from django.contrib.auth.decorators import login_required
from django.db.models import Q
from django.http import JsonResponse
from django.template import loader, Context, Template
from django.views.generic import View, CreateView, DetailView, ListView
from django.views.decorators.csrf import csrf_exempt
from django.views.decorators.http import require_http_methods
from .models import Course, Like, Lesson, CourseComment, LessonComment
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']
        }, status=400)
    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,
        })


@login_required
@csrf_exempt
@require_http_methods(['POST'])
def coursecomment(request, course_id):
    try:
        course = Course.objects.get(id=course_id)
    except Course.DoesNotExist:
        return JsonResponse({
            'success': False,
            'errors': ['Course with id f{cource_id} not found']
        }, status=400)
    else:
        reply_to = request.POST.get('reply_id', 0)
        comment = request.POST.get('comment', '')
        if not comment:
            return JsonResponse({
                'success': False,
                'errors': ['Comment can not be empty']
            }, status=400)

        if not int(reply_to):
            coursecomment = CourseComment.objects.create(
                author=request.user,
                content=comment,
                course=course,
            )
        else:
            try:
                _coursecomment = CourseComment.objects.get(id=reply_to)
            except CourseComment.DoesNotExist:
                return JsonResponse({
                    'success': False,
                    'errors': ['CourseComment with id f{reply_to} not found']
                }, status=400)
            else:
                coursecomment = CourseComment.objects.create(
                    author=request.user,
                    content=comment,
                    course=course,
                    parent=_coursecomment,
                )
        ctx = {'node': coursecomment, 'user': request.user}
        html = loader.render_to_string('course/blocks/comment.html', ctx)
        return JsonResponse({
            'success': True,
            'comment': html,
        })


@login_required
@csrf_exempt
@require_http_methods(['POST'])
def lessoncomment(request, lesson_id):
    try:
        lesson = Lesson.objects.get(id=lesson_id)
    except Lesson.DoesNotExist:
        return JsonResponse({
            'success': False,
            'errors': ['Lesson with id f{lesson_id} not found']
        }, status=400)
    else:
        reply_to = request.POST.get('reply_id', 0)
        comment = request.POST.get('comment', '')
        if not comment:
            return JsonResponse({
                'success': False,
                'errors': ['Comment can not be empty']
            }, status=400)

        if not int(reply_to):
            lessoncomment = LessonComment.objects.create(
                author=request.user,
                content=comment,
                lesson=lesson,
            )
        else:
            try:
                _lessoncomment = LessonComment.objects.get(id=reply_to)
            except LessonComment.DoesNotExist:
                return JsonResponse({
                    'success': False,
                    'errors': ['LessonComment with id f{reply_to} not found']
                }, status=400)
            else:
                lessoncomment = LessonComment.objects.create(
                    author=request.user,
                    content=comment,
                    lesson=lesson,
                    parent=_lessoncomment,
                )
        ctx = {'node': lessoncomment, 'user': request.user}
        html = loader.render_to_string('course/blocks/comment.html', ctx)
        return JsonResponse({
            'success': True,
            'comment': html,
        })


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

    def get_context_data(self, **kwargs):
        context = super().get_context_data(**kwargs)
        context['next'] = self.request.GET.get('next', None)
        return context


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, request=request)
            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().select_related(
            'author', 'category'
        ).prefetch_related(
            'likes', 'materials', 'content',
        )
        filtered = CourseFilter(self.request.GET, queryset=queryset)
        return filtered.qs

    def get_context_data(self):
        context = super().get_context_data()
        filtered = CourseFilter(self.request.GET)
        context.update(filtered.data)
        return context

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


class LessonView(DetailView):
    model = Lesson
    context_object_name = 'lesson'
    template_name = 'course/lesson.html'


class SearchView(CoursesView):
    template_name = 'course/result.html'

    def get_queryset(self):
        search_query = self.request.GET.get('q', None)
        queryset = super().get_queryset()
        if search_query:
            query = Q(title__icontains=search_query) | Q(short_description__icontains=search_query)
            queryset = queryset.filter(query)
        else:
            queryset = queryset.none()
        return queryset

    def get_context_data(self, **kwargs):
        context = super().get_context_data(**kwargs)
        context['q'] = self.request.GET.get('q', None) or ''
        return context
        if 'is_paginated' in context and context['is_paginated']:
            page_obj = context.get('page_obj')
            context['page'] = page_obj.number
            context['next_page'] = str(page_obj.next_page_number()) if page_obj.has_next() else None
        else:
            context['page'] = 1
            context['next_page'] = None
        return context

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