import secrets

from django.views import View
from django.views.generic.list import ListView
from django.views.generic.detail import DetailView
from django.contrib.auth.mixins import UserPassesTestMixin
from django.urls import reverse
from django.shortcuts import (
    render,
    redirect,
    get_object_or_404
)

from .forms import (
    ImageUploadForm,
    GalleryCreatingForm,
    AccessCodeForm,
    VisitorNameForm
)
from .models import (
    Image,
    Visitor,
    Gallery
)

class VisitorSessionMixin(View):
    def get_visitor(self):
        if self.request.session:
            if 'visitor_session' in self.request.session:
                if Visitor.objects.filter(session_id=self.request.session['visitor_session']).exists():
                    return Visitor.objects.get(session_id=self.request.session['visitor_session'])
            else:
                visitor = Visitor.objects.create()
                self.request.session['visitor_session'] = visitor.session_id
                return visitor
        else:   
            return None

    def can_access_image(self, image):
        if image.private:
            return self.get_visitor() == image.uploaded_by or self.get_visitor() in image.visible_to.all()
        else:
            return True

    def can_access_gallery(self, gallery):
        if gallery.private:
            return self.get_visitor() == gallery.created_by or self.get_visitor() in gallery.visitors.all()
        else:
            return True

    def get_context_data(self, **kwargs):
        context = super().get_context_data(**kwargs)
        context['visitor'] = self.get_visitor()
        return context
    

class ImageUploadView(VisitorSessionMixin, View):
    def get(self, request):
        form = ImageUploadForm()
        return render(
            request,
            'upload_image/upload.html',
            {
                'form': form,
                'visitor': self.get_visitor()
            }
        )

    def post(self, request):
        form = ImageUploadForm(
            request.POST,
            request.FILES
        )

        if form.is_valid():
            image = form.save(commit=False)

            if image.private:
                image.access_code = secrets.token_hex(16)

            image.uploaded_by = self.get_visitor()
            image.save()
            return redirect(
                reverse('home')
            )
        else:
            form = ImageUploadForm()
            return render(
                request,
                'upload_image/upload.html',
                {
                    'form': form,
                    'visitor': self.get_visitor()
                }
            )

class PublicImageListView(ListView):
    model = Image
    paginate_by = 20
    context_object_name = 'images'
    template_name = 'list_images/image_list.html'

    def get_queryset(self):
        return Image.objects.all().filter(private=False).order_by('-uploaded_when')[:10]

class MyImagesListView(VisitorSessionMixin, View):
    def get(self, request):
        visitor = self.get_visitor()
        uploaded_images = Image.objects.all().filter(
            uploaded_by=self.get_visitor()
        )
        shared_images = Image.objects.all().filter(
            visible_to__in=(visitor, )
        )

        return render(
            request,
            'image/my_images.html',
            {
                'uploaded_images': uploaded_images,
                'shared_images': shared_images,
                'visitor': self.get_visitor()
            }
        )
    

class GalleryCreateView(VisitorSessionMixin, View):

    def get(self, request):
        form = GalleryCreatingForm()
        return render(
            request,
            'gallery/create_gallery.html',
            {
                'form': form,
                'visitor': self.get_visitor()
            }
        )
    
    def post(self, request):
        form = GalleryCreatingForm(
            request.POST,
            request.FILES
        )

        if form.is_valid():
            gallery = form.save(commit=False)

            if gallery.private:
                gallery.access_code = secrets.token_hex(16)

            gallery.created_by = self.get_visitor()
            
            gallery.save()
            for image in request.FILES.getlist('images'):
                imageObject = Image.objects.create(
                    image_file=image,
                    uploaded_by=gallery.created_by,
                    private=gallery.private,
                    access_code=gallery.access_code

                )
                imageObject.galleries.add(gallery)
                imageObject.save()

            gallery.save()
            return redirect(
                reverse('home')
            )
        else:
            form = ImageUploadForm()
            return render(
                request,
                'upload_image/upload.html',
                {
                    'form': form,
                    'visitor': self.get_visitor()
                }
            )

class MyGalleriesListView(VisitorSessionMixin, View):

    def get(self, request):
        visitor = self.get_visitor()
        created_galleries = Gallery.objects.all().filter(
            created_by=self.get_visitor()
        )
        invited_galleries = Gallery.objects.all().filter(
            visitors__in=(visitor, )
        )

        return render(
            request,
            'gallery/my_galleries.html',
            {
                'created_galleries': created_galleries,
                'invited_galleries': invited_galleries,
                'visitor': self.get_visitor()
            }
        )

class GalleryDetailView(VisitorSessionMixin, UserPassesTestMixin, DetailView):
    model = Gallery
    template_name = 'gallery/gallery_detail.html'
    context_object_name = 'gallery'

    def test_func(self):
        return self.can_access_gallery(
            self.get_object()
        )

    def handle_no_permission(self):
        return redirect(
            reverse(
                'gallery_gain_access',
                kwargs={
                    'gallery_id': self.get_object().id
                }
            )
        )

class ImageDetailView(VisitorSessionMixin, UserPassesTestMixin, DetailView):
    model = Image
    template_name = 'image/image_detail.html'
    context_object_name = 'image'

    def test_func(self):
        return self.can_access_image(
            self.get_object()
        )

    def handle_no_permission(self):
        return redirect(
            reverse('home')
        )

class GainAccessToGalleryView(VisitorSessionMixin, View):
    def _redirect_to_gallery(self, gallery):
        return redirect(
            reverse(
                'gallery',
                kwargs={
                    'pk': gallery.id
                }
            )
        )

    def get(self, request, gallery_id):
        gallery = get_object_or_404(
            Gallery,
            id=gallery_id
        )
        if self.can_access_gallery(gallery):
            return self._redirect_to_gallery(gallery)
        else:
            return render(
                self.request,
                'gallery/gallery_no_access.html',
                {
                    'form': AccessCodeForm(),
                    'visitor': self.get_visitor()
                }
            )
        
    def post(self, request, gallery_id):
        gallery = get_object_or_404(
            Gallery,
            id=gallery_id
        )
        if self.can_access_gallery(gallery):
            return self._redirect_to_gallery(gallery)
        else:
            form = AccessCodeForm(
                request.POST
            )
            if form.is_valid():
                access_code = form.cleaned_data['access_code']
                if access_code == gallery.access_code:
                    gallery.visitors.add(self.get_visitor())
                    gallery.save()
                    self.get_visitor().save()
                    return self._redirect_to_gallery(gallery)

            return render(
                self.request,
                'gallery/gallery_no_access.html',
                {
                    'form': AccessCodeForm(),
                    'visitor': self.get_visitor()
                }
            )

class RevokeAccessToGallery(VisitorSessionMixin, View):
    def get(self, request, gallery_id, visitor_id):
        gallery = get_object_or_404(Gallery, id=gallery_id)
        visitor = self.get_visitor()

        if visitor == gallery.created_by:
            visitor_to_remove = get_object_or_404(Visitor, id=visitor_id)
            if visitor_to_remove in gallery.visitors.all():
                gallery.visitors.remove(visitor_to_remove)
                gallery.access_code = secrets.token_hex(16)
                gallery.save()

        return redirect(
            reverse(
                'gallery',
                kwargs={
                    'pk': gallery.id
                }
            )
        )

class VisitorSettingsView(VisitorSessionMixin, View):
    def get(self, request):
        name_form = VisitorNameForm(
            initial={
                'name': self.get_visitor().name
            }
        )

        return render(
            request,
            'visitor/visitor_settings.html',
            {
                'name_form': name_form,
                'visitor': self.get_visitor()
            }
        )

    def post(self, request):
        name_form = VisitorNameForm(
            request.POST
        )

        if name_form.is_valid():
            visitor = self.get_visitor()
            visitor.name = name_form.cleaned_data['name']
            visitor.save()

        name_form = VisitorNameForm(
            initial={
                'name': self.get_visitor().name
            }
        )
        return render(
            request,
            'visitor/visitor_settings.html',
            {
                'name_form': name_form,
                'visitor': self.get_visitor()
            }
        )