#[derive(Clone)]
pub struct NTreeNode<T>
{
    value: T,
    children: Vec<NTreeNode<T>>

}

#[derive(Default, Clone)]
pub struct NTree<T>
{
    root: Option<NTreeNode<T>>
}

impl<T> NTree<T>
{
    pub fn set_root_val(
        &mut self,
        val: T)
    {
        self.root = Some(NTreeNode { value: val, children: vec![] });
    }

    pub fn set_root(
        &mut self,
        node: NTreeNode<T>)
    {
        self.root = Some(node);
    }

    pub fn root(&self) -> &Option<NTreeNode<T>> { &self.root }
    pub fn root_mut(&mut self) -> &mut Option<NTreeNode<T>> { &mut self.root }
}

impl<T> NTreeNode<T>
{
    pub fn new(val: T)
    -> Self
    {
        Self {
            value: val,
            children: vec![]
        }
    }
    
    pub fn value(&self) -> &T { &self.value }
    pub fn value_mut(&mut self) -> &mut T { &mut self.value }

    pub fn children(&self) -> &[NTreeNode<T>] { &self.children.as_slice() }

    pub fn as_tree(self)
    -> NTree<T> 
    {
        NTree { root: Some(self) }
    }

    pub fn insert_value(
        &mut self,
        val: T)
    {
        self.children.push(NTreeNode { value: val, children: vec![] });
    }

    pub fn insert_node(
        &mut self,
        subtree: NTreeNode<T>)
    {
        self.children.push(subtree);
    }

    pub fn insert_tree(
        &mut self,
        subtree: NTree<T>)
    {
        match subtree.root {
            Some(subtree_root) => self.insert_node(subtree_root),
            None => { panic!("Tried to put null subtree") }
        }
    }
}