"use strict";var Buffer=require("safe-buffer").Buffer,isEncoding=Buffer.isEncoding||function(t){switch((t=""+t)&&t.toLowerCase()){case"hex":case"utf8":case"utf-8":case"ascii":case"binary":case"base64":case"ucs2":case"ucs-2":case"utf16le":case"utf-16le":case"raw":return!0;default:return!1}};function _normalizeEncoding(t){var e;if(!t)return"utf8";for(;;)switch(t){case"utf8":case"utf-8":return"utf8";case"ucs2":case"ucs-2":case"utf16le":case"utf-16le":return"utf16le";case"latin1":case"binary":return"latin1";case"base64":case"ascii":case"hex":return t;default:if(e)return;t=(""+t).toLowerCase(),e=!0}}function normalizeEncoding(t){var e=_normalizeEncoding(t);if("string"!=typeof e&&(Buffer.isEncoding===isEncoding||!isEncoding(t)))throw Error("Unknown encoding: "+t);return e||t}function StringDecoder(t){var e;switch(this.encoding=normalizeEncoding(t),this.encoding){case"utf16le":this.text=utf16Text,this.end=utf16End,e=4;break;case"utf8":this.fillLast=utf8FillLast,e=4;break;case"base64":this.text=base64Text,this.end=base64End,e=3;break;default:this.write=simpleWrite,this.end=simpleEnd;return}this.lastNeed=0,this.lastTotal=0,this.lastChar=Buffer.allocUnsafe(e)}function utf8CheckByte(t){return t<=127?0:t>>5==6?2:t>>4==14?3:t>>3==30?4:t>>6==2?-1:-2}function utf8CheckIncomplete(t,e,s){var i=e.length-1;if(i<s)return 0;var n=utf8CheckByte(e[i]);return n>=0?(n>0&&(t.lastNeed=n-1),n):--i<s||-2===n?0:(n=utf8CheckByte(e[i]))>=0?(n>0&&(t.lastNeed=n-2),n):--i<s||-2===n?0:(n=utf8CheckByte(e[i]))>=0?(n>0&&(2===n?n=0:t.lastNeed=n-3),n):0}function utf8CheckExtraBytes(t,e,s){if((192&e[0])!=128)return t.lastNeed=0,"�";if(t.lastNeed>1&&e.length>1){if((192&e[1])!=128)return t.lastNeed=1,"�";if(t.lastNeed>2&&e.length>2&&(192&e[2])!=128)return t.lastNeed=2,"�"}}function utf8FillLast(t){var e=this.lastTotal-this.lastNeed,s=utf8CheckExtraBytes(this,t,e);return void 0!==s?s:this.lastNeed<=t.length?(t.copy(this.lastChar,e,0,this.lastNeed),this.lastChar.toString(this.encoding,0,this.lastTotal)):void(t.copy(this.lastChar,e,0,t.length),this.lastNeed-=t.length)}function utf8Text(t,e){var s=utf8CheckIncomplete(this,t,e);if(!this.lastNeed)return t.toString("utf8",e);this.lastTotal=s;var i=t.length-(s-this.lastNeed);return t.copy(this.lastChar,0,i),t.toString("utf8",e,i)}function utf8End(t){var e=t&&t.length?this.write(t):"";return this.lastNeed?e+"�":e}function utf16Text(t,e){if((t.length-e)%2==0){var s=t.toString("utf16le",e);if(s){var i=s.charCodeAt(s.length-1);if(i>=55296&&i<=56319)return this.lastNeed=2,this.lastTotal=4,this.lastChar[0]=t[t.length-2],this.lastChar[1]=t[t.length-1],s.slice(0,-1)}return s}return this.lastNeed=1,this.lastTotal=2,this.lastChar[0]=t[t.length-1],t.toString("utf16le",e,t.length-1)}function utf16End(t){var e=t&&t.length?this.write(t):"";if(this.lastNeed){var s=this.lastTotal-this.lastNeed;return e+this.lastChar.toString("utf16le",0,s)}return e}function base64Text(t,e){var s=(t.length-e)%3;return 0===s?t.toString("base64",e):(this.lastNeed=3-s,this.lastTotal=3,1===s?this.lastChar[0]=t[t.length-1]:(this.lastChar[0]=t[t.length-2],this.lastChar[1]=t[t.length-1]),t.toString("base64",e,t.length-s))}function base64End(t){var e=t&&t.length?this.write(t):"";return this.lastNeed?e+this.lastChar.toString("base64",0,3-this.lastNeed):e}function simpleWrite(t){return t.toString(this.encoding)}function simpleEnd(t){return t&&t.length?this.write(t):""}exports.StringDecoder=StringDecoder,StringDecoder.prototype.write=function(t){var e,s;if(0===t.length)return"";if(this.lastNeed){if(void 0===(e=this.fillLast(t)))return"";s=this.lastNeed,this.lastNeed=0}else s=0;return s<t.length?e?e+this.text(t,s):this.text(t,s):e||""},StringDecoder.prototype.end=utf8End,StringDecoder.prototype.text=utf8Text,StringDecoder.prototype.fillLast=function(t){if(this.lastNeed<=t.length)return t.copy(this.lastChar,this.lastTotal-this.lastNeed,0,this.lastNeed),this.lastChar.toString(this.encoding,0,this.lastTotal);t.copy(this.lastChar,this.lastTotal-this.lastNeed,0,t.length),this.lastNeed-=t.length};