from itertools import takewhile, starmap, islice, repeat
from operator import truth

from pdf2image import pdf2image


def chunk_iterable(iterable, n):
    return takewhile(truth, map(tuple, starmap(islice, repeat((iter(iterable), n)))))


def get_page_count(pdf):
    return pdf2image.pdfinfo_from_bytes(pdf)["Pages"]


def stream_pages(pdf):
    def page_to_image(idx):
        return pdf2image.convert_from_bytes(pdf, first_page=idx, last_page=idx + 1)[0]

    page_count = get_page_count(pdf)
    return map(page_to_image, range(page_count))