from django.contrib.auth.mixins import LoginRequiredMixin
from django.http import HttpResponse
from django.template.defaultfilters import slugify
from django.views.decorators.csrf import csrf_exempt
from django.views.generic import FormView, DetailView

from rest_framework.mixins import (
    RetrieveModelMixin, UpdateModelMixin, DestroyModelMixin, ListModelMixin)
from rest_framework.pagination import PageNumberPagination
from rest_framework.permissions import IsAuthenticated
from rest_framework.viewsets import (
    ModelViewSet, ReadOnlyModelViewSet, GenericViewSet)

from paperless.db import GnuPG

from .forms import UploadForm
from .models import Sender, Tag, Document, Log
from .serialisers import (
    SenderSerializer, TagSerializer, DocumentSerializer, LogSerializer)


class FetchView(LoginRequiredMixin, DetailView):

    model = Document

    def render_to_response(self, context, **response_kwargs):
        """
        Override the default to return the unencrypted PDF as raw data.
        """

        content_types = {
            Document.TYPE_PDF: "application/pdf",
            Document.TYPE_PNG: "image/png",
            Document.TYPE_JPG: "image/jpeg",
            Document.TYPE_GIF: "image/gif",
            Document.TYPE_TIF: "image/tiff",
        }

        response = HttpResponse(
            GnuPG.decrypted(self.object.source_file),
            content_type=content_types[self.object.file_type]
        )
        response["Content-Disposition"] = 'attachment; filename="{}"'.format(
            slugify(str(self.object)) + "." + self.object.file_type)

        return response


class PushView(LoginRequiredMixin, FormView):
    """
    A crude REST-ish API for creating documents.
    """

    form_class = UploadForm

    @classmethod
    def as_view(cls, **kwargs):
        return csrf_exempt(FormView.as_view(**kwargs))

    def form_valid(self, form):
        return HttpResponse("1")

    def form_invalid(self, form):
        return HttpResponse("0")


class StandardPagination(PageNumberPagination):
    page_size = 25
    page_size_query_param = "page-size"
    max_page_size = 100000


class SenderViewSet(ModelViewSet):
    model = Sender
    queryset = Sender.objects.all()
    serializer_class = SenderSerializer
    pagination_class = StandardPagination
    permission_classes = (IsAuthenticated,)


class TagViewSet(ModelViewSet):
    model = Tag
    queryset = Tag.objects.all()
    serializer_class = TagSerializer
    pagination_class = StandardPagination
    permission_classes = (IsAuthenticated,)


class DocumentViewSet(RetrieveModelMixin,
                      UpdateModelMixin,
                      DestroyModelMixin,
                      ListModelMixin,
                      GenericViewSet):
    model = Document
    queryset = Document.objects.all()
    serializer_class = DocumentSerializer
    pagination_class = StandardPagination
    permission_classes = (IsAuthenticated,)


class LogViewSet(ReadOnlyModelViewSet):
    model = Log
    queryset = Log.objects.all().by_group()
    serializer_class = LogSerializer
    pagination_class = StandardPagination
    permission_classes = (IsAuthenticated,)