# Copyright (C) 2014-2016 Andrey Antukh <niwi@niwi.nz>
# Copyright (C) 2014-2016 Jesús Espino <jespinog@gmail.com>
# Copyright (C) 2014-2016 David Barragán <bameda@dbarragan.com>
# Copyright (C) 2014-2016 Alejandro Alonso <alejandro.alonso@kaleidos.net>
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU Affero General Public License as
# published by the Free Software Foundation, either version 3 of the
# License, or (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU Affero General Public License for more details.
#
# You should have received a copy of the GNU Affero General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.

import os.path as path
import mimetypes
mimetypes.init()

from django.utils.translation import ugettext as _
from django.contrib.contenttypes.models import ContentType

from taiga.base import filters
from taiga.base import exceptions as exc
from taiga.base.api import ModelCrudViewSet
from taiga.base.api.mixins import BlockedByProjectMixin
from taiga.base.api.utils import get_object_or_404

from taiga.projects.notifications.mixins import WatchedResourceMixin
from taiga.projects.history.mixins import HistoryResourceMixin

from . import permissions
from . import serializers
from . import models


class BaseAttachmentViewSet(HistoryResourceMixin, WatchedResourceMixin,
                            BlockedByProjectMixin, ModelCrudViewSet):

    model = models.Attachment
    serializer_class = serializers.AttachmentSerializer
    filter_fields = ["project", "object_id"]

    content_type = None

    def update(self, *args, **kwargs):
        partial = kwargs.get("partial", False)
        if not partial:
            raise exc.NotSupported(_("Partial updates are not supported"))
        return super().update(*args, **kwargs)

    def get_content_type(self):
        app_name, model = self.content_type.split(".", 1)
        return get_object_or_404(ContentType, app_label=app_name, model=model)

    def pre_save(self, obj):
        if not obj.id:
            obj.content_type = self.get_content_type()
            obj.owner = self.request.user
            obj.size = obj.attached_file.size
            obj.name = path.basename(obj.attached_file.name)

        if obj.project_id != obj.content_object.project_id:
            raise exc.WrongArguments(_("Project ID not matches between object and project"))

        super().pre_save(obj)

    def post_delete(self, obj):
        # NOTE: When destroy an attachment, the content_object change
        #       after and not before
        self.persist_history_snapshot(obj, delete=True)
        super().pre_delete(obj)

    def get_object_for_snapshot(self, obj):
        return obj.content_object


class UserStoryAttachmentViewSet(BaseAttachmentViewSet):
    permission_classes = (permissions.UserStoryAttachmentPermission,)
    filter_backends = (filters.CanViewUserStoryAttachmentFilterBackend,)
    content_type = "userstories.userstory"


class IssueAttachmentViewSet(BaseAttachmentViewSet):
    permission_classes = (permissions.IssueAttachmentPermission,)
    filter_backends = (filters.CanViewIssueAttachmentFilterBackend,)
    content_type = "issues.issue"


class TaskAttachmentViewSet(BaseAttachmentViewSet):
    permission_classes = (permissions.TaskAttachmentPermission,)
    filter_backends = (filters.CanViewTaskAttachmentFilterBackend,)
    content_type = "tasks.task"


class WikiAttachmentViewSet(BaseAttachmentViewSet):
    permission_classes = (permissions.WikiAttachmentPermission,)
    filter_backends = (filters.CanViewWikiAttachmentFilterBackend,)
    content_type = "wiki.wikipage"