import os
import random
import cv2
import einops
import torch
import numpy as np

import comfy.model_management
import comfy.sample
import comfy.utils

from comfy.sd import load_checkpoint_guess_config
from nodes import VAEDecode, EmptyLatentImage, CLIPTextEncode


opCLIPTextEncode = CLIPTextEncode()
opEmptyLatentImage = EmptyLatentImage()
opVAEDecode = VAEDecode()


class StableDiffusionModel:
    def __init__(self, unet, vae, clip, clip_vision):
        self.unet = unet
        self.vae = vae
        self.clip = clip
        self.clip_vision = clip_vision


@torch.no_grad()
def load_model(ckpt_filename):
    unet, clip, vae, clip_vision = load_checkpoint_guess_config(ckpt_filename)
    return StableDiffusionModel(unet=unet, clip=clip, vae=vae, clip_vision=clip_vision)


@torch.no_grad()
def encode_prompt_condition(clip, prompt):
    return opCLIPTextEncode.encode(clip=clip, text=prompt)[0]


@torch.no_grad()
def generate_empty_latent(width=1024, height=1024, batch_size=1):
    return opEmptyLatentImage.generate(width=width, height=height, batch_size=batch_size)[0]


@torch.no_grad()
def decode_vae(vae, latent_image):
    return opVAEDecode.decode(samples=latent_image, vae=vae)[0]


def get_previewer(device, latent_format):
    from latent_preview import TAESD, TAESDPreviewerImpl
    taesd_decoder_path = os.path.abspath(os.path.realpath(os.path.join("models", "vae_approx",
                                                                       latent_format.taesd_decoder_name)))

    if not os.path.exists(taesd_decoder_path):
        print(f"Warning: TAESD previews enabled, but could not find {taesd_decoder_path}")
        return None

    taesd = TAESD(None, taesd_decoder_path).to(device)

    def preview_function(x0):
        with torch.no_grad():
            x_sample = taesd.decoder(x0).detach() * 255.0
            x_sample = einops.rearrange(x_sample, 'b c h w -> b h w c')
            x_sample = x_sample.cpu().numpy()[..., ::-1].copy().clip(0, 255).astype(np.uint8)
            for i, s in enumerate(x_sample):
                cv2.imshow(f'Preview {i}', s)
                cv2.waitKey(1)

    taesd.preview = preview_function

    return taesd


def close_all_preview():
    cv2.destroyAllWindows()


@torch.no_grad()
def ksampler(model, positive, negative, latent, seed=None, steps=30, cfg=9.0, sampler_name='euler_ancestral', scheduler='normal', denoise=1.0, disable_noise=False, start_step=None, last_step=None, force_full_denoise=False):
    seed = seed if isinstance(seed, int) else random.randint(1, 2 ** 64)

    device = comfy.model_management.get_torch_device()
    latent_image = latent["samples"]

    if disable_noise:
        noise = torch.zeros(latent_image.size(), dtype=latent_image.dtype, layout=latent_image.layout, device="cpu")
    else:
        batch_inds = latent["batch_index"] if "batch_index" in latent else None
        noise = comfy.sample.prepare_noise(latent_image, seed, batch_inds)

    noise_mask = None
    if "noise_mask" in latent:
        noise_mask = latent["noise_mask"]

    previewer = get_previewer(device, model.model.latent_format)

    pbar = comfy.utils.ProgressBar(steps)

    def callback(step, x0, x, total_steps):
        if previewer and step % 3 == 0:
            previewer.preview(x0)
        pbar.update_absolute(step + 1, total_steps, None)

    samples = comfy.sample.sample(model, noise, steps, cfg, sampler_name, scheduler, positive, negative, latent_image,
                                  denoise=denoise, disable_noise=disable_noise, start_step=start_step, last_step=last_step,
                                  force_full_denoise=force_full_denoise, noise_mask=noise_mask, callback=callback, seed=seed)
    out = latent.copy()
    out["samples"] = samples

    return out


@torch.no_grad()
def image_to_numpy(x):
    return [np.clip(255. * y.cpu().numpy(), 0, 255).astype(np.uint8) for y in x]