Added CLI command for moving top-level nodes between projects.

Also introduces a slightly nicer way to get the database interface, and
an object-oriented way to allow dependency injection.

pillar/api/nodes/moving.py

@@ -0,0 +1,110 @@
+"""Code for moving around nodes."""
+
+import attr
+import flask_pymongo.wrappers
+from bson import ObjectId
+
+from pillar import attrs_extra
+import pillar.api.file_storage.moving
+
+
+@attr.s
+class NodeMover(object):
+    db = attr.ib(validator=attr.validators.instance_of(flask_pymongo.wrappers.Database))
+    skip_gcs = attr.ib(default=False, validator=attr.validators.instance_of(bool))
+    _log = attrs_extra.log('%s.NodeMover' % __name__)
+
+    def change_project(self, node, dest_proj):
+        """Moves a node and children to a new project."""
+
+        assert isinstance(node, dict)
+        assert isinstance(dest_proj, dict)
+
+        for move_node in self._children(node):
+            self._change_project(move_node, dest_proj)
+
+    def _change_project(self, node, dest_proj):
+        """Changes the project of a single node, non-recursively."""
+
+        node_id = node['_id']
+        proj_id = dest_proj['_id']
+        self._log.info('Moving node %s to project %s', node_id, proj_id)
+
+        # Find all files in the node.
+        moved_files = set()
+        self._move_files(moved_files, dest_proj, self._files(node.get('picture', None)))
+        self._move_files(moved_files, dest_proj, self._files(node['properties'], 'file'))
+        self._move_files(moved_files, dest_proj, self._files(node['properties'], 'files', 'file'))
+        self._move_files(moved_files, dest_proj,
+                         self._files(node['properties'], 'attachments', 'files', 'file'))
+
+        # Switch the node's project after its files have been moved.
+        self._log.info('Switching node %s to project %s', node_id, proj_id)
+        nodes_coll = self.db['nodes']
+        update_result = nodes_coll.update_one({'_id': node_id},
+                                              {'$set': {'project': proj_id}})
+        if update_result.matched_count != 1:
+            raise RuntimeError(
+                'Unable to update node %s in MongoDB: matched_count=%i; modified_count=%i' % (
+                    node_id, update_result.matched_count, update_result.modified_count))
+
+    def _move_files(self, moved_files, dest_proj, file_generator):
+        """Tries to find all files from the given properties."""
+
+        for file_id in file_generator:
+            if file_id in moved_files:
+                continue
+            moved_files.add(file_id)
+            self.move_file(dest_proj, file_id)
+
+    def move_file(self, dest_proj, file_id):
+        """Moves a single file to another project"""
+
+        self._log.info('Moving file %s to project %s', file_id, dest_proj['_id'])
+        pillar.api.file_storage.moving.gcs_move_to_bucket(file_id, dest_proj['_id'],
+                                                          skip_gcs=self.skip_gcs)
+
+    def _files(self, file_ref, *properties):
+        """Yields file ObjectIDs."""
+
+        # Degenerate cases.
+        if not file_ref:
+            return
+
+        # Single ObjectID
+        if isinstance(file_ref, ObjectId):
+            assert not properties
+            yield file_ref
+            return
+
+        # List of ObjectIDs
+        if isinstance(file_ref, list):
+            for item in file_ref:
+                for subitem in self._files(item, *properties):
+                    yield subitem
+            return
+
+        # Dict, use properties[0] as key
+        if isinstance(file_ref, dict):
+            try:
+                subref = file_ref[properties[0]]
+            except KeyError:
+                # Silently skip non-existing keys.
+                return
+
+            for subitem in self._files(subref, *properties[1:]):
+                yield subitem
+            return
+
+        raise TypeError('File ref is of type %s, not implemented' % type(file_ref))
+
+    def _children(self, node):
+        """Generator, recursively yields the node and its children."""
+
+        yield node
+
+        nodes_coll = self.db['nodes']
+        for child in nodes_coll.find({'parent': node['_id']}):
+            # "yield from self.children(child)" was introduced in Python 3.3
+            for grandchild in self._children(child):
+                yield grandchild