'use strict';
  
  var ESCAPES = [
  	'\u001b',
  	'\u009b'
  ];
  
  var END_CODE = 39;
  
  var ESCAPE_CODES = {
  	0: 0,
  	1: 22,
  	2: 22,
  	3: 23,
  	4: 24,
  	7: 27,
  	8: 28,
  	9: 29,
  	30: 39,
  	31: 39,
  	32: 39,
  	33: 39,
  	34: 39,
  	35: 39,
  	36: 39,
  	37: 39,
  	90: 39,
  	40: 49,
  	41: 49,
  	42: 49,
  	43: 49,
  	44: 49,
  	45: 49,
  	46: 49,
  	47: 49
  };
  
  function wrapAnsi(code) {
  	return ESCAPES[0] + '[' + code + 'm';
  }
  
  module.exports = function (str, begin, end) {
  	end = end || str.length;
  	var insideEscape = false;
  	var escapeCode;
  	var visible = 0;
  	var output = '';
  
  	for (var i = 0; i < str.length; i++) {
  		var leftEscape = false;
  		var x = str[i];
  
  		if (ESCAPES.indexOf(x) !== -1) {
  			insideEscape = true;
  			var code = /[0-9][^m]*/.exec(str.slice(i, i + 4));
  			escapeCode = code === END_CODE ? null : code;
  		} else if (insideEscape && x === 'm') {
  			insideEscape = false;
  			leftEscape = true;
  		}
  
  		if (!insideEscape && !leftEscape) {
  			++visible;
  		}
  
  		if (visible > begin && visible <= end) {
  			output += x;
  		} else if (visible === begin && escapeCode !== undefined && escapeCode !== END_CODE) {
  			output += wrapAnsi(escapeCode);
  		} else if (visible >= end) {
  			if (escapeCode !== undefined) {
  				output += wrapAnsi(ESCAPE_CODES[escapeCode] || END_CODE);
  			}
  			break;
  		}
  	}
  
  	return output;
  };