'use strict';

/** Highest positive signed 32-bit float value */ const maxInt = 2147483647; // aka. 0x7FFFFFFF or 2^31-1

/** Bootstring parameters */ const base = 36; const tMin = 1; const tMax = 26; const skew = 38; const damp = 700; const initialBias = 72; const initialN = 128; // 0x80 const delimiter = '-'; // 'x2D'

/** Regular expressions */ const regexPunycode = /^xn–/; const regexNonASCII = /[^0-x7E]/; // non-ASCII chars const regexSeparators = /[x2Eu3002uFF0EuFF61]/g; // RFC 3490 separators

/** Error messages */ const errors = {

'overflow': 'Overflow: input needs wider integers to process',
'not-basic': 'Illegal input >= 0x80 (not a basic code point)',
'invalid-input': 'Invalid input'

};

/** Convenience shortcuts */ const baseMinusTMin = base - tMin; const floor = Math.floor; const stringFromCharCode = String.fromCharCode;

/————————————————————————–/

/**

* A generic error utility function.
* @private
* @param {String} type The error type.
* @returns {Error} Throws a `RangeError` with the applicable error message.
*/

function error(type) {

throw new RangeError(errors[type]);

}

/**

* A generic `Array#map` utility function.
* @private
* @param {Array} array The array to iterate over.
* @param {Function} callback The function that gets called for every array
* item.
* @returns {Array} A new array of values returned by the callback function.
*/

function map(array, fn) {

const result = [];
let length = array.length;
while (length--) {
        result[length] = fn(array[length]);
}
return result;

}

/**

* A simple `Array#map`-like wrapper to work with domain name strings or email
* addresses.
* @private
* @param {String} domain The domain name or email address.
* @param {Function} callback The function that gets called for every
* character.
* @returns {Array} A new string of characters returned by the callback
* function.
*/

function mapDomain(string, fn) {

const parts = string.split('@');
let result = '';
if (parts.length > 1) {
        // In email addresses, only the domain name should be punycoded. Leave
        // the local part (i.e. everything up to `@`) intact.
        result = parts[0] + '@';
        string = parts[1];
}
// Avoid `split(regex)` for IE8 compatibility. See #17.
string = string.replace(regexSeparators, '\x2E');
const labels = string.split('.');
const encoded = map(labels, fn).join('.');
return result + encoded;

}

/**

* 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.
* @see `punycode.ucs2.encode`
* @see <https://mathiasbynens.be/notes/javascript-encoding>
* @memberOf punycode.ucs2
* @name decode
* @param {String} string The Unicode input string (UCS-2).
* @returns {Array} The new array of code points.
*/

function ucs2decode(string) {

const output = [];
let counter = 0;
const length = string.length;
while (counter < length) {
        const value = string.charCodeAt(counter++);
        if (value >= 0xD800 && value <= 0xDBFF && counter < length) {
                // It's a high surrogate, and there is a next character.
                const 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;

}

/**

* Creates a string based on an array of numeric code points.
* @see `punycode.ucs2.decode`
* @memberOf punycode.ucs2
* @name encode
* @param {Array} codePoints The array of numeric code points.
* @returns {String} The new Unicode string (UCS-2).
*/

const ucs2encode = array => String.fromCodePoint(…array);

/**

* Converts a basic code point into a digit/integer.
* @see `digitToBasic()`
* @private
* @param {Number} codePoint The basic numeric code point value.
* @returns {Number} The numeric value of a basic code point (for use in
* representing integers) in the range `0` to `base - 1`, or `base` if
* the code point does not represent a value.
*/

const basicToDigit = function(codePoint) {

if (codePoint - 0x30 < 0x0A) {
        return codePoint - 0x16;
}
if (codePoint - 0x41 < 0x1A) {
        return codePoint - 0x41;
}
if (codePoint - 0x61 < 0x1A) {
        return codePoint - 0x61;
}
return base;

};

/**

* Converts a digit/integer into a basic code point.
* @see `basicToDigit()`
* @private
* @param {Number} digit The numeric value of a basic code point.
* @returns {Number} The basic code point whose value (when used for
* representing integers) is `digit`, which needs to be in the range
* `0` to `base - 1`. If `flag` is non-zero, the uppercase form is
* used; else, the lowercase form is used. The behavior is undefined
* if `flag` is non-zero and `digit` has no uppercase form.
*/

const digitToBasic = function(digit, flag) {

//  0..25 map to ASCII a..z or A..Z
// 26..35 map to ASCII 0..9
return digit + 22 + 75 * (digit < 26) - ((flag != 0) << 5);

};

/**

* Bias adaptation function as per section 3.4 of RFC 3492.
* https://tools.ietf.org/html/rfc3492#section-3.4
* @private
*/

const adapt = function(delta, numPoints, firstTime) {

let k = 0;
delta = firstTime ? floor(delta / damp) : delta >> 1;
delta += floor(delta / numPoints);
for (/* no initialization */; delta > baseMinusTMin * tMax >> 1; k += base) {
        delta = floor(delta / baseMinusTMin);
}
return floor(k + (baseMinusTMin + 1) * delta / (delta + skew));

};

/**

* Converts a Punycode string of ASCII-only symbols to a string of Unicode
* symbols.
* @memberOf punycode
* @param {String} input The Punycode string of ASCII-only symbols.
* @returns {String} The resulting string of Unicode symbols.
*/

const decode = function(input) {

// Don't use UCS-2.
const output = [];
const inputLength = input.length;
let i = 0;
let n = initialN;
let bias = initialBias;

// Handle the basic code points: let `basic` be the number of input code
// points before the last delimiter, or `0` if there is none, then copy
// the first basic code points to the output.

let basic = input.lastIndexOf(delimiter);
if (basic < 0) {
        basic = 0;
}

for (let j = 0; j < basic; ++j) {
        // if it's not a basic code point
        if (input.charCodeAt(j) >= 0x80) {
                error('not-basic');
        }
        output.push(input.charCodeAt(j));
}

// Main decoding loop: start just after the last delimiter if any basic code
// points were copied; start at the beginning otherwise.

for (let index = basic > 0 ? basic + 1 : 0; index < inputLength; /* no final expression */) {

        // `index` is the index of the next character to be consumed.
        // Decode a generalized variable-length integer into `delta`,
        // which gets added to `i`. The overflow checking is easier
        // if we increase `i` as we go, then subtract off its starting
        // value at the end to obtain `delta`.
        let oldi = i;
        for (let w = 1, k = base; /* no condition */; k += base) {

                if (index >= inputLength) {
                        error('invalid-input');
                }

                const digit = basicToDigit(input.charCodeAt(index++));

                if (digit >= base || digit > floor((maxInt - i) / w)) {
                        error('overflow');
                }

                i += digit * w;
                const t = k <= bias ? tMin : (k >= bias + tMax ? tMax : k - bias);

                if (digit < t) {
                        break;
                }

                const baseMinusT = base - t;
                if (w > floor(maxInt / baseMinusT)) {
                        error('overflow');
                }

                w *= baseMinusT;

        }

        const out = output.length + 1;
        bias = adapt(i - oldi, out, oldi == 0);

        // `i` was supposed to wrap around from `out` to `0`,
        // incrementing `n` each time, so we'll fix that now:
        if (floor(i / out) > maxInt - n) {
                error('overflow');
        }

        n += floor(i / out);
        i %= out;

        // Insert `n` at position `i` of the output.
        output.splice(i++, 0, n);

}

return String.fromCodePoint(...output);

};

/**

* Converts a string of Unicode symbols (e.g. a domain name label) to a
* Punycode string of ASCII-only symbols.
* @memberOf punycode
* @param {String} input The string of Unicode symbols.
* @returns {String} The resulting Punycode string of ASCII-only symbols.
*/

const encode = function(input) {

const output = [];

// Convert the input in UCS-2 to an array of Unicode code points.
input = ucs2decode(input);

// Cache the length.
let inputLength = input.length;

// Initialize the state.
let n = initialN;
let delta = 0;
let bias = initialBias;

// Handle the basic code points.
for (const currentValue of input) {
        if (currentValue < 0x80) {
                output.push(stringFromCharCode(currentValue));
        }
}

let basicLength = output.length;
let handledCPCount = basicLength;

// `handledCPCount` is the number of code points that have been handled;
// `basicLength` is the number of basic code points.

// 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:
        let m = maxInt;
        for (const currentValue of input) {
                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.
        const handledCPCountPlusOne = handledCPCount + 1;
        if (m - n > floor((maxInt - delta) / handledCPCountPlusOne)) {
                error('overflow');
        }

        delta += (m - n) * handledCPCountPlusOne;
        n = m;

        for (const currentValue of input) {
                if (currentValue < n && ++delta > maxInt) {
                        error('overflow');
                }
                if (currentValue == n) {
                        // Represent delta as a generalized variable-length integer.
                        let q = delta;
                        for (let k = base; /* no condition */; k += base) {
                                const t = k <= bias ? tMin : (k >= bias + tMax ? tMax : k - bias);
                                if (q < t) {
                                        break;
                                }
                                const qMinusT = q - t;
                                const baseMinusT = base - t;
                                output.push(
                                        stringFromCharCode(digitToBasic(t + qMinusT % baseMinusT, 0))
                                );
                                q = floor(qMinusT / baseMinusT);
                        }

                        output.push(stringFromCharCode(digitToBasic(q, 0)));
                        bias = adapt(delta, handledCPCountPlusOne, handledCPCount == basicLength);
                        delta = 0;
                        ++handledCPCount;
                }
        }

        ++delta;
        ++n;

}
return output.join('');

};

/**

* Converts a Punycode string representing a domain name or an email address
* to Unicode. Only the Punycoded parts of the input will be converted, i.e.
* it doesn't matter if you call it on a string that has already been
* converted to Unicode.
* @memberOf punycode
* @param {String} input The Punycoded domain name or email address to
* convert to Unicode.
* @returns {String} The Unicode representation of the given Punycode
* string.
*/

const toUnicode = function(input) {

return mapDomain(input, function(string) {
        return regexPunycode.test(string)
                ? decode(string.slice(4).toLowerCase())
                : string;
});

};

/**

* Converts a Unicode string representing a domain name or an email address to
* Punycode. Only the non-ASCII parts of the domain name will be converted,
* i.e. it doesn't matter if you call it with a domain that's already in
* ASCII.
* @memberOf punycode
* @param {String} input The domain name or email address to convert, as a
* Unicode string.
* @returns {String} The Punycode representation of the given domain name or
* email address.
*/

const toASCII = function(input) {

return mapDomain(input, function(string) {
        return regexNonASCII.test(string)
                ? 'xn--' + encode(string)
                : string;
});

};

/————————————————————————–/

/** Define the public API */ const punycode = {

/**
 * A string representing the current Punycode.js version number.
 * @memberOf punycode
 * @type String
 */
'version': '2.1.0',
/**
 * An object of methods to convert from JavaScript's internal character
 * representation (UCS-2) to Unicode code points, and back.
 * @see <https://mathiasbynens.be/notes/javascript-encoding>
 * @memberOf punycode
 * @type Object
 */
'ucs2': {
        'decode': ucs2decode,
        'encode': ucs2encode
},
'decode': decode,
'encode': encode,
'toASCII': toASCII,
'toUnicode': toUnicode

};

export { ucs2decode, ucs2encode, decode, encode, toASCII, toUnicode }; export default punycode;