import { reUnicodeWords } from "../basic/_global";
import filter from "../#filter";

/**
 * Splits a Unicode `string` into an array of its words.
 *
 * @private
 * @param {string} the string to inspect.
 * @returns {Array} Returns the words of `string`.
 */
function unicodeWords(string: string): Array<string> | null {
    let matched = string.match(reUnicodeWords);
    return matched ? filter(matched, (string): string is string => string !== "") : null;
}

export default unicodeWords;
// /** Used to compose unicode character classes. */
// const rsAstralRange = "\\ud800-\\udfff";
// const rsComboMarksRange = "\\u0300-\\u036f";
// const reComboHalfMarksRange = "\\ufe20-\\ufe2f";
// const rsComboSymbolsRange = "\\u20d0-\\u20ff";
// const rsComboMarksExtendedRange = "\\u1ab0-\\u1aff";
// const rsComboMarksSupplementRange = "\\u1dc0-\\u1dff";
// const rsComboRange = rsComboMarksRange + reComboHalfMarksRange + rsComboSymbolsRange + rsComboMarksExtendedRange + rsComboMarksSupplementRange;
// const rsDingbatRange = "\\u2700-\\u27bf";
// const rsLowerRange = "a-z\\xdf-\\xf6\\xf8-\\xff";
// const rsMathOpRange = "\\xac\\xb1\\xd7\\xf7";
// const rsNonCharRange = "\\x00-\\x2f\\x3a-\\x40\\x5b-\\x60\\x7b-\\xbf";
// const rsPunctuationRange = "\\u2000-\\u206f";
// const rsSpaceRange = " \\t\\x0b\\f\\xa0\\ufeff\\n\\r\\u2028\\u2029\\u1680\\u180e\\u2000\\u2001\\u2002\\u2003\\u2004\\u2005\\u2006\\u2007\\u2008\\u2009\\u200a\\u202f\\u205f\\u3000";
// const rsUpperRange = "A-Z\\xc0-\\xd6\\xd8-\\xde";
// const rsVarRange = "\\ufe0e\\ufe0f";
// const rsBreakRange = rsMathOpRange + rsNonCharRange + rsPunctuationRange + rsSpaceRange;

// /** Used to compose unicode capture groups. */
// const rsApos = "['\u2019]";
// const rsBreak = `[${rsBreakRange}]`;
// const rsCombo = `[${rsComboRange}]`;
// const rsDigit = "\\d";
// const rsDingbat = `[${rsDingbatRange}]`;
// const rsLower = `[${rsLowerRange}]`;
// const rsMisc = `[^${rsAstralRange}${rsBreakRange + rsDigit + rsDingbatRange + rsLowerRange + rsUpperRange}]`;
// const rsFitz = "\\ud83c[\\udffb-\\udfff]";
// const rsModifier = `(?:${rsCombo}|${rsFitz})`;
// const rsNonAstral = `[^${rsAstralRange}]`;
// const rsRegional = "(?:\\ud83c[\\udde6-\\uddff]){2}";
// const rsSurrPair = "[\\ud800-\\udbff][\\udc00-\\udfff]";
// const rsUpper = `[${rsUpperRange}]`;
// const rsZWJ = "\\u200d";

// /** Used to compose unicode regexes. */
// const rsMiscLower = `(?:${rsLower}|${rsMisc})`;
// const rsMiscUpper = `(?:${rsUpper}|${rsMisc})`;
// const rsOptContrLower = `(?:${rsApos}(?:d|ll|m|re|s|t|ve))?`;
// const rsOptContrUpper = `(?:${rsApos}(?:D|LL|M|RE|S|T|VE))?`;
// const reOptMod = `${rsModifier}?`;
// const rsOptVar = `[${rsVarRange}]?`;
// const rsOptJoin = `(?:${rsZWJ}(?:${[rsNonAstral, rsRegional, rsSurrPair].join("|")})${rsOptVar + reOptMod})*`;
// const rsOrdLower = "\\d*(?:1st|2nd|3rd|(?![123])\\dth)(?=\\b|[A-Z_])";
// const rsOrdUpper = "\\d*(?:1ST|2ND|3RD|(?![123])\\dTH)(?=\\b|[a-z_])";
// const rsSeq = rsOptVar + reOptMod + rsOptJoin;
// const rsEmoji = `(?:${[rsDingbat, rsRegional, rsSurrPair].join("|")})${rsSeq}`;

// const reUnicodeWords = RegExp([`${rsUpper}?${rsLower}+${rsOptContrLower}(?=${[rsBreak, rsUpper, "$"].join("|")})`, `${rsMiscUpper}+${rsOptContrUpper}(?=${[rsBreak, rsUpper + rsMiscLower, "$"].join("|")})`, `${rsUpper}?${rsMiscLower}+${rsOptContrLower}`, `${rsUpper}+${rsOptContrUpper}`, rsOrdUpper, rsOrdLower, `${rsDigit}+`, rsEmoji].join("|"), "g");

// /**
//  * Splits a Unicode `string` into an array of its words.
//  *
//  * @private
//  * @param {string} The string to inspect.
//  * @returns {Array} Returns the words of `string`.
//  */
// function unicodeWords(string) {
//     return string.match(reUnicodeWords);
// }

// export default unicodeWords;