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'use strict';
// based on https://github.com/bestiejs/punycode.js/blob/master/punycode.js
var maxInt = 2147483647; // aka. 0x7FFFFFFF or 2^31-1
var base = 36;
var tMin = 1;
var tMax = 26;
var skew = 38;
var damp = 700;
var initialBias = 72;
var initialN = 128; // 0x80
var delimiter = '-'; // '\x2D'
var regexNonASCII = /[^\0-\u007E]/; // non-ASCII chars
var regexSeparators = /[.\u3002\uFF0E\uFF61]/g; // RFC 3490 separators
var OVERFLOW_ERROR = 'Overflow: input needs wider integers to process';
var baseMinusTMin = base - tMin;
var floor = Math.floor;
var stringFromCharCode = String.fromCharCode;
/**
* Creates an array containing the numeric code points of each Unicode
* character in the string. While JavaScript uses UCS-2 internally,
* this function will convert a pair of surrogate halves (each of which
* UCS-2 exposes as separate characters) into a single code point,
* matching UTF-16.
*/
var ucs2decode = function (string) {
var output = [];
var counter = 0;
var length = string.length;
while (counter < length) {
var value = string.charCodeAt(counter++);
if (value >= 0xD800 && value <= 0xDBFF && counter < length) {
// It's a high surrogate, and there is a next character.
var extra = string.charCodeAt(counter++);
if ((extra & 0xFC00) == 0xDC00) { // Low surrogate.
output.push(((value & 0x3FF) << 10) + (extra & 0x3FF) + 0x10000);
} else {
// It's an unmatched surrogate; only append this code unit, in case the
// next code unit is the high surrogate of a surrogate pair.
output.push(value);
counter--;
}
} else {
output.push(value);
}
}
return output;
};
/**
* Converts a digit/integer into a basic code point.
*/
var digitToBasic = function (digit) {
// 0..25 map to ASCII a..z or A..Z
// 26..35 map to ASCII 0..9
return digit + 22 + 75 * (digit < 26);
};
/**
* Bias adaptation function as per section 3.4 of RFC 3492.
* https://tools.ietf.org/html/rfc3492#section-3.4
*/
var adapt = function (delta, numPoints, firstTime) {
var k = 0;
delta = firstTime ? floor(delta / damp) : delta >> 1;
delta += floor(delta / numPoints);
for (; delta > baseMinusTMin * tMax >> 1; k += base) {
delta = floor(delta / baseMinusTMin);
}
return floor(k + (baseMinusTMin + 1) * delta / (delta + skew));
};
/**
* Converts a string of Unicode symbols (e.g. a domain name label) to a
* Punycode string of ASCII-only symbols.
*/
// eslint-disable-next-line max-statements
var encode = function (input) {
var output = [];
// Convert the input in UCS-2 to an array of Unicode code points.
input = ucs2decode(input);
// Cache the length.
var inputLength = input.length;
// Initialize the state.
var n = initialN;
var delta = 0;
var bias = initialBias;
var i, currentValue;
// Handle the basic code points.
for (i = 0; i < input.length; i++) {
currentValue = input[i];
if (currentValue < 0x80) {
output.push(stringFromCharCode(currentValue));
}
}
var basicLength = output.length; // number of basic code points.
var handledCPCount = basicLength; // number of code points that have been handled;
// Finish the basic string with a delimiter unless it's empty.
if (basicLength) {
output.push(delimiter);
}
// Main encoding loop:
while (handledCPCount < inputLength) {
// All non-basic code points < n have been handled already. Find the next larger one:
var m = maxInt;
for (i = 0; i < input.length; i++) {
currentValue = input[i];
if (currentValue >= n && currentValue < m) {
m = currentValue;
}
}
// Increase `delta` enough to advance the decoder's <n,i> state to <m,0>, but guard against overflow.
var handledCPCountPlusOne = handledCPCount + 1;
if (m - n > floor((maxInt - delta) / handledCPCountPlusOne)) {
throw RangeError(OVERFLOW_ERROR);
}
delta += (m - n) * handledCPCountPlusOne;
n = m;
for (i = 0; i < input.length; i++) {
currentValue = input[i];
if (currentValue < n && ++delta > maxInt) {
throw RangeError(OVERFLOW_ERROR);
}
if (currentValue == n) {
// Represent delta as a generalized variable-length integer.
var q = delta;
for (var k = base; /* no condition */; k += base) {
var t = k <= bias ? tMin : (k >= bias + tMax ? tMax : k - bias);
if (q < t) break;
var qMinusT = q - t;
var baseMinusT = base - t;
output.push(stringFromCharCode(digitToBasic(t + qMinusT % baseMinusT)));
q = floor(qMinusT / baseMinusT);
}
output.push(stringFromCharCode(digitToBasic(q)));
bias = adapt(delta, handledCPCountPlusOne, handledCPCount == basicLength);
delta = 0;
++handledCPCount;
}
}
++delta;
++n;
}
return output.join('');
};
module.exports = function (input) {
var encoded = [];
var labels = input.toLowerCase().replace(regexSeparators, '\u002E').split('.');
var i, label;
for (i = 0; i < labels.length; i++) {
label = labels[i];
encoded.push(regexNonASCII.test(label) ? 'xn--' + encode(label) : label);
}
return encoded.join('.');
};