//SceneManager整理の整理案 by fuku 18/02/26(update 1)
//書いただけでテストしておりませんので、ご注意ください。
//Chromeが認識してくれなかったのでUTF-8に致します。

(function(){
const SMS_WAITCREATE=0;
const SMS_WAITSTART=1;
const SMS_ACTIVE=2;
const SMS_WAITTERMINATE=3;
const SMS_END=4;
SceneManager._state=SMS_WAITCREATE;

SceneManager.changeScene=function(){};

SceneManager.updateScene=function(){
	switch(this._state){
	case SMS_ACTIVE:
		if(!this.isSceneChanging()){
			this._scene.update();
			break;
		}
		this._scene.stop();
		this._state=SMS_WAITTERMINATE;
	case SMS_WAITTERMINATE:
		if(this.isCurrentSceneBusy()){
			this._scene.update();
			break;
		}
		this._scene.terminate();
		this._scene.detachReservation();
		this._previousClass=this._scene.constructor;
		if(this._exiting){
			this._scene=this._nextScene;
			this.terminate();
			this._state=SMS_END;
			break;
		}
		this._state=SMS_WAITCREATE;
	case SMS_WAITCREATE:
		if(!this.isSceneChanging())break;
		this._scene=this._nextScene;
		this._scene.attachReservation();
		this._scene.create();
		if(this._loadingQueue.length>0){
			this._nextScene=this._loadingQueue.shift();
		}
		else this._nextScene=null;
		this._sceneStarted=false;
		this.onSceneCreate();
		this._state=SMS_WAITSTART;
	case SMS_WAITSTART:
		if(!this._scene.isReady())break;
		this._scene.start();
		this._sceneStarted=true;
		this.onSceneStart();
		this._state=SMS_ACTIVE;
		
		this._scene.update();
	}
};


SceneManager._loadingQueue=[];
SceneManager.goto=function(sceneClass){
	if(sceneClass){
		if(!this._nextScene)this._nextScene=new sceneClass();
		else{
			this._loadingQueue.push(new sceneClass());
			console.log('warning:unusual scene transition');
			console.trace();
		}
	}
};

})();