var dispCbs = [];
var dispIns = [];

function Dispatcher(){
	dispIns.push(this);
	dispCbs.push({});
}
Dispatcher.prototype = {
	on(type, cb){
		let cbtypes = dispCbs[dispIns.indexOf(this)];
		let cbs = cbtypes[type] = (cbtypes[type] || []);
		if(!~cbs.indexOf(cb)){
			cbs.push(cb);
		}
	},
	off(type, cb){
		let cbtypes = dispCbs[dispIns.indexOf(this)];
		let cbs = cbtypes[type] = (cbtypes[type] || []);
		let curTypeCbIdx = cbs.indexOf(cb);
		if(~curTypeCbIdx){
			cbs.splice(curTypeCbIdx, 1);
		}
	},
	fire(type, ...args){
		let cbtypes = dispCbs[dispIns.indexOf(this)];
		let cbs = cbtypes[type] = (cbtypes[type] || []);
		for(let i = 0; i < cbs.length; i++){
			cbs[i].apply(null, args);
		}
	}
};
module.exports = Dispatcher;