import math
import gradio as gr
import numpy as np
import torch
import safetensors.torch as sf
import db_examples

from PIL import Image
from diffusers import StableDiffusionPipeline, StableDiffusionImg2ImgPipeline
from diffusers import AutoencoderKL, UNet2DConditionModel, DDIMScheduler, EulerAncestralDiscreteScheduler, DPMSolverMultistepScheduler
from diffusers.models.attention_processor import AttnProcessor2_0
from transformers import CLIPTextModel, CLIPTokenizer
from briarmbg import BriaRMBG
from enum import Enum
# from torch.hub import download_url_to_file


# 'stablediffusionapi/realistic-vision-v51'
# 'runwayml/stable-diffusion-v1-5'
sd15_name = 'stablediffusionapi/realistic-vision-v51'
tokenizer = CLIPTokenizer.from_pretrained(sd15_name, subfolder="tokenizer")
text_encoder = CLIPTextModel.from_pretrained(sd15_name, subfolder="text_encoder")
vae = AutoencoderKL.from_pretrained(sd15_name, subfolder="vae")
unet = UNet2DConditionModel.from_pretrained(sd15_name, subfolder="unet")
rmbg = BriaRMBG.from_pretrained("briaai/RMBG-1.4")

# Change UNet

with torch.no_grad():
    new_conv_in = torch.nn.Conv2d(8, unet.conv_in.out_channels, unet.conv_in.kernel_size, unet.conv_in.stride, unet.conv_in.padding)
    new_conv_in.weight.zero_()
    new_conv_in.weight[:, :4, :, :].copy_(unet.conv_in.weight)
    new_conv_in.bias = unet.conv_in.bias
    unet.conv_in = new_conv_in

unet_original_forward = unet.forward


def hooked_unet_forward(sample, timestep, encoder_hidden_states, **kwargs):
    c_concat = kwargs['cross_attention_kwargs']['concat_conds'].to(sample)
    c_concat = torch.cat([c_concat] * (sample.shape[0] // c_concat.shape[0]), dim=0)
    new_sample = torch.cat([sample, c_concat], dim=1)
    kwargs['cross_attention_kwargs'] = {}
    return unet_original_forward(new_sample, timestep, encoder_hidden_states, **kwargs)


unet.forward = hooked_unet_forward

# Load

model_path = './models/iclight_sd15_fc.safetensors'
# download_url_to_file(url='https://huggingface.co/lllyasviel/ic-light/resolve/main/iclight_sd15_fc.safetensors', dst=model_path)
sd_offset = sf.load_file(model_path)
sd_origin = unet.state_dict()
keys = sd_origin.keys()
sd_merged = {k: sd_origin[k] + sd_offset[k] for k in sd_origin.keys()}
unet.load_state_dict(sd_merged, strict=True)
del sd_offset, sd_origin, sd_merged, keys

# Device

device = torch.device('cuda')
text_encoder = text_encoder.to(device=device, dtype=torch.float16)
vae = vae.to(device=device, dtype=torch.bfloat16)
unet = unet.to(device=device, dtype=torch.float16)
rmbg = rmbg.to(device=device, dtype=torch.float32)

# SDP

unet.set_attn_processor(AttnProcessor2_0())
vae.set_attn_processor(AttnProcessor2_0())

# Samplers

ddim_scheduler = DDIMScheduler(
    num_train_timesteps=1000,
    beta_start=0.00085,
    beta_end=0.012,
    beta_schedule="scaled_linear",
    clip_sample=False,
    set_alpha_to_one=False,
    steps_offset=1,
)

euler_a_scheduler = EulerAncestralDiscreteScheduler(
    num_train_timesteps=1000,
    beta_start=0.00085,
    beta_end=0.012,
    steps_offset=1
)

dpmpp_2m_sde_karras_scheduler = DPMSolverMultistepScheduler(
    num_train_timesteps=1000,
    beta_start=0.00085,
    beta_end=0.012,
    algorithm_type="sde-dpmsolver++",
    use_karras_sigmas=True,
    steps_offset=1
)

# Pipelines

t2i_pipe = StableDiffusionPipeline(
    vae=vae,
    text_encoder=text_encoder,
    tokenizer=tokenizer,
    unet=unet,
    scheduler=dpmpp_2m_sde_karras_scheduler,
    safety_checker=None,
    requires_safety_checker=False,
    feature_extractor=None,
    image_encoder=None
)

i2i_pipe = StableDiffusionImg2ImgPipeline(
    vae=vae,
    text_encoder=text_encoder,
    tokenizer=tokenizer,
    unet=unet,
    scheduler=dpmpp_2m_sde_karras_scheduler,
    safety_checker=None,
    requires_safety_checker=False,
    feature_extractor=None,
    image_encoder=None
)


@torch.inference_mode()
def encode_prompt_inner(txt: str):
    max_length = tokenizer.model_max_length
    chunk_length = tokenizer.model_max_length - 2
    id_start = tokenizer.bos_token_id
    id_end = tokenizer.eos_token_id
    id_pad = id_end

    def pad(x, p, i):
        return x[:i] if len(x) >= i else x + [p] * (i - len(x))

    tokens = tokenizer(txt, truncation=False, add_special_tokens=False)["input_ids"]
    chunks = [[id_start] + tokens[i: i + chunk_length] + [id_end] for i in range(0, len(tokens), chunk_length)]
    chunks = [pad(ck, id_pad, max_length) for ck in chunks]

    token_ids = torch.tensor(chunks).to(device=device, dtype=torch.int64)
    conds = text_encoder(token_ids).last_hidden_state

    return conds


@torch.inference_mode()
def encode_prompt_pair(positive_prompt, negative_prompt):
    c = encode_prompt_inner(positive_prompt)
    uc = encode_prompt_inner(negative_prompt)

    c_len = float(len(c))
    uc_len = float(len(uc))
    max_count = max(c_len, uc_len)
    c_repeat = int(math.ceil(max_count / c_len))
    uc_repeat = int(math.ceil(max_count / uc_len))
    max_chunk = max(len(c), len(uc))

    c = torch.cat([c] * c_repeat, dim=0)[:max_chunk]
    uc = torch.cat([uc] * uc_repeat, dim=0)[:max_chunk]

    c = torch.cat([p[None, ...] for p in c], dim=1)
    uc = torch.cat([p[None, ...] for p in uc], dim=1)

    return c, uc


@torch.inference_mode()
def pytorch2numpy(imgs, quant=True):
    results = []
    for x in imgs:
        y = x.movedim(0, -1)

        if quant:
            y = y * 127.5 + 127.5
            y = y.detach().float().cpu().numpy().clip(0, 255).astype(np.uint8)
        else:
            y = y * 0.5 + 0.5
            y = y.detach().float().cpu().numpy().clip(0, 1).astype(np.float32)

        results.append(y)
    return results


@torch.inference_mode()
def numpy2pytorch(imgs):
    h = torch.from_numpy(np.stack(imgs, axis=0)).float() / 127.0 - 1.0  # so that 127 must be strictly 0.0
    h = h.movedim(-1, 1)
    return h


def resize_and_center_crop(image, target_width, target_height):
    pil_image = Image.fromarray(image)
    original_width, original_height = pil_image.size
    scale_factor = max(target_width / original_width, target_height / original_height)
    resized_width = int(round(original_width * scale_factor))
    resized_height = int(round(original_height * scale_factor))
    resized_image = pil_image.resize((resized_width, resized_height), Image.LANCZOS)
    left = (resized_width - target_width) / 2
    top = (resized_height - target_height) / 2
    right = (resized_width + target_width) / 2
    bottom = (resized_height + target_height) / 2
    cropped_image = resized_image.crop((left, top, right, bottom))
    return np.array(cropped_image)


def resize_without_crop(image, target_width, target_height):
    pil_image = Image.fromarray(image)
    resized_image = pil_image.resize((target_width, target_height), Image.LANCZOS)
    return np.array(resized_image)


@torch.inference_mode()
def run_rmbg(img, sigma=0.0):
    H, W, C = img.shape
    assert C == 3
    k = (256.0 / float(H * W)) ** 0.5
    feed = resize_without_crop(img, int(64 * round(W * k)), int(64 * round(H * k)))
    feed = numpy2pytorch([feed]).to(device=device, dtype=torch.float32)
    alpha = rmbg(feed)[0][0]
    alpha = torch.nn.functional.interpolate(alpha, size=(H, W), mode="bilinear")
    alpha = alpha.movedim(1, -1)[0]
    alpha = alpha.detach().float().cpu().numpy().clip(0, 1)
    result = 127 + (img.astype(np.float32) - 127 + sigma) * alpha
    return result.clip(0, 255).astype(np.uint8), alpha


@torch.inference_mode()
def process(input_fg, prompt, image_width, image_height, num_samples, seed, steps, a_prompt, n_prompt, cfg, highres_scale, highres_denoise, lowres_denoise, bg_source):
    bg_source = BGSource(bg_source)
    input_bg = None

    if bg_source == BGSource.NONE:
        pass
    elif bg_source == BGSource.LEFT:
        gradient = np.linspace(255, 0, image_width)
        image = np.tile(gradient, (image_height, 1))
        input_bg = np.stack((image,) * 3, axis=-1).astype(np.uint8)
    elif bg_source == BGSource.RIGHT:
        gradient = np.linspace(0, 255, image_width)
        image = np.tile(gradient, (image_height, 1))
        input_bg = np.stack((image,) * 3, axis=-1).astype(np.uint8)
    elif bg_source == BGSource.TOP:
        gradient = np.linspace(255, 0, image_height)[:, None]
        image = np.tile(gradient, (1, image_width))
        input_bg = np.stack((image,) * 3, axis=-1).astype(np.uint8)
    elif bg_source == BGSource.BOTTOM:
        gradient = np.linspace(0, 255, image_height)[:, None]
        image = np.tile(gradient, (1, image_width))
        input_bg = np.stack((image,) * 3, axis=-1).astype(np.uint8)
    else:
        raise 'Wrong initial latent!'

    rng = torch.Generator(device=device).manual_seed(int(seed))

    fg = resize_and_center_crop(input_fg, image_width, image_height)

    concat_conds = numpy2pytorch([fg]).to(device=vae.device, dtype=vae.dtype)
    concat_conds = vae.encode(concat_conds).latent_dist.mode() * vae.config.scaling_factor

    conds, unconds = encode_prompt_pair(positive_prompt=prompt + ', ' + a_prompt, negative_prompt=n_prompt)

    if input_bg is None:
        latents = t2i_pipe(
            prompt_embeds=conds,
            negative_prompt_embeds=unconds,
            width=image_width,
            height=image_height,
            num_inference_steps=steps,
            num_images_per_prompt=num_samples,
            generator=rng,
            output_type='latent',
            guidance_scale=cfg,
            cross_attention_kwargs={'concat_conds': concat_conds},
        ).images.to(vae.dtype) / vae.config.scaling_factor
    else:
        bg = resize_and_center_crop(input_bg, image_width, image_height)
        bg_latent = numpy2pytorch([bg]).to(device=vae.device, dtype=vae.dtype)
        bg_latent = vae.encode(bg_latent).latent_dist.mode() * vae.config.scaling_factor
        latents = i2i_pipe(
            image=bg_latent,
            strength=lowres_denoise,
            prompt_embeds=conds,
            negative_prompt_embeds=unconds,
            width=image_width,
            height=image_height,
            num_inference_steps=int(round(steps / lowres_denoise)),
            num_images_per_prompt=num_samples,
            generator=rng,
            output_type='latent',
            guidance_scale=cfg,
            cross_attention_kwargs={'concat_conds': concat_conds},
        ).images.to(vae.dtype) / vae.config.scaling_factor

    pixels = vae.decode(latents).sample
    pixels = pytorch2numpy(pixels)
    pixels = [resize_without_crop(
        image=p,
        target_width=int(round(image_width * highres_scale / 64.0) * 64),
        target_height=int(round(image_height * highres_scale / 64.0) * 64))
    for p in pixels]

    pixels = numpy2pytorch(pixels).to(device=vae.device, dtype=vae.dtype)
    latents = vae.encode(pixels).latent_dist.mode() * vae.config.scaling_factor
    latents = latents.to(device=unet.device, dtype=unet.dtype)

    image_height, image_width = latents.shape[2] * 8, latents.shape[3] * 8

    fg = resize_and_center_crop(input_fg, image_width, image_height)
    concat_conds = numpy2pytorch([fg]).to(device=vae.device, dtype=vae.dtype)
    concat_conds = vae.encode(concat_conds).latent_dist.mode() * vae.config.scaling_factor

    latents = i2i_pipe(
        image=latents,
        strength=highres_denoise,
        prompt_embeds=conds,
        negative_prompt_embeds=unconds,
        width=image_width,
        height=image_height,
        num_inference_steps=int(round(steps / highres_denoise)),
        num_images_per_prompt=num_samples,
        generator=rng,
        output_type='latent',
        guidance_scale=cfg,
        cross_attention_kwargs={'concat_conds': concat_conds},
    ).images.to(vae.dtype) / vae.config.scaling_factor

    pixels = vae.decode(latents).sample

    return pytorch2numpy(pixels)


@torch.inference_mode()
def process_relight(input_fg, prompt, image_width, image_height, num_samples, seed, steps, a_prompt, n_prompt, cfg, highres_scale, highres_denoise, lowres_denoise, bg_source):
    input_fg, matting = run_rmbg(input_fg)
    results = process(input_fg, prompt, image_width, image_height, num_samples, seed, steps, a_prompt, n_prompt, cfg, highres_scale, highres_denoise, lowres_denoise, bg_source)
    return input_fg, results


quick_prompts = [
    'sunshine from window',
    'neon light, city',
    'sunset over sea',
    'golden time',
    'sci-fi RGB glowing, cyberpunk',
    'natural lighting',
    'warm atmosphere, at home, bedroom',
    'magic lit',
    'evil, gothic, Yharnam',
    'light and shadow',
    'shadow from window',
    'soft studio lighting',
    'home atmosphere, cozy bedroom illumination',
    'neon, Wong Kar-wai, warm'
]
quick_prompts = [[x] for x in quick_prompts]


quick_subjects = [
    'beautiful woman, detailed face',
    'handsome man, detailed face',
]
quick_subjects = [[x] for x in quick_subjects]


class BGSource(Enum):
    NONE = "None"
    LEFT = "Left Light"
    RIGHT = "Right Light"
    TOP = "Top Light"
    BOTTOM = "Bottom Light"


block = gr.Blocks().queue()
with block:
    with gr.Row():
        gr.Markdown("## IC-Light (Relighting with Foreground Condition)")
    with gr.Row():
        with gr.Column():
            with gr.Row():
                input_fg = gr.Image(source='upload', type="numpy", label="Image", height=480)
                output_bg = gr.Image(type="numpy", label="Preprocessed Foreground", height=480)
            prompt = gr.Textbox(label="Prompt")
            bg_source = gr.Radio(choices=[e.value for e in BGSource],
                                 value=BGSource.NONE.value,
                                 label="Lighting Preference (Initial Latent)", type='value')
            example_quick_subjects = gr.Dataset(samples=quick_subjects, label='Subject Quick List', samples_per_page=1000, components=[prompt])
            example_quick_prompts = gr.Dataset(samples=quick_prompts, label='Lighting Quick List', samples_per_page=1000, components=[prompt])
            relight_button = gr.Button(value="Relight")

            with gr.Group():
                with gr.Row():
                    num_samples = gr.Slider(label="Images", minimum=1, maximum=12, value=1, step=1)
                    seed = gr.Number(label="Seed", value=12345, precision=0)

                with gr.Row():
                    image_width = gr.Slider(label="Image Width", minimum=256, maximum=1024, value=512, step=64)
                    image_height = gr.Slider(label="Image Height", minimum=256, maximum=1024, value=640, step=64)

            with gr.Accordion("Advanced options", open=False):
                steps = gr.Slider(label="Steps", minimum=1, maximum=100, value=25, step=1)
                cfg = gr.Slider(label="CFG Scale", minimum=1.0, maximum=32.0, value=2, step=0.01)
                lowres_denoise = gr.Slider(label="Lowres Denoise (for initial latent)", minimum=0.1, maximum=1.0, value=0.9, step=0.01)
                highres_scale = gr.Slider(label="Highres Scale", minimum=1.0, maximum=3.0, value=1.5, step=0.01)
                highres_denoise = gr.Slider(label="Highres Denoise", minimum=0.1, maximum=1.0, value=0.5, step=0.01)
                a_prompt = gr.Textbox(label="Added Prompt", value='best quality')
                n_prompt = gr.Textbox(label="Negative Prompt", value='lowres, bad anatomy, bad hands, cropped, worst quality')
        with gr.Column():
            result_gallery = gr.Gallery(height=832, object_fit='contain', label='Outputs')
    with gr.Row():
        dummy_image_for_outputs = gr.Image(visible=False, label='Result')
        gr.Examples(
            fn=lambda *args: ([args[-1]], None),
            examples=db_examples.foreground_conditioned_examples,
            inputs=[
                input_fg, prompt, bg_source, image_width, image_height, seed, dummy_image_for_outputs
            ],
            outputs=[result_gallery, output_bg],
            run_on_click=True, examples_per_page=1024
        )
    ips = [input_fg, prompt, image_width, image_height, num_samples, seed, steps, a_prompt, n_prompt, cfg, highres_scale, highres_denoise, lowres_denoise, bg_source]
    relight_button.click(fn=process_relight, inputs=ips, outputs=[output_bg, result_gallery])
    example_quick_prompts.click(lambda x, y: ', '.join(y.split(', ')[:2] + [x[0]]), inputs=[example_quick_prompts, prompt], outputs=prompt, show_progress=False, queue=False)
    example_quick_subjects.click(lambda x: x[0], inputs=example_quick_subjects, outputs=prompt, show_progress=False, queue=False)


block.launch(server_name='0.0.0.0')