app.py

import os
import random
import cv2
import numpy
import gradio as gr
import spaces

from basicsr.archs.rrdbnet_arch import RRDBNet
from basicsr.utils.download_util import load_file_from_url
from realesrgan import RealESRGANer
from realesrgan.archs.srvgg_arch import SRVGGNetCompact

# --------------------
# Global (CPU-only data; KHÔNG chạm CUDA ở đây)
# --------------------
last_file = None
img_mode = "RGBA"

DEVICE = "cpu"      # set trong gpu_startup()
USE_HALF = False    # set trong gpu_startup()

# cache cho các upsampler đã khởi tạo
UPSAMPLER_CACHE = {}       # key: (model_name, denoise_strength, DEVICE, USE_HALF)
GFPGAN_FACE_ENHANCER = {}  # key: (outscale, DEVICE, USE_HALF)

# --------------------
# ZeroGPU: cấp GPU ngay khi khởi động
# --------------------
@spaces.GPU
def gpu_startup():
    """
    Hàm này chạy ngay khi Space bật trên ZeroGPU.
    Chỉ ở đây mới 'đụng' tới torch/cuda.
    """
    global DEVICE, USE_HALF
    import torch

    has_cuda = torch.cuda.is_available()
    DEVICE = "cuda" if has_cuda else "cpu"
    # half precision chỉ an toàn khi có CUDA
    USE_HALF = bool(has_cuda)

    print(f"[startup] CUDA available: {has_cuda}, device={DEVICE}, half={USE_HALF}")

# --------------------
# Utils
# --------------------
def rnd_string(x):
    chars = "abcdefghijklmnopqrstuvwxyz_0123456789"
    return "".join(random.choice(chars) for _ in range(x))

def has_transparency(img):
    if img.info.get("transparency", None) is not None:
        return True
    if img.mode == "P":
        transparent = img.info.get("transparency", -1)
        for _, index in img.getcolors():
            if index == transparent:
                return True
    elif img.mode == "RGBA":
        extrema = img.getextrema()
        if extrema[3][0] < 255:
            return True
    return False

def image_properties(img):
    global img_mode
    if img:
        if has_transparency(img):
            img_mode = "RGBA"
        else:
            img_mode = "RGB"
        return f"Resolution: Width: {img.size[0]}, Height: {img.size[1]}  |  Color Mode: {img_mode}"

def reset():
    global last_file
    if last_file:
        try:
            print(f"Deleting {last_file} ...")
            os.remove(last_file)
        except Exception as e:
            print("Delete error:", e)
        finally:
            last_file = None
    return gr.update(value=None), gr.update(value=None)

# --------------------
# Model builder (không gọi CUDA ở ngoài startup; mọi thứ phụ thuộc DEVICE/USE_HALF)
# --------------------
def get_model_and_paths(model_name, denoise_strength):
    """Chuẩn bị kiến trúc model + đường dẫn trọng số + dni_weight (nếu cần)."""
    if model_name in ('RealESRGAN_x4plus', 'RealESRNet_x4plus'):
        model = RRDBNet(num_in_ch=3, num_out_ch=3, num_feat=64, num_block=23, num_grow_ch=32, scale=4)
        netscale = 4
        file_url = ['https://github.com/xinntao/Real-ESRGAN/releases/download/v0.1.0/RealESRGAN_x4plus.pth'] \
            if model_name == 'RealESRGAN_x4plus' else \
            ['https://github.com/xinntao/Real-ESRGAN/releases/download/v0.1.1/RealESRNet_x4plus.pth']
    elif model_name == 'RealESRGAN_x4plus_anime_6B':
        model = RRDBNet(num_in_ch=3, num_out_ch=3, num_feat=64, num_block=6, num_grow_ch=32, scale=4)
        netscale = 4
        file_url = ['https://github.com/xinntao/Real-ESRGAN/releases/download/v0.2.2.4/RealESRGAN_x4plus_anime_6B.pth']
    elif model_name == 'RealESRGAN_x2plus':
        model = RRDBNet(num_in_ch=3, num_out_ch=3, num_feat=64, num_block=23, num_grow_ch=32, scale=2)
        netscale = 2
        file_url = ['https://github.com/xinntao/Real-ESRGAN/releases/download/v0.2.1/RealESRGAN_x2plus.pth']
    elif model_name == 'realesr-general-x4v3':
        model = SRVGGNetCompact(num_in_ch=3, num_out_ch=3, num_feat=64, num_conv=32, upscale=4, act_type='prelu')
        netscale = 4
        file_url = [
            'https://github.com/xinntao/Real-ESRGAN/releases/download/v0.2.5.0/realesr-general-wdn-x4v3.pth',
            'https://github.com/xinntao/Real-ESRGAN/releases/download/v0.2.5.0/realesr-general-x4v3.pth'
        ]
    else:
        raise ValueError(f"Unsupported model: {model_name}")

    # tải trọng số (nếu chưa có)
    model_path = os.path.join('weights', model_name + '.pth')
    if not os.path.isfile(model_path):
        ROOT_DIR = os.path.dirname(os.path.abspath(__file__))
        for url in file_url:
            model_path = load_file_from_url(url=url, model_dir=os.path.join(ROOT_DIR, 'weights'),
                                            progress=True, file_name=None)

    # dni (chỉ riêng general-x4v3)
    dni_weight = None
    if model_name == 'realesr-general-x4v3' and denoise_strength != 1:
        wdn_model_path = model_path.replace('realesr-general-x4v3', 'realesr-general-wdn-x4v3')
        model_path = [model_path, wdn_model_path]
        dni_weight = [denoise_strength, 1 - denoise_strength]

    return model, netscale, model_path, dni_weight

def get_upsampler(model_name, denoise_strength):
    """Khởi tạo/cached RealESRGANer theo device & half hiện hành."""
    key = (model_name, float(denoise_strength), DEVICE, USE_HALF)
    if key in UPSAMPLER_CACHE:
        return UPSAMPLER_CACHE[key]

    model, netscale, model_path, dni_weight = get_model_and_paths(model_name, denoise_strength)

    # Cấu hình theo thiết bị
    # - half=True khi GPU; False khi CPU
    # - gpu_id=0 khi GPU; None khi CPU
    half_flag = bool(USE_HALF)
    gpu_id = 0 if DEVICE == "cuda" else None

    upsampler = RealESRGANer(
        scale=netscale,
        model_path=model_path,
        dni_weight=dni_weight,
        model=model,
        tile=0,
        tile_pad=10,
        pre_pad=10,
        half=half_flag,
        gpu_id=gpu_id
    )
    UPSAMPLER_CACHE[key] = upsampler
    return upsampler

def get_face_enhancer(upsampler, outscale):
    key = (int(outscale), DEVICE, USE_HALF)
    if key in GFPGAN_FACE_ENHANCER:
        return GFPGAN_FACE_ENHANCER[key]
    from gfpgan import GFPGANer
    face_enhancer = GFPGANer(
        model_path='https://github.com/TencentARC/GFPGAN/releases/download/v1.3.0/GFPGANv1.3.pth',
        upscale=int(outscale),
        arch='clean',
        channel_multiplier=2,
        bg_upsampler=upsampler
    )
    GFPGAN_FACE_ENHANCER[key] = face_enhancer
    return face_enhancer

# --------------------
# Inference (đánh dấu @spaces.GPU vì có thể chạy trên GPU)
# --------------------
@spaces.GPU
def realesrgan(img, model_name, denoise_strength, face_enhance, outscale):
    """Real-ESRGAN restore/upscale."""
    if not img:
        return

    upsampler = get_upsampler(model_name, denoise_strength)

    # PIL -> cv2 BGRA
    cv_img = numpy.array(img)
    img_bgra = cv2.cvtColor(cv_img, cv2.COLOR_RGBA2BGRA)

    try:
        if face_enhance:
            face_enhancer = get_face_enhancer(upsampler, outscale)
            _, _, output = face_enhancer.enhance(
                img_bgra, has_aligned=False, only_center_face=False, paste_back=True
            )
        else:
            output, _ = upsampler.enhance(img_bgra, outscale=int(outscale))
    except RuntimeError as error:
        # Gợi ý tự động giảm tile nếu OOM
        print('Error', error)
        return None
    else:
        extension = 'png' if img_mode == 'RGBA' else 'jpg'
        out_filename = f"output_{rnd_string(8)}.{extension}"
        cv2.imwrite(out_filename, output)
        global last_file
        last_file = out_filename
        return out_filename

# --------------------
# UI
# --------------------
def main():
    with gr.Blocks(title="Real-ESRGAN Gradio Demo", theme="ParityError/Interstellar") as demo:
        gr.Markdown("## Image Upscaler")

        with gr.Accordion("Upscaling option"):
            with gr.Row():
                model_name = gr.Dropdown(
                    label="Upscaler model",
                    choices=[
                        "RealESRGAN_x4plus",
                        "RealESRNet_x4plus",
                        "RealESRGAN_x4plus_anime_6B",
                        "RealESRGAN_x2plus",
                        "realesr-general-x4v3",
                    ],
                    value="RealESRGAN_x4plus_anime_6B",
                    show_label=True
                )
                denoise_strength = gr.Slider(label="Denoise Strength", minimum=0, maximum=1, step=0.1, value=0.5)
                outscale = gr.Slider(label="Resolution upscale", minimum=1, maximum=6, step=1, value=4, show_label=True)
                face_enhance = gr.Checkbox(label="Face Enhancement (GFPGAN)")

        with gr.Row():
            with gr.Group():
                input_image = gr.Image(label="Input Image", type="pil", image_mode="RGBA")
                input_image_properties = gr.Textbox(label="Image Properties", max_lines=1)
            output_image = gr.Image(label="Output Image", image_mode="RGBA")
        with gr.Row():
            reset_btn = gr.Button("Remove images")
            restore_btn = gr.Button("Upscale")

        input_image.change(fn=image_properties, inputs=input_image, outputs=input_image_properties)
        restore_btn.click(fn=realesrgan,
                          inputs=[input_image, model_name, denoise_strength, face_enhance, outscale],
                          outputs=output_image)
        reset_btn.click(fn=reset, inputs=[], outputs=[output_image, input_image])

    demo.launch(server_name="0.0.0.0", server_port=7860)

if __name__ == "__main__":
    # Gọi hàm startup để ZeroGPU cấp GPU ngay khi Space boot
    gpu_startup()
    main()