import copy

from django.contrib.auth.mixins import UserPassesTestMixin
from django.contrib.messages.views import SuccessMessageMixin
from django.http import JsonResponse
from django.utils import translation
from django.utils.translation import ugettext_lazy as _
from django.views.generic import ListView
from django.views.generic.base import ContextMixin
from django.views.generic.detail import BaseDetailView, SingleObjectMixin
from django.views.generic.edit import ModelFormMixin
from django.contrib.auth import login, authenticate
from django.contrib.auth.mixins import LoginRequiredMixin

from ..models import (AppSettings, DataFile, DataSet, Lab, Log, Profile,
                      ShareGroup)

class TokenLoginMixin(LoginRequiredMixin):
    def dispatch(self, request, *args, **kwargs):
        if not request.user.is_authenticated:
            user = authenticate(request)
            if user:
                login(request, user)
            else:
                return JsonResponse({'error': _('Malformed authorization header or invalid token')}, status=401)
             
        return super().dispatch(request, *args, **kwargs)


class StaffViewMixin(UserPassesTestMixin):
    def test_func(self):
        return self.request.user.is_staff


class PageViewMixin(ContextMixin):
    page_title = ''

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

        return context


class SlugMixin(SingleObjectMixin):
    slug_field = 'iric_data_id'
    slug_url_kwarg = 'iric_data_id'


class ActivePageViewMixin(PageViewMixin):
    active_page = ''

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

        return context


class SubmitLabelMixin(ContextMixin):
    submit_label = ''

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


class SuccessUrlMixin(ContextMixin):
    success_url = '#'

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


class CreateViewMixin(SubmitLabelMixin, SuccessMessageMixin, SuccessUrlMixin, ActivePageViewMixin, ContextMixin):
    submit_label = _('Create')
    template_name = 'portal/secure/admin/create_update.html'
    success_message = _('Successfully Created "%(name)s"')


class UpdateViewMixin(SlugMixin, SubmitLabelMixin, SuccessMessageMixin, SuccessUrlMixin, ActivePageViewMixin, ContextMixin):
    submit_label = _('Update')
    template_name = 'portal/secure/admin/create_update.html'
    success_message = _('Successfully Updated "%(name)s"')


class DeleteViewMixin(SlugMixin, SubmitLabelMixin, SuccessMessageMixin, SuccessUrlMixin, ActivePageViewMixin, ContextMixin):
    submit_label = _('Delete')
    template_name = 'portal/secure/admin/delete.html'
    success_message = _('Successfully Deleted "%(name)s"')


class AppSettingsMixin(ContextMixin):
    def get_context_data(self, **kwargs):
        context = super().get_context_data(**kwargs)
        app_settings = AppSettings.objects.first()
        if app_settings and app_settings.home_institution:
            context['home_institution'] = app_settings.home_institution.id
        return context


class AjaxDatatableBackboneMixin(ContextMixin):
    """List view to display a Datatable with AJAX datasource"""
    template_name = 'portal/secure/admin/list.html'
    create_url = '#'
    create_label = _('Create New')
    api_url = ''
    dt_struct = {}

    def get_context_data(self, **kwargs):
        context = super().get_context_data(**kwargs)
        context['create_url'] = self.create_url
        context['create_label'] = self.create_label
        context['api_url'] = self.api_url
        context['dt_struct'] = copy.copy(self.dt_struct)
        return context


class JSONListView(ListView):
    """Children must implement get_rows()
    Keep in mind: overriding get_queryset() to add 'select_related' statements might provide nice speed boost
    """
    def get_rows(self):
        pass

    def render_to_response(self, context, **response_kwargs):
        return JsonResponse({'data': self.get_rows()}, **response_kwargs)


class JSONView(SlugMixin, BaseDetailView):
    """Children must implement get_rows()
    Keep in mind: overriding get_queryset() to add 'select_related' statements might provide nice speed boost
    """
    def get_data(self):
        pass

    def render_to_response(self, context, **response_kwargs):
        return JsonResponse(self.get_data(), **response_kwargs)


class LogMixin(ModelFormMixin):
    def form_valid(self, form):
        before = self.get_object()

        # m2m fields (Users attached to dataset, Files attached to dataset etc..)
        for d in self.qs_params:
            old = getattr(before, d)
            new = form.cleaned_data[d]

            if old != new:
                removed = set(old.all()) - set(new.all())
                added = set(new.all()) - set(old.all())

                for o in added.union(removed):
                    type = 'remove'
                    if o in added:
                        type = 'add'

                    with translation.override('en'):
                        label_en = str(form.fields[d].label)
                    with translation.override('fr'):
                        label_fr = str(form.fields[d].label) if str(form.fields[d].label) else label_en  # if no translations, save english

                    log = Log(action_type=type, profile=self.request.user.profile, obj_dataset=before, label_fr=label_fr, label_en=label_en)
                    if isinstance(o, Profile):
                        log.action_type += '_share'
                        log.obj_profile = o
                    elif isinstance(o, Lab):
                        log.action_type += '_share'
                        log.obj_lab = o
                    elif isinstance(o, ShareGroup):
                        log.action_type += '_share'
                        log.obj_group = o
                    elif isinstance(o, DataFile):
                        log.obj_datafile = o
                    log.save()

        # Standard fields (text, int etc..)
        for d in form.changed_data:
            if d not in self.qs_params:
                with translation.override('en'):
                    label_en = str(form.fields[d].label)
                with translation.override('fr'):
                    label_fr = str(form.fields[d].label) if str(form.fields[d].label) else label_en

                Log.objects.create(action_type='edit', profile=self.request.user.profile, obj_dataset=before, label_fr=label_fr, label_en=label_en)

        return super().form_valid(form)