const IDENT_RE = '[A-Za-z$_][0-9A-Za-z$_]*';
const KEYWORDS = [
  "as", // for exports
  "in",
  "of",
  "if",
  "for",
  "while",
  "finally",
  "var",
  "new",
  "function",
  "do",
  "return",
  "void",
  "else",
  "break",
  "catch",
  "instanceof",
  "with",
  "throw",
  "case",
  "default",
  "try",
  "switch",
  "continue",
  "typeof",
  "delete",
  "let",
  "yield",
  "const",
  "class",
  // JS handles these with a special rule
  // "get",
  // "set",
  "debugger",
  "async",
  "await",
  "static",
  "import",
  "from",
  "export",
  "extends"
];
const LITERALS = [
  "true",
  "false",
  "null",
  "undefined",
  "NaN",
  "Infinity"
];

const TYPES = [
  "Intl",
  "DataView",
  "Number",
  "Math",
  "Date",
  "String",
  "RegExp",
  "Object",
  "Function",
  "Boolean",
  "Error",
  "Symbol",
  "Set",
  "Map",
  "WeakSet",
  "WeakMap",
  "Proxy",
  "Reflect",
  "JSON",
  "Promise",
  "Float64Array",
  "Int16Array",
  "Int32Array",
  "Int8Array",
  "Uint16Array",
  "Uint32Array",
  "Float32Array",
  "Array",
  "Uint8Array",
  "Uint8ClampedArray",
  "ArrayBuffer",
  "BigInt64Array",
  "BigUint64Array",
  "BigInt"
];

const ERROR_TYPES = [
  "EvalError",
  "InternalError",
  "RangeError",
  "ReferenceError",
  "SyntaxError",
  "TypeError",
  "URIError"
];

const BUILT_IN_GLOBALS = [
  "setInterval",
  "setTimeout",
  "clearInterval",
  "clearTimeout",

  "require",
  "exports",

  "eval",
  "isFinite",
  "isNaN",
  "parseFloat",
  "parseInt",
  "decodeURI",
  "decodeURIComponent",
  "encodeURI",
  "encodeURIComponent",
  "escape",
  "unescape"
];

const BUILT_IN_VARIABLES = [
  "arguments",
  "this",
  "super",
  "console",
  "window",
  "document",
  "localStorage",
  "module",
  "global" // Node.js
];

const BUILT_INS = [].concat(
  BUILT_IN_GLOBALS,
  TYPES,
  ERROR_TYPES
);

/**
 * @param {string} value
 * @returns {RegExp}
 * */

/**
 * @param {RegExp | string } re
 * @returns {string}
 */
function source(re) {
  if (!re) return null;
  if (typeof re === "string") return re;

  return re.source;
}

/**
 * @param {RegExp | string } re
 * @returns {string}
 */
function lookahead(re) {
  return concat('(?=', re, ')');
}

/**
 * @param {...(RegExp | string) } args
 * @returns {string}
 */
function concat(...args) {
  const joined = args.map((x) => source(x)).join("");
  return joined;
}

/*
Language: JavaScript
Description: JavaScript (JS) is a lightweight, interpreted, or just-in-time compiled programming language with first-class functions.
Category: common, scripting, web
Website: https://developer.mozilla.org/en-US/docs/Web/JavaScript
*/

/** @type LanguageFn */
function javascript(hljs) {
  /**
   * Takes a string like "<Booger" and checks to see
   * if we can find a matching "</Booger" later in the
   * content.
   * @param {RegExpMatchArray} match
   * @param {{after:number}} param1
   */
  const hasClosingTag = (match, { after }) => {
    const tag = "</" + match[0].slice(1);
    const pos = match.input.indexOf(tag, after);
    return pos !== -1;
  };

  const IDENT_RE$1 = IDENT_RE;
  const FRAGMENT = {
    begin: '<>',
    end: '</>'
  };
  const XML_TAG = {
    begin: /<[A-Za-z0-9\\._:-]+/,
    end: /\/[A-Za-z0-9\\._:-]+>|\/>/,
    /**
     * @param {RegExpMatchArray} match
     * @param {CallbackResponse} response
     */
    isTrulyOpeningTag: (match, response) => {
      const afterMatchIndex = match[0].length + match.index;
      const nextChar = match.input[afterMatchIndex];
      // nested type?
      // HTML should not include another raw `<` inside a tag
      // But a type might: `<Array<Array<number>>`, etc.
      if (nextChar === "<") {
        response.ignoreMatch();
        return;
      }
      // <something>
      // This is now either a tag or a type.
      if (nextChar === ">") {
        // if we cannot find a matching closing tag, then we
        // will ignore it
        if (!hasClosingTag(match, { after: afterMatchIndex })) {
          response.ignoreMatch();
        }
      }
    }
  };
  const KEYWORDS$1 = {
    $pattern: IDENT_RE,
    keyword: KEYWORDS,
    literal: LITERALS,
    built_in: BUILT_INS,
    "variable.language": BUILT_IN_VARIABLES
  };

  // https://tc39.es/ecma262/#sec-literals-numeric-literals
  const decimalDigits = '[0-9](_?[0-9])*';
  const frac = `\\.(${decimalDigits})`;
  // DecimalIntegerLiteral, including Annex B NonOctalDecimalIntegerLiteral
  // https://tc39.es/ecma262/#sec-additional-syntax-numeric-literals
  const decimalInteger = `0|[1-9](_?[0-9])*|0[0-7]*[89][0-9]*`;
  const NUMBER = {
    className: 'number',
    variants: [
      // DecimalLiteral
      { begin: `(\\b(${decimalInteger})((${frac})|\\.)?|(${frac}))` +
        `[eE][+-]?(${decimalDigits})\\b` },
      { begin: `\\b(${decimalInteger})\\b((${frac})\\b|\\.)?|(${frac})\\b` },

      // DecimalBigIntegerLiteral
      { begin: `\\b(0|[1-9](_?[0-9])*)n\\b` },

      // NonDecimalIntegerLiteral
      { begin: "\\b0[xX][0-9a-fA-F](_?[0-9a-fA-F])*n?\\b" },
      { begin: "\\b0[bB][0-1](_?[0-1])*n?\\b" },
      { begin: "\\b0[oO][0-7](_?[0-7])*n?\\b" },

      // LegacyOctalIntegerLiteral (does not include underscore separators)
      // https://tc39.es/ecma262/#sec-additional-syntax-numeric-literals
      { begin: "\\b0[0-7]+n?\\b" },
    ],
    relevance: 0
  };

  const SUBST = {
    className: 'subst',
    begin: '\\$\\{',
    end: '\\}',
    keywords: KEYWORDS$1,
    contains: [] // defined later
  };
  const HTML_TEMPLATE = {
    begin: 'html`',
    end: '',
    starts: {
      end: '`',
      returnEnd: false,
      contains: [
        hljs.BACKSLASH_ESCAPE,
        SUBST
      ],
      subLanguage: 'xml'
    }
  };
  const CSS_TEMPLATE = {
    begin: 'css`',
    end: '',
    starts: {
      end: '`',
      returnEnd: false,
      contains: [
        hljs.BACKSLASH_ESCAPE,
        SUBST
      ],
      subLanguage: 'css'
    }
  };
  const TEMPLATE_STRING = {
    className: 'string',
    begin: '`',
    end: '`',
    contains: [
      hljs.BACKSLASH_ESCAPE,
      SUBST
    ]
  };
  const JSDOC_COMMENT = hljs.COMMENT(
    /\/\*\*(?!\/)/,
    '\\*/',
    {
      relevance: 0,
      contains: [
        {
          begin: '(?=@[A-Za-z]+)',
          relevance: 0,
          contains: [
            {
              className: 'doctag',
              begin: '@[A-Za-z]+'
            },
            {
              className: 'type',
              begin: '\\{',
              end: '\\}',
              excludeEnd: true,
              excludeBegin: true,
              relevance: 0
            },
            {
              className: 'variable',
              begin: IDENT_RE$1 + '(?=\\s*(-)|$)',
              endsParent: true,
              relevance: 0
            },
            // eat spaces (not newlines) so we can find
            // types or variables
            {
              begin: /(?=[^\n])\s/,
              relevance: 0
            }
          ]
        }
      ]
    }
  );
  const COMMENT = {
    className: "comment",
    variants: [
      JSDOC_COMMENT,
      hljs.C_BLOCK_COMMENT_MODE,
      hljs.C_LINE_COMMENT_MODE
    ]
  };
  const SUBST_INTERNALS = [
    hljs.APOS_STRING_MODE,
    hljs.QUOTE_STRING_MODE,
    HTML_TEMPLATE,
    CSS_TEMPLATE,
    TEMPLATE_STRING,
    NUMBER,
    hljs.REGEXP_MODE
  ];
  SUBST.contains = SUBST_INTERNALS
    .concat({
      // we need to pair up {} inside our subst to prevent
      // it from ending too early by matching another }
      begin: /\{/,
      end: /\}/,
      keywords: KEYWORDS$1,
      contains: [
        "self"
      ].concat(SUBST_INTERNALS)
    });
  const SUBST_AND_COMMENTS = [].concat(COMMENT, SUBST.contains);
  const PARAMS_CONTAINS = SUBST_AND_COMMENTS.concat([
    // eat recursive parens in sub expressions
    {
      begin: /\(/,
      end: /\)/,
      keywords: KEYWORDS$1,
      contains: ["self"].concat(SUBST_AND_COMMENTS)
    }
  ]);
  const PARAMS = {
    className: 'params',
    begin: /\(/,
    end: /\)/,
    excludeBegin: true,
    excludeEnd: true,
    keywords: KEYWORDS$1,
    contains: PARAMS_CONTAINS
  };

  // ES6 classes
  const CLASS_OR_EXTENDS = {
    variants: [
      {
        match: [
          /class/,
          /\s+/,
          IDENT_RE$1
        ],
        scope: {
          1: "keyword",
          3: "title.class"
        }
      },
      {
        match: [
          /extends/,
          /\s+/,
          concat(IDENT_RE$1, "(", concat(/\./, IDENT_RE$1), ")*")
        ],
        scope: {
          1: "keyword",
          3: "title.class.inherited"
        }
      }
    ]
  };

  const CLASS_REFERENCE = {
    relevance: 0,
    match: /\b[A-Z][a-z]+([A-Z][a-z]+)*/,
    className: "title.class",
    keywords: {
      _: [
        // se we still get relevance credit for JS library classes
        ...TYPES,
        ...ERROR_TYPES
      ]
    }
  };

  const USE_STRICT = {
    label: "use_strict",
    className: 'meta',
    relevance: 10,
    begin: /^\s*['"]use (strict|asm)['"]/
  };

  const FUNCTION_DEFINITION = {
    variants: [
      {
        match: [
          /function/,
          /\s+/,
          IDENT_RE$1,
          /(?=\s*\()/
        ]
      },
      // anonymous function
      {
        match: [
          /function/,
          /\s*(?=\()/
        ]
      }
    ],
    className: {
      1: "keyword",
      3: "title.function"
    },
    label: "func.def",
    contains: [ PARAMS ],
    illegal: /%/
  };

  const UPPER_CASE_CONSTANT = {
    relevance: 0,
    match: /\b[A-Z][A-Z_0-9]+\b/,
    className: "variable.constant"
  };

  function noneOf(list) {
    return concat("(?!", list.join("|"), ")");
  }

  const FUNCTION_CALL = {
    match: concat(
      /\b/,
      noneOf([
        ...BUILT_IN_GLOBALS,
        "super"
      ]),
      IDENT_RE$1, lookahead(/\(/)),
    className: "title.function",
    relevance: 0
  };

  const PROPERTY_ACCESS = {
    begin: concat(/\./, lookahead(
      concat(IDENT_RE$1, /(?![0-9A-Za-z$_(])/)
    )),
    end: IDENT_RE$1,
    excludeBegin: true,
    keywords: "prototype",
    className: "property",
    relevance: 0
  };

  const GETTER_OR_SETTER = {
    match: [
      /get|set/,
      /\s+/,
      IDENT_RE$1,
      /(?=\()/
    ],
    className: {
      1: "keyword",
      3: "title.function"
    },
    contains: [
      { // eat to avoid empty params
        begin: /\(\)/
      },
      PARAMS
    ]
  };

  const FUNC_LEAD_IN_RE = '(\\(' +
    '[^()]*(\\(' +
    '[^()]*(\\(' +
    '[^()]*' +
    '\\)[^()]*)*' +
    '\\)[^()]*)*' +
    '\\)|' + hljs.UNDERSCORE_IDENT_RE + ')\\s*=>';

  const FUNCTION_VARIABLE = {
    match: [
      /const|var|let/, /\s+/,
      IDENT_RE$1, /\s*/,
      /=\s*/,
      lookahead(FUNC_LEAD_IN_RE)
    ],
    className: {
      1: "keyword",
      3: "title.function"
    },
    contains: [
      PARAMS
    ]
  };

  return {
    name: 'Javascript',
    aliases: ['js', 'jsx', 'mjs', 'cjs'],
    keywords: KEYWORDS$1,
    // this will be extended by TypeScript
    exports: { PARAMS_CONTAINS },
    illegal: /#(?![$_A-z])/,
    contains: [
      hljs.SHEBANG({
        label: "shebang",
        binary: "node",
        relevance: 5
      }),
      USE_STRICT,
      hljs.APOS_STRING_MODE,
      hljs.QUOTE_STRING_MODE,
      HTML_TEMPLATE,
      CSS_TEMPLATE,
      TEMPLATE_STRING,
      COMMENT,
      NUMBER,
      CLASS_REFERENCE,
      {
        className: 'attr',
        begin: IDENT_RE$1 + lookahead(':'),
        relevance: 0
      },
      FUNCTION_VARIABLE,
      { // "value" container
        begin: '(' + hljs.RE_STARTERS_RE + '|\\b(case|return|throw)\\b)\\s*',
        keywords: 'return throw case',
        relevance: 0,
        contains: [
          COMMENT,
          hljs.REGEXP_MODE,
          {
            className: 'function',
            // we have to count the parens to make sure we actually have the
            // correct bounding ( ) before the =>.  There could be any number of
            // sub-expressions inside also surrounded by parens.
            begin: FUNC_LEAD_IN_RE,
            returnBegin: true,
            end: '\\s*=>',
            contains: [
              {
                className: 'params',
                variants: [
                  {
                    begin: hljs.UNDERSCORE_IDENT_RE,
                    relevance: 0
                  },
                  {
                    className: null,
                    begin: /\(\s*\)/,
                    skip: true
                  },
                  {
                    begin: /\(/,
                    end: /\)/,
                    excludeBegin: true,
                    excludeEnd: true,
                    keywords: KEYWORDS$1,
                    contains: PARAMS_CONTAINS
                  }
                ]
              }
            ]
          },
          { // could be a comma delimited list of params to a function call
            begin: /,/,
            relevance: 0
          },
          {
            match: /\s+/,
            relevance: 0
          },
          { // JSX
            variants: [
              { begin: FRAGMENT.begin, end: FRAGMENT.end },
              {
                begin: XML_TAG.begin,
                // we carefully check the opening tag to see if it truly
                // is a tag and not a false positive
                'on:begin': XML_TAG.isTrulyOpeningTag,
                end: XML_TAG.end
              }
            ],
            subLanguage: 'xml',
            contains: [
              {
                begin: XML_TAG.begin,
                end: XML_TAG.end,
                skip: true,
                contains: ['self']
              }
            ]
          }
        ],
      },
      FUNCTION_DEFINITION,
      {
        // prevent this from getting swallowed up by function
        // since they appear "function like"
        beginKeywords: "while if switch catch for"
      },
      {
        // we have to count the parens to make sure we actually have the correct
        // bounding ( ).  There could be any number of sub-expressions inside
        // also surrounded by parens.
        begin: '\\b(?!function)' + hljs.UNDERSCORE_IDENT_RE +
          '\\(' + // first parens
          '[^()]*(\\(' +
            '[^()]*(\\(' +
              '[^()]*' +
            '\\)[^()]*)*' +
          '\\)[^()]*)*' +
          '\\)\\s*\\{', // end parens
        returnBegin:true,
        label: "func.def",
        contains: [
          PARAMS,
          hljs.inherit(hljs.TITLE_MODE, { begin: IDENT_RE$1, className: "title.function" })
        ]
      },
      // catch ... so it won't trigger the property rule below
      {
        match: /\.\.\./,
        relevance: 0
      },
      PROPERTY_ACCESS,
      // hack: prevents detection of keywords in some circumstances
      // .keyword()
      // $keyword = x
      {
        match: '\\$' + IDENT_RE$1,
        relevance: 0
      },
      {
        match: [ /\bconstructor(?=\s*\()/ ],
        className: { 1: "title.function" },
        contains: [ PARAMS ]
      },
      FUNCTION_CALL,
      UPPER_CASE_CONSTANT,
      CLASS_OR_EXTENDS,
      GETTER_OR_SETTER,
      {
        match: /\$[(.]/ // relevance booster for a pattern common to JS libs: `$(something)` and `$.something`
      }
    ]
  };
}

module.exports = javascript;