package hashmap

import (
	"474420502.top/eson/structure/compare"
	"github.com/davecgh/go-spew/spew"
)

type avlNode struct {
	children   [2]*avlNode
	parent     *avlNode
	height     int
	key, value interface{}
}

type avlTree struct {
	root    *avlNode
	size    int
	Compare compare.Compare
}

func avlNew(Compare compare.Compare) *avlTree {
	return &avlTree{Compare: Compare}
}

func (tree *avlTree) Clear() {
	tree.size = 0
	tree.root = nil
}

func (tree *avlTree) Size() int {
	return tree.size
}

func (tree *avlTree) Remove(key interface{}) (interface{}, bool) {

	if n, ok := tree.GetNode(key); ok {

		tree.size--
		if tree.size == 0 {
			tree.root = nil
			return n.value, true
		}

		left := getHeight(n.children[0])
		right := getHeight(n.children[1])

		if left == -1 && right == -1 {
			p := n.parent
			p.children[getRelationship(n)] = nil
			tree.fixRemoveHeight(p)
			return n.value, true
		}

		var cur *avlNode
		if left > right {
			cur = n.children[0]
			for cur.children[1] != nil {
				cur = cur.children[1]
			}

			cleft := cur.children[0]
			cur.parent.children[getRelationship(cur)] = cleft
			if cleft != nil {
				cleft.parent = cur.parent
			}

		} else {
			cur = n.children[1]
			for cur.children[0] != nil {
				cur = cur.children[0]
			}

			cright := cur.children[1]
			cur.parent.children[getRelationship(cur)] = cright

			if cright != nil {
				cright.parent = cur.parent
			}
		}

		cparent := cur.parent
		// 修改为interface 交换
		n.value, cur.value = cur.value, n.value
		n.key, cur.key = cur.key, n.key

		// 考虑到刚好替换的节点是 被替换节点的孩子节点的时候, 从自身修复高度
		if cparent == n {
			tree.fixRemoveHeight(n)
		} else {
			tree.fixRemoveHeight(cparent)
		}

		return cur.value, true
	}

	return nil, false
}

func (tree *avlTree) Get(key interface{}) (interface{}, bool) {
	n, ok := tree.GetNode(key)
	if ok {
		return n.value, true
	}
	return n, false
}

func (tree *avlTree) GetNode(key interface{}) (*avlNode, bool) {

	for n := tree.root; n != nil; {
		switch c := tree.Compare(key, n.key); c {
		case -1:
			n = n.children[0]
		case 1:
			n = n.children[1]
		case 0:
			return n, true
		default:
			panic("Get Compare only is allowed in -1, 0, 1")
		}
	}
	return nil, false
}

func (tree *avlTree) PutNode(pnode *avlNode) bool {

	pnode.height = 0
	pnode.children[0] = nil
	pnode.children[1] = nil
	// pnode.parent = nil

	if tree.size == 0 {
		tree.size++
		tree.root = pnode
		pnode.parent = nil
		return true
	}

	for cur, c := tree.root, 0; ; {
		c = tree.Compare(pnode.key, cur.key)
		if c == -1 {
			if cur.children[0] == nil {
				tree.size++
				cur.children[0] = pnode
				cur.children[0].parent = cur
				if cur.height == 0 {
					tree.fixPutHeight(cur)
				}
				return true
			}
			cur = cur.children[0]
		} else if c == 1 {
			if cur.children[1] == nil {
				tree.size++
				cur.children[1] = pnode
				cur.children[1].parent = cur
				if cur.height == 0 {
					tree.fixPutHeight(cur)
				}
				return true
			}
			cur = cur.children[1]
		} else {
			cur.key = pnode.key
			cur.value = pnode.value
			return false
		}
	}
}

func (tree *avlTree) Put(key, value interface{}) bool {

	if tree.size == 0 {
		tree.size++
		tree.root = &avlNode{key: key, value: value}
		return true
	}

	for cur, c := tree.root, 0; ; {
		c = tree.Compare(key, cur.key)
		if c == -1 {
			if cur.children[0] == nil {
				tree.size++
				cur.children[0] = &avlNode{key: key, value: value}
				cur.children[0].parent = cur
				if cur.height == 0 {
					tree.fixPutHeight(cur)
				}
				return true
			}
			cur = cur.children[0]
		} else if c == 1 {
			if cur.children[1] == nil {
				tree.size++
				cur.children[1] = &avlNode{key: key, value: value}
				cur.children[1].parent = cur
				if cur.height == 0 {
					tree.fixPutHeight(cur)
				}
				return true
			}
			cur = cur.children[1]
		} else {
			cur.key = key
			cur.value = value
			return false
		}
	}
}

type TraversalMethod int

const (
	// L = left R = right D = Value(dest)
	_ TraversalMethod = iota
	//DLR 先值 然后左递归 右递归 下面同理
	DLR
	//LDR 先从左边有序访问到右边 从小到大
	LDR
	// LRD 同理
	LRD
	// DRL 同理
	DRL
	// RDL 先从右边有序访问到左边 从大到小
	RDL
	// RLD 同理
	RLD
)

// Traversal 遍历的方法 默认是LDR 从小到大 Compare 为 l < r
func (tree *avlTree) Traversal(every func(node *avlNode) bool, traversalMethod ...interface{}) {
	if tree.root == nil {
		return
	}

	method := LDR
	if len(traversalMethod) != 0 {
		method = traversalMethod[0].(TraversalMethod)
	}

	switch method {
	case DLR:
		var traverasl func(cur *avlNode) bool
		traverasl = func(cur *avlNode) bool {
			if cur == nil {
				return true
			}
			if !every(cur) {
				return false
			}
			if !traverasl(cur.children[0]) {
				return false
			}
			if !traverasl(cur.children[1]) {
				return false
			}
			return true
		}
		traverasl(tree.root)
	case LDR:
		var traverasl func(cur *avlNode) bool
		traverasl = func(cur *avlNode) bool {
			if cur == nil {
				return true
			}
			if !traverasl(cur.children[0]) {
				return false
			}
			if !every(cur) {
				return false
			}
			if !traverasl(cur.children[1]) {
				return false
			}
			return true
		}
		traverasl(tree.root)
	case LRD:
		var traverasl func(cur *avlNode) bool
		traverasl = func(cur *avlNode) bool {
			if cur == nil {
				return true
			}
			if !traverasl(cur.children[0]) {
				return false
			}
			if !traverasl(cur.children[1]) {
				return false
			}
			if !every(cur) {
				return false
			}
			return true
		}
		traverasl(tree.root)
	case DRL:
		var traverasl func(cur *avlNode) bool
		traverasl = func(cur *avlNode) bool {
			if cur == nil {
				return true
			}
			if !every(cur) {
				return false
			}
			if !traverasl(cur.children[0]) {
				return false
			}
			if !traverasl(cur.children[1]) {
				return false
			}
			return true
		}
		traverasl(tree.root)
	case RDL:
		var traverasl func(cur *avlNode) bool
		traverasl = func(cur *avlNode) bool {
			if cur == nil {
				return true
			}
			if !traverasl(cur.children[1]) {
				return false
			}
			if !every(cur) {
				return false
			}
			if !traverasl(cur.children[0]) {
				return false
			}
			return true
		}
		traverasl(tree.root)
	case RLD:
		var traverasl func(cur *avlNode) bool
		traverasl = func(cur *avlNode) bool {
			if cur == nil {
				return true
			}
			if !traverasl(cur.children[1]) {
				return false
			}
			if !traverasl(cur.children[0]) {
				return false
			}
			if !every(cur) {
				return false
			}
			return true
		}
		traverasl(tree.root)
	}
}

func (tree *avlTree) lrrotate(cur *avlNode) {

	const l = 1
	const r = 0

	movparent := cur.children[l]
	mov := movparent.children[r]

	mov.value, cur.value = cur.value, mov.value //交换值达到, 相对位移
	mov.key, cur.key = cur.key, mov.key

	if mov.children[l] != nil {
		movparent.children[r] = mov.children[l]
		movparent.children[r].parent = movparent
		//movparent.children[r].child = l
	} else {
		movparent.children[r] = nil
	}

	if mov.children[r] != nil {
		mov.children[l] = mov.children[r]
		//mov.children[l].child = l
	} else {
		mov.children[l] = nil
	}

	if cur.children[r] != nil {
		mov.children[r] = cur.children[r]
		mov.children[r].parent = mov
	} else {
		mov.children[r] = nil
	}

	cur.children[r] = mov
	mov.parent = cur

	mov.height = getMaxChildrenHeight(mov) + 1
	movparent.height = getMaxChildrenHeight(movparent) + 1
	cur.height = getMaxChildrenHeight(cur) + 1
}

func (tree *avlTree) rlrotate(cur *avlNode) {

	const l = 0
	const r = 1

	movparent := cur.children[l]
	mov := movparent.children[r]

	mov.value, cur.value = cur.value, mov.value //交换值达到, 相对位移
	mov.key, cur.key = cur.key, mov.key

	if mov.children[l] != nil {
		movparent.children[r] = mov.children[l]
		movparent.children[r].parent = movparent
	} else {
		movparent.children[r] = nil
	}

	if mov.children[r] != nil {
		mov.children[l] = mov.children[r]
	} else {
		mov.children[l] = nil
	}

	if cur.children[r] != nil {
		mov.children[r] = cur.children[r]
		mov.children[r].parent = mov
	} else {
		mov.children[r] = nil
	}

	cur.children[r] = mov
	mov.parent = cur

	mov.height = getMaxChildrenHeight(mov) + 1
	movparent.height = getMaxChildrenHeight(movparent) + 1
	cur.height = getMaxChildrenHeight(cur) + 1
}

func (tree *avlTree) rrotate(cur *avlNode) {

	const l = 0
	const r = 1
	// 1 right 0 left
	mov := cur.children[l]

	mov.value, cur.value = cur.value, mov.value //交换值达到, 相对位移
	mov.key, cur.key = cur.key, mov.key

	//  mov.children[l]不可能为nil
	mov.children[l].parent = cur
	cur.children[l] = mov.children[l]

	// 解决mov节点孩子转移的问题
	if mov.children[r] != nil {
		mov.children[l] = mov.children[r]
	} else {
		mov.children[l] = nil
	}

	if cur.children[r] != nil {
		mov.children[r] = cur.children[r]
		mov.children[r].parent = mov
	} else {
		mov.children[r] = nil
	}

	// 连接转移后的节点 由于mov只是与cur交换值,parent不变
	cur.children[r] = mov

	mov.height = getMaxChildrenHeight(mov) + 1
	cur.height = getMaxChildrenHeight(cur) + 1
}

func (tree *avlTree) lrotate(cur *avlNode) {

	const l = 1
	const r = 0

	mov := cur.children[l]

	mov.value, cur.value = cur.value, mov.value //交换值达到, 相对位移
	mov.key, cur.key = cur.key, mov.key

	// 不可能为nil
	mov.children[l].parent = cur
	cur.children[l] = mov.children[l]

	if mov.children[r] != nil {
		mov.children[l] = mov.children[r]
	} else {
		mov.children[l] = nil
	}

	if cur.children[r] != nil {
		mov.children[r] = cur.children[r]
		mov.children[r].parent = mov
	} else {
		mov.children[r] = nil
	}

	cur.children[r] = mov

	mov.height = getMaxChildrenHeight(mov) + 1
	cur.height = getMaxChildrenHeight(cur) + 1
}

func getMaxAndChildrenHeight(cur *avlNode) (h1, h2, maxh int) {
	h1 = getHeight(cur.children[0])
	h2 = getHeight(cur.children[1])
	if h1 > h2 {
		maxh = h1
	} else {
		maxh = h2
	}

	return
}

func getMaxChildrenHeight(cur *avlNode) int {
	h1 := getHeight(cur.children[0])
	h2 := getHeight(cur.children[1])
	if h1 > h2 {
		return h1
	}
	return h2
}

func getHeight(cur *avlNode) int {
	if cur == nil {
		return -1
	}
	return cur.height
}

func (tree *avlTree) fixRemoveHeight(cur *avlNode) {
	for {

		lefth, rigthh, lrmax := getMaxAndChildrenHeight(cur)

		// 判断当前节点是否有变化, 如果没变化的时候, 不需要往上修复
		curheight := lrmax + 1
		cur.height = curheight

		// 计算高度的差值 绝对值大于2的时候需要旋转
		diff := lefth - rigthh
		if diff < -1 {
			r := cur.children[1] // 根据左旋转的右边节点的子节点 左右高度选择旋转的方式
			if getHeight(r.children[0]) > getHeight(r.children[1]) {
				tree.lrrotate(cur)
			} else {
				tree.lrotate(cur)
			}
		} else if diff > 1 {
			l := cur.children[0]
			if getHeight(l.children[1]) > getHeight(l.children[0]) {
				tree.rlrotate(cur)
			} else {
				tree.rrotate(cur)
			}
		} else {
			if cur.height == curheight {
				return
			}
		}

		if cur.parent == nil {
			return
		}

		cur = cur.parent
	}

}

func (tree *avlTree) fixPutHeight(cur *avlNode) {

	for {

		lefth := getHeight(cur.children[0])
		rigthh := getHeight(cur.children[1])

		// 计算高度的差值 绝对值大于2的时候需要旋转
		diff := lefth - rigthh
		if diff < -1 {
			r := cur.children[1] // 根据左旋转的右边节点的子节点 左右高度选择旋转的方式
			if getHeight(r.children[0]) > getHeight(r.children[1]) {
				tree.lrrotate(cur)
			} else {
				tree.lrotate(cur)
			}
		} else if diff > 1 {
			l := cur.children[0]
			if getHeight(l.children[1]) > getHeight(l.children[0]) {
				tree.rlrotate(cur)
			} else {
				tree.rrotate(cur)
			}

		} else {
			// 选择一个child的最大高度 + 1为 高度
			if lefth > rigthh {
				cur.height = lefth + 1
			} else {
				cur.height = rigthh + 1
			}
		}

		if cur.parent == nil || cur.height < cur.parent.height {
			return
		}
		cur = cur.parent
	}
}

func getRelationship(cur *avlNode) int {
	if cur.parent.children[1] == cur {
		return 1
	}
	return 0
}

func output(node *avlNode, prefix string, isTail bool, str *string) {

	if node.children[1] != nil {
		newPrefix := prefix
		if isTail {
			newPrefix += "│   "
		} else {
			newPrefix += "    "
		}
		output(node.children[1], newPrefix, false, str)
	}
	*str += prefix
	if isTail {
		*str += "└── "
	} else {
		*str += "┌── "
	}

	*str += spew.Sprint(node.value) + "\n"

	if node.children[0] != nil {
		newPrefix := prefix
		if isTail {
			newPrefix += "    "
		} else {
			newPrefix += "│   "
		}
		output(node.children[0], newPrefix, true, str)
	}

}

func outputfordebug(node *avlNode, prefix string, isTail bool, str *string) {

	if node.children[1] != nil {
		newPrefix := prefix
		if isTail {
			newPrefix += "│   "
		} else {
			newPrefix += "    "
		}
		outputfordebug(node.children[1], newPrefix, false, str)
	}
	*str += prefix
	if isTail {
		*str += "└── "
	} else {
		*str += "┌── "
	}

	suffix := "("
	parentv := ""
	if node.parent == nil {
		parentv = "nil"
	} else {
		parentv = spew.Sprint(node.parent.value)
	}
	suffix += parentv + "|" + spew.Sprint(node.height) + ")"
	*str += spew.Sprint(node.value) + suffix + "\n"

	if node.children[0] != nil {
		newPrefix := prefix
		if isTail {
			newPrefix += "    "
		} else {
			newPrefix += "│   "
		}
		outputfordebug(node.children[0], newPrefix, true, str)
	}
}

func (tree *avlTree) debugString() string {
	if tree.size == 0 {
		return ""
	}
	str := "AVLTree\n"
	outputfordebug(tree.root, "", true, &str)
	return str
}