import gradio as gr
import cv2
import matplotlib.pyplot as plt
import numpy as np
import torch
import torchvision
import kornia as K

def inference(file1,num_iters):
    img: np.ndarray = cv2.imread(file1.name)
    img = cv2.cvtColor(img, cv2.COLOR_BGR2RGB) / 255.0
    img = img + np.random.normal(loc=0.0, scale=0.1, size=img.shape)
    img = np.clip(img, 0.0, 1.0)

    # convert to torch tensor
    noisy_image = K.utils.image_to_tensor(img).squeeze()

    class TVDenoise(torch.nn.Module):
        def __init__(self, noisy_image):
            super(TVDenoise, self).__init__()
            self.l2_term = torch.nn.MSELoss(reduction='mean')
            self.regularization_term = K.losses.TotalVariation()
            # create the variable which will be optimized to produce the noise free image
            self.clean_image = torch.nn.Parameter(data=noisy_image.clone(), requires_grad=True)
            self.noisy_image = noisy_image

        def forward(self):
            # print(self.l2_term(self.clean_image, self.noisy_image))
            # print(self.regularization_term(self.clean_image))
            return self.l2_term(self.clean_image, self.noisy_image) + 0.0001 * self.regularization_term(self.clean_image)

        def get_clean_image(self):
            return self.clean_image


    tv_denoiser = TVDenoise(noisy_image)

    # define the optimizer to optimize the 1 parameter of tv_denoiser
    optimizer = torch.optim.SGD(tv_denoiser.parameters(), lr=0.1, momentum=0.9)

    for i in range(int(num_iters)):
      optimizer.zero_grad()
      loss = torch.mean(tv_denoiser())
      if i % 50 == 0:
          print("Loss in iteration {} of {}: {:.3f}".format(i, num_iters, loss.item()))
      loss.backward()
      optimizer.step()

    img_clean: np.ndarray = K.utils.tensor_to_image(tv_denoiser.get_clean_image())

    return img, img_clean

examples = [
]


inputs = [
    gr.Image(type='file', label='Input Image'),
    gr.Slider(minimum=50, maximum=10000, step=50, default=500, label="num_iters")
]

outputs = [
    gr.Image(type='file', label='Noised Image'),
    gr.Image(type='file', label='Denoised Image'),
]

title = "Image Stitching using Kornia and LoFTR"

demo_app = gr.Interface(
    fn=inference,
    inputs=inputs,
    outputs=outputs,
    title=title,
    examples=examples,
    theme='huggingface',
)
demo_app.launch(debug=True)