exports.format_date = function (date, friendly) {
  var year = date.getFullYear();
  var month = date.getMonth() + 1;
  var day = date.getDate();
  var hour = date.getHours();
  var minute = date.getMinutes();
  var second = date.getSeconds();
  
  if (friendly) {
    var now = new Date();
    var mseconds = -(date.getTime() - now.getTime());
    var time_std = [ 1000, 60 * 1000, 60 * 60 * 1000, 24 * 60 * 60 * 1000 ];
    if (mseconds < time_std[3]) {
      if (mseconds > 0 && mseconds < time_std[1]) {
        return Math.floor(mseconds / time_std[0]).toString() + ' 秒前';
      }
      if (mseconds > time_std[1] && mseconds < time_std[2]) {
        return Math.floor(mseconds / time_std[1]).toString() + ' 分钟前';
      }
      if (mseconds > time_std[2]) {
        return Math.floor(mseconds / time_std[2]).toString() + ' 小时前';
      }
    }
  }
  
  //month = ((month < 10) ? '0' : '') + month;
  //day = ((day < 10) ? '0' : '') + day;
  hour = ((hour < 10) ? '0' : '') + hour;
  minute = ((minute < 10) ? '0' : '') + minute;
  second = ((second < 10) ? '0': '') + second;

  thisYear = new Date().getFullYear();
  year = (thisYear === year) ? '' : (year + '-');
  return year + month + '-' + day + ' ' + hour + ':' + minute;
};

/**
 * Escape the given string of `html`.
 *
 * @param {String} html
 * @return {String}
 * @api private
 */

exports.escape = function(html){
  var codeReg = /(^|[^\\])(`+)([^\r]*?[^`])\2(?!`)/gm;
  var codes = [];
  return String(html).replace(/\r\n/g, '\n')
  .replace(codeReg, function(code) {
    codes.push(code);
    return '`uc`';
  })
  .replace(/&(?!\w+;)/g, '&amp;')
  .replace(/</g, '&lt;')
  .replace(/>/g, '&gt;')
  .replace(/"/g, '&quot;')
  .replace(/`uc`/g, function() {
    return codes.shift();
  });
};