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# Adapted from OpenSora and DiT

# This source code is licensed under the license found in the
# LICENSE file in the root directory of this source tree.
# --------------------------------------------------------
# References:
# DiT:      https://github.com/facebookresearch/DiT
# OpenSora: https://github.com/hpcaitech/Open-Sora
# --------------------------------------------------------

import html
import math
import re

import ftfy
import numpy
import numpy as np
import torch
import torch.nn as nn
import torch.nn.functional as F
import transformers
from timm.models.vision_transformer import Mlp
from transformers import AutoTokenizer, CLIPTextModel, CLIPTokenizer, T5EncoderModel

from videosys.modules.embed import get_1d_sincos_pos_embed_from_grid, get_2d_sincos_pos_embed_from_grid

transformers.logging.set_verbosity_error()


# ===============================================
# Text Embed
# ===============================================


class AbstractEncoder(nn.Module):
    def __init__(self):
        super().__init__()

    def encode(self, *args, **kwargs):
        raise NotImplementedError


class FrozenCLIPEmbedder(AbstractEncoder):
    """Uses the CLIP transformer encoder for text (from Hugging Face)"""

    def __init__(self, path="openai/clip-vit-huge-patch14", device="cuda", max_length=77):
        super().__init__()
        self.tokenizer = CLIPTokenizer.from_pretrained(path)
        self.transformer = CLIPTextModel.from_pretrained(path)
        self.device = device
        self.max_length = max_length
        self._freeze()

    def _freeze(self):
        self.transformer = self.transformer.eval()
        for param in self.parameters():
            param.requires_grad = False

    def forward(self, text):
        batch_encoding = self.tokenizer(
            text,
            truncation=True,
            max_length=self.max_length,
            return_length=True,
            return_overflowing_tokens=False,
            padding="max_length",
            return_tensors="pt",
        )
        tokens = batch_encoding["input_ids"].to(self.device)
        outputs = self.transformer(input_ids=tokens)

        z = outputs.last_hidden_state
        pooled_z = outputs.pooler_output
        return z, pooled_z

    def encode(self, text):
        return self(text)


class TextEmbedder(nn.Module):
    """
    Embeds text prompt into vector representations. Also handles text dropout for classifier-free guidance.
    """

    def __init__(self, path, hidden_size, dropout_prob=0.1):
        super().__init__()
        self.text_encoder = FrozenCLIPEmbedder(path=path)
        self.dropout_prob = dropout_prob

        output_dim = self.text_encoder.transformer.config.hidden_size
        self.output_projection = nn.Linear(output_dim, hidden_size)

    def token_drop(self, text_prompts, force_drop_ids=None):
        """
        Drops text to enable classifier-free guidance.
        """
        if force_drop_ids is None:
            drop_ids = numpy.random.uniform(0, 1, len(text_prompts)) < self.dropout_prob
        else:
            # TODO
            drop_ids = force_drop_ids == 1
        labels = list(numpy.where(drop_ids, "", text_prompts))
        # print(labels)
        return labels

    def forward(self, text_prompts, train, force_drop_ids=None):
        use_dropout = self.dropout_prob > 0
        if (train and use_dropout) or (force_drop_ids is not None):
            text_prompts = self.token_drop(text_prompts, force_drop_ids)
        embeddings, pooled_embeddings = self.text_encoder(text_prompts)
        # return embeddings, pooled_embeddings
        text_embeddings = self.output_projection(pooled_embeddings)
        return text_embeddings


class CaptionEmbedder(nn.Module):
    """
    copied from https://github.com/hpcaitech/Open-Sora

    Embeds class labels into vector representations. Also handles label dropout for classifier-free guidance.
    """

    def __init__(self, in_channels, hidden_size, uncond_prob, act_layer=nn.GELU(approximate="tanh"), token_num=120):
        super().__init__()

        self.y_proj = Mlp(
            in_features=in_channels, hidden_features=hidden_size, out_features=hidden_size, act_layer=act_layer, drop=0
        )
        self.register_buffer("y_embedding", nn.Parameter(torch.randn(token_num, in_channels) / in_channels**0.5))
        self.uncond_prob = uncond_prob

    def token_drop(self, caption, force_drop_ids=None):
        """
        Drops labels to enable classifier-free guidance.
        """
        if force_drop_ids is None:
            drop_ids = torch.rand(caption.shape[0]).cuda() < self.uncond_prob
        else:
            drop_ids = force_drop_ids == 1
        caption = torch.where(drop_ids[:, None, None, None], self.y_embedding, caption)
        return caption

    def forward(self, caption, train, force_drop_ids=None):
        if train:
            assert caption.shape[2:] == self.y_embedding.shape
        use_dropout = self.uncond_prob > 0
        if (train and use_dropout) or (force_drop_ids is not None):
            caption = self.token_drop(caption, force_drop_ids)
        caption = self.y_proj(caption)
        return caption


class T5Embedder:
    available_models = ["DeepFloyd/t5-v1_1-xxl"]

    def __init__(
        self,
        device,
        from_pretrained=None,
        *,
        cache_dir=None,
        hf_token=None,
        use_text_preprocessing=True,
        t5_model_kwargs=None,
        torch_dtype=None,
        use_offload_folder=None,
        model_max_length=120,
        local_files_only=False,
    ):
        self.device = torch.device(device)
        self.torch_dtype = torch_dtype or torch.bfloat16
        self.cache_dir = cache_dir

        if t5_model_kwargs is None:
            t5_model_kwargs = {
                "low_cpu_mem_usage": True,
                "torch_dtype": self.torch_dtype,
            }

            if use_offload_folder is not None:
                t5_model_kwargs["offload_folder"] = use_offload_folder
                t5_model_kwargs["device_map"] = {
                    "shared": self.device,
                    "encoder.embed_tokens": self.device,
                    "encoder.block.0": self.device,
                    "encoder.block.1": self.device,
                    "encoder.block.2": self.device,
                    "encoder.block.3": self.device,
                    "encoder.block.4": self.device,
                    "encoder.block.5": self.device,
                    "encoder.block.6": self.device,
                    "encoder.block.7": self.device,
                    "encoder.block.8": self.device,
                    "encoder.block.9": self.device,
                    "encoder.block.10": self.device,
                    "encoder.block.11": self.device,
                    "encoder.block.12": "disk",
                    "encoder.block.13": "disk",
                    "encoder.block.14": "disk",
                    "encoder.block.15": "disk",
                    "encoder.block.16": "disk",
                    "encoder.block.17": "disk",
                    "encoder.block.18": "disk",
                    "encoder.block.19": "disk",
                    "encoder.block.20": "disk",
                    "encoder.block.21": "disk",
                    "encoder.block.22": "disk",
                    "encoder.block.23": "disk",
                    "encoder.final_layer_norm": "disk",
                    "encoder.dropout": "disk",
                }
            else:
                t5_model_kwargs["device_map"] = {
                    "shared": self.device,
                    "encoder": self.device,
                }

        self.use_text_preprocessing = use_text_preprocessing
        self.hf_token = hf_token

        assert from_pretrained in self.available_models
        self.tokenizer = AutoTokenizer.from_pretrained(
            from_pretrained,
            cache_dir=cache_dir,
            local_files_only=local_files_only,
        )
        self.model = T5EncoderModel.from_pretrained(
            from_pretrained,
            cache_dir=cache_dir,
            local_files_only=local_files_only,
            **t5_model_kwargs,
        ).eval()
        self.model_max_length = model_max_length

    def get_text_embeddings(self, texts):
        text_tokens_and_mask = self.tokenizer(
            texts,
            max_length=self.model_max_length,
            padding="max_length",
            truncation=True,
            return_attention_mask=True,
            add_special_tokens=True,
            return_tensors="pt",
        )

        input_ids = text_tokens_and_mask["input_ids"].to(self.device)
        attention_mask = text_tokens_and_mask["attention_mask"].to(self.device)
        with torch.no_grad():
            text_encoder_embs = self.model(
                input_ids=input_ids,
                attention_mask=attention_mask,
            )["last_hidden_state"].detach()
        return text_encoder_embs, attention_mask


class T5Encoder:
    def __init__(
        self,
        from_pretrained="DeepFloyd/t5-v1_1-xxl",
        model_max_length=120,
        device="cuda",
        dtype=torch.float,
        shardformer=False,
    ):
        assert from_pretrained is not None, "Please specify the path to the T5 model"

        self.t5 = T5Embedder(
            device=device,
            torch_dtype=dtype,
            from_pretrained=from_pretrained,
            model_max_length=model_max_length,
        )
        self.t5.model.to(dtype=dtype)
        self.y_embedder = None

        self.model_max_length = model_max_length
        self.output_dim = self.t5.model.config.d_model

        if shardformer:
            self.shardformer_t5()

    def shardformer_t5(self):
        from colossalai.shardformer import ShardConfig, ShardFormer

        from videosys.core.shardformer.t5.policy import T5EncoderPolicy
        from videosys.utils.utils import requires_grad

        shard_config = ShardConfig(
            tensor_parallel_process_group=None,
            pipeline_stage_manager=None,
            enable_tensor_parallelism=False,
            enable_fused_normalization=False,
            enable_flash_attention=False,
            enable_jit_fused=True,
            enable_sequence_parallelism=False,
            enable_sequence_overlap=False,
        )
        shard_former = ShardFormer(shard_config=shard_config)
        optim_model, _ = shard_former.optimize(self.t5.model, policy=T5EncoderPolicy())
        self.t5.model = optim_model.half()

        # ensure the weights are frozen
        requires_grad(self.t5.model, False)

    def encode(self, text):
        caption_embs, emb_masks = self.t5.get_text_embeddings(text)
        caption_embs = caption_embs[:, None]
        return dict(y=caption_embs, mask=emb_masks)

    def null(self, n):
        null_y = self.y_embedder.y_embedding[None].repeat(n, 1, 1)[:, None]
        return null_y


def basic_clean(text):
    text = ftfy.fix_text(text)
    text = html.unescape(html.unescape(text))
    return text.strip()


BAD_PUNCT_REGEX = re.compile(
    r"[" + "#®•©™&@·º½¾¿¡§~" + "\)" + "\(" + "\]" + "\[" + "\}" + "\{" + "\|" + "\\" + "\/" + "\*" + r"]{1,}"
)  # noqa


def clean_caption(caption):
    import urllib.parse as ul

    from bs4 import BeautifulSoup

    caption = str(caption)
    caption = ul.unquote_plus(caption)
    caption = caption.strip().lower()
    caption = re.sub("<person>", "person", caption)
    # urls:
    caption = re.sub(
        r"\b((?:https?:(?:\/{1,3}|[a-zA-Z0-9%])|[a-zA-Z0-9.\-]+[.](?:com|co|ru|net|org|edu|gov|it)[\w/-]*\b\/?(?!@)))",  # noqa
        "",
        caption,
    )  # regex for urls
    caption = re.sub(
        r"\b((?:www:(?:\/{1,3}|[a-zA-Z0-9%])|[a-zA-Z0-9.\-]+[.](?:com|co|ru|net|org|edu|gov|it)[\w/-]*\b\/?(?!@)))",  # noqa
        "",
        caption,
    )  # regex for urls
    # html:
    caption = BeautifulSoup(caption, features="html.parser").text

    # @<nickname>
    caption = re.sub(r"@[\w\d]+\b", "", caption)

    # 31C0—31EF CJK Strokes
    # 31F0—31FF Katakana Phonetic Extensions
    # 3200—32FF Enclosed CJK Letters and Months
    # 3300—33FF CJK Compatibility
    # 3400—4DBF CJK Unified Ideographs Extension A
    # 4DC0—4DFF Yijing Hexagram Symbols
    # 4E00—9FFF CJK Unified Ideographs
    caption = re.sub(r"[\u31c0-\u31ef]+", "", caption)
    caption = re.sub(r"[\u31f0-\u31ff]+", "", caption)
    caption = re.sub(r"[\u3200-\u32ff]+", "", caption)
    caption = re.sub(r"[\u3300-\u33ff]+", "", caption)
    caption = re.sub(r"[\u3400-\u4dbf]+", "", caption)
    caption = re.sub(r"[\u4dc0-\u4dff]+", "", caption)
    caption = re.sub(r"[\u4e00-\u9fff]+", "", caption)
    #######################################################

    # все виды тире / all types of dash --> "-"
    caption = re.sub(
        r"[\u002D\u058A\u05BE\u1400\u1806\u2010-\u2015\u2E17\u2E1A\u2E3A\u2E3B\u2E40\u301C\u3030\u30A0\uFE31\uFE32\uFE58\uFE63\uFF0D]+",  # noqa
        "-",
        caption,
    )

    # кавычки к одному стандарту
    caption = re.sub(r"[`´«»“”¨]", '"', caption)
    caption = re.sub(r"[‘’]", "'", caption)

    # &quot;
    caption = re.sub(r"&quot;?", "", caption)
    # &amp
    caption = re.sub(r"&amp", "", caption)

    # ip adresses:
    caption = re.sub(r"\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}", " ", caption)

    # article ids:
    caption = re.sub(r"\d:\d\d\s+$", "", caption)

    # \n
    caption = re.sub(r"\\n", " ", caption)

    # "#123"
    caption = re.sub(r"#\d{1,3}\b", "", caption)
    # "#12345.."
    caption = re.sub(r"#\d{5,}\b", "", caption)
    # "123456.."
    caption = re.sub(r"\b\d{6,}\b", "", caption)
    # filenames:
    caption = re.sub(r"[\S]+\.(?:png|jpg|jpeg|bmp|webp|eps|pdf|apk|mp4)", "", caption)

    #
    caption = re.sub(r"[\"\']{2,}", r'"', caption)  # """AUSVERKAUFT"""
    caption = re.sub(r"[\.]{2,}", r" ", caption)  # """AUSVERKAUFT"""

    caption = re.sub(BAD_PUNCT_REGEX, r" ", caption)  # ***AUSVERKAUFT***, #AUSVERKAUFT
    caption = re.sub(r"\s+\.\s+", r" ", caption)  # " . "

    # this-is-my-cute-cat / this_is_my_cute_cat
    regex2 = re.compile(r"(?:\-|\_)")
    if len(re.findall(regex2, caption)) > 3:
        caption = re.sub(regex2, " ", caption)

    caption = basic_clean(caption)

    caption = re.sub(r"\b[a-zA-Z]{1,3}\d{3,15}\b", "", caption)  # jc6640
    caption = re.sub(r"\b[a-zA-Z]+\d+[a-zA-Z]+\b", "", caption)  # jc6640vc
    caption = re.sub(r"\b\d+[a-zA-Z]+\d+\b", "", caption)  # 6640vc231

    caption = re.sub(r"(worldwide\s+)?(free\s+)?shipping", "", caption)
    caption = re.sub(r"(free\s)?download(\sfree)?", "", caption)
    caption = re.sub(r"\bclick\b\s(?:for|on)\s\w+", "", caption)
    caption = re.sub(r"\b(?:png|jpg|jpeg|bmp|webp|eps|pdf|apk|mp4)(\simage[s]?)?", "", caption)
    caption = re.sub(r"\bpage\s+\d+\b", "", caption)

    caption = re.sub(r"\b\d*[a-zA-Z]+\d+[a-zA-Z]+\d+[a-zA-Z\d]*\b", r" ", caption)  # j2d1a2a...

    caption = re.sub(r"\b\d+\.?\d*[xх×]\d+\.?\d*\b", "", caption)

    caption = re.sub(r"\b\s+\:\s+", r": ", caption)
    caption = re.sub(r"(\D[,\./])\b", r"\1 ", caption)
    caption = re.sub(r"\s+", " ", caption)

    caption.strip()

    caption = re.sub(r"^[\"\']([\w\W]+)[\"\']$", r"\1", caption)
    caption = re.sub(r"^[\'\_,\-\:;]", r"", caption)
    caption = re.sub(r"[\'\_,\-\:\-\+]$", r"", caption)
    caption = re.sub(r"^\.\S+$", "", caption)

    return caption.strip()


def text_preprocessing(text, use_text_preprocessing: bool = True):
    if use_text_preprocessing:
        # The exact text cleaning as was in the training stage:
        text = clean_caption(text)
        text = clean_caption(text)
        return text
    else:
        return text.lower().strip()


class TimestepEmbedder(nn.Module):
    """
    Embeds scalar timesteps into vector representations.
    """

    def __init__(self, hidden_size, frequency_embedding_size=256):
        super().__init__()
        self.mlp = nn.Sequential(
            nn.Linear(frequency_embedding_size, hidden_size, bias=True),
            nn.SiLU(),
            nn.Linear(hidden_size, hidden_size, bias=True),
        )
        self.frequency_embedding_size = frequency_embedding_size

    @staticmethod
    def timestep_embedding(t, dim, max_period=10000):
        """
        Create sinusoidal timestep embeddings.
        :param t: 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, D) Tensor of positional embeddings.
        """
        # https://github.com/openai/glide-text2im/blob/main/glide_text2im/nn.py
        half = dim // 2
        freqs = torch.exp(-math.log(max_period) * torch.arange(start=0, end=half, dtype=torch.float32) / half)
        freqs = freqs.to(device=t.device)
        args = t[:, 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)
        return embedding

    def forward(self, t, dtype):
        t_freq = self.timestep_embedding(t, self.frequency_embedding_size)
        if t_freq.dtype != dtype:
            t_freq = t_freq.to(dtype)
        t_emb = self.mlp(t_freq)
        return t_emb


# ===============================================
# Sine/Cosine Positional Embedding Functions
# ===============================================


def get_2d_sincos_pos_embed(embed_dim, grid_size, cls_token=False, extra_tokens=0, scale=1.0, base_size=None):
    """
    grid_size: int of the grid height and width
    return:
    pos_embed: [grid_size*grid_size, embed_dim] or [1+grid_size*grid_size, embed_dim] (w/ or w/o cls_token)
    """
    if not isinstance(grid_size, tuple):
        grid_size = (grid_size, grid_size)

    grid_h = np.arange(grid_size[0], dtype=np.float32) / scale
    grid_w = np.arange(grid_size[1], dtype=np.float32) / scale
    if base_size is not None:
        grid_h *= base_size / grid_size[0]
        grid_w *= base_size / grid_size[1]
    grid = np.meshgrid(grid_w, grid_h)  # here w goes first
    grid = np.stack(grid, axis=0)

    grid = grid.reshape([2, 1, grid_size[1], grid_size[0]])
    pos_embed = get_2d_sincos_pos_embed_from_grid(embed_dim, grid)
    if cls_token and extra_tokens > 0:
        pos_embed = np.concatenate([np.zeros([extra_tokens, embed_dim]), pos_embed], axis=0)
    return pos_embed


def get_1d_sincos_pos_embed(embed_dim, length, scale=1.0):
    pos = np.arange(0, length)[..., None] / scale
    return get_1d_sincos_pos_embed_from_grid(embed_dim, pos)


# ===============================================
# Patch Embed
# ===============================================


class PatchEmbed3D(nn.Module):
    """Video to Patch Embedding.

    Args:
        patch_size (int): Patch token size. Default: (2,4,4).
        in_chans (int): Number of input video channels. Default: 3.
        embed_dim (int): Number of linear projection output channels. Default: 96.
        norm_layer (nn.Module, optional): Normalization layer. Default: None
    """

    def __init__(
        self,
        patch_size=(2, 4, 4),
        in_chans=3,
        embed_dim=96,
        norm_layer=None,
        flatten=True,
    ):
        super().__init__()
        self.patch_size = patch_size
        self.flatten = flatten

        self.in_chans = in_chans
        self.embed_dim = embed_dim

        self.proj = nn.Conv3d(in_chans, embed_dim, kernel_size=patch_size, stride=patch_size)
        if norm_layer is not None:
            self.norm = norm_layer(embed_dim)
        else:
            self.norm = None

    def forward(self, x):
        """Forward function."""
        # padding
        _, _, D, H, W = x.size()
        if W % self.patch_size[2] != 0:
            x = F.pad(x, (0, self.patch_size[2] - W % self.patch_size[2]))
        if H % self.patch_size[1] != 0:
            x = F.pad(x, (0, 0, 0, self.patch_size[1] - H % self.patch_size[1]))
        if D % self.patch_size[0] != 0:
            x = F.pad(x, (0, 0, 0, 0, 0, self.patch_size[0] - D % self.patch_size[0]))

        x = self.proj(x)  # (B C T H W)
        if self.norm is not None:
            D, Wh, Ww = x.size(2), x.size(3), x.size(4)
            x = x.flatten(2).transpose(1, 2)
            x = self.norm(x)
            x = x.transpose(1, 2).view(-1, self.embed_dim, D, Wh, Ww)
        if self.flatten:
            x = x.flatten(2).transpose(1, 2)  # BCTHW -> BNC
        return x