from __future__ import absolute_import, unicode_literals

import logging

from django.conf import settings
from django.contrib import messages
from django.core.exceptions import PermissionDenied
from django.core.urlresolvers import reverse, reverse_lazy
from django.http import HttpResponseRedirect
from django.shortcuts import get_object_or_404, render_to_response
from django.template import RequestContext
from django.utils.translation import ugettext_lazy as _, ungettext

from acls.models import AccessControlList
from common.utils import encapsulate
from common.views import (
    SingleObjectCreateView, SingleObjectEditView, SingleObjectListView
)
from documents.permissions import permission_document_view
from documents.models import Document
from documents.views import DocumentListView
from permissions import Permission

from .forms import FolderListForm
from .models import Folder
from .permissions import (
    permission_folder_add_document, permission_folder_create,
    permission_folder_delete, permission_folder_edit, permission_folder_view,
    permission_folder_remove_document
)

logger = logging.getLogger(__name__)


class FolderEditView(SingleObjectEditView):
    fields = ('label',)
    model = Folder
    object_permission = permission_folder_edit
    post_action_redirect = reverse_lazy('folders:folder_list')

    def get_extra_context(self):
        return {
            'object': self.get_object(),
            'title': _('Edit folder: %s') % self.get_object(),
        }


class FolderListView(SingleObjectListView):
    @staticmethod
    def get_document_count(instance, user):
        queryset = instance.documents

        try:
            Permission.check_permissions(user, (permission_document_view,))
        except PermissionDenied:
            queryset = AccessControlList.objects.filter_by_access(
                permission_document_view, user, queryset
            )

        return queryset.count()

    object_permission = permission_folder_view

    def get_queryset(self):
        self.queryset = self.get_folder_queryset()
        return super(FolderListView, self).get_queryset()

    def get_folder_queryset(self):
        return Folder.objects.all()

    def get_extra_context(self):
        return {
            'extra_columns': [
                {
                    'name': _('Documents'),
                    'attribute': encapsulate(
                        lambda instance: FolderListView.get_document_count(
                            instance=instance, user=self.request.user
                        )
                    )
                },
            ],
            'title': _('Folders'),
            'hide_link': True,
        }


class FolderCreateView(SingleObjectCreateView):
    fields = ('label',)
    model = Folder
    view_permission = permission_folder_create

    def form_valid(self, form):
        try:
            Folder.objects.get(
                label=form.cleaned_data['label'], user=self.request.user
            )
        except Folder.DoesNotExist:
            instance = form.save(commit=False)
            instance.user = self.request.user
            instance.save()
            return super(FolderCreateView, self).form_valid(form)
        else:
            messages.error(
                self.request,
                _(
                    'A folder named: %s, already exists.'
                ) % form.cleaned_data['label']
            )
            return super(FolderCreateView, self).form_invalid(form)

    def get_extra_context(self):
        return {
            'title': _('Create folder'),
        }


def folder_delete(request, folder_id):
    folder = get_object_or_404(Folder, pk=folder_id)

    try:
        Permission.check_permissions(request.user, (permission_folder_delete,))
    except PermissionDenied:
        AccessControlList.objects.check_access(
            permission_folder_delete, request.user, folder
        )

    post_action_redirect = reverse('folders:folder_list')

    previous = request.POST.get('previous', request.GET.get('previous', request.META.get('HTTP_REFERER', reverse(settings.LOGIN_REDIRECT_URL))))
    next = request.POST.get('next', request.GET.get('next', post_action_redirect if post_action_redirect else request.META.get('HTTP_REFERER', reverse(settings.LOGIN_REDIRECT_URL))))

    if request.method == 'POST':
        try:
            folder.delete()
            messages.success(request, _('Folder: %s deleted successfully.') % folder)
        except Exception as exception:
            messages.error(request, _('Folder: %(folder)s delete error: %(error)s') % {
                'folder': folder, 'error': exception})

        return HttpResponseRedirect(next)

    context = {
        'delete_view': True,
        'previous': previous,
        'next': next,
        'object': folder,
        'title': _('Delete the folder: %s?') % folder,
    }

    return render_to_response('appearance/generic_confirm.html', context,
                              context_instance=RequestContext(request))


class FolderDetailView(DocumentListView):
    def get_folder(self):
        folder = get_object_or_404(Folder, pk=self.kwargs['pk'])

        try:
            Permission.check_permissions(
                self.request.user, (permission_folder_view,)
            )
        except PermissionDenied:
            AccessControlList.objects.check_access(
                permission_folder_view, self.request.user, folder
            )

        return folder

    def get_document_queryset(self):
        return self.get_folder().documents.all()

    def get_extra_context(self):
        return {
            'title': _('Documents in folder: %s') % self.get_folder(),
            'hide_links': True,
            'object': self.get_folder(),
        }


def folder_add_document(request, document_id=None, document_id_list=None):

    if document_id:
        documents = [get_object_or_404(Document, pk=document_id)]
    elif document_id_list:
        documents = [get_object_or_404(Document, pk=document_id) for document_id in document_id_list.split(',')]
    else:
        messages.error(request, _('Must provide at least one document.'))
        return HttpResponseRedirect(request.META.get('HTTP_REFERER', reverse(settings.LOGIN_REDIRECT_URL)))

    try:
        Permission.check_permissions(request.user, (permission_folder_add_document,))
    except PermissionDenied:
        documents = AccessControlList.objects.filter_by_access(permission_folder_add_document, request.user, documents)

    post_action_redirect = None
    previous = request.POST.get('previous', request.GET.get('previous', request.META.get('HTTP_REFERER', reverse(settings.LOGIN_REDIRECT_URL))))
    next = request.POST.get('next', request.GET.get('next', post_action_redirect if post_action_redirect else request.META.get('HTTP_REFERER', reverse(settings.LOGIN_REDIRECT_URL))))

    if request.method == 'POST':
        form = FolderListForm(request.POST, user=request.user)
        if form.is_valid():
            folder = form.cleaned_data['folder']
            for document in documents:
                if document.pk not in folder.documents.values_list('pk', flat=True):
                    folder.documents.add(document)
                    messages.success(request, _('Document: %(document)s added to folder: %(folder)s successfully.') % {
                        'document': document, 'folder': folder})
                else:
                    messages.warning(request, _('Document: %(document)s is already in folder: %(folder)s.') % {
                        'document': document, 'folder': folder})

            return HttpResponseRedirect(next)
    else:
        form = FolderListForm(user=request.user)

    context = {
        'form': form,
        'previous': previous,
        'next': next,
    }

    if len(documents) == 1:
        context['object'] = documents[0]

    context['title'] = ungettext(
        'Add document to folder',
        'Add documents to folder',
        len(documents)
    )

    return render_to_response('appearance/generic_form.html', context,
                              context_instance=RequestContext(request))


class DocumentFolderListView(FolderListView):
    def dispatch(self, request, *args, **kwargs):
        self.document = get_object_or_404(Document, pk=self.kwargs['pk'])

        try:
            Permission.check_permissions(
                request.user, (permission_document_view,)
            )
        except PermissionDenied:
            AccessControlList.objects.check_access(
                permission_document_view, request.user, self.document
            )

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

    def get_folder_queryset(self):
        return self.document.folders.all()

    def get_extra_context(self):
        return {
            'extra_columns': [
                {
                    'name': _('Documents'),
                    'attribute': encapsulate(
                        lambda instance: FolderListView.get_document_count(
                            instance=instance, user=self.request.user
                        )
                    )
                },
            ],
            'hide_link': True,
            'object': self.document,
            'title': _('Folders containing document: %s') % self.document,
        }


def folder_document_remove(request, folder_id, document_id=None, document_id_list=None):
    post_action_redirect = None

    folder = get_object_or_404(Folder, pk=folder_id)

    if document_id:
        folder_documents = [get_object_or_404(Document, pk=document_id)]
    elif document_id_list:
        folder_documents = [get_object_or_404(Document, pk=document_id) for document_id in document_id_list.split(',')]
    else:
        messages.error(request, _('Must provide at least one folder document.'))
        return HttpResponseRedirect(request.META.get('HTTP_REFERER', reverse(settings.LOGIN_REDIRECT_URL)))

    logger.debug('folder_documents (pre permission check): %s', folder_documents)
    try:
        Permission.check_permissions(request.user, (permission_folder_remove_document,))
    except PermissionDenied:
        folder_documents = AccessControlList.objects.filter_by_access(permission_folder_remove_document, request.user, folder_documents)

    logger.debug('folder_documents (post permission check): %s', folder_documents)

    previous = request.POST.get('previous', request.GET.get('previous', request.META.get('HTTP_REFERER', reverse(settings.LOGIN_REDIRECT_URL))))
    next = request.POST.get('next', request.GET.get('next', post_action_redirect if post_action_redirect else request.META.get('HTTP_REFERER', reverse(settings.LOGIN_REDIRECT_URL))))

    if request.method == 'POST':
        for folder_document in folder_documents:
            try:
                folder.documents.remove(folder_document)
                messages.success(request, _('Document: %s removed successfully.') % folder_document)
            except Exception as exception:
                messages.error(request, _('Document: %(document)s delete error: %(error)s') % {
                    'document': folder_document, 'error': exception})

        return HttpResponseRedirect(next)

    context = {
        'next': next,
        'object': folder,
        'previous': previous,
        'title': ungettext(
            'Remove the selected document from the folder: %(folder)s?',
            'Remove the selected documents from the folder: %(folder)s?',
            len(folder_documents)
        ) % {'folder': folder}
    }

    if len(folder_documents) == 1:
        context['object'] = folder_documents[0]

    return render_to_response('appearance/generic_confirm.html', context,
                              context_instance=RequestContext(request))


def folder_document_multiple_remove(request, folder_id):
    return folder_document_remove(request, folder_id, document_id_list=request.GET.get('id_list', []))


def folder_add_multiple_documents(request):
    return folder_add_document(
        request, document_id_list=request.GET.get('id_list', [])
    )