import string
import random
from django.utils.text import slugify


def random_string_generator(size=10, chars=string.ascii_lowercase + string.digits):
    return ''.join(random.choice(chars) for _ in range(size))


def unique_order_id_generator(inst):
    """
    Generate unique order_id.
    Model should have an order_id field to use this function.
    """
    print('i am here')
    order_new_id = random_string_generator()

    Klass = inst.__class__
    qs_exists = Klass.objects.filter(order_id =order_new_id).exists()
    if qs_exists:
        return unique_slug_generator(inst)
    return order_new_id


def unique_slug_generator(inst, new_slug=None):
    """
    Generate unique slug from title or based on provided slug.
    Model should have a slug field and a title (char) field to use this function.
    """
    if new_slug is not None:
        slug = new_slug
    else:
        slug = slugify(inst.title)

    Klass = inst.__class__
    qs_exists = Klass.objects.filter(slug=slug).exists()
    if qs_exists:
        new_slug = "{slug}-{randstr}".format(
                    slug=slug,
                    randstr=random_string_generator(size=4)
                )
        return unique_slug_generator(inst, new_slug=new_slug)
    return slug