package plist

import (
	"github.com/davecgh/go-spew/spew"
	"github.com/emirpasic/gods/utils"
)

// PriorityQueue 优先队列 适合数据量不大, 加索引
type PriorityQueue struct {
	data             []interface{}
	left, right, mid int
	cap              int
	size             int
	isSorted         bool
	comparator       utils.Comparator
}

// NewWithInt compare use int
func NewWithInt() *PriorityQueue {
	p := new(PriorityQueue)
	p.cap = 11
	p.mid = 5
	p.data = make([]interface{}, p.cap, p.cap)

	p.comparator = func(a, b interface{}) int {
		if a.(int) > b.(int) {
			return 1
		}
		return -1
	}
	return p
}

func (pq *PriorityQueue) String() string {

	return "(" + spew.Sprint(pq.data[pq.mid]) + "," + spew.Sprint(pq.size) + ")" + spew.Sprint(pq.Values())
}

func (pq *PriorityQueue) reMakeData() {
	var temp []interface{}

	if pq.cap <= 1024 {
		pq.cap = pq.cap*2 + 1
		temp = make([]interface{}, pq.cap, pq.cap)
	} else {
		pq.cap = pq.cap*5/8*2 + 1
		temp = make([]interface{}, pq.cap, pq.cap)
	}

	pq.mid = (pq.cap - 1) / 2
	left := pq.mid - pq.size/2

	copy(temp[left:], pq.data[pq.left:pq.right])

	pq.left = left
	pq.right = pq.left + pq.size

	pq.data = temp
}
func (pq *PriorityQueue) Push(v interface{}) {

	if pq.size == 0 {
		pq.data[pq.mid] = v
		pq.left = pq.mid
		pq.right = pq.mid + 1
		pq.size = 1
		return
	}

	midvalue := pq.data[pq.mid]
	if pq.comparator(v, midvalue) > 0 {
		if pq.left == 0 {
			pq.reMakeData()
		}

		pq.left--
		pq.data[pq.left] = v
	} else {

		if pq.right == pq.cap {
			pq.reMakeData()
		}

		pq.data[pq.right] = v
		pq.right++
	}

	pq.isSorted = false
	pq.size++
}

// func (pq *PriorityQueue) Top() (interface{}, bool) {
// 	return pq.Get(0)
// }

// func (pq *PriorityQueue) Bottom() (interface{}, bool) {
// 	return pq.Get(pq.right - 1)
// }

// func (pq *PriorityQueue) Get(index int) (interface{}, bool) {
// 	if index < pq.size {
// 		return pq.Values()[index], true
// 	}
// 	return nil, false
// }

func (pq *PriorityQueue) Values() []interface{} {
	values := pq.data[pq.left:pq.right]
	if !pq.isSorted {
		utils.Sort(values, pq.comparator)
		pq.isSorted = true
	}
	return values
}