from django.http import JsonResponse
from django.views.generic import ListView
from django.template import loader

from .models import Course
from .filters import CourseFilter


class CoursesView(ListView):
    model = Course
    context_object_name = 'course_items'
    paginate_by = 6

    def get(self, request, *args, **kwargs):
        self.object_list = self.get_queryset()
        allow_empty = self.get_allow_empty()
        if request.is_ajax():
            context = self.get_context_data()
            template_name = self.get_template_names()
            html = loader.render_to_string(template_name, context)
            is_paginated = context.get('is_paginated')
            if is_paginated:
                page_obj = context.get('page_obj')
                prev_url = request.path + '?page=' + str(page_obj.previous_page_number()) if page_obj.has_previous() else None
                next_url = request.path + '?page=' + str(page_obj.next_page_number()) if page_obj.has_next() else None
            else:
                prev_url = None
                next_url = None
            return JsonResponse({
                'success': True,
                'content': html,
                'prev_url': prev_url,
                'next_url': next_url,
            })
        else:
            return super().get(request, args, kwargs)

    def get_queryset(self):
        queryset = super().get_queryset()
        filtered = CourseFilter(self.request.GET, queryset=queryset)
        return filtered.qs

    def get_template_names(self):
        if self.request.is_ajax():
            return 'course/course_items.html'
        return 'course/courses.html'