#######################################################################################
#
# MIT License
#
# Copyright (c) [2025] [leonelhs@gmail.com]
#
# Permission is hereby granted, free of charge, to any person obtaining a copy
# of this software and associated documentation files (the "Software"), to deal
# in the Software without restriction, including without limitation the rights
# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
# copies of the Software, and to permit persons to whom the Software is
# furnished to do so, subject to the following conditions:
#
# The above copyright notice and this permission notice shall be included in all
# copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
# SOFTWARE.
#
#######################################################################################

# This file implements an API endpoint ESRGAN system.
# It provides functionality to enhances an image by upscaling it 4 times its original size .


# Source code is based on or inspired by several projects.
# For more details and proper attribution, please refer to the following resources:
#
# This code aims to study ESRGAN image restoration.
# It has isolated te minimal functionalities from ESRGAN x4 plus project.
#
# [Real-ESRGAN] - [https://github.com/xinntao/Real-ESRGAN]
#

import torch
from basicsr.archs.rrdbnet_arch import RRDBNet
from huggingface_hub import hf_hub_download
from realesrgan import RealESRGANer

REPO_ID = 'leonelhs/realesrgan'

class TinyESRGAN:
    def __init__(self):
        half = True if torch.cuda.is_available() else False
        model_path = hf_hub_download(repo_id=REPO_ID, filename="RealESRGAN_x4plus.pth")
        model = RRDBNet(num_in_ch=3, num_out_ch=3, num_feat=64, num_block=23, num_grow_ch=32, scale=4)
        self.esrgan = RealESRGANer(scale=4, model_path=model_path, model=model, half=half)

    def enhance(self, img):
        return self.esrgan.enhance(img)[0]