"""Pagination"""
from django import template

# pylint: disable=invalid-name
register = template.Library()


@register.filter(name='proper_paginate')
def proper_paginate(paginator, current_page, neighbors=10):
    """Proper Pagination Filter"""
    if paginator.num_pages > 2*neighbors:
        start_index = max(1, current_page-neighbors)
        end_index = min(paginator.num_pages, current_page + neighbors)
        if end_index < start_index + 2*neighbors:
            end_index = start_index + 2*neighbors
        elif start_index > end_index - 2*neighbors:
            start_index = end_index - 2*neighbors
        if start_index < 1:
            end_index -= start_index
            start_index = 1
        elif end_index > paginator.num_pages:
            start_index -= (end_index-paginator.num_pages)
            end_index = paginator.num_pages
        page_list = [f for f in range(start_index, end_index+1)]
        return page_list[:(2*neighbors + 1)]
    return paginator.page_range
