import os
import random
import numpy as np
import torch
from PIL import Image


def set_seed(seed: int):
    random.seed(seed)
    np.random.seed(seed)
    torch.manual_seed(seed)
    torch.cuda.manual_seed_all(seed)


def ensure_dir(path: str):
    os.makedirs(path, exist_ok=True)


def tensor_to_pil(x: torch.Tensor) -> Image.Image:
    """
    x: (3, H, W) in [-1, 1]
    """
    x = x.detach().cpu().clamp(-1, 1)
    x = (x + 1.0) / 2.0
    x = (x * 255).byte()
    x = x.permute(1, 2, 0).numpy()
    return Image.fromarray(x)


def save_gif(frames, out_path, duration=350):
    """
    frames: list of PIL Images
    """
    if len(frames) == 0:
        return
    frames[0].save(
        out_path,
        save_all=True,
        append_images=frames[1:],
        duration=duration,
        loop=0,
    )


def save_side_by_side(frame1: Image.Image, frame2: Image.Image, out_path: str):
    w, h = frame1.size
    canvas = Image.new("RGB", (w * 2, h))
    canvas.paste(frame1, (0, 0))
    canvas.paste(frame2, (w, 0))
    canvas.save(out_path)