import base64
import mimetypes

from typing.io import BinaryIO


class FileNotFoundError(Exception):
    pass


def bytes_to_datauri(fp: BinaryIO, name):
    """Convert a file (specified by a path) into a data URI."""
    mime, _ = mimetypes.guess_type(name)
    fp.seek(0)
    data = fp.read()
    data64 = b''.join(base64.encodebytes(data).splitlines())
    return 'data:%s;base64,%s' % (mime, data64.decode('utf-8'))