import argparse
import cv2
import glob
import numpy as np
import os
import torch
from basicsr.archs.rrdbnet_arch import RRDBNet
from torch.nn import functional as F


def main():
    parser = argparse.ArgumentParser()
    parser.add_argument('--model_path', type=str, default='experiments/pretrained_models/RealESRGAN_x4plus.pth')
    parser.add_argument('--scale', type=int, default=4)
    parser.add_argument('--input', type=str, default='inputs', help='input image or folder')
    args = parser.parse_args()

    device = torch.device('cuda' if torch.cuda.is_available() else 'cpu')
    # set up model
    model = RRDBNet(num_in_ch=3, num_out_ch=3, num_feat=64, num_block=23, num_grow_ch=32, scale=args.scale)
    loadnet = torch.load(args.model_path)
    model.load_state_dict(loadnet['params_ema'], strict=True)
    model.eval()
    model = model.to(device)

    os.makedirs('results/', exist_ok=True)
    for idx, path in enumerate(sorted(glob.glob(os.path.join(args.input, '*')))):
        imgname = os.path.splitext(os.path.basename(path))[0]
        print('Testing', idx, imgname)
        # read image
        img = cv2.imread(path, cv2.IMREAD_COLOR).astype(np.float32) / 255.
        img = torch.from_numpy(np.transpose(img[:, :, [2, 1, 0]], (2, 0, 1))).float()
        img = img.unsqueeze(0).to(device)

        if args.scale == 2:
            mod_scale = 2
        elif args.scale == 1:
            mod_scale = 4
        else:
            mod_scale = None
        if mod_scale is not None:
            h_pad, w_pad = 0, 0
            _, _, h, w = img.size()
            if (h % mod_scale != 0):
                h_pad = (mod_scale - h % mod_scale)
            if (w % mod_scale != 0):
                w_pad = (mod_scale - w % mod_scale)
            img = F.pad(img, (0, w_pad, 0, h_pad), 'reflect')

        try:
            # inference
            with torch.no_grad():
                output = model(img)
            # remove extra pad
            if mod_scale is not None:
                _, _, h, w = output.size()
                output = output[:, :, 0:h - h_pad, 0:w - w_pad]
            # save image
            output = output.data.squeeze().float().cpu().clamp_(0, 1).numpy()
            output = np.transpose(output[[2, 1, 0], :, :], (1, 2, 0))
            output = (output * 255.0).round().astype(np.uint8)
            cv2.imwrite(f'results/{imgname}_RealESRGAN.png', output)
        except Exception as error:
            print('Error', error)


if __name__ == '__main__':
    main()