from django.contrib.auth.decorators import login_required
from django.http import JsonResponse
from django.template import loader
from django.views.generic import View, DetailView, ListView
from django.views.decorators.csrf import csrf_exempt
from django.views.decorators.http import require_http_methods
from .models import Course, Like
from .filters import CourseFilter


@login_required
@csrf_exempt
@require_http_methods(['POST'])
def likes(request, course_id):
    try:
        course = Course.objects.prefetch_related('likes').get(id=course_id)
    except Course.DoesNotExist:
        return JsonResponse({
            'success': False,
            'errors': ['Course with id f{cource_id} not found']
        })
    else:
        course_user_likes = course.likes.filter(user=request.user)
        if course_user_likes.exists():
            is_liked = False
            for _course in course_user_likes.all():
                course.likes.remove(_course)
            course_user_likes.delete()
        else:
            is_liked = True
            course.likes.add(Like.objects.create(user=request.user))
        count = course.likes.count()
        return JsonResponse({
            "success": True,
            "likes_count": count,
            "is_liked": is_liked,
        })


class CourseView(DetailView):
    model = Course
    context_object_name = 'course'
    template_name = 'course/course.html'


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'