var util = require('util');
var EventEmitter = require('events').EventEmitter;
var exec = require('child_process').exec

var IpPoll = function(switchaddr, hostsaddr) {
	var self = this;

	var regexp = /\(([0-9]+) hosts* up\)/;
	var nmap = "nmap -n -sP -T5 --host-timeout 10ms ";
		
	this.pollCount = function() {	
		exec(nmap + "--min-hostgroup 10 " + hostsaddr, function (error, stdout, stderr) {			
			if(error == null) {		
				var matches = regexp.exec(stdout);		
				if(matches != null && matches.length == 2) {
					self.emit('doneCount', parseInt(matches[1]));
				}
			}
		});	
	}
	
	this.pollState = function() {
		exec(nmap + switchaddr, function (error, stdout, stderr) {			
			if(error == null) {		
				var matches = regexp.exec(stdout);
				if(matches != null && matches.length == 2) {
					self.emit('doneState', matches[1] == "1");
				}
			} else {
				self.emit('doneState', "unknown");
			}
		});			
	}
}

util.inherits(IpPoll, EventEmitter);

module.exports = IpPoll;