"""

"""


from django.shortcuts import get_object_or_404, redirect, resolve_url
from django.views.generic import RedirectView
from django.views.generic.detail import DetailView
from django.views.generic.list import ListView
from django.views.generic.edit import CreateView, UpdateView
from django.core.exceptions import SuspiciousOperation
from django.http import Http404, HttpResponseRedirect
from django.db.models import Q
from django.utils import timezone

from markdown2 import markdown

from . import models, forms
from interface.utils import check_signed_url

import logging
logger = logging.getLogger(__name__)

class AuthorizedResourceMixin(object):
    """
    Handles these parts of the permission system:
        * signed urls
        * persistent authenticated resources
        * Admin enforcing
    """

    SESSION_KEY = 'authorized'
    admin_required = False

    def is_authorized(self):
        "By default check if superuser or a signed request"
        if self.request.is_admin:
            logger.debug("is_authorized: superuser")
            return True
        
        if 'sig' in self.request.GET:
            check_signed_url(self.request.get_full_path())
            self.on_signed_request()
            return True

        return False
    
    def on_signed_request(self):
        pass

    def is_authorized_key(self, resource, key, auth):
        current = self.get_authorized_keys(resource).get(str(key), None)
        if current is None:
            logger.debug("is_authorized_key: %s %s not in session", resource, key)
            return False
        if auth == current:
            return True

        logger.info("Authorisation revoked")
        self.del_authorized_key(resource, key)
        return False

    def get_authorized_keys(self, resource):
        'Returns a set of authorized keys for this resource'
        return self._authorized.get(resource, {})
    
    def add_authorized_key(self, resource, key, auth):
        'Adds a key to the authorized list for this resource'
        current = self.get_authorized_keys(resource)
        current[str(key)] = auth
        self._authorized[resource] = current
        self.request.session[self.SESSION_KEY] = self._authorized

    def del_authorized_key(self, resource, key):
        logger.info("Revoking authorization for %s %s", resource, key)
        current = self.get_authorized_keys(resource)
        if current.pop(key, None) is None:
            return False
        if current:
            self._authorized[resource] = current
        else:
            self._authorized.pop(resource)
        self.request.session[self.SESSION_KEY] = self._authorized
        return True

    def request_denied(self):
        raise Http404("Either the given resource doesn't exist or you dont have access to it.")

    def dispatch(self, request, *args, **kwargs):

        self._authorized = request.session.get('authorized', {})
        request.is_admin = request.user.is_superuser

        if not self.is_authorized():
            return self.request_denied()
        
        if self.admin_required and not request.is_admin:
            return self.request_denied()

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

class ForgetResourceView(AuthorizedResourceMixin, RedirectView):
    
    def is_authorized(self):
        return True

    def get_redirect_url(self, resource, key):
        self.del_authorized_key(resource, key)
        return "/" 

class EnsembleMixin(AuthorizedResourceMixin):

    ensemble_slug_kwarg = 'ensemble'
    limited_project_access = False

    def is_authorized(self):
        ensemble_slug = self.kwargs[self.ensemble_slug_kwarg]
        self.ensemble = get_object_or_404(models.Ensemble, slug=ensemble_slug)

        if super().is_authorized():
            return True
        
        if self.ensemble.has_admin(self.request.user):
            self.request.is_admin = True
            return True

        if self.is_authorized_key('ensemble', ensemble_slug, self.ensemble.nonce):
            return True
        
        authorized = set([ int(x) for x in self.get_authorized_keys('project').keys() ])
        projects = set(self.ensemble.projects.values_list('pk', flat=True))
        logger.debug("is_authorized: %r & %r", authorized, projects)
        if authorized & projects:
            self.limited_project_access = True
            logger.debug("is_authorized: allowing due to project link")
            return True
        return False

    def get_object(self):
        return self.ensemble


class ProjectMixin(AuthorizedResourceMixin):

    project_kwarg = 'project'

    def is_authorized(self):
        project_id = self.kwargs[self.project_kwarg]
        self.project = get_object_or_404(models.Project.objects.select_related('ensemble'), pk=project_id)

        if super().is_authorized():
            return True
        
        
        # check if the current user is an admin on the ensemble
        if self.project.ensemble.has_admin(self.request.user):
            logger.debug("is_authorized: ensemble admin for project")
            self.request.is_admin = True
            return True
        
        if self.is_authorized_key('ensemble', self.project.ensemble.pk, self.project.ensemble.nonce):
            logger.debug('is_authorized: has ensemble link for project')
            return True

        if self.is_authorized_key('project', project_id, self.project.nonce):
            logger.debug('is_authorized: has project link')
            return True

        return False

    # filter any generated querysets
    def get_queryset(self):
        return super().get_queryset().filter(project=self.project)

    def get_context_data(self, **kwargs):
        context = super().get_context_data(**kwargs)
        if 'project' in self.kwargs:
            context['project'] = self.project
            context['modules'] = self.project.active_modules
        return context

class CrispyFormMixin(object):

    cancel_url = None

    def get_cancel_url(self):
        return self.cancel_url

""" ENSEMBLE VIEWS """

class EnsembleListView(AuthorizedResourceMixin, ListView):

    def is_authorized(self):
        return True
    
    def get_queryset(self):
        ensembles = models.Ensemble.objects.all()

        if self.request.is_admin:
            return ensembles

        # limit to registered ensembles
        f = Q(slug__in=self.get_authorized_keys('ensemble').keys()) | Q(projects__in=self.get_authorized_keys('project').keys())
        
        # or ensembles where the user is admin
        if self.request.user.is_authenticated:
            f |= Q(admins=self.request.user.pk)

        return ensembles.filter(f).distinct()

class EnsembleDetailView(EnsembleMixin, DetailView):

    def request_denied(self):
        if 'auth' in self.request.GET:
            if self.request.GET['auth'] != self.ensemble.auth():
                raise SuspiciousOperation("Bad ensemble link")    
            self.add_authorized_key('ensemble', self.ensemble.slug, self.ensemble.nonce)
            return HttpResponseRedirect(resolve_url('ensemble_detail', self.ensemble.slug))
        
        return super().request_denied()
    
    def get_context_data(self, **kwargs):
        data = super().get_context_data(**kwargs)
        inactive = 'inactive' in self.request.GET and self.request.is_admin

        projects = self.ensemble.projects.all()
        if self.limited_project_access:
            projects = projects.filter(pk__in=self.get_authorized_keys('project').keys())

        if inactive:
            projects = projects.order_by('-pk')
        else:
            projects = projects.filter(active=True, event_date__gte=timezone.now()-timezone.timedelta(7))

        data['inactive'] = inactive
        data['object_list'] = projects
        if self.request.is_admin:
            #data['ensemble_link'] = signed_url(f'{self.request.path}?nonce={self.ensemble.nonce}')
            data['ensemble_link'] = self.request.path + "?auth=" + self.ensemble.auth()
        return data

""" PROJECT VIEWS """

class ProjectListView(ProjectMixin, ListView):

    def is_authorized(self):
        return True
    
    def get_project_queryset(self):
        projects = models.Project.objects.select_related('ensemble')
        if self.request.is_admin:
            return projects

        f = Q(pk__in=self.get_authorized_keys('project').keys()) | Q(ensemble__slug__in=self.get_authorized_keys('ensemble').keys())
        
        if self.request.user.is_authenticated:
            f |= Q(ensemble__admins=self.request.user.pk)

        return projects.filter(f)

    def get_queryset(self):
        qs = self.get_project_queryset()
        return qs.filter(active=True, event_date__gte=timezone.now()-timezone.timedelta(7))

class ProjectCreateView(EnsembleMixin, CreateView):
    admin_required = True
    model = models.Project
    template_name = "interface/default_form.html"
    title = "Add a new project"
    form_class = forms.ProjectForm

    def form_valid(self, form):
        self.object = form.save(commit=False)
        self.object.ensemble = self.ensemble
        self.object.owner = self.request.user
        self.object.save()
        return redirect('project_detail', project=self.object.pk)

class ProjectDetailView(ProjectMixin, DetailView):

    def request_denied(self):
        if 'auth' in self.request.GET:
            if self.request.GET['auth'] != self.project.auth():
                raise SuspiciousOperation("Bad project link")
            self.add_authorized_key('project', self.project.pk, self.project.nonce)
            return HttpResponseRedirect(resolve_url('project_detail', self.project.pk))
        return super().request_denied()

    def get_object(self, queryset=None):
        return self.project

    def get_context_data(self, **kwargs):
        data = super().get_context_data(**kwargs)
        if self.request.is_admin:
            #data['project_link'] = signed_url(f'{self.request.path}?nonce={self.project.nonce}')
            data['project_link'] = self.request.path + "?auth=" + self.project.auth()
        return data

class ProjectUpdateView(ProjectMixin, UpdateView):
    admin_required = True
    template_name = "interface/default_form.html"
    pk_url_kwarg = 'project'
    form_class = forms.ProjectForm

    def get_object(self):
        return self.project

    @property
    def cancel_url(self):
        return self.get_success_url()

    def get_success_url(self):
        return resolve_url('project_detail', project=self.kwargs['project'])

# Old Makefile from submission module
#class ProjectMakefileView(EnsembleMixin, DetailView):
#    template_name = 'interface/project_submissions.mk'
#    content_type = 'text/plain'
#
#    def get_queryset(self):
#        if self.request.is_admin:
#            return models.Project.objects.all()
#
#        return models.Project.objects.filter(ensemble=self.request.ensemble_id)
#
#    def get_context_data(self, **kwargs):
#        data = super().get_context_data(**kwargs)
#
#        data['submissions'] = []
#        data['targets'] = []
#        for s in self.object.submissions:
#            name = s.short_name
#            data['targets'].append(name)
#            data['submissions'].append({
#                'url': self.request.build_absolute_uri(signed_url('submission_download', project=self.kwargs['pk'], pk=s.pk)),
#                'name': name,
#            })
#
#        return data

""" WIKI VIEWS """

class WikiView(ProjectMixin, DetailView):
    template_name = 'interface/wiki.html'
    model = models.WikiPage

    def get_context_data(self, **kwargs):
        data = super().get_context_data(**kwargs)
        data['wiki_html'] = markdown(self.object.markdown)
        return data

class WikiCreateView(ProjectMixin, CreateView):
    admin_required = True
    model = models.WikiPage
    template_name = 'interface/default_form.html'
    form_class = forms.WikiForm

    def cancel_url(self):
        return resolve_url('project_detail', self.kwargs['project'])

    def form_valid(self, form):
        self.object = form.save(commit=False)
        self.object.project = self.project
        self.object.save()
        return redirect('wiki', project=self.object.project_id, pk=self.object.pk)

class WikiEditView(ProjectMixin, UpdateView):
    admin_required = True
    model = models.WikiPage
    form_class = forms.WikiForm

    def cancel_url(self):
        return resolve_url('wiki', self.kwargs['project'], self.kwargs['pk'])

""" RESOURCE VIEWS """

class ResourceCreateView(ProjectMixin, CreateView):
    admin_required = True
    model = models.Resource
    form_class = forms.ResourceForm
    template_name = 'interface/default_form.html'
    title = "Add a new resource"

    def form_valid(self, form):
        self.object = form.save(commit=False)
        self.object.project = self.project
        self.object.save()
        return redirect('resource_upload', project=self.object.project_id, pk=self.object.pk)

class ResourceUploadView(ProjectMixin, UpdateView):
    admin_required = True
    model = models.Resource
    fields = ['file']
    template_name = 'interface/default_form.html'

    def get_success_url(self):
        return resolve_url('resource_list', project=self.kwargs['project'])

class ResourceListView(ProjectMixin, ListView):
    model = models.Resource

    def get_queryset(self):
        qs = super().get_queryset()
        if not self.request.is_admin:
            qs = qs.filter(visible=True)
        return qs

class ResourceEditView(ProjectMixin, UpdateView):
    admin_required = True
    model = models.Resource
    fields = ['name', 'description', 'visible']
    template_name = 'interface/default_form.html'

    def get_success_url(self):
        return resolve_url('resource_list', project=self.kwargs['project'])