var fs = require('fs');
var moment = require('moment');
var helper = require('../lib/helper');
var _ = require('lodash');

/*
 * parameters:
 *   dirname: string
 *   rotation: interger (ms)
 */
function log(dirname, opts) {

  opts = opts || {};
	this.dirname = dirname;
  this.rotation = opts.rotation || 15 * 60 * 1000;
  this.maxsize = opts.maxsize || 20000;
  this.currentsize = 0;
  this.timestamp = 0;
  this.foldername = 'log/';
  helper.mkdirIfNotExist(`${this.dirname}/${this.foldername}`);
};

/*
 * parameters:
 *   data: any
 */
log.prototype.append = function(data) {

  data = this.formatData(data);
  this.currentsize = this.currentsize + helper.getLengthOfContent(data);
  fs.appendFile(this.getDir(), data, function(err) {});
};

/*
 * parameters:
 *   none
 */
log.prototype.getDir = function() {

  var time = moment(Math.floor((+moment()) / this.rotation) * this.rotation);
  this.resetCurrentSize(time.unix());
  time = time.format('YYYY-MM-DDTHH-mm-ss');
  var count = this.getCount();
	return `${this.dirname}${this.foldername}${time}_${count}.txt`;
};

/*
 * parameters:
 *   time_unix: string
 */
log.prototype.resetCurrentSize = function(time_unix) {

  if(time_unix > this.timestamp) {
    this.currentsize = 0
    this.timestamp = time_unix;
  }
};

/*
 * parameters:
 *   none
 */
log.prototype.getCount = function() {

  var count = Math.floor((this.currentsize / this.maxsize) + 1);
  return ((count * 1e-5).toFixed(5)).split('.')[1];
};

/*
 * parameters:
 *   data: any
 */
log.prototype.formatData = function(data) {

  var date = moment().toISOString().trim();
  var timestamp = moment().unix();
  data = this._formatObject(data).trim();
  return `${date} ${timestamp} ${data}\r\n`;
};

/*
 * parameters:
 *   data: any
 */
log.prototype._formatObject = function(data) {

  if(_.isObject(data)) {
    return JSON.stringify(data);
  }
  if(_.isNumber(data)) {
    return toString(data);
  }
  return data;
};

module.exports = log;