var Event = Event || class Event { constructor(type){this.type=type} }
// eventoj lancilo = events launcher
var EventojLancilo = function( obj )
{
	obj = this instanceof EventojLancilo ? this : obj
	obj = obj instanceof Function ? obj.prototype : obj
	
	let has = {
		add: obj.addEventListener || obj.on
	,	rem: obj.removeEventListener || obj.off
	,	emit: obj.dispatchEvent || obj.emit || obj.fire || obj.fireEvent
	}
	// console.log(has)
	if( !has.add )
		obj[Symbol.Eventoj] = {}
	
	// obj.on = tplOrCall(add)		tpl?
	// obj.on('a',cb)				n	ok
	// obj.on('a',cb,opt)			n	ok
	// obj.on('a b',cb)				n	ok
	// obj.on(['a','b'],cb)			y	ko
	// obj.on(['a','b'],cb,opt)		n	ok
	// obj.on(['a','b','c'],cb,{})	y	ko
	// obj.on({a:cba,b:cb2,c:cb3})	n	ok
	
	// obj.on('a')(cb)				n	ko
	// obj.on(['a'])(cb)			y	ok
	
	// obj.on`a`(cb)				y	ok
	// obj.on`${str}change`(cb)		y	ok
	function tplOrCall( fn )
	{
		return function( ss, ...pp )
		{
			let isTpl = Array.isArray( ss ) && ss.every( o=> typeof o == 'string' ) && ss.length == pp.length + 1
			return isTpl
					? (...a)=> fn.bind(this)( String.merge(ss,...pp), ...a )
					: fn.bind(this)( ss, ...pp )
		}
	}
	// obj.on(['a','b'],cb,opt)
	// obj.on({a:cba,b:cb2,c:cb3},opt)
	// obj.on('a b',cb,opt)
	function multi( fn )
	{
		return ( ev, ...args )=>
			Array.isArray( ev )
				? ev.map( e=> fn(e,...args) )
			: typeof ev == 'object'
					? Object.keys( ev ).map( e=> fn(e,ev[e],...args) )
			: fn(ev,...args)
	}
	function on( event, handler, options )
	{
		let  evs = this[Symbol.Eventoj][event] = this[Symbol.Eventoj][event] || []
		!evs.includes( handler )
			&& evs.push( handler )
		return this
	}
	function one( event, handler, options )
	{
		return on( event, (...args)=> off(handler) && handler(...args) )
	}
	function off( event, handler )
	{
		let  evs = obj[Symbol.Eventoj][event] = obj[Symbol.Eventoj][event] || []
		evs.includes( handler )
			&& evs.splice( evs.indexOf(handler), 1 )
		return obj
	}
	function fire( event, ...args )
	{
		event = typeof event == 'string'
					? new Event( event )
					: event
		event.target = obj
		event.details = args
		event.type in obj[Symbol.Eventoj]
			&& obj[Symbol.Eventoj][event.type].map( h=> h.call(obj, event, ...args) )
		return event
	}
	Object.defineProperties( obj, {
		on: { value: tplOrCall(has.add ? has.add : on) }
	,	off: { value: tplOrCall(has.rem ? has.rem : off) }
	,	fire: { value: tplOrCall(has.emit ? has.emit : fire) }
	,	one: { value: tplOrCall(has.add ? has.add : one) }
	,	once: { value: tplOrCall(has.add ? has.add : one) }
	,	addEventListener: { value: tplOrCall(has.add ? has.add : on) }
	,	removeEventListener: { value: tplOrCall(has.rem ? has.rem : off) }
	,	dispatchEvent: { value: tplOrCall(has.emit ? has.emit : fire) }
	,	emit: { value: tplOrCall(has.emit ? has.emit : fire) }
	})
}
Symbol.Eventoj = Symbol`Eventoj`


export { Event, EventojLancilo }