#!/usr/bin/env python
# -*- coding: utf-8 -*-

''' Django views. '''
from django.shortcuts import render, redirect, get_object_or_404
from django.urls import reverse_lazy
from django.views.generic.edit import CreateView, UpdateView, DeleteView
from django.views.generic.detail import SingleObjectMixin
from django.views.generic import ListView
from django.views import View
from django.http import Http404
from django.contrib import messages
from django.contrib.auth.mixins import UserPassesTestMixin, LoginRequiredMixin

from django.contrib.messages.views import SuccessMessageMixin

from .forms import (
    ExplorerCreationForm, 
    PlaceForm, 
    PlaceImageCreateForm
)
from .models import Place, PlaceImage, Voucher, PhotoAlbum

# Create your views here.

# BaseView that checks if user is logged in.
class IsAuthenticated(LoginRequiredMixin, View):
    redirect_field_name = 'redirect_to'
    permission_denied_message = 'Please login to proceed'

    def handle_no_permission(self):
        messages.error(self.request, self.permission_denied_message)
        return super().handle_no_permission()

# BaseView that checks if logged in user is submitter of place.
class IsPlaceSubmitter(UserPassesTestMixin, View):
    place_submitter_error_message = None

    def get_place(self):
        pass

    def test_func(self):
        """ Check if user is eligible to modify place. """

        if not hasattr(self.request, 'user'):
            return False

        if self.request.user.is_superuser:
            return True
        
        # Check if currently logged in user was the submitter
        place_obj = self.get_place()

        if place_obj and hasattr(place_obj, 'submitted_by') and self.request.user == place_obj.submitted_by:
            return True

        if self.place_submitter_error_message:
            messages.error(self.request, self.place_submitter_error_message)
        return False

class SignUpView(SuccessMessageMixin, CreateView):
    form_class = ExplorerCreationForm
    success_url = reverse_lazy('login')
    template_name = 'signup.html'
    success_message = 'User created.'

class PlaceListView(IsAuthenticated, ListView):
    paginate_by = 5
    model = Place
    template_name = 'place/place_list.html'
    ordering = ['name']

    def get_context_data(self, **kwargs):
        context = super().get_context_data(**kwargs)
        context['place_map_center'] = Place.average_latlon(context['place_list'])
        return context

class PlaceDetailView(IsAuthenticated, View):
    def get(self, request, pk):
        place = Place.objects.get(pk=pk)
        context = {
            'place': place,
            'place_list': [ place ],
            'place_map_center': [ place.latitude, place.longitude ]
        }
        return render(request, 'place/place_detail.html', context)

class HomeView(View):
    def get(self, request, *args, **kwargs):
        place_list = Place.objects.all().order_by('-submitted_when')[:10]
        place_map_center = Place.average_latlon(place_list)
        context = {
            'place_list': place_list,
            'place_map_center': place_map_center
        }
        return render(request, 'home.html', context)

class PlaceUpdateView(IsAuthenticated, IsPlaceSubmitter, SuccessMessageMixin, UpdateView):
    template_name = 'place/place_update.html'
    model = Place
    form_class = PlaceForm
    success_message = 'Successfully updated place.'
    place_submitter_error_message = 'You do no have permissions to alter this place'

    def get_success_url(self):
        return reverse_lazy('place_detail', kwargs={'pk':self.get_object().pk})

    def get_place(self):
        return self.get_object()

class PlaceCreateView(IsAuthenticated, View):

    def get(self, request, *args, **kwargs):
        place_image_form = PlaceImageCreateForm()
        place_form = PlaceForm()

        context = {
            'place_form': place_form,
            'place_image_form': place_image_form
        }
        return render(request, 'place/place_create.html', context)

    def post(self, request, *args, **kwargs):
        place_form = PlaceForm(request.POST)

        if place_form.is_valid():
            submitter = request.user
            place = place_form.save(commit=False)
            # Save logged in user as "submitted_by"
            place.submitted_by = submitter
            place.save()

            if request.FILES:
                self._apply_multipart_image_upload(
                    files=request.FILES.getlist('filename'),
                    place=place, 
                    submitter=submitter
                )
            
            kwargs_to_pass = {
                'pk': place.pk
            }

            messages.success(
                self.request, 'Successfully created place.')
            return redirect(reverse_lazy('place_detail', kwargs=kwargs_to_pass))
        
        else:
            context = {
                'form': form_place
            }

            # Usually the browser should have checked the form before sending.
            messages.error(
                self.request, 'Please fill in all required fields.')
            return render(request, 'place/place_create.html', context)

    def _apply_multipart_image_upload(self, files, place, submitter):
        for image in files:
            place_image = PlaceImage.objects.create(
                filename=image,
                place=place,
                submitted_by=submitter
            )
            place_image.save()

class PlaceDeleteView(IsAuthenticated, IsPlaceSubmitter, DeleteView):
    template_name = 'place/place_delete.html'
    model = Place
    success_message = 'Successfully deleted place.'
    success_url = reverse_lazy('place_list')
    success_message = 'Place deleted'
    place_submitter_error_message = 'You do no have permission to delete this place'

    def delete(self, request, *args, **kwargs):
        messages.success(self.request, self.success_message)
        return super().delete(request, *args, **kwargs)

    def get_place(self):
        return self.get_object()

class PhotoAlbumCreateView(IsAuthenticated, SuccessMessageMixin, CreateView):
    model = PhotoAlbum
    fields = ['url', 'label']
    template_name = 'photo_album/photo_album_create.html'
    success_message = 'Photo Album submitted'

    def get(self, request, place_id, *args, **kwargs):
        self.place = Place.objects.get(pk=place_id)
        return super().get(request, *args, **kwargs)

    def post(self, request, place_id, *args, **kwargs):
        self.place = Place.objects.get(pk=place_id)
        response = super().post(request, *args, **kwargs)
        self.object.place = self.place
        self.object.submitted_by = request.user
        self.object.save()
        return response

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

    def get_success_url(self):
        return reverse_lazy('place_detail', kwargs={'pk': self.place.id})

class PhotoAlbumDeleteView(IsAuthenticated, IsPlaceSubmitter, SingleObjectMixin, View):
    model = PhotoAlbum
    pk_url_kwarg = 'pk'
    success_message = 'Photo Album deleted'

    def get_place(self):
        place_id = self.get_object().place.id
        return Place.objects.get(pk=place_id)

    def test_func(self):
        can_edit_place = super().test_func()
        if can_edit_place:
            return True
        
        if self.get_object().submitted_by == self.request.user:
            return True
        
        messages.error(self.request, 'You do not have permissions to alter this photo album')
        return False

    def get(self, request, *args, **kwargs):
        place_id = self.get_object().place.id
        self.get_object().delete()
        messages.success(self.request, self.success_message)
        return redirect(reverse_lazy('place_detail', kwargs={'pk': place_id}))