index.js

var request = require('superagent');
var debug   = require('debug')('open-falcon');

function Falcon(options){
  if(!(this instanceof Falcon)){
    return new Falcon(options);
  }
  if(typeof options == 'string'){
    options = {
      api: options
    };
  }
  var self = this, defaults = {
    tags        : ''          ,
    step        : 60          ,
    value       : 0           ,
    endpoint    : 'localhost' ,
    counterType : 'GAUGE'     ,
    api         : 'http://127.0.0.1:1988/v1/push',
    timestamp   : function(){
      return Math.floor(+new Date() / 1000);
    },
  };
  //
  for(var key in options){
    defaults[ key ] = options[ key ];
  }
  //
  this.data    = {};
  this.queue   = [];
  this.options = defaults;
  return this;
}

Falcon.COUNTER_TYPE = {
  GAUGE  : 'GAUGE',
  COUNTER: 'COUNTER'
};

Falcon.prototype.use = function(middleware){
  middleware.apply(this, [ this ]);
  return this;
};

Falcon.prototype.set = function(key, value){
  this.data[ key ] = value;
  return this;
};

Falcon.prototype.metric = function(name, value){
  if(name){
    this.set('metric', name);
  }
  if(value){
    this.set('value', value);
  }
  return this;
};
/**
 * [function description]
 * @return {[type]} [description]
 */
Falcon.prototype.endpoint = function(value){
  this.set.apply(this, [ 'endpoint', value ]);
  return this;
};
/**
 * [function description]
 * @return {[type]} [description]
 */
Falcon.prototype.timestamp = function(value){
  this.set.apply(this, [ 'timestamp', value ]);
  return this;
};
/**
 * [function description]
 * @return {[type]} [description]
 */
Falcon.prototype.value = function(value){
  this.set.apply(this, [ 'value', value ]);
  return this;
};
/**
 * [function description]
 * @return {[type]} [description]
 */
Falcon.prototype.step = function(value){
  this.set.apply(this, [ 'step', value ]);
  return this;
};
/**
 * [function description]
 * @return {[type]} [description]
 */
Falcon.prototype.type = function(value){
  this.set.apply(this, [ 'counterType', value.toUpperCase() ]);
  return this;
};
/**
 * [function description]
 * @return {[type]} [description]
 */
Falcon.prototype.tags = function(tags){
  var arr = [];
  Object.keys(tags || {}).map(function(key){
    arr.push([ key, tags[key] ].join('='));
  });
  this.data[ 'tags' ] = arr.join(',');
  return this;
};

Falcon.prototype.end = function(){
  var self = this;
  ([
    'step'        ,
    'tags'        ,
    'value'       ,
    'metric'      ,
    'endpoint'    ,
    'timestamp'   ,
    'counterType'
  ]).map(function(key){
    if(
      typeof self.data[ key ]  == 'undefined' &&
      typeof self.options[key] == 'undefined'
    ) throw new Error( `'${key}' is required .`);
    //
    if(typeof self.data[key] == 'undefined'){
      if(typeof self.options[key] == 'function'){
        self.data[ key ] = self.options[key](self);
      }else if(typeof self.options[key] != 'undefined'){
        self.data[ key ] = self.options[key];
      }
    }
  });
  this.queue.push(this.data);
  this.data = {};
  return this;
}

/**
 * [function description]
 * @return {[type]} [description]
 */
Falcon.prototype.send = function(callback){
  var self = this;
  request
    .post(this.options.api)
    .send(this.queue)
    .end(function(){
      callback && callback.apply(self, arguments);
      self.queue = [];
    });
  return this;
};

module.exports = Falcon;