import numpy as np
import torch

from transformers.tools.base import Tool, get_default_device
from transformers.utils import is_accelerate_available

from diffusers import DiffusionPipeline


IMAGE_UPSCALING_DESCRIPTION = (
    "This is a tool that upscales an image. It takes one input: `image`, which should be "
    "the image to upscale. It returns the upscaled image."
)


class ImageUpscalingTool(Tool):
    default_stable_diffusion_checkpoint = "stabilityai/sd-x2-latent-upscaler"
    description = IMAGE_UPSCALING_DESCRIPTION 
    name = "image_upscaler"
    inputs = ['image']
    outputs = ['image']

    def __init__(self, device=None, controlnet=None, stable_diffusion=None, **hub_kwargs) -> None:
        if not is_accelerate_available():
            raise ImportError("Accelerate should be installed in order to use tools.")

        super().__init__()

        self.stable_diffusion = self.default_stable_diffusion_checkpoint

        self.device = device
        self.hub_kwargs = hub_kwargs

    def setup(self):
        if self.device is None:
            self.device = get_default_device()

        self.pipeline = DiffusionPipeline.from_pretrained(self.stable_diffusion)

        self.pipeline.to(self.device)
        if self.device.type == "cuda":
            self.pipeline.to(torch_dtype=torch.float16)

        self.is_initialized = True

    def __call__(self, image):
        if not self.is_initialized:
            self.setup()

        return self.pipeline(
            image=image,
            prompt="",
            num_inference_steps=30,
            guidance_scale=0,
        ).images[0]