from __future__ import absolute_import, unicode_literals

from django.http import HttpResponse
from django.shortcuts import get_object_or_404
from django.views.decorators.cache import cache_control, patch_cache_control

from rest_framework import generics

from mayan.apps.acls.models import AccessControlList
from mayan.apps.documents.models import Document, DocumentType
from mayan.apps.documents.permissions import permission_document_type_view
from mayan.apps.rest_api.filters import MayanObjectPermissionsFilter
from mayan.apps.rest_api.permissions import MayanPermission

from .literals import CONTROL_SHEET_CODE_IMAGE_TASK_TIMEOUT
from .models import ControlSheet
#from .permissions import (
#    permission_workflow_create, permission_workflow_delete,
#    permission_workflow_edit, permission_workflow_view
#)
from .serializers import (
    ControlSheetSerializer, ControlSheetCodeSerializer
)

from .settings import settings_control_sheet_code_image_cache_time
from .tasks import task_generate_control_sheet_code_image


class APIControlSheetListView(generics.ListCreateAPIView):
    """
    get: Returns a list of all the control sheets.
    post: Create a new control sheet.
    """
    filter_backends = (MayanObjectPermissionsFilter,)
    #mayan_object_permissions = {'GET': (permission_control_sheet_view,)}
    #mayan_view_permissions = {'POST': (permission_control_sheet_create,)}
    permission_classes = (MayanPermission,)
    queryset = ControlSheet.objects.all()
    serializer_class = ControlSheetSerializer

    def get_serializer(self, *args, **kwargs):
        if not self.request:
            return None

        return super(APIControlSheetListView, self).get_serializer(
            *args, **kwargs
        )

    #def get_serializer_class(self):
    #    if self.request.method == 'GET':
    #        return ControlSheetSerializer
    #    else:
    #        return WritableControlSheetSerializer


class APIControlSheetView(generics.RetrieveUpdateDestroyAPIView):
    """
    delete: Delete the selected control sheet.
    get: Return the details of the selected control sheet.
    patch: Edit the selected control sheet.
    put: Edit the selected control sheet.
    """
    filter_backends = (MayanObjectPermissionsFilter,)
    #mayan_object_permissions = {
    #    'DELETE': (permission_control sheet_delete,),
    #    'GET': (permission_control sheet_view,),
    #    'PATCH': (permission_control sheet_edit,),
    #    'PUT': (permission_control sheet_edit,)
    #}
    lookup_url_kwarg = 'control_sheet_id'
    queryset = ControlSheet.objects.all()
    serializer_class = ControlSheetSerializer

    def get_serializer(self, *args, **kwargs):
        if not self.request:
            return None

        return super(APIControlSheetView, self).get_serializer(
            *args, **kwargs
        )

    #def get_serializer_class(self):
    #   if self.request.method == 'GET':
    #        return ControlSheetSerializer
    #    else:
    #        return WritableControlSheetSerializer



class APIControlSheetCodeListView(generics.ListCreateAPIView):
    """
    get: Returns a list of all the control sheet codes.
    post: Create a new control sheet code.
    """
    serializer_class = ControlSheetCodeSerializer

    def get_queryset(self):
        return self.get_control_sheet().codes.all()

    def get_serializer_context(self):
        """
        Extra context provided to the serializer class.
        """
        context = super(APIControlSheetCodeListView, self).get_serializer_context()
        if self.kwargs:
            context.update(
                {
                    'control_sheet': self.get_control_sheet(),
                }
            )

        return context

    def get_control_sheet(self):
        #if self.request.method == 'GET':
        #    permission_required = permission_control_sheet_view
        #else:
        #    permission_required = permission_control_sheet_edit

        control_sheet = get_object_or_404(
            klass=ControlSheet, pk=self.kwargs['control_sheet_id']
        )

        #AccessControlList.objects.check_access(
        #    obj=control_sheet, permissions=(permission_required,),
        #    user=self.request.user
        #)

        return control_sheet


class APIControlSheetCodeView(generics.RetrieveUpdateDestroyAPIView):
    """
    delete: Delete the selected control sheet code.
    get: Return the details of the selected control sheet code.
    patch: Edit the selected control sheet code.
    put: Edit the selected control sheet code.
    """
    lookup_url_kwarg = 'control_sheet_code_id'
    serializer_class = ControlSheetCodeSerializer

    def get_queryset(self):
        return self.get_control_sheet().codes.all()

    def get_serializer_context(self):
        """
        Extra context provided to the serializer class.
        """
        context = super(APIControlSheetCodeView, self).get_serializer_context()
        if self.kwargs:
            context.update(
                {
                    'control_sheet': self.get_control_sheet(),
                }
            )

        return context

    def get_control_sheet(self):
        #if self.request.method == 'GET':
        #    permission_required = permission_control_sheet_view
        #else:
        #   permission_required = permission_control_sheet_edit

        control_sheet = get_object_or_404(
            klass=ControlSheet, pk=self.kwargs['control_sheet_id']
        )

        #AccessControlList.objects.check_access(
        #    obj=control_sheet, permissions=(permission_required,),
        #   user=self.request.user
        #)

        return control_sheet


class APIControlSheetCodeImageView(generics.RetrieveAPIView):
    """
    get: Returns an image representation of the selected control_sheet.
    """
    filter_backends = (MayanObjectPermissionsFilter,)
    #mayan_object_permissions = {
    #    'GET': (permission_control_sheet_view,),
    #}
    lookup_url_kwarg = 'control_sheet_code_id'
    #queryset = ControlSheetCode.objects.all()

    def get_queryset(self):
        return self.get_control_sheet().codes.all()

    def get_control_sheet(self):
        #if self.request.method == 'GET':
        #    permission_required = permission_control_sheet_view
        #else:
        #   permission_required = permission_control_sheet_edit

        control_sheet = get_object_or_404(
            klass=ControlSheet, pk=self.kwargs['control_sheet_id']
        )

        #AccessControlList.objects.check_access(
        #    obj=control_sheet, permissions=(permission_required,),
        #   user=self.request.user
        #)

        return control_sheet

    def get_serializer(self, *args, **kwargs):
        return None

    def get_serializer_class(self):
        return None

    @cache_control(private=True)
    def retrieve(self, request, *args, **kwargs):
        task = task_generate_control_sheet_code_image.apply_async(
            kwargs=dict(
                control_sheet_code_id=self.get_object().pk,
            )
        )

        cache_filename = task.get(timeout=CONTROL_SHEET_CODE_IMAGE_TASK_TIMEOUT)
        cache_file = self.get_object().cache_partition.get_file(filename=cache_filename)
        with cache_file.open() as file_object:
            response = HttpResponse(file_object.read(), content_type='image')
            if '_hash' in request.GET:
                patch_cache_control(
                    response,
                    max_age=settings_control_sheet_image_cache_time.value
                )
            return response