import os
import sys
import torch
import gradio as gr
from PIL import Image
import numpy as np
from omegaconf import OmegaConf
import subprocess
from tqdm import tqdm
import requests
import spaces
import einops
import math
import random
import pytorch_lightning as pl

def download_file(url, filename):
    response = requests.get(url, stream=True)
    total_size = int(response.headers.get('content-length', 0))
    block_size = 1024
    with open(filename, 'wb') as file, tqdm(
        desc=filename,
        total=total_size,
        unit='iB',
        unit_scale=True,
        unit_divisor=1024,
    ) as progress_bar:
        for data in response.iter_content(block_size):
            size = file.write(data)
            progress_bar.update(size)

def setup_environment():
    if not os.path.exists("CCSR"):
        print("Cloning CCSR repository...")
        subprocess.run(["git", "clone", "-b", "dev", "https://github.com/camenduru/CCSR.git"])
    
    os.chdir("CCSR")
    sys.path.append(os.getcwd())
    
    os.makedirs("weights", exist_ok=True)
    if not os.path.exists("weights/real-world_ccsr.ckpt"):
        print("Downloading model checkpoint...")
        download_file(
            "https://huggingface.co./camenduru/CCSR/resolve/main/real-world_ccsr.ckpt",
            "weights/real-world_ccsr.ckpt"
        )
    else:
        print("Model checkpoint already exists. Skipping download.")

setup_environment()

from ldm.xformers_state import disable_xformers
from model.q_sampler import SpacedSampler
from model.ccsr_stage1 import ControlLDM
from utils.common import instantiate_from_config, load_state_dict
from utils.image import auto_resize

config = OmegaConf.load("configs/model/ccsr_stage2.yaml")
model = instantiate_from_config(config)
ckpt = torch.load("weights/real-world_ccsr.ckpt", map_location="cpu")
load_state_dict(model, ckpt, strict=True)
model.freeze()
model.to("cuda")

sampler = SpacedSampler(model, var_type="fixed_small")

@spaces.GPU
@torch.no_grad()
def process(
    control_img: Image.Image,
    num_samples: int,
    sr_scale: float,
    strength: float,
    positive_prompt: str,
    negative_prompt: str,
    cfg_scale: float,
    steps: int,
    use_color_fix: bool,
    seed: int,
    tile_diffusion: bool,
    tile_diffusion_size: int,
    tile_diffusion_stride: int
):
    print(
        f"control image shape={control_img.size}\n"
        f"num_samples={num_samples}, sr_scale={sr_scale}, strength={strength}\n"
        f"positive_prompt='{positive_prompt}', negative_prompt='{negative_prompt}'\n"
        f"cdf scale={cfg_scale}, steps={steps}, use_color_fix={use_color_fix}\n"
        f"seed={seed}\n"
        f"tile_diffusion={tile_diffusion}, tile_diffusion_size={tile_diffusion_size}, tile_diffusion_stride={tile_diffusion_stride}"
    )
    pl.seed_everything(seed)

    # Resize lr
    if sr_scale != 1:
        control_img = control_img.resize(
            tuple(math.ceil(x * sr_scale) for x in control_img.size),
            Image.BICUBIC
        )

    input_size = control_img.size

    # Resize the lr image
    if not tile_diffusion:
        control_img = auto_resize(control_img, 512)
    else:
        control_img = auto_resize(control_img, tile_diffusion_size)

    # Resize image to be multiples of 64
    control_img = control_img.resize(
        tuple((s // 64 + 1) * 64 for s in control_img.size), Image.LANCZOS
    )
    control_img = np.array(control_img)

    # Convert to tensor (NCHW, [0,1])
    control = torch.tensor(control_img[None] / 255.0, dtype=torch.float32, device=model.device).clamp_(0, 1)
    control = einops.rearrange(control, "n h w c -> n c h w").contiguous()
    height, width = control.size(-2), control.size(-1)
    model.control_scales = [strength] * 13

    preds = []
    for _ in tqdm(range(num_samples)):
        shape = (1, 4, height // 8, width // 8)
        x_T = torch.randn(shape, device=model.device, dtype=torch.float32)

        if not tile_diffusion:
            samples = sampler.sample_ccsr(
                steps=steps, t_max=0.6667, t_min=0.3333, shape=shape, cond_img=control,
                positive_prompt=positive_prompt, negative_prompt=negative_prompt, x_T=x_T,
                cfg_scale=cfg_scale,
                color_fix_type="adain" if use_color_fix else "none"
            )
        else:
            samples = sampler.sample_with_tile_ccsr(
                tile_size=tile_diffusion_size, tile_stride=tile_diffusion_stride,
                steps=steps, t_max=0.6667, t_min=0.3333, shape=shape, cond_img=control,
                positive_prompt=positive_prompt, negative_prompt=negative_prompt, x_T=x_T,
                cfg_scale=cfg_scale,
                color_fix_type="adain" if use_color_fix else "none"
            )

        x_samples = samples.clamp(0, 1)
        x_samples = (einops.rearrange(x_samples, "b c h w -> b h w c") * 255).cpu().numpy().clip(0, 255).astype(np.uint8)

        img = Image.fromarray(x_samples[0, ...]).resize(input_size, Image.LANCZOS)
        preds.append(np.array(img))

    return preds

def update_output_resolution(image, scale):
    if image is not None:
        width, height = image.size
        return f"Current resolution: {width}x{height}. Output resolution: {int(width*scale)}x{int(height*scale)}"
    return "Upload an image to see the output resolution"

block = gr.Blocks().queue()
with block:
    with gr.Row():
        input_image = gr.Image(type="pil", label="Input Image")
    
    with gr.Row():
        sr_scale = gr.Slider(label="SR Scale", minimum=1, maximum=8, value=4, step=0.1, info="Super-resolution scale factor.")
    
    output_resolution = gr.Markdown("Upload an image to see the output resolution")
    
    with gr.Row():
        run_button = gr.Button(value="Run")
    
    with gr.Accordion("Options", open=False):
        with gr.Column():
            num_samples = gr.Slider(label="Number Of Samples", minimum=1, maximum=12, value=1, step=1)
            strength = gr.Slider(label="Control Strength", minimum=0.0, maximum=2.0, value=1.0, step=0.01)
            positive_prompt = gr.Textbox(label="Positive Prompt", value="")
            negative_prompt = gr.Textbox(
                label="Negative Prompt",
                value="longbody, lowres, bad anatomy, bad hands, missing fingers, extra digit, fewer digits, cropped, worst quality, low quality"
            )
            cfg_scale = gr.Slider(label="Classifier Free Guidance Scale", minimum=0.1, maximum=30.0, value=1.0, step=0.1)
            steps = gr.Slider(label="Steps", minimum=1, maximum=100, value=45, step=1)
            use_color_fix = gr.Checkbox(label="Use Color Correction", value=True)
            seed = gr.Slider(label="Seed", minimum=-1, maximum=2147483647, step=1, value=231)
            tile_diffusion = gr.Checkbox(label="Tile diffusion", value=False)
            tile_diffusion_size = gr.Slider(label="Tile diffusion size", minimum=512, maximum=1024, value=512, step=256)
            tile_diffusion_stride = gr.Slider(label="Tile diffusion stride", minimum=256, maximum=512, value=256, step=128)
    
    with gr.Column():
        result_gallery = gr.Gallery(label="Output", show_label=False, elem_id="gallery")

    inputs = [
        input_image,
        num_samples,
        sr_scale,
        strength,
        positive_prompt,
        negative_prompt,
        cfg_scale,
        steps,
        use_color_fix,
        seed,
        tile_diffusion,
        tile_diffusion_size,
        tile_diffusion_stride,
    ]
    run_button.click(fn=process, inputs=inputs, outputs=[result_gallery])

    # Update output resolution when image is uploaded or SR scale is changed
    input_image.change(update_output_resolution, inputs=[input_image, sr_scale], outputs=[output_resolution])
    sr_scale.change(update_output_resolution, inputs=[input_image, sr_scale], outputs=[output_resolution])

    # Disable SR scale slider when no image is uploaded
    input_image.change(
        lambda x: gr.update(interactive=x is not None),
        inputs=[input_image],
        outputs=[sr_scale]
    )

block.launch()