# 手元で推論を行うための最低限のコード。HuggingFace／DiffusersのCLIP、schedulerとVAEを使う
# Minimal code for performing inference at local. Use HuggingFace/Diffusers CLIP, scheduler and VAE

import argparse
import datetime
import math
import os
import random
from einops import repeat
import numpy as np

import torch
from library.device_utils import init_ipex, get_preferred_device

init_ipex()

from tqdm import tqdm
from transformers import CLIPTokenizer
from diffusers import EulerDiscreteScheduler
from PIL import Image

# import open_clip
from safetensors.torch import load_file

from library import model_util, sdxl_model_util
import networks.lora as lora
from library.utils import setup_logging

setup_logging()
import logging

logger = logging.getLogger(__name__)

# scheduler: このあたりの設定はSD1/2と同じでいいらしい
# scheduler: The settings around here seem to be the same as SD1/2
SCHEDULER_LINEAR_START = 0.00085
SCHEDULER_LINEAR_END = 0.0120
SCHEDULER_TIMESTEPS = 1000
SCHEDLER_SCHEDULE = "scaled_linear"


# Time EmbeddingはDiffusersからのコピー
# Time Embedding is copied from Diffusers


def timestep_embedding(timesteps, dim, max_period=10000, repeat_only=False):
    """
    Create sinusoidal timestep embeddings.
    :param timesteps: a 1-D Tensor of N indices, one per batch element.
                      These may be fractional.
    :param dim: the dimension of the output.
    :param max_period: controls the minimum frequency of the embeddings.
    :return: an [N x dim] Tensor of positional embeddings.
    """
    if not repeat_only:
        half = dim // 2
        freqs = torch.exp(-math.log(max_period) * torch.arange(start=0, end=half, dtype=torch.float32) / half).to(
            device=timesteps.device
        )
        args = timesteps[:, None].float() * freqs[None]
        embedding = torch.cat([torch.cos(args), torch.sin(args)], dim=-1)
        if dim % 2:
            embedding = torch.cat([embedding, torch.zeros_like(embedding[:, :1])], dim=-1)
    else:
        embedding = repeat(timesteps, "b -> b d", d=dim)
    return embedding


def get_timestep_embedding(x, outdim):
    assert len(x.shape) == 2
    b, dims = x.shape[0], x.shape[1]
    # x = rearrange(x, "b d -> (b d)")
    x = torch.flatten(x)
    emb = timestep_embedding(x, outdim)
    # emb = rearrange(emb, "(b d) d2 -> b (d d2)", b=b, d=dims, d2=outdim)
    emb = torch.reshape(emb, (b, dims * outdim))
    return emb


if __name__ == "__main__":
    # 画像生成条件を変更する場合はここを変更 / change here to change image generation conditions

    # SDXLの追加のvector embeddingへ渡す値 / Values to pass to additional vector embedding of SDXL
    target_height = 1024
    target_width = 1024
    original_height = target_height
    original_width = target_width
    crop_top = 0
    crop_left = 0

    steps = 50
    guidance_scale = 7
    seed = None  # 1

    DEVICE = get_preferred_device()
    DTYPE = torch.float16  # bfloat16 may work

    parser = argparse.ArgumentParser()
    parser.add_argument("--ckpt_path", type=str, required=True)
    parser.add_argument("--prompt", type=str, default="A photo of a cat")
    parser.add_argument("--prompt2", type=str, default=None)
    parser.add_argument("--negative_prompt", type=str, default="")
    parser.add_argument("--output_dir", type=str, default=".")
    parser.add_argument(
        "--lora_weights",
        type=str,
        nargs="*",
        default=[],
        help="LoRA weights, only supports networks.lora, each argument is a `path;multiplier` (semi-colon separated)",
    )
    parser.add_argument("--interactive", action="store_true")
    args = parser.parse_args()

    if args.prompt2 is None:
        args.prompt2 = args.prompt

    # HuggingFaceのmodel id
    text_encoder_1_name = "openai/clip-vit-large-patch14"
    text_encoder_2_name = "laion/CLIP-ViT-bigG-14-laion2B-39B-b160k"

    # checkpointを読み込む。モデル変換についてはそちらの関数を参照
    # Load checkpoint. For model conversion, see this function

    # 本体RAMが少ない場合はGPUにロードするといいかも
    # If the main RAM is small, it may be better to load it on the GPU
    text_model1, text_model2, vae, unet, _, _ = sdxl_model_util.load_models_from_sdxl_checkpoint(
        sdxl_model_util.MODEL_VERSION_SDXL_BASE_V1_0, args.ckpt_path, "cpu"
    )

    # Text Encoder 1はSDXL本体でもHuggingFaceのものを使っている
    # In SDXL, Text Encoder 1 is also using HuggingFace's

    # Text Encoder 2はSDXL本体ではopen_clipを使っている
    # それを使ってもいいが、SD2のDiffusers版に合わせる形で、HuggingFaceのものを使う
    # 重みの変換コードはSD2とほぼ同じ
    # In SDXL, Text Encoder 2 is using open_clip
    # It's okay to use it, but to match the Diffusers version of SD2, use HuggingFace's
    # The weight conversion code is almost the same as SD2

    # VAEの構造はSDXLもSD1/2と同じだが、重みは異なるようだ。何より謎のscale値が違う
    # fp16でNaNが出やすいようだ
    # The structure of VAE is the same as SD1/2, but the weights seem to be different. Above all, the mysterious scale value is different.
    # NaN seems to be more likely to occur in fp16

    unet.to(DEVICE, dtype=DTYPE)
    unet.eval()

    vae_dtype = DTYPE
    if DTYPE == torch.float16:
        logger.info("use float32 for vae")
        vae_dtype = torch.float32
    vae.to(DEVICE, dtype=vae_dtype)
    vae.eval()

    text_model1.to(DEVICE, dtype=DTYPE)
    text_model1.eval()
    text_model2.to(DEVICE, dtype=DTYPE)
    text_model2.eval()

    unet.set_use_memory_efficient_attention(True, False)
    if torch.__version__ >= "2.0.0":  # PyTorch 2.0.0 以上対応のxformersなら以下が使える
        vae.set_use_memory_efficient_attention_xformers(True)

    # Tokenizers
    tokenizer1 = CLIPTokenizer.from_pretrained(text_encoder_1_name)
    # tokenizer2 = lambda x: open_clip.tokenize(x, context_length=77)
    tokenizer2 = CLIPTokenizer.from_pretrained(text_encoder_2_name)

    # LoRA
    for weights_file in args.lora_weights:
        if ";" in weights_file:
            weights_file, multiplier = weights_file.split(";")
            multiplier = float(multiplier)
        else:
            multiplier = 1.0

        lora_model, weights_sd = lora.create_network_from_weights(
            multiplier, weights_file, vae, [text_model1, text_model2], unet, None, True
        )
        lora_model.merge_to([text_model1, text_model2], unet, weights_sd, DTYPE, DEVICE)

    # scheduler
    scheduler = EulerDiscreteScheduler(
        num_train_timesteps=SCHEDULER_TIMESTEPS,
        beta_start=SCHEDULER_LINEAR_START,
        beta_end=SCHEDULER_LINEAR_END,
        beta_schedule=SCHEDLER_SCHEDULE,
    )

    def generate_image(prompt, prompt2, negative_prompt, seed=None):
        # 将来的にサイズ情報も変えられるようにする / Make it possible to change the size information in the future
        # prepare embedding
        with torch.no_grad():
            # vector
            emb1 = get_timestep_embedding(torch.FloatTensor([original_height, original_width]).unsqueeze(0), 256)
            emb2 = get_timestep_embedding(torch.FloatTensor([crop_top, crop_left]).unsqueeze(0), 256)
            emb3 = get_timestep_embedding(torch.FloatTensor([target_height, target_width]).unsqueeze(0), 256)
            # logger.info("emb1", emb1.shape)
            c_vector = torch.cat([emb1, emb2, emb3], dim=1).to(DEVICE, dtype=DTYPE)
            uc_vector = c_vector.clone().to(
                DEVICE, dtype=DTYPE
            )  # ちょっとここ正しいかどうかわからない I'm not sure if this is right

            # crossattn

        # Text Encoderを二つ呼ぶ関数  Function to call two Text Encoders
        def call_text_encoder(text, text2):
            # text encoder 1
            batch_encoding = tokenizer1(
                text,
                truncation=True,
                return_length=True,
                return_overflowing_tokens=False,
                padding="max_length",
                return_tensors="pt",
            )
            tokens = batch_encoding["input_ids"].to(DEVICE)

            with torch.no_grad():
                enc_out = text_model1(tokens, output_hidden_states=True, return_dict=True)
                text_embedding1 = enc_out["hidden_states"][11]
                # text_embedding = pipe.text_encoder.text_model.final_layer_norm(text_embedding)    # layer normは通さないらしい

            # text encoder 2
            # tokens = tokenizer2(text2).to(DEVICE)
            tokens = tokenizer2(
                text,
                truncation=True,
                return_length=True,
                return_overflowing_tokens=False,
                padding="max_length",
                return_tensors="pt",
            )
            tokens = batch_encoding["input_ids"].to(DEVICE)

            with torch.no_grad():
                enc_out = text_model2(tokens, output_hidden_states=True, return_dict=True)
                text_embedding2_penu = enc_out["hidden_states"][-2]
                # logger.info("hidden_states2", text_embedding2_penu.shape)
                text_embedding2_pool = enc_out["text_embeds"]  # do not support Textual Inversion

            # 連結して終了 concat and finish
            text_embedding = torch.cat([text_embedding1, text_embedding2_penu], dim=2)
            return text_embedding, text_embedding2_pool

        # cond
        c_ctx, c_ctx_pool = call_text_encoder(prompt, prompt2)
        # logger.info(c_ctx.shape, c_ctx_p.shape, c_vector.shape)
        c_vector = torch.cat([c_ctx_pool, c_vector], dim=1)

        # uncond
        uc_ctx, uc_ctx_pool = call_text_encoder(negative_prompt, negative_prompt)
        uc_vector = torch.cat([uc_ctx_pool, uc_vector], dim=1)

        text_embeddings = torch.cat([uc_ctx, c_ctx])
        vector_embeddings = torch.cat([uc_vector, c_vector])

        # メモリ使用量を減らすにはここでText Encoderを削除するかCPUへ移動する

        if seed is not None:
            random.seed(seed)
            np.random.seed(seed)
            torch.manual_seed(seed)
            torch.cuda.manual_seed_all(seed)

            # # random generator for initial noise
            # generator = torch.Generator(device="cuda").manual_seed(seed)
            generator = None
        else:
            generator = None

        # get the initial random noise unless the user supplied it
        # SDXLはCPUでlatentsを作成しているので一応合わせておく、Diffusersはtarget deviceでlatentsを作成している
        # SDXL creates latents in CPU, Diffusers creates latents in target device
        latents_shape = (1, 4, target_height // 8, target_width // 8)
        latents = torch.randn(
            latents_shape,
            generator=generator,
            device="cpu",
            dtype=torch.float32,
        ).to(DEVICE, dtype=DTYPE)

        # scale the initial noise by the standard deviation required by the scheduler
        latents = latents * scheduler.init_noise_sigma

        # set timesteps
        scheduler.set_timesteps(steps, DEVICE)

        # このへんはDiffusersからのコピペ
        # Copy from Diffusers
        timesteps = scheduler.timesteps.to(DEVICE)  # .to(DTYPE)
        num_latent_input = 2
        with torch.no_grad():
            for i, t in enumerate(tqdm(timesteps)):
                # expand the latents if we are doing classifier free guidance
                latent_model_input = latents.repeat((num_latent_input, 1, 1, 1))
                latent_model_input = scheduler.scale_model_input(latent_model_input, t)

                noise_pred = unet(latent_model_input, t, text_embeddings, vector_embeddings)

                noise_pred_uncond, noise_pred_text = noise_pred.chunk(num_latent_input)  # uncond by negative prompt
                noise_pred = noise_pred_uncond + guidance_scale * (noise_pred_text - noise_pred_uncond)

                # compute the previous noisy sample x_t -> x_t-1
                # latents = scheduler.step(noise_pred, t, latents, **extra_step_kwargs).prev_sample
                latents = scheduler.step(noise_pred, t, latents).prev_sample

            # latents = 1 / 0.18215 * latents
            latents = 1 / sdxl_model_util.VAE_SCALE_FACTOR * latents
            latents = latents.to(vae_dtype)
            image = vae.decode(latents).sample
            image = (image / 2 + 0.5).clamp(0, 1)

        # we always cast to float32 as this does not cause significant overhead and is compatible with bfloa16
        image = image.cpu().permute(0, 2, 3, 1).float().numpy()

        # image = self.numpy_to_pil(image)
        image = (image * 255).round().astype("uint8")
        image = [Image.fromarray(im) for im in image]

        # 保存して終了 save and finish
        timestamp = datetime.datetime.now().strftime("%Y%m%d-%H%M%S")
        for i, img in enumerate(image):
            img.save(os.path.join(args.output_dir, f"image_{timestamp}_{i:03d}.png"))

    if not args.interactive:
        generate_image(args.prompt, args.prompt2, args.negative_prompt, seed)
    else:
        # loop for interactive
        while True:
            prompt = input("prompt: ")
            if prompt == "":
                break
            prompt2 = input("prompt2: ")
            if prompt2 == "":
                prompt2 = prompt
            negative_prompt = input("negative prompt: ")
            seed = input("seed: ")
            if seed == "":
                seed = None
            else:
                seed = int(seed)
            generate_image(prompt, prompt2, negative_prompt, seed)

    logger.info("Done!")