+ @property
+ def is_deletable(self) -> bool:
+ """Decide whether self be deletable (not if preserve-worthy values)."""
+ if self.comment:
+ return False
+ if self.effort and self.effort >= 0:
+ return False
+ return True
+
+ @property
+ def performed_effort(self) -> float:
+ """Return performed effort, i.e. self.effort or default if done.."""
+ if self.effort is not None:
+ return self.effort
+ if self.is_done:
+ return self.effort_then
+ return 0
+
+ @property
+ def process_id(self) -> int | str | None:
+ """Needed for super().save to save Processes as attributes."""
+ return self.process.id_
+
+ @property
+ def is_done(self) -> bool:
+ """Wrapper around self._is_done so we can control its setter."""
+ return self._is_done
+
+ @is_done.setter
+ def is_done(self, value: bool) -> None:
+ if value != self.is_done and not self.is_doable:
+ raise BadFormatException('cannot change doneness of undoable Todo')
+ if self._is_done != value:
+ self._is_done = value
+ if value is True:
+ for condition in self.enables:
+ condition.is_active = True
+ for condition in self.disables:
+ condition.is_active = False
+
+ @property
+ def title(self) -> VersionedAttribute:
+ """Shortcut to .process.title."""
+ return self.process.title
+
+ @property
+ def title_then(self) -> str:
+ """Shortcut to .process.title.at(self.date)"""
+ title_then = self.process.title.at(self.date)
+ assert isinstance(title_then, str)
+ return title_then
+
+ @property
+ def effort_then(self) -> float:
+ """Shortcut to .process.effort.at(self.date)"""
+ effort_then = self.process.effort.at(self.date)
+ assert isinstance(effort_then, float)
+ return effort_then
+
+ @property
+ def has_doneness_in_path(self) -> bool:
+ """Check whether self is done or has any children that are."""
+ if self.is_done:
+ return True
+ for child in self.children:
+ if child.is_done:
+ return True
+ if child.has_doneness_in_path:
+ return True
+ return False
+
+ def get_step_tree(self, seen_todos: set[int]) -> TodoNode:
+ """Return tree of depended-on Todos."""
+
+ def make_node(todo: Todo) -> TodoNode:
+ children = []
+ seen = todo.id_ in seen_todos
+ assert isinstance(todo.id_, int)
+ seen_todos.add(todo.id_)
+ for child in todo.children:
+ children += [make_node(child)]
+ return TodoNode(todo, seen, children)
+
+ return make_node(self)
+
+ @property
+ def tree_effort(self) -> float:
+ """Return sum of performed efforts of self and all descendants."""
+
+ def walk_tree(node: Todo) -> float:
+ local_effort = 0.0
+ for child in node.children:
+ local_effort += walk_tree(child)
+ return node.performed_effort + local_effort
+
+ return walk_tree(self)
+