var async = require('../utils/async_extend.js');

var ServicesMonitor = function(options) {
  this.events = options.events;
  this.logger = options.logger;
  this.checkList = {};
  this.checkTimers = {};
  this.checkState = {};
};

ServicesMonitor.prototype.addCheck = function(name, checkFn, time) {
  this.logger.info('add check: ' + name);
  this.checkList[name] = {fn: checkFn, interval: time || 5000};
};

ServicesMonitor.prototype.stopCheck = function(name) {
  clearInterval(this.checkTimers[name]);
  delete this.checkTimers[name];
  delete this.checkList[name];
  delete this.checkState[name];
};

ServicesMonitor.prototype.startMonitor = function() {
  this.logger.info('startMonitor');
  var self = this;

  async.eachObject(this.checkList, function(checkName, check, callback) {
    self.events.on('check:' + checkName, function(obj) {
      self.checkState[checkName] = obj.name[obj.status];
      self.events.emit("servicesState", self.checkState);
    });

    if (check.interval !== 0) {
      self.checkTimers[checkName] = setInterval(function() {
        check.fn.call(check.fn, function(obj) {
          self.events.emit('check:' + checkName, obj);
        });
      }, check.interval);
    }

    check.fn.call(check.fn, function(obj) {
      self.events.emit('check:' + checkName, obj);
    });
    callback();
  }, function(err) {
    if (err) {
      self.logger.error("error running service check");
      self.logger.error(err.message);
    }
  });
};

module.exports = ServicesMonitor;