facebookresearch.github.io/xformers/components/ops.html#xformers.ops.memory_efficient_attention)
                function of xFormers.

        Examples:

        ```py
        >>> import torch
        >>> from diffusers import DiffusionPipeline
        >>> from xformers.ops import MemoryEfficientAttentionFlashAttentionOp

        >>> pipe = DiffusionPipeline.from_pretrained("stabilityai/stable-diffusion-2-1", torch_dtype=torch.float16)
        >>> pipe = pipe.to("cuda")
        >>> pipe.enable_xformers_memory_efficient_attention(attention_op=MemoryEfficientAttentionFlashAttentionOp)
        >>> # Workaround for not accepting attention shape using VAE for Flash Attention
        >>> pipe.vae.enable_xformers_memory_efficient_attention(attention_op=None)
        ```
        """
        self.set_use_memory_efficient_attention_xformers(True, attention_op)

    def disable_xformers_memory_efficient_attention(self):
        r"""
        Disable memory efficient attention as implemented in xformers.
        """
        self.set_use_memory_efficient_attention_xformers(False)

    def set_use_memory_efficient_attention_xformers(
        self, valid: bool, attention_op: Optional[Callable] = None
    ) -> None:
        # Recursively walk through all the children.
        # Any children which exposes the set_use_memory_efficient_attention_xformers method
        # gets the message
        def fn_recursive_set_mem_eff(module: torch.nn.Module):
            if hasattr(module, "set_use_memory_efficient_attention_xformers"):
                module.set_use_memory_efficient_attention_xformers(valid, attention_op)

            for child in module.children():
                fn_recursive_set_mem_eff(child)

        module_names, _, _ = self.extract_init_dict(dict(self.config))
        for module_name in module_names:
            module = getattr(self, module_name)
            if isinstance(module, torch.nn.Module):
                fn_recursive_set_mem_eff(module)

    def enable_attention_slicing(self, slice_size: Optional[Union[str, int]] = "auto"):
        r"""
        Enable sliced attention computation.

        When this option is enabled, the attention module will split the input tensor in slices, to compute attention
        in several steps. This is useful to save some memory in exchange for a small speed decrease.

        Args:
            slice_size (`str` or `int`, *optional*, defaults to `"auto"`):
                When `"auto"`, halves the input to the attention heads, so attention will be computed in two steps. If
                `"max"`, maximum amount of memory will be saved by running only one slice at a time. If a number is
                provided, uses as many slices as `attention_head_dim // slice_size`. In this case, `attention_head_dim`
                must be a multiple of `slice_size`.
        """
        self.set_attention_slice(slice_size)

    def disable_attention_slicing(self):
        r"""
        Disable sliced attention computation. If `enable_attention_slicing` was previously invoked, this method will go
        back to computing attention in one step.
        """
        # set slice_size = `None` to disable `attention slicing`
        self.enable_attention_slicing(None)

    def set_attention_slice(self, slice_size: Optional[int]):
        module_names, _, _ = self.extract_init_dict(dict(self.config))
        for module_name in module_names:
            module = getattr(self, module_name)
            if isinstance(module, torch.nn.Module) and hasattr(module, "set_attention_slice"):
                module.set_attention_slice(slice_size)
