"""
Views for displaying or manipulating models in the 'people' app.
"""

from django.contrib.auth.mixins import LoginRequiredMixin
from django.http import HttpResponseRedirect
from django.urls import reverse
from django.views.generic import CreateView, DetailView, ListView, TemplateView, UpdateView

from rest_framework.views import APIView, Response

from . import forms, models, permissions, serializers


class PersonCreateView(CreateView):
    """
    View to create a new instance of :class:`Person`.

    If 'user' is passed as a URL parameter - link the new person to the current user.
    """
    model = models.Person
    template_name = 'people/person/create.html'
    form_class = forms.PersonForm

    def form_valid(self, form):
        if 'user' in self.request.GET:
            form.instance.user = self.request.user

        return super().form_valid(form)


class PersonListView(ListView):
    """
    View displaying a list of :class:`Person` objects - searchable.
    """
    model = models.Person
    template_name = 'people/person/list.html'


class ProfileView(permissions.UserIsLinkedPersonMixin, DetailView):
    """
    View displaying the profile of a :class:`Person` - who may be a user.
    """
    model = models.Person
    template_name = 'people/person/detail.html'

    def get_object(self, queryset=None) -> models.Person:
        """
        Get the :class:`Person` object to be represented by this page.

        If not determined from url get current user.
        """
        try:
            return super().get_object(queryset)

        except AttributeError:
            # pk was not provided in URL
            return self.request.user.person


class PersonUpdateView(permissions.UserIsLinkedPersonMixin, UpdateView):
    """
    View for updating a :class:`Person` record.
    """
    model = models.Person
    template_name = 'people/person/update.html'
    form_class = forms.PersonForm


class RelationshipDetailView(permissions.UserIsLinkedPersonMixin, DetailView):
    """
    View displaying details of a :class:`Relationship`.
    """
    model = models.Relationship
    template_name = 'people/relationship/detail.html'
    related_person_field = 'source'


class RelationshipCreateView(permissions.UserIsLinkedPersonMixin, CreateView):
    """
    View for creating a :class:`Relationship`.

    Displays / processes a form containing the :class:`RelationshipQuestion`s.
    """
    model = models.Relationship
    template_name = 'people/relationship/create.html'
    fields = [
        'source',
        'target',
    ]

    def get_test_person(self) -> models.Person:
        """
        Get the person instance which should be used for access control checks.
        """
        if self.request.method == 'POST':
            return models.Person.objects.get(pk=self.request.POST.get('source'))

        return models.Person.objects.get(pk=self.kwargs.get('person_pk'))

    def get(self, request, *args, **kwargs):
        self.person = models.Person.objects.get(pk=self.kwargs.get('person_pk'))

        return super().get(request, *args, **kwargs)

    def post(self, request, *args, **kwargs):
        self.person = models.Person.objects.get(pk=self.kwargs.get('person_pk'))

        return super().post(request, *args, **kwargs)

    def get_initial(self):
        initial = super().get_initial()

        initial['source'] = self.request.user.person
        initial['target'] = self.person

        return initial

    def get_context_data(self, **kwargs):
        context = super().get_context_data(**kwargs)

        context['person'] = self.person

        return context

    def get_success_url(self):
        return reverse('people:relationship.update', kwargs={'pk': self.object.pk})


class RelationshipUpdateView(permissions.UserIsLinkedPersonMixin, CreateView):
    """
    View for creating a :class:`Relationship`.

    Displays / processes a form containing the :class:`RelationshipQuestion`s.
    """
    model = models.RelationshipAnswerSet
    template_name = 'people/relationship/update.html'
    form_class = forms.RelationshipAnswerSetForm

    def get_test_person(self) -> models.Person:
        """
        Get the person instance which should be used for access control checks.
        """
        relationship = models.Relationship.objects.get(pk=self.kwargs.get('relationship_pk'))

        return relationship.source

    def get(self, request, *args, **kwargs):
        self.relationship = models.Relationship.objects.get(pk=self.kwargs.get('relationship_pk'))
        self.person = self.relationship.source

        return super().get(request, *args, **kwargs)

    def post(self, request, *args, **kwargs):
        self.relationship = models.Relationship.objects.get(pk=self.kwargs.get('relationship_pk'))
        self.person = self.relationship.source

        return super().post(request, *args, **kwargs)

    def get_context_data(self, **kwargs):
        context = super().get_context_data(**kwargs)

        context['person'] = self.person
        context['relationship'] = self.relationship

        return context
    
    def get_initial(self):
        initial = super().get_initial()
        
        initial['relationship'] = self.relationship
        
        return initial

    def form_valid(self, form):
        """
        Don't rebind self.object to be the result of the form - it is a :class:`RelationshipAnswerSet`.
        """
        form.save()
        
        return HttpResponseRedirect(self.relationship.get_absolute_url())
    

class PersonApiView(APIView):
    """
    List all :class:`Person` instances.
    """
    def get(self, request, format=None):
        """
        List all :class:`Person` instances.
        """
        serializer = serializers.PersonSerializer(models.Person.objects.all(),
                                                  many=True)
        return Response(serializer.data)
    
    
class RelationshipApiView(APIView):
    """
    List all :class:`Relationship` instances.
    """
    def get(self, request, format=None):
        """
        List all :class:`Relationship` instances.
        """
        serializer = serializers.RelationshipSerializer(models.Relationship.objects.all(),
                                                        many=True)
        return Response(serializer.data)
    
    
class NetworkView(LoginRequiredMixin, TemplateView):
    """
    View to display relationship network.
    """
    template_name = 'people/network.html'