import * as THREE from "../../libs/three.js/build/three.module.js";

export class ExtendEventDispatcher extends THREE.EventDispatcher {
	constructor () {
		super();
	}

    addEventListener(type, listener, importance=0){    //add importance
        if ( this._listeners === undefined ) this._listeners = {};
    
            const listeners = this._listeners;
    
            if ( listeners[ type ] === undefined ) {
    
                listeners[ type ] = [];
    
            }
    
            if ( !listeners[ type ].some(e=>e.listener == listener )  ) { 
                //listeners[ type ].push( listener );
                listeners[type].push({ listener,  importance});
                listeners[type] = listeners[type].sort((e,a)=> a.importance - e.importance)//add
            }
    }
    
    hasEventListener(type, listener){
        if ( this._listeners === undefined ) return false;
    
        const listeners = this._listeners;
    
        return listeners[ type ] !== undefined &&  listeners[ type ].some(e=>e.listener == listener )  
    }
    
    removeEventListener(type, listener){
        if ( this._listeners === undefined ) return;
    
        const listeners = this._listeners;
        const listenerArray = listeners[ type ];
    
        if ( listenerArray !== undefined ) {
    
            /* const index = listenerArray.indexOf( listener );
    
            if ( index !== - 1 ) {
    
                listenerArray.splice( index, 1 );
    
            } */
    
            let item = listenerArray.find(e=>e.listener == listener)
            item && listenerArray.splice(listenerArray.indexOf(item), 1);
    
        }
    }
    
    removeEventListeners(type){  //add
        if(this._listeners && this._listeners[type] !== undefined){
            delete this._listeners[type];
        }
    }
    
    removeAllListeners(){  //add
        this._listeners = {};
    }
    
    dispatchEvent(event){ 
        if(typeof event == 'string'){//add
                event = {type:event}
            }
            if ( this._listeners === undefined ) return;
    
            const listeners = this._listeners;
            const listenerArray = listeners[ event.type ];
    
            if ( listenerArray !== undefined ) {
    
                event.target = this;
    
                // Make a copy, in case listeners are removed while iterating.
                 
                for(let {listener} of listenerArray.slice(0)){
                    let result = listener.call(this, event);   //add stopContinue
                    if(result && result.stopContinue){
                        break
                    }
                }
    
            }
    }
    
    traverse(callback){ 
            let result = callback( this );
            if(result && result.stopContinue){//xzw add
                return 
            }
                 
            const children = this.children;
    
            for ( let i = 0, l = children.length; i < l; i ++ ) {
    
                children[ i ].traverse( callback );
    
            }
    }
    
};