import os
from einops import rearrange

import torch
import torchvision
import numpy as np
import imageio
import random

import os


def seed_all(seed):
    random.seed(seed)
    os.environ["PYTHONHASHSEED"] = str(seed)
    np.random.seed(seed)
    torch.manual_seed(seed)
    torch.cuda.manual_seed(seed)
    torch.cuda.manual_seed_all(seed)
    torch.backends.cudnn.benchmark = False
    torch.backends.cudnn.deterministic = True


def save_videos_grid(videos: torch.Tensor, path: str, rescale=False, n_rows=1, fps=24):
    """save videos by video tensor
       copy from https://github.com/guoyww/AnimateDiff/blob/e92bd5671ba62c0d774a32951453e328018b7c5b/animatediff/utils/util.py#L61

    Args:
        videos (torch.Tensor): video tensor predicted by the model
        path (str): path to save video
        rescale (bool, optional): rescale the video tensor from [-1, 1] to  . Defaults to False.
        n_rows (int, optional): Defaults to 1.
        fps (int, optional): video save fps. Defaults to 8.
    """
    videos = rearrange(videos, "b c t h w -> t b c h w")
    outputs = []
    for x in videos:
        x = torchvision.utils.make_grid(x, nrow=n_rows)
        x = x.transpose(0, 1).transpose(1, 2).squeeze(-1)
        if rescale:
            x = (x + 1.0) / 2.0  # -1,1 -> 0,1
        x = torch.clamp(x, 0, 1)
        x = (x * 255).numpy().astype(np.uint8)
        outputs.append(x)

    os.makedirs(os.path.dirname(path), exist_ok=True)
    imageio.mimsave(path, outputs, fps=fps)


def cache_video(
    tensor,
    save_file,
    fps=30,
    suffix=".mp4",
    nrow=8,
    normalize=True,
    value_range=(-1, 1),
    retry=5,
):
    cache_file = save_file

    # save to cache
    error = None
    for _ in range(retry):
        try:
            # preprocess
            tensor = tensor.clamp(min(value_range), max(value_range))
            tensor = torch.stack(
                [torchvision.utils.make_grid(u, nrow=nrow, normalize=normalize, value_range=value_range) for u in tensor.unbind(2)],
                dim=1,
            ).permute(1, 2, 3, 0)
            tensor = (tensor * 255).type(torch.uint8).cpu()

            # write video
            writer = imageio.get_writer(cache_file, fps=fps, codec="libx264", quality=8)
            for frame in tensor.numpy():
                writer.append_data(frame)
            writer.close()
            return cache_file
        except Exception as e:
            error = e
            continue
    else:
        print(f"cache_video failed, error: {error}", flush=True)
        return None