from io import BytesIO

import numpy as np
from PIL import Image
import torch


def bytesio_to_image_tensor(image_bytesio: BytesIO, mode: str = "RGBA") -> torch.Tensor:
    """Converts image data from BytesIO to a torch.Tensor.

    Args:
        image_bytesio: BytesIO object containing the image data.
        mode: The PIL mode to convert the image to (e.g., "RGB", "RGBA").

    Returns:
        A torch.Tensor representing the image (1, H, W, C).

    Raises:
        PIL.UnidentifiedImageError: If the image data cannot be identified.
        ValueError: If the specified mode is invalid.
    """
    image = Image.open(image_bytesio)
    image = image.convert(mode)
    image_array = np.array(image).astype(np.float32) / 255.0
    return torch.from_numpy(image_array).unsqueeze(0)