using System.Collections.Generic;
using System.Collections;
using System;

public class BlackNode<K,V> 
	:TreeMapNode<K,V>
{
	
	public BlackNode (K key, V value, TreeMapNode<K, V> left, TreeMapNode<K, V> right)
		: base (key, value, left, right)
	{
	}

	public override rebuildNode<K,V> deleteNode ()
	{
		EmptyNode<K, V> emptyNode = new EmptyNode<K,V> (key);
		return new rebuildNode<K,V> (true, emptyNode);
	}

	public override int checkDepth (int count, int minCount)
	{ // test method
		count++;
		minCount = lefts ().checkDepth (count, minCount);
		minCount = rights ().checkDepth (count, minCount);
		return minCount;
	}

	public override bool isNotEmpty ()
	{
		return true;
	}

	public override TreeMapNode<K, V> createNode (K key, V value, TreeMapNode<K, V> left, TreeMapNode<K, V> right)
	{
		return new BlackNode<K,V> (key, value, left, right);
	}

	public override TreeMapNode<K, V> insBalance ()
	{
		Rotate spin = left.checkRotate (Rotate.L);

		if (spin == Rotate.R) {
			TreeMapNode<K, V> leftChild = new BlackNode<K,V> (left.lefts ().getKey (), left.lefts ().getValue (), left.lefts ().lefts (), left.lefts ().rights ());
			TreeMapNode<K, V> rightChild = new BlackNode<K,V> (getKey (), getValue (), left.rights (), right);
			return new RedNode<K,V> (left.getKey (), left.getValue (), leftChild, rightChild);

		} else if (spin == Rotate.LR) {
			TreeMapNode<K, V> leftChild = new BlackNode<K,V> (left.getKey (), left.getValue (), left.lefts (), left.rights ().lefts ());
			TreeMapNode<K, V> rightChild = new BlackNode<K,V> (getKey (), getValue (), left.rights ().rights (), right);
			return new RedNode<K,V> (left.rights ().getKey (), left.rights ().getValue (), leftChild, rightChild);

		}

		spin = right.checkRotate (Rotate.R);
		if (spin == Rotate.L) {
			TreeMapNode<K, V> leftChild = new BlackNode<K,V> (getKey (), getValue (), left, right.lefts ());
			TreeMapNode<K, V> rightChild = new BlackNode<K,V> (right.rights ().getKey (), right.rights ().getValue (), right.rights ().lefts (), right.rights ().rights ());
			return new RedNode<K,V> (right.getKey (), right.getValue (), leftChild, rightChild);

		} else if (spin == Rotate.RL) {
			TreeMapNode<K, V> leftChild = new BlackNode<K,V> (getKey (), getValue (), left, right.lefts ().lefts ());
			TreeMapNode<K, V> rightChild = new BlackNode<K,V> (right.getKey (), right.getValue (), right.lefts ().rights (), right.rights ());
			return new RedNode<K,V> (right.lefts ().getKey (), right.lefts ().getValue (), leftChild, rightChild);

		}

		return this;
	}

	public override Rotate checkRotate (Rotate side)
	{
		return Rotate.N;
	}

	public override bool isRed ()
	{
		return false;
	}

	public override rebuildNode<K,V> replaceNode (TreeMapNode<K, V> parent, Comparer<K> ctr)
	{
		TreeMapNode<K, V> newNode;
		if (!this.lefts ().isNotEmpty () && !this.rights ().isNotEmpty ()) { //自身を削除する
			return deleteNode ();//黒が1つ減るので木のバランスを取る
		} else if (this.lefts ().isNotEmpty () && !this.rights ().isNotEmpty ()) { //左の部分木を昇格させる
			newNode = createNode (lefts ().getKey (), lefts ().getValue (), lefts ().lefts (), lefts ().rights ());
			if (!this.lefts ().isRed ()) //昇格させる木のrootが黒だったらバランスを取る
				return new rebuildNode<K,V> (true, newNode);
			return new rebuildNode<K,V> (false, newNode);
		} else if (!this.lefts ().isNotEmpty () && this.rights ().isNotEmpty ()) { //右の部分木を昇格させる
			newNode = createNode (rights ().getKey (), rights ().getValue (), rights ().lefts (), rights ().rights ());
			if (!this.rights ().isRed ()) //昇格させる木のrootが黒だったらバランスを取る
				return new rebuildNode<K,V> (true, newNode);
			return new rebuildNode<K,V> (false, newNode);
		} else {//子ノードが左右にある場合 二回目はここには入らない
			//左の部分木の最大の値を持つNodeと自身を置き換える
			TreeMapNode<K, V> cur = this.lefts ();
			while (cur.rights ().isNotEmpty ()) { //左の部分期の最大値を持つNodeを取得する
				cur = cur.rights ();
			}
			if (this.lefts ().rights ().isNotEmpty ()) { //左の部分木が右の子を持っているか
				rebuildNode<K, V> leftSubTreeNodeRebuildNode = this.lefts ().deleteSubTreeMaxNode (null, ctr, Rotate.L);//最大値を削除した左の部分木を返す。rootはthisと同じ。
				if (leftSubTreeNodeRebuildNode.rebuilds ()) {
					TreeMapNode<K, V> leftSubTreeNode = leftSubTreeNodeRebuildNode.getNode ();
					TreeMapNode<K, V> newParent = createNode (cur.getKey (), cur.getValue (), leftSubTreeNode, this.rights ());
					return leftSubTreeNode.deleteBalance (newParent, ctr);
				}
				//same name onece used.
				TreeMapNode<K, V> leftSubTreeNodes = leftSubTreeNodeRebuildNode.getNode ();
				newNode = createNode (cur.getKey (), cur.getValue (), leftSubTreeNodes, this.rights ()); //rootをcurと入れ替えることでNodeの削除は完了する
				return new rebuildNode<K,V> (false, newNode);
			} else {
				rebuildNode<K, V> leftSubTreeNodeRebuildNode = this.lefts ().replaceNode (this, ctr);//右の子がいなかった場合、左の子を昇格させるだけで良い。
				if (leftSubTreeNodeRebuildNode.rebuilds ()) {
					TreeMapNode<K, V> node = leftSubTreeNodeRebuildNode.getNode ();
					TreeMapNode<K, V> newParent = createNode (this.lefts ().getKey (), this.lefts ().getValue (), node, this.rights ());
					return node.deleteBalance (newParent, ctr);
				}
				TreeMapNode<K,V> leftSubTreeNode = leftSubTreeNodeRebuildNode.getNode ();
				newNode = createNode (this.lefts ().getKey (), this.lefts ().getValue (), leftSubTreeNode, this.rights ());
				return new rebuildNode<K,V> (false, newNode);
			}
		}
	}
}