/**
 *
 * EventEmitter
 * @description Events emitter and handler with pre-cached and timed emitters
 * @author Fernando Costa <ferco0@live.com>
 *
 */

interface IEventEmitter{
	listeners: any
	emitts: any[]

	emit(eventName: string, data: any): void
	timed(eventName: string, data, time: number): void
	registryListener(eventName: string, callback: ( data?: any) => void ): void
	on(eventName: string, callback: ( data?: any) => void , once: boolean): void
	once(eventName: string, callback: ( data?: any) => void ): void
	remove(eventName: string, callback: ( data?: any) => void ): void

}

/**
 * Class EventEmitter
 * @class
 */
class EventEmitter implements IEventEmitter{

	/**
	 * @description The events listeners
	 * @type {Object}  
	*/ 
	listeners: any = {}

	/**
	 * @description Cached emitts
	 * @type {array}  
	*/ 
	emitts: any[] = []

	/**
	 * @description Emit and cache for future listeners
	 * @param {stirng} eventName - The event indentifier 
	 * @param {mixin} data - Opitional data
	 * @return {void}
	 */
	emit(eventName: string, data: any = false): void {

		if(typeof this.emitts[eventName] === 'undefined')
			this.emitts[eventName] = []

		this.emitts[eventName].push(data);
		
		if(typeof this.listeners[eventName] !== 'undefined'){

			let listenersLength = this.listeners[eventName].length;
			let count = 0;

			for(; count < listenersLength; ++count){

				this.listeners[eventName][count].call(this, data );

			}

		}
	}

	/**
	 * @description Timed emitter
	 * @param {string} eventName - The event indentifier
	 * @param {mixin} data - Opitional data
	 * @param {number} time - The time of delay
	 * @return {void}  
	 */
	timed(eventName: string, data = false, time: number): void {

		let _this = this;

		setTimeout(function(){

			_this.emit(eventName, data);

		}, time)

	}

	/**
	 * @description Register listener
	 * @param {string} eventName - The event indentifier
	 * @param {callback} callback - The callback handler
	 * @return {void}  
	 */
	registryListener(eventName: string, callback: ( data?: any) => void ): void {

		if(typeof this.listeners[eventName] === 'undefined')
			this.listeners[eventName] = [];

		this.listeners[eventName].push( callback );

	}

	/**
	 * @description Register listener
	 * @param {string} eventName - The event indentifier
	 * @param {callback} callback - The callback handler
	 * @param {boolean} once - Check if is one-time execution
	 * @return {void}  
	 */
	on(eventName: string, callback: ( data?: any) => void , once: boolean = false): void {

		if(this.emitts.hasOwnProperty(eventName)){

			let length = this.emitts[eventName].length;
			let count = 0;

			for(; count < length; ++count){

				callback.call(this, this.emitts[eventName][count]);
				if(once) break;
			}

			if(!once) this.registryListener(eventName, callback);

		}
		else{

			this.registryListener(eventName, callback);

		}

	}

	/**
	 * @description One-time execution listener
	 * @param {string} eventName - The event indentifier
	 * @param {callback} callback - The callback handler
	 * @return {void}  
	 */
	once(eventName: string, callback: ( data?: any) => void ): void {

		this.on(eventName, function _once(data){

			callback.call(this, data);

			this.remove(eventName, _once);

		}, true)

	}

	/**
	 * @description Remove listener
	 * @param {string} eventName - The event indentifier
	 * @param {callback} callback - The callback handler
	 * @return {void}  
	 */
	remove(eventName: string, callback: ( data?: any) => void ): void {

		if(this.listeners.hasOwnProperty(eventName)){

			let index = this.listeners[eventName].indexOf( callback );

			if (index > -1) {
				this.listeners[eventName].splice(index, 1);
			}

		}

	}

}