(in-package :cl-bodge.scene)

(defclass node (parent)

((name :initarg :name :initform nil :reader name-of)

(parent :initform nil)))

(defgeneric parent-of (node)

(:method ((child node))

(with-slots (parent) child

(unless (null parent)

(tg:weak-pointer-value parent)))))

(defgeneric node-attaching (this-node new-node)

(:method ((this node) (new node))

(when-let ((parent (parent-of this)))

(node-attaching parent new))))

(defgeneric node-detached (this-node removed-node)

(:method ((this node) (removed node))

(when-let ((parent (parent-of this)))

(node-detached parent removed))))

(defmethod adopt :before ((parent node) (child node))

(when-let ((prev-parent (parent-of child)))

(abandon parent child))

(with-slots ((child-parent parent)) child

(setf child-parent (tg:make-weak-pointer parent)))

(node-attaching parent child))

(defmethod abandon :after ((parent node) (child node))

(with-slots ((child-parent parent)) child

(setf child-parent nil))

(node-detached parent child))

(labels ((%find-nodes (root name)

(loop for child in (children-of root)

when (eq (name-of child) name) append (list child)

append (%find-nodes child name))))

(defun find-node (root name)

(let ((result (%find-nodes root name)))

(if (eq (name-of root) name)

(values root result)

(values (first result) (rest result))))))