import math
import html
import ftfy
import regex as re
import random
from typing import Any, Dict, List, Optional, Tuple, Union
import argparse
import os
from tqdm import tqdm
from diffusers import AutoencoderKLWan
from transformers import (
    AutoTokenizer, 
    CLIPImageProcessor, 
    CLIPVisionModel,  
    UMT5EncoderModel,
    SiglipImageProcessor,
    SiglipVisionModel
)
from diffusers.video_processor import VideoProcessor
from diffusers.utils import export_to_video, load_image

from dataset_tool import CollectionDataset, collate_fn_map
from omegaconf import OmegaConf
from torch.utils.data import DataLoader

import torch
import torch.distributed as dist
import torch.nn as nn
from torch.nn.parallel import DistributedDataParallel as DDP
from torch.utils.data.distributed import DistributedSampler
from torch.utils.data import Subset
import torchvision.transforms as transforms
import numpy as np
import matplotlib.pyplot as plt
from matplotlib.animation import FuncAnimation
from IPython.display import HTML, display
from IPython.display import clear_output  # 用于清理历史输出

from accelerate import Accelerator, DistributedType
from accelerate.logging import get_logger
from accelerate.utils import DistributedDataParallelKwargs, ProjectConfiguration, set_seed
from diffusers.training_utils import free_memory

from utils_framepack import encode_image

def encode_image_1(
    image_processor,
    image_encoder,
    image,
    device: Optional[torch.device] = "cuda",
):
    device = device
    image = image_processor(images=image, return_tensors="pt").to(device)
    image_embeds = image_encoder(**image, output_hidden_states=True)
    return image_embeds.hidden_states[-2]

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


def whitespace_clean(text):
    text = re.sub(r"\s+", " ", text)
    text = text.strip()
    return text


def prompt_clean(text):
    text = whitespace_clean(basic_clean(text))
    return text


def _get_t5_prompt_embeds(
    tokenizer,
    text_encoder,
    prompt: Union[str, List[str]] = None,
    num_videos_per_prompt: int = 1,
    max_sequence_length: int = 512,
    caption_dropout_p: float = 0.0,
    device: Optional[torch.device] = "cuda",
    dtype: Optional[torch.dtype] = torch.bfloat16,
):
    device = device
    dtype = dtype

    prompt = [prompt] if isinstance(prompt, str) else prompt
    prompt = [prompt_clean(u) for u in prompt]
    batch_size = len(prompt)

    text_inputs = tokenizer(
        prompt,
        padding="max_length",
        max_length=max_sequence_length,
        truncation=True,
        add_special_tokens=True,
        return_attention_mask=True,
        return_tensors="pt",
    )
    text_input_ids, mask = text_inputs.input_ids, text_inputs.attention_mask

    prompt_embeds = text_encoder(text_input_ids.to(device), mask.to(device)).last_hidden_state
    prompt_embeds = prompt_embeds.to(dtype=dtype, device=device)

    if random.random() < caption_dropout_p:
        prompt_embeds.fill_(0)
        mask.fill_(False)
    seq_lens = mask.gt(0).sum(dim=1).long()

    prompt_embeds = [u[:v] for u, v in zip(prompt_embeds, seq_lens)]
    prompt_embeds = torch.stack([
        torch.cat([u,
                   u.new_zeros(max_sequence_length - u.size(0), u.size(1))])
        for u in prompt_embeds
    ],
                                dim=0)

    # duplicate text embeddings for each generation per prompt, using mps friendly method
    _, seq_len, _ = prompt_embeds.shape
    prompt_embeds = prompt_embeds.repeat(1, num_videos_per_prompt, 1)
    prompt_embeds = prompt_embeds.view(batch_size * num_videos_per_prompt,
                                       seq_len, -1)

    return prompt_embeds


# Copied from diffusers.pipelines.wan.pipeline_wan.WanPipeline.encode_prompt
def encode_prompt(
    tokenizer,
    text_encoder,
    prompt: Union[str, List[str]],
    num_videos_per_prompt: int = 1,
    prompt_embeds: Optional[torch.Tensor] = None,
    max_sequence_length: int = 512,
    caption_dropout_p: float = 0.0,
    device: Optional[torch.device] = "cuda",
    dtype: Optional[torch.dtype] = torch.bfloat16,
):
    device = device

    prompt = [prompt] if isinstance(prompt, str) else prompt
    if prompt is not None:
        batch_size = len(prompt)
    else:
        batch_size = prompt_embeds.shape[0]

    if prompt_embeds is None:
        prompt_embeds = _get_t5_prompt_embeds(
            tokenizer,
            text_encoder,
            prompt=prompt,
            num_videos_per_prompt=num_videos_per_prompt,
            max_sequence_length=max_sequence_length,
            caption_dropout_p=caption_dropout_p,
            device=device,
            dtype=dtype,
        )

    return prompt_embeds

def setup_distributed_env():
    dist.init_process_group(backend="nccl")
    torch.cuda.set_device(int(os.environ["LOCAL_RANK"]))

def cleanup_distributed_env():
    dist.destroy_process_group()

def main(rank, world_size, global_rank, batch_size, dataloader_num_workers, config_path, output_latent_folder, pretrained_model_name_or_path, siglip_model_name_or_path):
    weight_dtype = torch.bfloat16
    # batch_size = 2
    # dataloader_num_workers = 8
    # config_path = "512_collection_config_vae1011_aligned_full_dump.yaml"
    # output_latent_folder = "/mnt/bn/yufan-dev-my/ysh/Datasets/fp_offload_latents"
    # pretrained_model_name_or_path = "/mnt/bn/yufan-dev-my/ysh/Ckpts/hunyuanvideo-community/HunyuanVideo"
    # siglip_model_name_or_path = "/mnt/bn/yufan-dev-my/ysh/Ckpts/lllyasviel/flux_redux_bfl"
    os.makedirs(output_latent_folder, exist_ok=True)

    device = rank

    # load tokenizers
    tokenizer = AutoTokenizer.from_pretrained(
        args.pretrained_model_name_or_path,
        subfolder="tokenizer",
    )
    clip_image_processor = CLIPImageProcessor.from_pretrained(
        args.pretrained_model_name_or_path,
        subfolder="image_processor",
    )
    feature_extractor = SiglipImageProcessor.from_pretrained(
        siglip_model_name_or_path,
        subfolder="feature_extractor",
    )

    # load encoders
    text_encoder = UMT5EncoderModel.from_pretrained(
        args.pretrained_model_name_or_path,
        subfolder="text_encoder",
        torch_dtype=torch.float16,
    )
    clip_image_encoder = CLIPVisionModel.from_pretrained(
        args.pretrained_model_name_or_path,
        subfolder="image_encoder",
        torch_dtype=torch.float16,
    )
    image_encoder = SiglipVisionModel.from_pretrained(
        siglip_model_name_or_path,
        subfolder="image_encoder",
        torch_dtype=weight_dtype,
    )
    

    vae = AutoencoderKLWan.from_pretrained(
        pretrained_model_name_or_path,
        subfolder="vae",
        torch_dtype=torch.float32,
    )
    vae_scale_factor_spatial = vae.spatial_compression_ratio
    video_processor = VideoProcessor(vae_scale_factor=vae_scale_factor_spatial)

    vae.requires_grad_(False)
    text_encoder.requires_grad_(False)
    clip_image_encoder.requires_grad_(False)
    image_encoder.requires_grad_(False)
    vae.eval()
    text_encoder.eval()
    clip_image_encoder.eval()
    image_encoder.eval()

    vae = vae.to(device)
    text_encoder = text_encoder.to(device)
    image_encoder = image_encoder.to(device)
    clip_image_encoder = clip_image_encoder.to(device)

    dist.barrier()
    configs = OmegaConf.load(config_path)
    dataset = CollectionDataset.create_dataset_function(configs['train_data'],
                                                            configs['train_data_weights'],
                                                            **configs['data']['params'])
    print(len(dataset))

    if global_rank == 0:
        pbar = tqdm(total=len(dataset) // world_size, desc="Processing")
    dist.barrier()

    # dataloader = DataLoader(
    #     dataset,
    #     shuffle=False,
    #     batch_size=batch_size,
    #     collate_fn=collate_fn_map,
    #     num_workers=dataloader_num_workers,
    #     pin_memory=True,
    #     prefetch_factor=2 if dataloader_num_workers != 0 else None,
    #     persistent_workers=True if dataloader_num_workers != 0 else False,
    # )

    # def distributed_iterate_dataloader(dataloader, world_size, rank):
    #     sample_count = 0
    #     for idx, batch in enumerate(dataloader):
    #         if sample_count % world_size == rank:
    #             # No need to call collate_fn_map again as it's already done by DataLoader
    #             yield batch  # Yield the batch directly
    #         sample_count += 1

    # for idx, batch in enumerate(distributed_iterate_dataloader(dataloader, dist.get_world_size(), dist.get_rank())):


    def distributed_iterate_dataset(dataset, world_size, rank):
        iterator = iter(dataset)
        sample_count = 0
        
        while True:
            try:
                batch = next(iterator)
                
                if sample_count % world_size == rank:
                    processed_batch = collate_fn_map(batch)
                    yield processed_batch
                
                sample_count += 1
                
            except StopIteration:
                break

    for idx, batch in enumerate(distributed_iterate_dataset(dataset, dist.get_world_size(), dist.get_rank())):
        valid_indices = []
        valid_uttids = []
        valid_num_frames = []
        valid_heights = []
        valid_widths = []
        valid_videos = []
        valid_prompts = []
        valid_first_frames_images = []
        
        for i, (uttid, num_frame, height, width) in enumerate(zip(batch["uttid"], batch["video_metadata"]["num_frames"], batch["video_metadata"]["height"], batch["video_metadata"]["width"])):
            output_path = os.path.join(output_latent_folder, f"{uttid}_{num_frame}_{height}_{width}.pt")
            if not os.path.exists(output_path):
                valid_indices.append(i)
                valid_uttids.append(uttid)
                valid_num_frames.append(num_frame)
                valid_heights.append(height)
                valid_widths.append(width)
                valid_videos.append(batch["videos"][i])
                valid_prompts.append(batch["prompts"][i])
                valid_first_frames_images.append(batch["first_frames_images"][i])
            else:
                print(f"skipping {uttid}")
        
        if not valid_indices:
            print("skipping entire batch!")
            continue

        batch = {
            "uttid": valid_uttids,
            "video_metadata": {
                "num_frames": valid_num_frames,
                "height": valid_heights,
                "width": valid_widths
            },
            "videos": torch.stack(valid_videos),
            "prompts": valid_prompts,
            "first_frames_images": torch.stack(valid_first_frames_images)
        }
        
        if len(batch["uttid"]) == 0:
            print("All samples in this batch are already processed, skipping!")
            continue

        with torch.no_grad():
            # Get Vae feature
            latents_mean = torch.tensor(
               vae.config.latents_mean).view(
                   1, vae.config.z_dim, 1, 1,
                   1).to(vae.device, vae.dtype)
            latents_std = 1.0 / torch.tensor(
               vae.config.latents_std).view(
                   1, vae.config.z_dim, 1, 1, 1).to(
                       vae.device, vae.dtype)
            pixel_values = batch["videos"].permute(0, 2, 1, 3, 4).to(dtype=vae.dtype, device=device)
            vae_latents = vae.encode(pixel_values).latent_dist.sample()
            vae_latents = (vae_latents - latents_mean) * latents_std

            # Encode prompts
            prompts = batch["prompts"]
            prompt_embeds = encode_prompt(
                tokenizer=tokenizer,
                text_encoder=text_encoder,
                prompt=prompts,
                device=device,
            )

            # Prepare images
            image_tensor = batch["first_frames_images"]
            images = [transforms.ToPILImage()(x.to(torch.uint8)) for x in image_tensor]

            clip_image_embeds = encode_image_1(
                image_processor=clip_image_processor,
                image_encoder=clip_image_encoder,
                image=images,
                device=device
            )

            image = video_processor.preprocess(image=images, height=batch["videos"].shape[-2], width=batch["videos"].shape[-1])
            image_embeds = encode_image(
                feature_extractor,
                image_encoder,
                image,
                device=device,
                dtype=weight_dtype,
            )

        for uttid, num_frame, height, width, cur_vae_latent, cur_prompt_embed, cur_clip_image_embed, cur_image_embed in zip(batch["uttid"], batch["video_metadata"]["num_frames"], batch["video_metadata"]["height"], batch["video_metadata"]["width"], vae_latents, prompt_embeds, clip_image_embeds, image_embeds):
            output_path = os.path.join(output_latent_folder, f"{uttid}_{num_frame}_{height}_{width}.pt")
            torch.save(
                {
                    "vae_latent": cur_vae_latent.cpu().detach(),
                    "prompt_embed": cur_prompt_embed.cpu().detach(),
                    "clip_image_embeds": cur_clip_image_embed.cpu().detach(),
                    "image_embeds": cur_image_embed.cpu().detach(),
                },
                output_path
            )
            print(f"save to: {output_path}")
        
        if global_rank == 0:
            pbar.update(1)
            pbar.set_postfix({"batch": idx})
        free_memory()

if __name__ == "__main__":
    parser = argparse.ArgumentParser(description="Script for running model training and data processing.")
    parser.add_argument("--batch_size", type=int, default=1, help="Batch size for processing")
    parser.add_argument("--dataloader_num_workers", type=int, default=8, help="Number of workers for data loading")
    parser.add_argument("--config_path", type=str, default="part1.yaml", help="Path to the config file")
    parser.add_argument("--output_latent_folder", type=str, default="/mnt/bn/yufan-dev-my/ysh/Datasets/fp_offload_latents_wan", help="Folder to store output latents")
    parser.add_argument("--pretrained_model_name_or_path", type=str, default="/mnt/bn/yufan-dev-my/ysh/Ckpts/Wan-AI/Wan2.1-I2V-14B-720P-Diffusers/", help="Pretrained model path")
    parser.add_argument("--siglip_model_name_or_path", type=str, default="/mnt/bn/yufan-dev-my/ysh/Ckpts/lllyasviel/flux_redux_bfl", help="Siglip model path")
    args = parser.parse_args()


    setup_distributed_env()

    global_rank = dist.get_rank()
    local_rank = int(os.environ["LOCAL_RANK"])
    device = torch.cuda.current_device()
    world_size = dist.get_world_size()

    main(
        world_size=world_size, 
        rank=device, 
        global_rank=global_rank,
        batch_size=args.batch_size,
        dataloader_num_workers=args.dataloader_num_workers,
        config_path=args.config_path,
        output_latent_folder=args.output_latent_folder,
        pretrained_model_name_or_path=args.pretrained_model_name_or_path,
        siglip_model_name_or_path=args.siglip_model_name_or_path
    )