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from huggingface_hub.utils import validate_hf_hub_args

from .single_file_utils import (
    create_diffusers_vae_model_from_ldm,
    fetch_ldm_config_and_checkpoint,
)


class FromOriginalVAEMixin:
    """
    Load pretrained AutoencoderKL weights saved in the `.ckpt` or `.safetensors` format into a [`AutoencoderKL`].
    """

    @classmethod
    @validate_hf_hub_args
    def from_single_file(cls, pretrained_model_link_or_path, **kwargs):
        r"""
        Instantiate a [`AutoencoderKL`] from pretrained ControlNet weights saved in the original `.ckpt` or
        `.safetensors` format. The pipeline is set in evaluation mode (`model.eval()`) by default.

        Parameters:
            pretrained_model_link_or_path (`str` or `os.PathLike`, *optional*):
                Can be either:
                    - A link to the `.ckpt` file (for example
                      `"https://huggingface.co/<repo_id>/blob/main/<path_to_file>.ckpt"`) on the Hub.
                    - A path to a *file* containing all pipeline weights.
            torch_dtype (`str` or `torch.dtype`, *optional*):
                Override the default `torch.dtype` and load the model with another dtype. If `"auto"` is passed, the
                dtype is automatically derived from the model's weights.
            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 where a downloaded pretrained model configuration is cached if the standard cache
                is not used.
            resume_download (`bool`, *optional*, defaults to `False`):
                Whether or not to resume downloading the model weights and configuration files. If set to `False`, any
                incompletely downloaded files are deleted.
            proxies (`Dict[str, str]`, *optional*):
                A dictionary of proxy servers to use by protocol or endpoint, for example, `{'http': 'foo.bar:3128',
                'http://hostname': 'foo.bar:4012'}`. The proxies are used on each request.
            local_files_only (`bool`, *optional*, defaults to `False`):
                Whether to only load local model weights and configuration files or not. If set to True, the model
                won't be downloaded from the Hub.
            token (`str` or *bool*, *optional*):
                The token to use as HTTP bearer authorization for remote files. If `True`, the token generated from
                `diffusers-cli login` (stored in `~/.huggingface`) is used.
            revision (`str`, *optional*, defaults to `"main"`):
                The specific model version to use. It can be a branch name, a tag name, a commit id, or any identifier
                allowed by Git.
            image_size (`int`, *optional*, defaults to 512):
                The image size the model was trained on. Use 512 for all Stable Diffusion v1 models and the Stable
                Diffusion v2 base model. Use 768 for Stable Diffusion v2.
            use_safetensors (`bool`, *optional*, defaults to `None`):
                If set to `None`, the safetensors weights are downloaded if they're available **and** if the
                safetensors library is installed. If set to `True`, the model is forcibly loaded from safetensors
                weights. If set to `False`, safetensors weights are not loaded.
            kwargs (remaining dictionary of keyword arguments, *optional*):
                Can be used to overwrite load and saveable variables (for example the pipeline components of the
                specific pipeline class). The overwritten components are directly passed to the pipelines `__init__`
                method. See example below for more information.

        <Tip warning={true}>

            Make sure to pass both `image_size` and `scaling_factor` to `from_single_file()` if you're loading
            a VAE from SDXL or a Stable Diffusion v2 model or higher.

        </Tip>

        Examples:

        ```py
        from diffusers import AutoencoderKL

        url = "https://huggingface.co/stabilityai/sd-vae-ft-mse-original/blob/main/vae-ft-mse-840000-ema-pruned.safetensors"  # can also be local file
        model = AutoencoderKL.from_single_file(url)
        ```
        """

        original_config_file = kwargs.pop("original_config_file", None)
        resume_download = kwargs.pop("resume_download", False)
        force_download = kwargs.pop("force_download", False)
        proxies = kwargs.pop("proxies", None)
        token = kwargs.pop("token", None)
        cache_dir = kwargs.pop("cache_dir", None)
        local_files_only = kwargs.pop("local_files_only", None)
        revision = kwargs.pop("revision", None)
        torch_dtype = kwargs.pop("torch_dtype", None)
        use_safetensors = kwargs.pop("use_safetensors", True)

        class_name = cls.__name__
        original_config, checkpoint = fetch_ldm_config_and_checkpoint(
            pretrained_model_link_or_path=pretrained_model_link_or_path,
            class_name=class_name,
            original_config_file=original_config_file,
            resume_download=resume_download,
            force_download=force_download,
            proxies=proxies,
            token=token,
            revision=revision,
            local_files_only=local_files_only,
            use_safetensors=use_safetensors,
            cache_dir=cache_dir,
        )

        image_size = kwargs.pop("image_size", None)
        component = create_diffusers_vae_model_from_ldm(class_name, original_config, checkpoint, image_size=image_size)
        vae = component["vae"]
        if torch_dtype is not None:
            vae = vae.to(torch_dtype)

        return vae
