# coding:utf-8

from django.core.paginator import InvalidPage
from rest_framework.response import Response
from rest_framework.pagination import PageNumberPagination
from rest_framework.exceptions import NotFound


class CustomPagination(PageNumberPagination):
    page_size = 10
    page_query_param = "page"
    page_size_query_param = "page_size"

    def paginate_queryset(self, queryset, request, view=None):
        """
        Paginate a queryset if required, either returning a
        page object, or `None` if pagination is not configured for this view.
        """
        page_size = self.get_page_size(request)
        if not page_size:
            return None
        paginator = self.django_paginator_class(queryset, page_size)
        if request.query_params.get(self.page_query_param):
            page_number = int(request.query_params.get(self.page_query_param))
        else:
            page_number = 1
        if page_number in self.last_page_strings:
            page_number = int(paginator.num_pages)

        page_number = min(page_number, paginator.num_pages)

        try:
            self.page = paginator.page(page_number)
        except InvalidPage as exc:
            msg = self.invalid_page_message.format(
                page_number=page_number, message=str(exc)
            )
            raise NotFound(msg)

        if paginator.num_pages > 1 and self.template is not None:
            # The browsable API should display pagination controls.
            self.display_page_controls = True

        self.request = request
        return list(self.page)

    def get_paginated_response(self, data):
        return Response({
            'total_page': self.page.paginator.num_pages,
            'total_counts': self.page.paginator.count,
            'page_size': self.page.paginator.per_page,
            'current_page': self.page.number,
            'current_counts': len(data),
            'items': data
        })