package tower

import (
	"f1-game/internal/algorithm/aoi"
	"math"

	clog "github.com/cherry-game/cherry/logger"
)

type (
	Config struct {
		Width          int32 // 地图宽(x)
		Height         int32 // 地图高(y)
		TowerWidth     int32 // 灯塔宽(x)
		TowerHeight    int32 // 灯塔高(y)
		TowerOffset    int32 // 灯塔宽高偏移值
		RangeLimit     int32 // 观察者视野
		PrintTowerInfo bool  // 初始化时,是否打印Tower的信息
	}

	AOI struct {
		aoi.EventBase
		config    Config                     // config
		towerNumX int32                      // x轴的灯塔数量
		towerNumY int32                      // y轴的灯塔数量
		towers    map[int32]map[int32]*Tower // 灯塔列表 key:灯塔y, value:{key:灯塔x, value:*Tower}
		objects   aoi.Objects                // 所有对象 key:ObjectID, value:*aoi.Object
	}
)

// 实现一个灯塔的aoi算法，对象分为观察者和被观察者， 对象可以 “进入”、“离开”、 “移动”、“属性更新”四个动作，
// 当上层业务触发这些动作时，过滤出要广播的对象，并进行函数回调。
// 1、观察者的动作主要是移动屏幕时同步灯塔相关的被观察者。
// 2、被观察会进行移动、属性更新的触发操作，这时需要通知观察者。
// 3、观察者“进入”时，触发回调函数，下发被观察者的对象列表。
// 4、观察者移动屏幕时，触发新的灯塔被观察者对象。如果没有移动出当前灯塔，被观察者对象也不用再重复下发广播了。之前已经同步过的被观察者无需再同步，
// 除非被观察者有触发新的移动和属性更新。
// 5、被观察者中途改变了寻路列表，则再次广播给灯塔相关的观察者。 当被观察者触发更新属性动作时，也通知灯塔相关的观察者。

func New(config Config) aoi.AOI {
	towerAOI := &AOI{
		EventBase: aoi.EventBase{},
		config:    config,
		towers:    make(map[int32]map[int32]*Tower),
		objects:   aoi.Objects{},
	}
	towerAOI.init()

	return towerAOI
}

func (p *AOI) init() {
	if p.config.Width < 1 || p.config.Height < 1 {
		clog.Panicf("Config params error. %v", p)
	}

	if p.config.TowerWidth < 1 /*|| p.config.TowerWidth > p.config.Width*/ {
		clog.Panicf("Config params error. %v", p)
	}

	if p.config.TowerHeight < 1 /*|| p.config.TowerHeight > p.config.Height*/ {
		clog.Panicf("Config params error. %v", p)
	}

	if p.config.TowerOffset < 0 || p.config.RangeLimit < 1 {
		clog.Panicf("Config params error. %v", p)
	}

	p.towerNumX = int32(math.Ceil(float64(p.config.Width) / float64(p.config.TowerWidth)))
	p.towerNumY = int32(math.Ceil(float64(p.config.Height) / float64(p.config.TowerHeight)))

	towerID := int32(0)
	for x := range p.towerNumX {
		p.towers[x] = make(map[int32]*Tower)
		for y := range p.towerNumY {
			p.towers[x][y] = p.newTower(towerID, x, y)
			towerID++
		}
	}
}

func (p *AOI) Get(objectID int64) *aoi.Object {
	return p.objects.Get(objectID)
}

func (p *AOI) Enter(object *aoi.Object) bool {
	if !p.CheckPoint(object.Point.X, object.Point.Y) {
		clog.Warnf("[Enter] check point error. %s", object.Info())
		return false
	}

	if p.objects.Contains(object.ObjectID) {
		clog.Warnf("[Enter] object has entered. %s", object.Info())
		return false
	}

	if object.IsWatcher() {
		towers := p.GetRangeTowers(object.Point.X, object.Point.Y)
		if len(towers) < 1 {
			clog.Warnf("[Enter] get tower fail. %s", object.Info())
			return false
		}

		p.objects.Add(object)

		// 获取相关范围的tower，并把观察者加入到观察列表
		for _, tower := range towers {
			tower.AddWatcher(object)
		}

		if p.WatcherEnterFunc != nil {
			markers := towers.MakersFilter(object)
			if !markers.IsEmpty() {
				p.WatcherEnterFunc(object, markers)
			}
		}
	}

	if object.IsMarker() {
		tower := p.GetTowerByPoint(object.Point.X, object.Point.Y)
		if tower == nil {
			clog.Warnf("[Enter] get tower fail. %s", object.Info())
			return false
		}

		// add object
		p.objects.Add(object)

		tower.AddMarker(object)

		if p.MarkerEnterFunc != nil {
			if !tower.watchers.IsEmpty() {
				p.MarkerEnterFunc(object, tower.watchers)
			}
		}
	}

	return true
}

func (p *AOI) Move(objectID int64, x, y int32) bool {
	object := p.objects.Get(objectID)
	if object == nil {
		return false
	}

	if object.Point.X == x && object.Point.Y == y {
		return false
	}

	if !p.CheckPoint(x, y) {
		clog.Warnf("[Move] check point error. %s", object.Info())
		return false
	}

	// old tower point
	oldTower := p.GetTowerByPoint(object.Point.X, object.Point.Y)
	if oldTower == nil {
		clog.Warnf("[Move] old tower not found. %s", object.Info())
		return false
	}

	// new tower point
	newTower := p.GetTowerByPoint(x, y)
	if newTower == nil {
		clog.Warnf("[Move] new tower not found. %s", object.Info())
		return false
	}

	var (
		oldX = object.Point.X
		oldY = object.Point.Y
	)

	// 先把对象设置到新的位置
	object.SetPoint(x, y)

	// 移动时,如果object没有改变tower，则不进行对象同步
	if oldTower.id == newTower.id {
		return false
	}

	if object.IsWatcher() {
		// 获取需要添加观察者、需要删除观察者的towers
		addTowers, delTowers := p.GetDiffTowers(oldX, oldY, x, y)

		// object作为观察者加入tower列表
		for _, dt := range addTowers {
			dt.AddWatcher(object)
		}

		// object从旧的tower列表移除
		for _, dt := range delTowers {
			dt.DelWatcher(object)
		}

		if p.WatcherMoveFunc != nil {
			markers := addTowers.MakersFilter(object)
			if !markers.IsEmpty() {
				p.WatcherMoveFunc(object, markers) // , delTowers.Watchers()
			}
		}
	}

	if object.IsMarker() {
		oldTower.DelMarker(object)
		newTower.AddMarker(object)

		// 如果对象是移动的第一个路点，则需要同步对象给观察者列表
		if p.MarkerMoveFunc != nil && !newTower.watchers.IsEmpty() {
			p.MarkerMoveFunc(object, newTower.watchers)
		}
	}

	return true
}

func (p *AOI) Leave(objectID int64) {
	object := p.objects.Get(objectID)
	if object == nil {
		clog.Debugf("[Leave] objectID = %d not found.", objectID)
		return
	}

	// remove object
	p.objects.Remove(objectID)

	tower := p.GetTowerByPoint(object.Point.X, object.Point.Y)
	if tower == nil {
		return
	}

	if object.IsWatcher() {
		rangeTowers := p.GetRangeTowers(object.Point.X, object.Point.Y)
		for _, ranteTower := range rangeTowers {
			ranteTower.DelWatcher(object)
		}

		// TODO trigger watcher leave func ?
	}

	if object.IsMarker() {
		tower.DelMarker(object)

		if p.MarkerLeaveFunc != nil && !tower.watchers.IsEmpty() {
			p.MarkerLeaveFunc(object, tower.watchers)
		}
	}

	// object clean
	object.Clean()
}

func (p *AOI) Update(objectID int64, updateID uint32, funcName string) {
	object := p.objects.Get(objectID)
	if object == nil {
		clog.Debugf("[Update] objectID = %d not found.", objectID)
		return
	}

	if object.IsWatcher() {
		return
	}

	thisTower := p.GetTowerByPoint(object.Point.X, object.Point.Y)
	if thisTower == nil {
		clog.Warnf("[Update] objectID = {%s}, tower not found. %s", object.Info())
		return
	}

	watchers := aoi.Objects{}
	for _, watcher := range thisTower.watchers {
		watchers.Add(watcher)
	}

	if p.MarkerUpdateFunc != nil {
		p.MarkerUpdateFunc(object, watchers, updateID, funcName)
	}
}

func (p *AOI) newTower(id, tx, ty int32) *Tower {
	var (
		minX = tx*p.config.TowerWidth - p.config.TowerOffset
		minY = ty*p.config.TowerHeight - p.config.TowerOffset
		maxX = minX + p.config.TowerWidth
		maxY = minY + p.config.TowerHeight
	)

	if p.config.PrintTowerInfo {
		clog.Infof("id = %d, min(X = %d, Y = %d), max(X = %d, Y = %d)", id, minX, minY, maxX, maxY)
	}

	return &Tower{
		id:       id,
		markers:  aoi.Objects{},
		watchers: aoi.Objects{},
		minX:     minX,
		minY:     minY,
		maxX:     maxX,
		maxY:     maxY,
	}
}

// CheckPoint 坐标是否合法
func (p *AOI) CheckPoint(x, y int32) bool {
	return x >= 0 && y >= 0 && x < p.config.Width && y < p.config.Height
}

func (p *AOI) InArea(x, y int32, sx, sy, ex, ey int32) bool {
	return x >= sx && x <= ex && y >= sy && y <= ey
}

// ToTowerPoint 场景坐标切换为灯塔坐标
func (p *AOI) ToTowerPoint(x, y int32) (tx int32, ty int32) {
	tx = x / p.config.TowerWidth
	ty = y / p.config.TowerHeight
	return
}

// GetTower 根据对象的场景坐标获取灯塔
func (p *AOI) GetTower(tx, ty int32) *Tower {
	if tower, found := p.towers[tx][ty]; found {
		return tower
	}

	return nil
}

func (p *AOI) GetTowerByPoint(x, y int32) *Tower {
	tx, ty := p.ToTowerPoint(x, y)
	return p.GetTower(tx, ty)
}

func (p *AOI) GetDiffTowers(ox, oy, nx, ny int32) (addTowers Towers, delTowers Towers) {
	oldTowers := p.GetRangeTowers(ox, oy)
	newTowers := p.GetRangeTowers(nx, ny)

	oldIDSet := oldTowers.IDSet()
	for _, newTower := range newTowers {
		if !oldIDSet.Contains(newTower.id) {
			addTowers = append(addTowers, newTower)
		}
	}

	newIDSet := newTowers.IDSet()
	for _, oldTower := range oldTowers {
		if !newIDSet.Contains(oldTower.id) {
			delTowers = append(delTowers, oldTower)
		}
	}

	return
}

func (p *AOI) GetRangeTowers(x, y int32) Towers {
	var list Towers

	tx, ty := p.ToTowerPoint(x, y)
	sx, sy, ex, ey := p.GetRangeTowerPoint(tx, ty)
	for x := sx; x <= ex; x++ {
		for y := sy; y <= ey; y++ {
			if rangeTower := p.GetTower(x, y); rangeTower != nil {
				list = append(list, rangeTower)
			}
		}
	}

	return list
}

func (p *AOI) GetRangeTowerPoint(tx, ty int32) (sx, sy, ex, ey int32) {
	sx = tx - p.config.RangeLimit
	ex = tx + p.config.RangeLimit
	sy = ty - p.config.RangeLimit
	ey = ty + p.config.RangeLimit

	if sx < 0 {
		sx = 0
	}

	if sy < 0 {
		sy = 0
	}

	if ex > p.towerNumX {
		ex = p.towerNumX
	}

	if ey > p.towerNumY {
		ey = p.towerNumY
	}

	return sx, sy, ex, ey
}