"""Pagination adapters for clients built with ngx-jsonapi."""

from rest_framework.response import Response
from rest_framework_json_api.pagination import JsonApiPageNumberPagination


class NgxJsonApiPageNumberPagination(JsonApiPageNumberPagination):
    """Expose page-number metadata in the shape expected by ngx-jsonapi."""

    def get_paginated_response(self, data):
        next_page = None
        previous_page = None

        if self.page.has_next():
            next_page = self.page.next_page_number()
        if self.page.has_previous():
            previous_page = self.page.previous_page_number()

        return Response(
            {
                "results": data,
                "meta": {
                    "page": self.page.number,
                    "pages": self.page.paginator.num_pages,
                    "total_resources": self.page.paginator.count,
                    "resources_per_page": self.page.paginator.per_page,
                },
                "links": {
                    "first": self.build_link(1),
                    "last": self.build_link(self.page.paginator.num_pages),
                    "next": self.build_link(next_page),
                    "prev": self.build_link(previous_page),
                },
            }
        )