From 1ddd8525c7e977cd340fb3e0612472d326bbc891 Mon Sep 17 00:00:00 2001
From: Tobias Johansson <tobias@tobias-johansson.se>
Date: Fri, 21 Sep 2018 14:23:47 +0200
Subject: [PATCH] Remove references to node from projects when the node is
 deleted.

Removes node references  in project fields header_node, nodes_blog, nodes_featured, nodes_latest.
---
 pillar/api/nodes/eve_hooks.py | 43 +++++++++++++++++++++++++++-
 tests/test_api/test_nodes.py  | 54 +++++++++++++++++++++++++++++++++++
 2 files changed, 96 insertions(+), 1 deletion(-)

diff --git a/pillar/api/nodes/eve_hooks.py b/pillar/api/nodes/eve_hooks.py
index d179fa81..a11f434a 100644
--- a/pillar/api/nodes/eve_hooks.py
+++ b/pillar/api/nodes/eve_hooks.py
@@ -1,14 +1,17 @@
+import collections
 import functools
 import logging
 import urllib.parse
+
 from bson import ObjectId
-from flask import current_app
 from werkzeug import exceptions as wz_exceptions
 
+from pillar import current_app
 import pillar.markdown
 from pillar.api.activities import activity_subscribe, activity_object_add
 from pillar.api.file_storage_backends.gcs import update_file_name
 from pillar.api.node_types import PILLAR_NAMED_NODE_TYPES
+from pillar.api.utils import random_etag
 from pillar.api.utils.authorization import check_permissions
 
 log = logging.getLogger(__name__)
@@ -243,6 +246,44 @@ def nodes_set_default_picture(nodes):
 
 def before_deleting_node(node: dict):
     check_permissions('nodes', node, 'DELETE')
+    remove_project_references(node)
+
+
+def remove_project_references(node):
+    project_id = node.get('project')
+    if not project_id:
+        return
+
+    node_id = node['_id']
+    log.info('Removing references to node %s from project %s', node_id, project_id)
+
+    projects_col = current_app.db('projects')
+    project = projects_col.find_one({'_id': project_id})
+    updates = collections.defaultdict(dict)
+
+    if project.get('header_node') == node_id:
+        updates['$unset']['header_node'] = node_id
+
+    project_reference_lists = ('nodes_blog', 'nodes_featured', 'nodes_latest')
+    for list_name in project_reference_lists:
+        references = project.get(list_name)
+        if not references:
+            continue
+        try:
+            references.remove(node_id)
+        except ValueError:
+            continue
+
+        updates['$set'][list_name] = references
+
+    if not updates:
+        return
+
+    updates['$set']['_etag'] = random_etag()
+    result = projects_col.update_one({'_id': project_id}, updates)
+    if result.modified_count != 1:
+        log.warning('Removing references to node %s from project %s resulted in %d modified documents (expected 1)',
+                    node_id, project_id, result.modified_count)
 
 
 def after_deleting_node(item):
diff --git a/tests/test_api/test_nodes.py b/tests/test_api/test_nodes.py
index 420f95e9..4acf70e8 100644
--- a/tests/test_api/test_nodes.py
+++ b/tests/test_api/test_nodes.py
@@ -1,3 +1,4 @@
+import copy
 import json
 import typing
 from unittest import mock
@@ -633,3 +634,56 @@ class TaggedNodesTest(AbstractPillarTest):
             resp = do_query()
             for node in resp:
                 self.assertNotIn('view_progress', node)
+
+
+class NodesReferencedByProjectTest(AbstractPillarTest):
+    def setUp(self, **kwargs):
+        super().setUp(**kwargs)
+        node = copy.deepcopy(ctd.EXAMPLE_NODE)
+        self.pid, self.project = self.ensure_project_exists(
+            project_overrides={'picture_header':None,
+                               'picture_square': None}
+        )
+        self.create_valid_auth_token(ctd.EXAMPLE_PROJECT_OWNER_ID, 'token')
+
+        node['project'] = self.pid
+        self.node_id = self.create_node(node)
+        self.node_etag = node['_etag']
+
+        with self.app.app_context():
+            self.app.db('projects').update(
+                {'_id': self.pid},
+                {'$set': {
+                    'header_node': self.node_id,
+                    'nodes_blog': [self.node_id],
+                    'nodes_featured': [self.node_id],
+                    'nodes_latest': [self.node_id],
+                }}
+            )
+
+    def test_delete_node(self):
+        with self.app.app_context():
+            self.delete(f'/api/nodes/{self.node_id}',
+                        auth_token='token',
+                        headers={'If-Match': self.node_etag},
+                        expected_status=204)
+
+            node_after = self.app.db('nodes').find_one(self.node_id)
+            self.assertTrue(node_after.get('_deleted'))
+
+            project_after = self.app.db('projects').find_one(self.pid)
+            self.assertIsNone(project_after.get('header_node'))
+            self.assertNotEqual(self.project['_etag'], project_after['_etag'])
+            self.assertNotIn(self.node_id, project_after['nodes_blog'])
+            self.assertNotIn(self.node_id, project_after['nodes_featured'])
+            self.assertNotIn(self.node_id, project_after['nodes_latest'])
+
+        # Verifying that the project is still valid
+        from pillar.api.utils import remove_private_keys
+        self.put(f'/api/projects/{self.pid}', json=remove_private_keys(project_after),
+                 etag=project_after['_etag'],
+                 auth_token='token')
+
+
+
+