'use strict';

// Generated using scripts/write-decode-map.ts
const xmlDecodeTree = /* #__PURE__ */ new Uint16Array(
// prettier-ignore
/* #__PURE__ */ "\u0200aglq\t\x15\x18\x1b\u026d\x0f\0\0\x12p;\u4026os;\u4027t;\u403et;\u403cuot;\u4022"
    .split("")
    .map((c) => c.charCodeAt(0)));

// Adapted from https://github.com/mathiasbynens/he/blob/36afe179392226cf1b6ccdb16ebbb7a5a844d93a/src/he.js#L106-L134
var _a;
const decodeMap = new Map([
    [0, 65533],
    // C1 Unicode control character reference replacements
    [128, 8364],
    [130, 8218],
    [131, 402],
    [132, 8222],
    [133, 8230],
    [134, 8224],
    [135, 8225],
    [136, 710],
    [137, 8240],
    [138, 352],
    [139, 8249],
    [140, 338],
    [142, 381],
    [145, 8216],
    [146, 8217],
    [147, 8220],
    [148, 8221],
    [149, 8226],
    [150, 8211],
    [151, 8212],
    [152, 732],
    [153, 8482],
    [154, 353],
    [155, 8250],
    [156, 339],
    [158, 382],
    [159, 376],
]);
/**
 * Polyfill for `String.fromCodePoint`. It is used to create a string from a Unicode code point.
 */
const fromCodePoint = 
// eslint-disable-next-line @typescript-eslint/no-unnecessary-condition, n/no-unsupported-features/es-builtins
(_a = String.fromCodePoint) !== null && _a !== void 0 ? _a : function (codePoint) {
    let output = "";
    if (codePoint > 65535) {
        codePoint -= 65536;
        output += String.fromCharCode(((codePoint >>> 10) & 1023) | 55296);
        codePoint = 56320 | (codePoint & 1023);
    }
    output += String.fromCharCode(codePoint);
    return output;
};
/**
 * Replace the given code point with a replacement character if it is a
 * surrogate or is outside the valid range. Otherwise return the code
 * point unchanged.
 */
function replaceCodePoint(codePoint) {
    var _a;
    if ((codePoint >= 55296 && codePoint <= 57343) ||
        codePoint > 1114111) {
        return 65533;
    }
    return (_a = decodeMap.get(codePoint)) !== null && _a !== void 0 ? _a : codePoint;
}

var CharCodes;
(function (CharCodes) {
    CharCodes[CharCodes["NUM"] = 35] = "NUM";
    CharCodes[CharCodes["SEMI"] = 59] = "SEMI";
    CharCodes[CharCodes["EQUALS"] = 61] = "EQUALS";
    CharCodes[CharCodes["ZERO"] = 48] = "ZERO";
    CharCodes[CharCodes["NINE"] = 57] = "NINE";
    CharCodes[CharCodes["LOWER_A"] = 97] = "LOWER_A";
    CharCodes[CharCodes["LOWER_F"] = 102] = "LOWER_F";
    CharCodes[CharCodes["LOWER_X"] = 120] = "LOWER_X";
    CharCodes[CharCodes["LOWER_Z"] = 122] = "LOWER_Z";
    CharCodes[CharCodes["UPPER_A"] = 65] = "UPPER_A";
    CharCodes[CharCodes["UPPER_F"] = 70] = "UPPER_F";
    CharCodes[CharCodes["UPPER_Z"] = 90] = "UPPER_Z";
})(CharCodes || (CharCodes = {}));
/** Bit that needs to be set to convert an upper case ASCII character to lower case */
const TO_LOWER_BIT = 32;
var BinTrieFlags;
(function (BinTrieFlags) {
    BinTrieFlags[BinTrieFlags["VALUE_LENGTH"] = 49152] = "VALUE_LENGTH";
    BinTrieFlags[BinTrieFlags["BRANCH_LENGTH"] = 16256] = "BRANCH_LENGTH";
    BinTrieFlags[BinTrieFlags["JUMP_TABLE"] = 127] = "JUMP_TABLE";
})(BinTrieFlags || (BinTrieFlags = {}));
function isNumber(code) {
    return code >= CharCodes.ZERO && code <= CharCodes.NINE;
}
function isHexadecimalCharacter(code) {
    return ((code >= CharCodes.UPPER_A && code <= CharCodes.UPPER_F) ||
        (code >= CharCodes.LOWER_A && code <= CharCodes.LOWER_F));
}
function isAsciiAlphaNumeric(code) {
    return ((code >= CharCodes.UPPER_A && code <= CharCodes.UPPER_Z) ||
        (code >= CharCodes.LOWER_A && code <= CharCodes.LOWER_Z) ||
        isNumber(code));
}
/**
 * Checks if the given character is a valid end character for an entity in an attribute.
 *
 * Attribute values that aren't terminated properly aren't parsed, and shouldn't lead to a parser error.
 * See the example in https://html.spec.whatwg.org/multipage/parsing.html#named-character-reference-state
 */
function isEntityInAttributeInvalidEnd(code) {
    return code === CharCodes.EQUALS || isAsciiAlphaNumeric(code);
}
var EntityDecoderState;
(function (EntityDecoderState) {
    EntityDecoderState[EntityDecoderState["EntityStart"] = 0] = "EntityStart";
    EntityDecoderState[EntityDecoderState["NumericStart"] = 1] = "NumericStart";
    EntityDecoderState[EntityDecoderState["NumericDecimal"] = 2] = "NumericDecimal";
    EntityDecoderState[EntityDecoderState["NumericHex"] = 3] = "NumericHex";
    EntityDecoderState[EntityDecoderState["NamedEntity"] = 4] = "NamedEntity";
})(EntityDecoderState || (EntityDecoderState = {}));
var DecodingMode;
(function (DecodingMode) {
    /** Entities in text nodes that can end with any character. */
    DecodingMode[DecodingMode["Legacy"] = 0] = "Legacy";
    /** Only allow entities terminated with a semicolon. */
    DecodingMode[DecodingMode["Strict"] = 1] = "Strict";
    /** Entities in attributes have limitations on ending characters. */
    DecodingMode[DecodingMode["Attribute"] = 2] = "Attribute";
})(DecodingMode || (DecodingMode = {}));
/**
 * Token decoder with support of writing partial entities.
 */
class EntityDecoder {
    constructor(
    /** The tree used to decode entities. */
    decodeTree, 
    /**
     * The function that is called when a codepoint is decoded.
     *
     * For multi-byte named entities, this will be called multiple times,
     * with the second codepoint, and the same `consumed` value.
     *
     * @param codepoint The decoded codepoint.
     * @param consumed The number of bytes consumed by the decoder.
     */
    emitCodePoint, 
    /** An object that is used to produce errors. */
    errors) {
        this.decodeTree = decodeTree;
        this.emitCodePoint = emitCodePoint;
        this.errors = errors;
        /** The current state of the decoder. */
        this.state = EntityDecoderState.EntityStart;
        /** Characters that were consumed while parsing an entity. */
        this.consumed = 1;
        /**
         * The result of the entity.
         *
         * Either the result index of a numeric entity, or the codepoint of a
         * numeric entity.
         */
        this.result = 0;
        /** The current index in the decode tree. */
        this.treeIndex = 0;
        /** The number of characters that were consumed in excess. */
        this.excess = 1;
        /** The mode in which the decoder is operating. */
        this.decodeMode = DecodingMode.Strict;
    }
    /** Resets the instance to make it reusable. */
    startEntity(decodeMode) {
        this.decodeMode = decodeMode;
        this.state = EntityDecoderState.EntityStart;
        this.result = 0;
        this.treeIndex = 0;
        this.excess = 1;
        this.consumed = 1;
    }
    /**
     * Write an entity to the decoder. This can be called multiple times with partial entities.
     * If the entity is incomplete, the decoder will return -1.
     *
     * Mirrors the implementation of `getDecoder`, but with the ability to stop decoding if the
     * entity is incomplete, and resume when the next string is written.
     *
     * @param input The string containing the entity (or a continuation of the entity).
     * @param offset The offset at which the entity begins. Should be 0 if this is not the first call.
     * @returns The number of characters that were consumed, or -1 if the entity is incomplete.
     */
    write(input, offset) {
        switch (this.state) {
            case EntityDecoderState.EntityStart: {
                if (input.charCodeAt(offset) === CharCodes.NUM) {
                    this.state = EntityDecoderState.NumericStart;
                    this.consumed += 1;
                    return this.stateNumericStart(input, offset + 1);
                }
                this.state = EntityDecoderState.NamedEntity;
                return this.stateNamedEntity(input, offset);
            }
            case EntityDecoderState.NumericStart: {
                return this.stateNumericStart(input, offset);
            }
            case EntityDecoderState.NumericDecimal: {
                return this.stateNumericDecimal(input, offset);
            }
            case EntityDecoderState.NumericHex: {
                return this.stateNumericHex(input, offset);
            }
            case EntityDecoderState.NamedEntity: {
                return this.stateNamedEntity(input, offset);
            }
        }
    }
    /**
     * Switches between the numeric decimal and hexadecimal states.
     *
     * Equivalent to the `Numeric character reference state` in the HTML spec.
     *
     * @param input The string containing the entity (or a continuation of the entity).
     * @param offset The current offset.
     * @returns The number of characters that were consumed, or -1 if the entity is incomplete.
     */
    stateNumericStart(input, offset) {
        if (offset >= input.length) {
            return -1;
        }
        if ((input.charCodeAt(offset) | TO_LOWER_BIT) === CharCodes.LOWER_X) {
            this.state = EntityDecoderState.NumericHex;
            this.consumed += 1;
            return this.stateNumericHex(input, offset + 1);
        }
        this.state = EntityDecoderState.NumericDecimal;
        return this.stateNumericDecimal(input, offset);
    }
    addToNumericResult(input, start, end, base) {
        if (start !== end) {
            const digitCount = end - start;
            this.result =
                this.result * Math.pow(base, digitCount) +
                    Number.parseInt(input.substr(start, digitCount), base);
            this.consumed += digitCount;
        }
    }
    /**
     * Parses a hexadecimal numeric entity.
     *
     * Equivalent to the `Hexademical character reference state` in the HTML spec.
     *
     * @param input The string containing the entity (or a continuation of the entity).
     * @param offset The current offset.
     * @returns The number of characters that were consumed, or -1 if the entity is incomplete.
     */
    stateNumericHex(input, offset) {
        const startIndex = offset;
        while (offset < input.length) {
            const char = input.charCodeAt(offset);
            if (isNumber(char) || isHexadecimalCharacter(char)) {
                offset += 1;
            }
            else {
                this.addToNumericResult(input, startIndex, offset, 16);
                return this.emitNumericEntity(char, 3);
            }
        }
        this.addToNumericResult(input, startIndex, offset, 16);
        return -1;
    }
    /**
     * Parses a decimal numeric entity.
     *
     * Equivalent to the `Decimal character reference state` in the HTML spec.
     *
     * @param input The string containing the entity (or a continuation of the entity).
     * @param offset The current offset.
     * @returns The number of characters that were consumed, or -1 if the entity is incomplete.
     */
    stateNumericDecimal(input, offset) {
        const startIndex = offset;
        while (offset < input.length) {
            const char = input.charCodeAt(offset);
            if (isNumber(char)) {
                offset += 1;
            }
            else {
                this.addToNumericResult(input, startIndex, offset, 10);
                return this.emitNumericEntity(char, 2);
            }
        }
        this.addToNumericResult(input, startIndex, offset, 10);
        return -1;
    }
    /**
     * Validate and emit a numeric entity.
     *
     * Implements the logic from the `Hexademical character reference start
     * state` and `Numeric character reference end state` in the HTML spec.
     *
     * @param lastCp The last code point of the entity. Used to see if the
     *               entity was terminated with a semicolon.
     * @param expectedLength The minimum number of characters that should be
     *                       consumed. Used to validate that at least one digit
     *                       was consumed.
     * @returns The number of characters that were consumed.
     */
    emitNumericEntity(lastCp, expectedLength) {
        var _a;
        // Ensure we consumed at least one digit.
        if (this.consumed <= expectedLength) {
            (_a = this.errors) === null || _a === void 0 ? void 0 : _a.absenceOfDigitsInNumericCharacterReference(this.consumed);
            return 0;
        }
        // Figure out if this is a legit end of the entity
        if (lastCp === CharCodes.SEMI) {
            this.consumed += 1;
        }
        else if (this.decodeMode === DecodingMode.Strict) {
            return 0;
        }
        this.emitCodePoint(replaceCodePoint(this.result), this.consumed);
        if (this.errors) {
            if (lastCp !== CharCodes.SEMI) {
                this.errors.missingSemicolonAfterCharacterReference();
            }
            this.errors.validateNumericCharacterReference(this.result);
        }
        return this.consumed;
    }
    /**
     * Parses a named entity.
     *
     * Equivalent to the `Named character reference state` in the HTML spec.
     *
     * @param input The string containing the entity (or a continuation of the entity).
     * @param offset The current offset.
     * @returns The number of characters that were consumed, or -1 if the entity is incomplete.
     */
    stateNamedEntity(input, offset) {
        const { decodeTree } = this;
        let current = decodeTree[this.treeIndex];
        // The mask is the number of bytes of the value, including the current byte.
        let valueLength = (current & BinTrieFlags.VALUE_LENGTH) >> 14;
        for (; offset < input.length; offset++, this.excess++) {
            const char = input.charCodeAt(offset);
            this.treeIndex = determineBranch(decodeTree, current, this.treeIndex + Math.max(1, valueLength), char);
            if (this.treeIndex < 0) {
                return this.result === 0 ||
                    // If we are parsing an attribute
                    (this.decodeMode === DecodingMode.Attribute &&
                        // We shouldn't have consumed any characters after the entity,
                        (valueLength === 0 ||
                            // And there should be no invalid characters.
                            isEntityInAttributeInvalidEnd(char)))
                    ? 0
                    : this.emitNotTerminatedNamedEntity();
            }
            current = decodeTree[this.treeIndex];
            valueLength = (current & BinTrieFlags.VALUE_LENGTH) >> 14;
            // If the branch is a value, store it and continue
            if (valueLength !== 0) {
                // If the entity is terminated by a semicolon, we are done.
                if (char === CharCodes.SEMI) {
                    return this.emitNamedEntityData(this.treeIndex, valueLength, this.consumed + this.excess);
                }
                // If we encounter a non-terminated (legacy) entity while parsing strictly, then ignore it.
                if (this.decodeMode !== DecodingMode.Strict) {
                    this.result = this.treeIndex;
                    this.consumed += this.excess;
                    this.excess = 0;
                }
            }
        }
        return -1;
    }
    /**
     * Emit a named entity that was not terminated with a semicolon.
     *
     * @returns The number of characters consumed.
     */
    emitNotTerminatedNamedEntity() {
        var _a;
        const { result, decodeTree } = this;
        const valueLength = (decodeTree[result] & BinTrieFlags.VALUE_LENGTH) >> 14;
        this.emitNamedEntityData(result, valueLength, this.consumed);
        (_a = this.errors) === null || _a === void 0 ? void 0 : _a.missingSemicolonAfterCharacterReference();
        return this.consumed;
    }
    /**
     * Emit a named entity.
     *
     * @param result The index of the entity in the decode tree.
     * @param valueLength The number of bytes in the entity.
     * @param consumed The number of characters consumed.
     *
     * @returns The number of characters consumed.
     */
    emitNamedEntityData(result, valueLength, consumed) {
        const { decodeTree } = this;
        this.emitCodePoint(valueLength === 1
            ? decodeTree[result] & ~BinTrieFlags.VALUE_LENGTH
            : decodeTree[result + 1], consumed);
        if (valueLength === 3) {
            // For multi-byte values, we need to emit the second byte.
            this.emitCodePoint(decodeTree[result + 2], consumed);
        }
        return consumed;
    }
    /**
     * Signal to the parser that the end of the input was reached.
     *
     * Remaining data will be emitted and relevant errors will be produced.
     *
     * @returns The number of characters consumed.
     */
    end() {
        var _a;
        switch (this.state) {
            case EntityDecoderState.NamedEntity: {
                // Emit a named entity if we have one.
                return this.result !== 0 &&
                    (this.decodeMode !== DecodingMode.Attribute ||
                        this.result === this.treeIndex)
                    ? this.emitNotTerminatedNamedEntity()
                    : 0;
            }
            // Otherwise, emit a numeric entity if we have one.
            case EntityDecoderState.NumericDecimal: {
                return this.emitNumericEntity(0, 2);
            }
            case EntityDecoderState.NumericHex: {
                return this.emitNumericEntity(0, 3);
            }
            case EntityDecoderState.NumericStart: {
                (_a = this.errors) === null || _a === void 0 ? void 0 : _a.absenceOfDigitsInNumericCharacterReference(this.consumed);
                return 0;
            }
            case EntityDecoderState.EntityStart: {
                // Return 0 if we have no entity.
                return 0;
            }
        }
    }
}
/**
 * Creates a function that decodes entities in a string.
 *
 * @param decodeTree The decode tree.
 * @returns A function that decodes entities in a string.
 */
function getDecoder(decodeTree) {
    let returnValue = "";
    const decoder = new EntityDecoder(decodeTree, (data) => (returnValue += fromCodePoint(data)));
    return function decodeWithTrie(input, decodeMode) {
        let lastIndex = 0;
        let offset = 0;
        while ((offset = input.indexOf("&", offset)) >= 0) {
            returnValue += input.slice(lastIndex, offset);
            decoder.startEntity(decodeMode);
            const length = decoder.write(input, 
            // Skip the "&"
            offset + 1);
            if (length < 0) {
                lastIndex = offset + decoder.end();
                break;
            }
            lastIndex = offset + length;
            // If `length` is 0, skip the current `&` and continue.
            offset = length === 0 ? lastIndex + 1 : lastIndex;
        }
        const result = returnValue + input.slice(lastIndex);
        // Make sure we don't keep a reference to the final string.
        returnValue = "";
        return result;
    };
}
/**
 * Determines the branch of the current node that is taken given the current
 * character. This function is used to traverse the trie.
 *
 * @param decodeTree The trie.
 * @param current The current node.
 * @param nodeIdx The index right after the current node and its value.
 * @param char The current character.
 * @returns The index of the next node, or -1 if no branch is taken.
 */
function determineBranch(decodeTree, current, nodeIndex, char) {
    const branchCount = (current & BinTrieFlags.BRANCH_LENGTH) >> 7;
    const jumpOffset = current & BinTrieFlags.JUMP_TABLE;
    // Case 1: Single branch encoded in jump offset
    if (branchCount === 0) {
        return jumpOffset !== 0 && char === jumpOffset ? nodeIndex : -1;
    }
    // Case 2: Multiple branches encoded in jump table
    if (jumpOffset) {
        const value = char - jumpOffset;
        return value < 0 || value >= branchCount
            ? -1
            : decodeTree[nodeIndex + value] - 1;
    }
    // Case 3: Multiple branches encoded in dictionary
    // Binary search for the character.
    let lo = nodeIndex;
    let hi = lo + branchCount - 1;
    while (lo <= hi) {
        const mid = (lo + hi) >>> 1;
        const midValue = decodeTree[mid];
        if (midValue < char) {
            lo = mid + 1;
        }
        else if (midValue > char) {
            hi = mid - 1;
        }
        else {
            return decodeTree[mid + branchCount];
        }
    }
    return -1;
}
const xmlDecoder = /* #__PURE__ */ getDecoder(xmlDecodeTree);
/**
 * Decodes an XML string, requiring all entities to be terminated by a semicolon.
 *
 * @param xmlString The string to decode.
 * @returns The decoded string.
 */
function decodeXML(xmlString) {
    return xmlDecoder(xmlString, DecodingMode.Strict);
}

const attrRE = /\s([^'"/\s><]+?)[\s/>]|([^\s=]+)=\s?(".*?"|'.*?')/g;

function stringify$1(tag) {
  const res = {
    type: 'tag',
    name: '',
    voidElement: false,
    attribs: {},
    children: []
  };

  const tagMatch = tag.match(/<\/?([^\s]+?)[/\s>]/);
  if (tagMatch) {
    res.name = tagMatch[1];
    if (tag.charAt(tag.length - 2) === '/') {
      res.voidElement = true;
    }

    // handle comment tag
    if (res.name.startsWith('!--')) {
      const endIndex = tag.indexOf('-->');
      return {
        type: 'comment',
        comment: endIndex !== -1 ? tag.slice(4, endIndex) : ''
      }
    }
  }

  const reg = new RegExp(attrRE);
  let result = null;
  for (;;) {
    result = reg.exec(tag);

    if (result === null) {
      break
    }

    if (!result[0].trim()) {
      continue
    }

    if (result[1]) {
      const attr = result[1].trim();
      let arr = [attr, ''];

      if (attr.indexOf('=') > -1) {
        arr = attr.split('=');
      }

      res.attribs[arr[0]] = arr[1];
      reg.lastIndex--;
    } else if (result[2]) {
      res.attribs[result[2]] = result[3].trim().substring(1, result[3].length - 1);
    }
  }

  return res
}

const tagRE = /<[a-zA-Z0-9\-!/](?:"[^"]*"|'[^']*'|[^'">])*>/g;
const whitespaceRE = /^\s*$/;

const textContainerNames = ['mtext', 'mi', 'mn', 'mo', 'ms'];

function parse(html, options = {}) {
  const result = [];
  const arr = [];
  let current;
  let level = -1;

  html.replace(tagRE, (tag, index) => {
    const isOpen = tag.charAt(1) !== '/';
    const isComment = tag.startsWith('<!--');
    const start = index + tag.length;
    const nextChar = html.charAt(start);
    let parent;

    if (isComment) {
      const comment = stringify$1(tag);

      // if we're at root, push new base node
      if (level < 0) {
        result.push(comment);
        return result
      }
      parent = arr[level];
      parent.children.push(comment);
      return result
    }

    if (isOpen) {
      level++;

      current = stringify$1(tag);
      if (current.type === 'tag' && options.components?.[current.name]) {
        current.type = 'component';
      }

      if (
        textContainerNames.includes(current.name) &&
        !current.voidElement &&
        nextChar &&
        nextChar !== '<'
      ) {
        const data = html.slice(start, html.indexOf('<', start)).trim();
        current.children.push({
          type: 'text',
          data: options.disableDecode ? data : decodeXML(data)
        });
      }

      // if we're at root, push new base node
      if (level === 0) {
        result.push(current);
      }

      parent = arr[level - 1];

      if (parent) {
        parent.children.push(current);
      }

      arr[level] = current;
    }

    if (!isOpen || current.voidElement) {
      if (level > -1 && (current.voidElement || current.name === tag.slice(2, -1))) {
        level--;
        // move current up a level to match the end tag
        current = level === -1 ? result : arr[level];
      }
      if (
        level > -1 &&
        textContainerNames.includes[arr[level].name] &&
        nextChar !== '<' &&
        nextChar
      ) {
        // trailing text node
        parent = arr[level].children;

        // calculate correct end of the content slice in case there's
        // no tag after the text node.
        const end = html.indexOf('<', start);
        let data = html.slice(start, end === -1 ? undefined : end);
        // if a node is nothing but whitespace, collapse it as the spec states:
        // https://www.w3.org/TR/html4/struct/text.html#h-9.1
        if (whitespaceRE.test(data)) {
          data = ' ';
        }
        // don't add whitespace-only text nodes if they would be trailing text nodes
        // or if they would be leading whitespace-only text nodes:
        //  * end > -1 indicates this is not a trailing text node
        //  * leading node is when level is -1 and parent has length 0
        if ((end > -1 && level + parent.length >= 0) || data !== ' ') {
          parent.push({
            type: 'text',
            data: options.disableDecode ? data : decodeXML(data)
          });
        }
      }
    }
  });

  return result
}

function attrString(attribs) {
  const buff = [];
  for (const key in attribs) {
    buff.push(`${key}="${attribs[key]}"`);
  }
  if (!buff.length) {
    return ''
  }
  return ` ${buff.join(' ')}`
}

function escapeXmlText(str) {
  return str.replace(/&/g, '&amp;').replace(/</g, '&lt;').replace(/>/g, '&gt;')
}

function stringify(buff, doc) {
  switch (doc.type) {
    case 'text':
      return buff + escapeXmlText(doc.data)
    case 'tag': {
      const voidElement =
        doc.voidElement || (!doc.children.length && doc.attribs['xml:space'] !== 'preserve');
      buff += `<${doc.name}${doc.attribs ? attrString(doc.attribs) : ''}${voidElement ? '/>' : '>'}`;
      if (voidElement) {
        return buff
      }
      return `${buff + doc.children.reduce(stringify, '')}</${doc.name}>`
    }
    case 'comment':
      buff += `<!--${doc.comment}-->`;
      return buff
  }
}

function stringifyDoc(doc) {
  return doc.reduce((token, rootEl) => token + stringify('', rootEl), '')
}

function math(element, targetParent, previousSibling, nextSibling, ancestors) {
  targetParent.name = 'm:oMath';
  targetParent.attribs = {
    'xmlns:m': 'http://schemas.openxmlformats.org/officeDocument/2006/math',
    'xmlns:w': 'http://schemas.openxmlformats.org/wordprocessingml/2006/main'
  };
  targetParent.type = 'tag';
  targetParent.children = [];
  return targetParent
}

function semantics(element, targetParent, previousSibling, nextSibling, ancestors) {
  // Ignore as default behavior
  return targetParent
}

function menclose(element, targetParent, previousSibling, nextSibling, ancestors) {
  const type = element.attribs?.notation?.split(' ')[0] || 'longdiv';

  const targetElement = {
    type: 'tag',
    name: 'm:e',
    attribs: {},
    children: []
  };

  if (type === 'longdiv') {
    targetParent.children.push({
      type: 'tag',
      name: 'm:rad',
      attribs: {},
      children: [
        {
          type: 'tag',
          name: 'm:radPr',
          attribs: {},
          children: [{ type: 'tag', name: 'm:degHide', attribs: { 'm:val': 'on' }, children: [] }]
        },
        { type: 'tag', name: 'm:deg', attribs: {}, children: [] },
        targetElement
      ]
    });
  } else {
    const hide = {
      t: { type: 'tag', name: 'm:hideTop', attribs: { 'm:val': 'on' }, children: [] },
      b: { type: 'tag', name: 'm:hideBot', attribs: { 'm:val': 'on' }, children: [] },
      l: { type: 'tag', name: 'm:hideLeft', attribs: { 'm:val': 'on' }, children: [] },
      r: { type: 'tag', name: 'm:hideRight', attribs: { 'm:val': 'on' }, children: [] }
    };
    const borderBoxPr = { type: 'tag', name: 'm:borderBoxPr', attribs: {}, children: [] };

    const containerElement = {
      type: 'tag',
      name: 'm:borderBox',
      attribs: {},
      children: []
    };
    switch (type) {
      case 'actuarial':
      case 'radical':
      case 'box':
        containerElement.children = [targetElement];
        break
      case 'left':
      case 'roundedbox':
        borderBoxPr.children = [hide.t, hide.b, hide.r];
        containerElement.children = [borderBoxPr, targetElement];
        break
      case 'right':
      case 'circle':
        borderBoxPr.children = [hide.t, hide.b, hide.l];
        containerElement.children = [borderBoxPr, targetElement];
        break
      case 'top':
        borderBoxPr.children = [hide.b, hide.l, hide.r];
        containerElement.children = [borderBoxPr, targetElement];
        break
      case 'bottom':
        borderBoxPr.children = [hide.t, hide.l, hide.r];
        containerElement.children = [borderBoxPr, targetElement];
        break
      case 'updiagonalstrike':
        borderBoxPr.children = [
          hide.t,
          hide.b,
          hide.l,
          hide.r,
          { type: 'tag', name: 'm:strikeBLTR', attribs: { 'm:val': 'on' }, children: [] }
        ];
        containerElement.children = [borderBoxPr, targetElement];
        break
      case 'downdiagonalstrike':
        borderBoxPr.children = [
          hide.t,
          hide.b,
          hide.l,
          hide.r,
          { type: 'tag', name: 'm:strikeTLBR', attribs: { 'm:val': 'on' }, children: [] }
        ];
        containerElement.children = [borderBoxPr, targetElement];
        break
      case 'verticalstrike':
        borderBoxPr.children = [
          hide.t,
          hide.b,
          hide.l,
          hide.r,
          { type: 'tag', name: 'm:strikeV', attribs: { 'm:val': 'on' }, children: [] }
        ];
        containerElement.children = [borderBoxPr, targetElement];
        break
      case 'horizontalstrike':
        borderBoxPr.children = [
          hide.t,
          hide.b,
          hide.l,
          hide.r,
          { type: 'tag', name: 'm:strikeH', attribs: { 'm:val': 'on' }, children: [] }
        ];
        containerElement.children = [borderBoxPr, targetElement];
        break
      default:
        borderBoxPr.children = [hide.t, hide.b, hide.l, hide.r];
        containerElement.children = [borderBoxPr, targetElement];
        break
    }
    targetParent.children.push(containerElement);
  }
  return targetElement
}

function mfrac(element, targetParent, previousSibling, nextSibling, ancestors) {
  if (element.children.length !== 2) {
    // treat as mrow
    return targetParent
  }

  const numerator = element.children[0];
  const denumerator = element.children[1];
  const numeratorTarget = {
    name: 'm:num',
    type: 'tag',
    attribs: {},
    children: []
  };
  const denumeratorTarget = {
    name: 'm:den',
    type: 'tag',
    attribs: {},
    children: []
  };
  ancestors = [...ancestors];
  ancestors.unshift(element);
  walker(numerator, numeratorTarget, false, false, ancestors);
  walker(denumerator, denumeratorTarget, false, false, ancestors);
  const lt = element.attribs?.linethickness;
  const fracType = (lt === '0' || lt === '0px' || lt === '0em' || lt === '0pt') ? 'noBar' : 'bar';
  targetParent.children.push({
    type: 'tag',
    name: 'm:f',
    attribs: {},
    children: [
      {
        type: 'tag',
        name: 'm:fPr',
        attribs: {},
        children: [
          {
            type: 'tag',
            name: 'm:type',
            attribs: {
              'm:val': fracType
            },
            children: []
          }
        ]
      },
      numeratorTarget,
      denumeratorTarget
    ]
  });
  // Don't iterate over children in the usual way.
}

function mglyph(element, targetParent, previousSibling, nextSibling, ancestors) {
  // No support in omml. Output alt text.
  if (element.attribs?.alt) {
    targetParent.children.push({
      type: 'text',
      data: element.attribs.alt
    });
  }
}

function mmultiscripts(element, targetParent, previousSibling, nextSibling, ancestors) {
  if (element.children.length === 0) {
    // Don't use
    return
  }

  const base = element.children[0];
  const postSubs = [];
  const postSupers = [];
  const preSubs = [];
  const preSupers = [];
  const children = element.children.slice(1);
  let dividerFound = false;
  children.forEach((child, index) => {
    if (child.name === 'mprescripts') {
      dividerFound = true;
    } else if (child.name !== 'none') {
      if (index % 2) {
        if (dividerFound) {
          preSubs.push(child);
        } else {
          postSupers.push(child);
        }
      } else {
        if (dividerFound) {
          preSupers.push(child);
        } else {
          postSubs.push(child);
        }
      }
    }
  });
  ancestors = [...ancestors];
  ancestors.unshift(element);
  const tempTarget = {
    children: []
  };
  walker(base, tempTarget, false, false, ancestors);
  let topTarget = tempTarget.children[0];

  if (postSubs.length || postSupers.length) {
    const subscriptTarget = {
      name: 'm:sub',
      type: 'tag',
      attribs: {},
      children: []
    };
    postSubs.forEach((subscript) => walker(subscript, subscriptTarget, false, false, ancestors));

    const superscriptTarget = {
      name: 'm:sup',
      type: 'tag',
      attribs: {},
      children: []
    };

    postSupers.forEach((superscript) =>
      walker(superscript, superscriptTarget, false, false, ancestors)
    );

    const topPostTarget = {
      type: 'tag',
      attribs: {},
      children: [
        {
          type: 'tag',
          name: 'm:e',
          attribs: {},
          children: [topTarget]
        }
      ]
    };
    if (postSubs.length && postSupers.length) {
      topPostTarget.name = 'm:sSubSup';
      topPostTarget.children.push(subscriptTarget);
      topPostTarget.children.push(superscriptTarget);
    } else if (postSubs.length) {
      topPostTarget.name = 'm:sSub';
      topPostTarget.children.push(subscriptTarget);
    } else {
      topPostTarget.name = 'm:sSup';
      topPostTarget.children.push(superscriptTarget);
    }
    topTarget = topPostTarget;
  }

  if (preSubs.length || preSupers.length) {
    const preSubscriptTarget = {
      name: 'm:sub',
      type: 'tag',
      attribs: {},
      children: []
    };
    preSubs.forEach((subscript) => walker(subscript, preSubscriptTarget, false, false, ancestors));

    const preSuperscriptTarget = {
      name: 'm:sup',
      type: 'tag',
      attribs: {},
      children: []
    };

    preSupers.forEach((superscript) =>
      walker(superscript, preSuperscriptTarget, false, false, ancestors)
    );
    const topPreTarget = {
      name: 'm:sPre',
      type: 'tag',
      attribs: {},
      children: [
        {
          name: 'm:e',
          type: 'tag',
          attribs: {},
          children: [topTarget]
        },
        preSubscriptTarget,
        preSuperscriptTarget
      ]
    };
    topTarget = topPreTarget;
  }
  targetParent.children.push(topTarget);
  // Don't iterate over children in the usual way.
}

function mrow(element, targetParent, previousSibling, nextSibling, ancestors) {
  // Detect fence pattern: <mo fence="true">OPEN ... <mo fence="true">CLOSE
  // Convert to OMML <m:d> delimiter (e.g. binomial, \left(\right))
  const children = element.children || [];
  if (children.length >= 2) {
    const first = children[0];
    const last = children[children.length - 1];
    if (first?.name === 'mo' && first?.attribs?.fence === 'true' &&
        last?.name === 'mo' && last?.attribs?.fence === 'true') {
      const begChar = first.children?.[0]?.data || '(';
      const endChar = last.children?.[0]?.data || ')';
      const dNode = {
        type: 'tag', name: 'm:d', attribs: {}, children: [
          { type: 'tag', name: 'm:dPr', attribs: {}, children: [
            { type: 'tag', name: 'm:begChr', attribs: { 'm:val': begChar }, children: [] },
            { type: 'tag', name: 'm:endChr', attribs: { 'm:val': endChar }, children: [] },
            { type: 'tag', name: 'm:ctrlPr', attribs: {}, children: [] }
          ]},
          { type: 'tag', name: 'm:e', attribs: {}, children: [] }
        ]
      };
      targetParent.children.push(dNode);
      // Mark fence operators so the walker child loop skips them
      first.skipInWalker = true;
      last.skipInWalker = true;
      // Return <m:e> as target — inner children go here
      return dNode.children[1]
    }
  }
  // isNary redirect is now handled in walker's child loop
  return targetParent
}

function mspace(element, targetParent, previousSibling, nextSibling, ancestors) {
  targetParent.children.push({
    name: 'm:r',
    type: 'tag',
    attribs: {},
    children: [
      {
        name: 'm:t',
        type: 'tag',
        attribs: {
          'xml:space': 'preserve'
        },
        children: [
          {
            type: 'text',
            data: ' '
          }
        ]
      }
    ]
  });
}

function msqrt(element, targetParent, previousSibling, nextSibling, ancestors) {
  const targetElement = {
    name: 'm:e',
    type: 'tag',
    attribs: {},
    children: []
  };
  targetParent.children.push({
    name: 'm:rad',
    type: 'tag',
    attribs: {},
    children: [
      {
        name: 'm:radPr',
        type: 'tag',
        attribs: {},
        children: [
          {
            name: 'm:degHide',
            type: 'tag',
            attribs: {
              'm:val': 'on'
            },
            children: []
          }
        ]
      },
      {
        name: 'm:deg',
        type: 'tag',
        attribs: {},
        children: []
      },
      targetElement
    ]
  });
  return targetElement
}

function mstyle(element, targetParent, previousSibling, nextSibling, ancestors) {
  // Ignore as default behavior
  return targetParent
}

function getTextContent(node, trim = true) {
  let returnString = '';
  if (node.type === 'text') {
    let text = node.data.replace(/[\u2062]|[\u200B]/g, '');
    if (trim) {
      text = text.trim();
    }
    returnString += text;
  } else if (node.children) {
    node.children.forEach((subNode) => {
      returnString += getTextContent(subNode, trim);
    });
  }
  return returnString
}

const NARY_REGEXP = /^[\u220f-\u2211]|[\u2229-\u2233]|[\u22c0-\u22c3]$/;
const GROW_REGEXP = /^\u220f|\u2211|[\u2229-\u222b]|\u222e|\u222f|\u2232|\u2233|[\u22c0-\u22c3]$/;

function getNary(node) {
  // Check if node contains only a nary operator.
  const text = getTextContent(node);
  if (NARY_REGEXP.test(text)) {
    return text
  }
  return false
}

function getNaryTarget(naryChar, element, type, subHide = false, supHide = false) {
  const stretchy = element.attribs?.stretchy;
  const grow =
    stretchy === 'true' ? '1' : stretchy === 'false' ? '0' : GROW_REGEXP.test(naryChar) ? '1' : '0';
  return {
    type: 'tag',
    name: 'm:nary',
    attribs: {},
    children: [
      {
        type: 'tag',
        name: 'm:naryPr',
        attribs: {},
        children: [
          { type: 'tag', name: 'm:chr', attribs: { 'm:val': naryChar }, children: [] },
          { type: 'tag', name: 'm:limLoc', attribs: { 'm:val': type }, children: [] },
          { type: 'tag', name: 'm:grow', attribs: { 'm:val': grow }, children: [] },
          {
            type: 'tag',
            name: 'm:subHide',
            attribs: { 'm:val': subHide ? 'on' : 'off' },
            children: []
          },
          {
            type: 'tag',
            name: 'm:supHide',
            attribs: { 'm:val': supHide ? 'on' : 'off' },
            children: []
          }
        ]
      }
    ]
  }
}

function addScriptlevel(target, ancestors) {
  const scriptlevel = ancestors.find((ancestor) => ancestor.attribs?.scriptlevel)?.attribs
    ?.scriptlevel;
  if (['0', '1', '2'].includes(scriptlevel)) {
    target.children.unshift({
      type: 'tag',
      name: 'm:argPr',
      attribs: {},
      children: [
        {
          type: 'tag',
          name: 'm:scrLvl',
          attribs: { 'm:val': scriptlevel },
          children: []
        }
      ]
    });
  }
}

function msub(element, targetParent, previousSibling, nextSibling, ancestors) {
  // Subscript
  if (element.children.length !== 2) {
    // treat as mrow
    return targetParent
  }
  ancestors = [...ancestors];
  ancestors.unshift(element);
  const base = element.children[0];
  const subscript = element.children[1];

  let topTarget;
  //
  // m:nAry
  //
  // Conditions:
  // 1. base text must be nary operator
  // 2. no accents
  const naryChar = getNary(base);
  if (
    naryChar &&
    element.attribs?.accent?.toLowerCase() !== 'true' &&
    element.attribs?.accentunder?.toLowerCase() !== 'true'
  ) {
    topTarget = getNaryTarget(naryChar, element, 'subSup', false, true);
    element.isNary = true;
  } else {
    // Check for empty base → prescript pattern (LaTeX {}_{sub}X)
    const isEmptyBase = base.name === 'mrow' && (!base.children || base.children.length === 0);

    if (isEmptyBase) {
      topTarget = {
        type: 'tag',
        name: 'm:sPre',
        attribs: {},
        children: [
          {
            type: 'tag',
            name: 'm:sPrePr',
            attribs: {},
            children: [
              {
                type: 'tag',
                name: 'm:ctrlPr',
                attribs: {},
                children: []
              }
            ]
          }
        ]
      };
      element.isPrescript = true;
    } else {
      const baseTarget = {
        name: 'm:e',
        type: 'tag',
        attribs: {},
        children: []
      };
      walker(base, baseTarget, false, false, ancestors);
      topTarget = {
        type: 'tag',
        name: 'm:sSub',
        attribs: {},
        children: [
          {
            type: 'tag',
            name: 'm:sSubPr',
            attribs: {},
            children: [
              {
                type: 'tag',
                name: 'm:ctrlPr',
                attribs: {},
                children: []
              }
            ]
          },
          baseTarget
        ]
      };
    }
  }

  const subscriptTarget = {
    name: 'm:sub',
    type: 'tag',
    attribs: {},
    children: []
  };

  walker(subscript, subscriptTarget, false, false, ancestors);
  topTarget.children.push(subscriptTarget);
  if (element.isNary) {
    topTarget.children.push({ type: 'tag', name: 'm:sup', attribs: {}, children: [] });
    topTarget.children.push({ type: 'tag', name: 'm:e', attribs: {}, children: [] });
  }
  // For prescript, add empty m:sup and m:e (base filled by walker redirect)
  if (element.isPrescript) {
    topTarget.children.push({ type: 'tag', name: 'm:sup', attribs: {}, children: [] });
    topTarget.children.push({ type: 'tag', name: 'm:e', attribs: {}, children: [] });
  }
  targetParent.children.push(topTarget);
  // Don't iterate over children in the usual way.
}

function msubsup(element, targetParent, previousSibling, nextSibling, ancestors) {
  // Sub + superscript
  if (element.children.length !== 3) {
    // treat as mrow
    return targetParent
  }

  ancestors = [...ancestors];
  ancestors.unshift(element);

  const base = element.children[0];
  const subscript = element.children[1];
  const superscript = element.children[2];

  let topTarget;
  //
  // m:nAry
  //
  // Conditions:
  // 1. base text must be nary operator
  // 2. no accents
  const naryChar = getNary(base);
  if (
    naryChar &&
    element.attribs?.accent?.toLowerCase() !== 'true' &&
    element.attribs?.accentunder?.toLowerCase() !== 'true'
  ) {
    topTarget = getNaryTarget(naryChar, element, 'subSup');
    element.isNary = true;
  } else {
    // Check for empty base → prescript pattern (LaTeX {}^{sup}_{sub}X)
    const isEmptyBase = base.name === 'mrow' && (!base.children || base.children.length === 0);

    if (isEmptyBase) {
      topTarget = {
        type: 'tag',
        name: 'm:sPre',
        attribs: {},
        children: [
          {
            type: 'tag',
            name: 'm:sPrePr',
            attribs: {},
            children: [
              {
                type: 'tag',
                name: 'm:ctrlPr',
                attribs: {},
                children: []
              }
            ]
          }
        ]
      };
      element.isPrescript = true;
    } else {
      // Regular m:sSubSup
      const baseTarget = {
        name: 'm:e',
        type: 'tag',
        attribs: {},
        children: []
      };

      walker(base, baseTarget, false, false, ancestors);
      topTarget = {
        type: 'tag',
        name: 'm:sSubSup',
        attribs: {},
        children: [
          {
            type: 'tag',
            name: 'm:sSubSupPr',
            attribs: {},
            children: [
              {
                type: 'tag',
                name: 'm:ctrlPr',
                attribs: {},
                children: []
              }
            ]
          },
          baseTarget
        ]
      };
    }
  }

  const subscriptTarget = {
    name: 'm:sub',
    type: 'tag',
    attribs: {},
    children: []
  };
  const superscriptTarget = {
    name: 'm:sup',
    type: 'tag',
    attribs: {},
    children: []
  };
  walker(subscript, subscriptTarget, false, false, ancestors);
  walker(superscript, superscriptTarget, false, false, ancestors);
  topTarget.children.push(subscriptTarget);
  topTarget.children.push(superscriptTarget);
  if (element.isNary) {
    topTarget.children.push({ type: 'tag', name: 'm:e', attribs: {}, children: [] });
  }
  if (element.isPrescript) {
    topTarget.children.push({ type: 'tag', name: 'm:e', attribs: {}, children: [] });
  }
  targetParent.children.push(topTarget);
  // Don't iterate over children in the usual way.
}

function msup(element, targetParent, previousSibling, nextSibling, ancestors) {
  // Superscript
  if (element.children.length !== 2) {
    // treat as mrow
    return targetParent
  }
  ancestors = [...ancestors];
  ancestors.unshift(element);
  const base = element.children[0];
  const superscript = element.children[1];

  let topTarget;
  //
  // m:nAry
  //
  // Conditions:
  // 1. base text must be nary operator
  // 2. no accents
  const naryChar = getNary(base);
  if (
    naryChar &&
    element.attribs?.accent?.toLowerCase() !== 'true' &&
    element.attribs?.accentunder?.toLowerCase() !== 'true'
  ) {
    topTarget = getNaryTarget(naryChar, element, 'subSup', true);
    element.isNary = true;
    topTarget.children.push({ type: 'tag', name: 'm:sub' });
  } else {
    // Check for empty base → prescript pattern (LaTeX {}^{sup}X)
    const isEmptyBase = base.name === 'mrow' && (!base.children || base.children.length === 0);

    if (isEmptyBase) {
      topTarget = {
        type: 'tag',
        name: 'm:sPre',
        attribs: {},
        children: [
          {
            type: 'tag',
            name: 'm:sPrePr',
            attribs: {},
            children: [
              {
                type: 'tag',
                name: 'm:ctrlPr',
                attribs: {},
                children: []
              }
            ]
          }
        ]
      };
      element.isPrescript = true;
    } else {
      const baseTarget = {
        name: 'm:e',
        type: 'tag',
        attribs: {},
        children: []
      };
      walker(base, baseTarget, false, false, ancestors);

      topTarget = {
        type: 'tag',
        name: 'm:sSup',
        attribs: {},
        children: [
          {
            type: 'tag',
            name: 'm:sSupPr',
            attribs: {},
            children: [
              {
                type: 'tag',
                name: 'm:ctrlPr',
                attribs: {},
                children: []
              }
            ]
          },
          baseTarget
        ]
      };
    }
  }

  const superscriptTarget = {
    name: 'm:sup',
    type: 'tag',
    attribs: {},
    children: []
  };

  walker(superscript, superscriptTarget, false, false, ancestors);

  // For prescript, also add an empty m:sub
  if (element.isPrescript) {
    topTarget.children.push({ type: 'tag', name: 'm:sub', attribs: {}, children: [] });
  }
  topTarget.children.push(superscriptTarget);
  if (element.isNary) {
    topTarget.children.push({ type: 'tag', name: 'm:e', attribs: {}, children: [] });
  }
  if (element.isPrescript) {
    topTarget.children.push({ type: 'tag', name: 'm:e', attribs: {}, children: [] });
  }
  targetParent.children.push(topTarget);
  // Don't iterate over children in the usual way.
}

function mtable(element, targetParent, previousSibling, nextSibling, ancestors) {
  const cellsPerRowCount = Math.max(...element.children.map((row) => row.children.length));
  const targetElement = {
    name: 'm:m',
    type: 'tag',
    attribs: {},
    children: [
      {
        name: 'm:mPr',
        type: 'tag',
        attribs: {},
        children: [
          {
            name: 'm:baseJc',
            type: 'tag',
            attribs: {
              'm:val': 'center'
            },
            children: []
          },
          {
            name: 'm:plcHide',
            type: 'tag',
            attribs: {
              'm:val': 'on'
            },
            children: []
          },
          {
            name: 'm:mcs',
            type: 'tag',
            attribs: {},
            children: [
              {
                name: 'm:mc',
                type: 'tag',
                attribs: {},
                children: [
                  {
                    name: 'm:mcPr',
                    type: 'tag',
                    attribs: {},
                    children: [
                      {
                        name: 'm:count',
                        type: 'tag',
                        attribs: {
                          'm:val': cellsPerRowCount.toString()
                        },
                        children: []
                      },
                      {
                        name: 'm:mcJc',
                        type: 'tag',
                        attribs: {
                          'm:val': 'center'
                        },
                        children: []
                      }
                    ]
                  }
                ]
              }
            ]
          }
        ]
      }
    ]
  };
  targetParent.children.push(targetElement);
  return targetElement
}

function mtd(element, targetParent, previousSibling, nextSibling, ancestors) {
  // table cell
  const targetElement = {
    name: 'm:e',
    type: 'tag',
    attribs: {},
    children: []
  };
  targetParent.children.push(targetElement);
  return targetElement
}

function mtr(element, targetParent, previousSibling, nextSibling, ancestors) {
  // table row
  const targetElement = {
    name: 'm:mr',
    type: 'tag',
    attribs: {},
    children: []
  };
  targetParent.children.push(targetElement);
  return targetElement
}

function munderover(element, targetParent, previousSibling, nextSibling, ancestors) {
  // Munderover
  if (element.children.length !== 3) {
    // treat as mrow
    return targetParent
  }

  ancestors = [...ancestors];
  ancestors.unshift(element);

  const base = element.children[0];
  const underscript = element.children[1];
  const overscript = element.children[2];

  //
  // m:nAry
  //
  // Conditions:
  // 1. base text must be nary operator
  // 2. no accents
  const naryChar = getNary(base);
  if (
    naryChar &&
    element.attributes?.accent?.toLowerCase() !== 'true' &&
    element.attributes?.accentunder?.toLowerCase() !== 'true'
  ) {
    const topTarget = getNaryTarget(naryChar, element, 'undOvr');
    element.isNary = true;
    const subscriptTarget = {
      name: 'm:sub',
      type: 'tag',
      attribs: {},
      children: []
    };
    const superscriptTarget = {
      name: 'm:sup',
      type: 'tag',
      attribs: {},
      children: []
    };
    walker(underscript, subscriptTarget, false, false, ancestors);
    walker(overscript, superscriptTarget, false, false, ancestors);
    topTarget.children.push(subscriptTarget);
    topTarget.children.push(superscriptTarget);
    topTarget.children.push({ type: 'tag', name: 'm:e', attribs: {}, children: [] });
    targetParent.children.push(topTarget);
    return
  }

  // Fallback: m:limUpp()m:limlow

  const baseTarget = {
    name: 'm:e',
    type: 'tag',
    attribs: {},
    children: []
  };

  walker(base, baseTarget, false, false, ancestors);

  const underscriptTarget = {
    name: 'm:lim',
    type: 'tag',
    attribs: {},
    children: []
  };
  const overscriptTarget = {
    name: 'm:lim',
    type: 'tag',
    attribs: {},
    children: []
  };

  walker(underscript, underscriptTarget, false, false, ancestors);
  walker(overscript, overscriptTarget, false, false, ancestors);
  targetParent.children.push({
    type: 'tag',
    name: 'm:limUpp',
    attribs: {},
    children: [
      {
        type: 'tag',
        name: 'm:e',
        attribs: {},
        children: [
          {
            type: 'tag',
            name: 'm:limLow',
            attribs: {},
            children: [baseTarget, underscriptTarget]
          }
        ]
      },
      overscriptTarget
    ]
  });
  // Don't iterate over children in the usual way.
}

function getStyle(element, ancestors, previousStyle = {}) {
  const elAttributes = element.attribs || {};
  const color =
    elAttributes.mathcolor ||
    ancestors.find(
      (element) => element.name === 'mstyle' && element.attribs && element.attribs.color
    )?.attribs.color ||
    '';
  // const minsize = parseFloat(elAttributes.scriptminsize || ancestors.find(element => element.name === 'mstyle' && element.attribs && element.attribs.scriptminsize)?.attribs.scriptminsize || '8pt')
  // const sizemultiplier = parseFloat(elAttributes.scriptsizemultiplier || ancestors.find(element => element.name === 'mstyle' && element.attribs && element.attribs.scriptsizemultiplier)?.attribs.scriptsizemultiplier || '0.71')
  const size =
    elAttributes.mathsize ||
    ancestors.find(
      (element) => element.name === 'mstyle' && element.attribs && element.attribs.mathsize
    )?.attribs.mathsize ||
    '';
  const scriptlevel =
    elAttributes.scriptlevel ||
    ancestors.find(
      (element) => element.name === 'mstyle' && element.attribs && element.attribs.scriptlevel
    )?.attribs.scriptlevel ||
    '';
  const background =
    elAttributes.mathbackground ||
    ancestors.find(
      (element) => element.name === 'mstyle' && element.attribs && element.attribs.mathbackground
    )?.attribs.mathbackground ||
    '';
  let variant =
    elAttributes.mathvariant ||
    ancestors.find(
      (element) => element.name === 'mstyle' && element.attribs && element.attribs.mathvariant
    )?.attribs.mathvariant ||
    '';
  if (variant === 'b-i') {
    variant = 'bold-italic';
  }
  const fontweight =
    elAttributes.fontweight ||
    ancestors.find(
      (element) => element.name === 'mstyle' && element.attribs && element.attribs.fontweight
    )?.attribs.fontweight ||
    '';
  if (fontweight === 'bold' && !['bold', 'bold-italic'].includes(variant)) {
    if (variant.includes('italic')) {
      variant = 'bold-italic';
    } else {
      variant = 'bold';
    }
  } else if (fontweight === 'normal' && ['bold', 'bold-italic'].includes(variant)) {
    if (variant.includes('italic')) {
      variant = 'italic';
    } else {
      variant = '';
    }
  }
  const fontstyle =
    elAttributes.fontstyle ||
    ancestors.find(
      (element) => element.name === 'mstyle' && element.attribs && element.attribs.fontstyle
    )?.attribs.fontstyle ||
    '';
  if (fontstyle === 'italic' && !['italic', 'bold-italic'].includes(variant)) {
    if (variant.includes('bold')) {
      variant = 'bold-italic';
    } else {
      variant = 'italic';
    }
  } else if (fontstyle === 'normal' && ['italic', 'bold-italic'].includes(variant)) {
    if (variant.includes('bold')) {
      variant = 'bold';
    } else {
      variant = '';
    }
  }
  // Override variant for some types
  if (!elAttributes.mathvariant) {
    const textContent = getTextContent(element);
    if (
      previousStyle.variant === '' &&
      ((element.name === 'mi' && textContent.length > 1) ||
        (element.name === 'mn' && !/^\d+\.\d+$/.test(textContent)))
    ) {
      variant = '';
    } else if (
      ['mi', 'mn', 'mo'].includes(element.name) &&
      ['italic', 'bold-italic'].includes(previousStyle.variant)
    ) {
      if (fontweight === 'bold') {
        variant = 'bold-italic';
      } else {
        variant = 'italic';
      }
    }
  }

  return {
    color,
    variant,
    size,
    scriptlevel,
    background,
    fontstyle
  }
}

const STYLES = {
  bold: 'b',
  italic: 'i',
  'bold-italic': 'bi'
};

function textContainer(element, targetParent, previousSibling, nextSibling, ancestors, textType) {
  // isNary redirect is now handled in walker's child loop

  const hasMglyphChild = element.children?.find((element) => element.name === 'mglyph');
  const style = getStyle(element, ancestors, previousSibling?.style);
  element.style = style; // Add it to element to make it comparable
  element.hasMglyphChild = hasMglyphChild;
  const styleSame =
    Object.keys(style).every((key) => {
      const previousStyle = previousSibling?.style;
      return previousStyle && style[key] === previousStyle[key]
    }) && previousSibling?.hasMglyphChild === hasMglyphChild;
  const sameGroup = // Only group mtexts or mi, mn, mo with oneanother.
    textType === previousSibling?.name ||
    (['mi', 'mn', 'mo'].includes(textType) && ['mi', 'mn', 'mo'].includes(previousSibling?.name));
  let targetElement;
  const lastChild = targetParent.children[targetParent.children.length - 1];
  if (sameGroup && styleSame && !hasMglyphChild && lastChild?.name === 'm:r') {
    targetElement = lastChild.children[lastChild.children.length - 1];
  } else {
    const rElement = {
      name: 'm:r',
      type: 'tag',
      attribs: {},
      children: []
    };

    if (style.variant) {
      const wrPr = {
        name: 'w:rPr',
        type: 'tag',
        attribs: {},
        children: []
      };
      if (style.variant.includes('bold')) {
        wrPr.children.push({ name: 'w:b', type: 'tag', attribs: {}, children: [] });
      }
      if (style.variant.includes('italic')) {
        wrPr.children.push({ name: 'w:i', type: 'tag', attribs: {}, children: [] });
      }
      rElement.children.push(wrPr);
      const mrPr = {
        name: 'm:rPr',
        type: 'tag',
        attribs: {},
        children: [
          {
            name: 'm:nor',
            type: 'tag',
            attribs: {},
            children: []
          }
        ]
      };
      if (style.variant !== 'italic') {
        mrPr.children.push({
          name: 'm:sty',
          type: 'tag',
          attribs: {
            'm:val': STYLES[style.variant]
          },
          children: []
        });
      }
      rElement.children.push(mrPr);
    } else if (hasMglyphChild || textType === 'mtext') {
      rElement.children.push({
        name: 'm:rPr',
        type: 'tag',
        attribs: {},
        children: [
          {
            name: 'm:nor',
            type: 'tag',
            attribs: {},
            children: []
          }
        ]
      });
    } else if (style.fontstyle === 'normal' || (textType === 'ms' && style.fontstyle === '')) {
      rElement.children.push({
        name: 'm:rPr',
        type: 'tag',
        attribs: {},
        children: [
          {
            name: 'm:sty',
            type: 'tag',
            attribs: { 'm:val': 'p' },
            children: []
          }
        ]
      });
    }

    targetElement = {
      name: 'm:t',
      type: 'tag',
      attribs: {
        'xml:space': 'preserve'
      },
      children: []
    };
    rElement.children.push(targetElement);
    targetParent.children.push(rElement);
  }
  return targetElement
}

function mtext(element, targetParent, previousSibling, nextSibling, ancestors) {
  return textContainer(element, targetParent, previousSibling, nextSibling, ancestors, 'mtext')
}

function mi(element, targetParent, previousSibling, nextSibling, ancestors) {
  return textContainer(element, targetParent, previousSibling, nextSibling, ancestors, 'mi')
}

function mn(element, targetParent, previousSibling, nextSibling, ancestors) {
  return textContainer(element, targetParent, previousSibling, nextSibling, ancestors, 'mn')
}

function mo(element, targetParent, previousSibling, nextSibling, ancestors) {
  return textContainer(element, targetParent, previousSibling, nextSibling, ancestors, 'mo')
}

function ms(element, targetParent, previousSibling, nextSibling, ancestors) {
  return textContainer(element, targetParent, previousSibling, nextSibling, ancestors, 'ms')
}

const UPPER_COMBINATION = {
  '\u2190': '\u20D6', // arrow left
  '\u27F5': '\u20D6', // arrow left, long
  '\u2192': '\u20D7', // arrow right
  '\u27F6': '\u20D7', // arrow right, long
  '\u00B4': '\u0301', // accute
  '\u02DD': '\u030B', // accute, double
  '\u02D8': '\u0306', // breve
  ˇ: '\u030C', // caron
  '\u00B8': '\u0312', // cedilla
  '\u005E': '\u0302', // circumflex accent
  '\u00A8': '\u0308', // diaresis
  '\u02D9': '\u0307', // dot above
  '\u0060': '\u0300', // grave accent
  '\u002D': '\u0305', // hyphen -> overline
  '\u00AF': '\u0305', // macron
  '\u2212': '\u0305', // minus -> overline
  '\u002E': '\u0307', // period -> dot above
  '\u007E': '\u0303', // tilde
  '\u02DC': '\u0303' // small tilde
};

function underOrOver(element, targetParent, previousSibling, nextSibling, ancestors, direction) {
  // Munder/Mover

  if (element.children.length !== 2) {
    // treat as mrow
    return targetParent
  }

  ancestors = [...ancestors];
  ancestors.unshift(element);

  const base = element.children[0];
  const script = element.children[1];

  // Munder/Mover can be translated to ooml in different ways.

  // First we check for m:nAry.
  //
  // m:nAry
  //
  // Conditions:
  // 1. base text must be nary operator
  // 2. no accents
  const naryChar = getNary(base);

  if (
    naryChar &&
    element.attribs?.accent?.toLowerCase() !== 'true' &&
    element.attribs?.accentunder?.toLowerCase() !== 'true'
  ) {
    const topTarget = getNaryTarget(
      naryChar,
      element,
      'undOvr',
      direction === 'over',
      direction === 'under'
    );
    element.isNary = true;

    const subscriptTarget = {
      name: 'm:sub',
      type: 'tag',
      attribs: {},
      children: []
    };
    const superscriptTarget = {
      name: 'm:sup',
      type: 'tag',
      attribs: {},
      children: []
    };
    walker(
      script,
      direction === 'under' ? subscriptTarget : superscriptTarget,
      false,
      false,
      ancestors
    );
    topTarget.children.push(subscriptTarget);
    topTarget.children.push(superscriptTarget);
    topTarget.children.push({ type: 'tag', name: 'm:e', attribs: {}, children: [] });
    targetParent.children.push(topTarget);
    return
  }

  const scriptText = getTextContent(script);

  const baseTarget = {
    name: 'm:e',
    type: 'tag',
    attribs: {},
    children: []
  };
  walker(base, baseTarget, false, false, ancestors);

  //
  // m:bar
  //
  // Then we check whether it should be an m:bar.
  // This happens if:
  // 1. The script text is a single character that corresponds to
  //    \u0332/\u005F (underbar) or \u0305/\u00AF (overbar)
  // 2. The type of the script element is mo.
  if (
    (direction === 'under' && script.name === 'mo' && ['\u0332', '\u005F'].includes(scriptText)) ||
    (direction === 'over' && script.name === 'mo' && ['\u0305', '\u00AF'].includes(scriptText))
  ) {
    // m:bar
    targetParent.children.push({
      type: 'tag',
      name: 'm:bar',
      attribs: {},
      children: [
        {
          type: 'tag',
          name: 'm:barPr',
          attribs: {},
          children: [
            {
              type: 'tag',
              name: 'm:pos',
              attribs: {
                'm:val': direction === 'under' ? 'bot' : 'top'
              },
              children: []
            }
          ]
        },
        {
          type: 'tag',
          name: 'm:e',
          attribs: {},
          children: [
            {
              type: 'tag',
              name: direction === 'under' ? 'm:sSub' : 'm:sSup',
              attribs: {},
              children: [
                {
                  type: 'tag',
                  name: direction === 'under' ? 'm:sSubPr' : 'm:sSupPr',
                  attribs: {},
                  children: [{ type: 'tag', name: 'm:ctrlPr', attribs: {}, children: [] }]
                },
                baseTarget,
                { type: 'tag', name: 'm:sub', attribs: {}, children: [] }
              ]
            }
          ]
        }
      ]
    });
    return
  }

  // m:acc
  //
  // Next we try to see if it is an m:acc. This is the case if:
  // 1. The scriptText is 0-1 characters long.
  // 2. The script is an mo-element
  // 3. The accent is set.
  if (
    (direction === 'under' &&
      element.attribs?.accentunder?.toLowerCase() === 'true' &&
      script.name === 'mo' &&
      scriptText.length < 2) ||
    (direction === 'over' &&
      element.attribs?.accent?.toLowerCase() === 'true' &&
      script.name === 'mo' &&
      scriptText.length < 2)
  ) {
    // m:acc
    targetParent.children.push({
      type: 'tag',
      name: 'm:acc',
      attribs: {},
      children: [
        {
          type: 'tag',
          name: 'm:accPr',
          attribs: {},
          children: [
            {
              type: 'tag',
              name: 'm:chr',
              attribs: {
                'm:val': UPPER_COMBINATION[scriptText] || scriptText
              },
              children: []
            }
          ]
        },
        baseTarget
      ]
    });
    return
  }
  // m:groupChr
  //
  // Now we try m:groupChr. Conditions are:
  // 1. Base is an 'mrow' and script is an 'mo'.
  // 2. Script length is 1.
  // 3. No accent
  if (
    element.attribs?.accent?.toLowerCase() !== 'true' &&
    element.attribs?.accentunder?.toLowerCase() !== 'true' &&
    script.name === 'mo' &&
    base.name === 'mrow' &&
    scriptText.length === 1
  ) {
    targetParent.children.push({
      type: 'tag',
      name: 'm:groupChr',
      attribs: {},
      children: [
        {
          type: 'tag',
          name: 'm:groupChrPr',
          attribs: {},
          children: [
            {
              type: 'tag',
              name: 'm:chr',
              attribs: {
                'm:val': scriptText,
                'm:pos': direction === 'under' ? 'bot' : 'top'
              },
              children: []
            }
          ]
        },
        baseTarget
      ]
    });
    return
  }
  // Fallback: m:lim

  const scriptTarget = {
    name: 'm:lim',
    type: 'tag',
    attribs: {},
    children: []
  };

  walker(script, scriptTarget, false, false, ancestors);
  targetParent.children.push({
    type: 'tag',
    name: direction === 'under' ? 'm:limLow' : 'm:limUpp',
    attribs: {},
    children: [baseTarget, scriptTarget]
  });
  // Don't iterate over children in the usual way.
}

function munder(element, targetParent, previousSibling, nextSibling, ancestors) {
  return underOrOver(element, targetParent, previousSibling, nextSibling, ancestors, 'under')
}

function mover(element, targetParent, previousSibling, nextSibling, ancestors) {
  return underOrOver(element, targetParent, previousSibling, nextSibling, ancestors, 'over')
}

function mroot(element, targetParent, previousSibling, nextSibling, ancestors) {
  // Root
  if (element.children.length !== 2) {
    // treat as mrow
    return targetParent
  }
  ancestors = [...ancestors];
  ancestors.unshift(element);
  const base = element.children[0];
  const root = element.children[1];

  const baseTarget = {
    type: 'tag',
    name: 'm:e',
    attribs: {},
    children: []
  };
  walker(base, baseTarget, false, false, ancestors);

  const rootTarget = {
    type: 'tag',
    name: 'm:deg',
    attribs: {},
    children: []
  };
  walker(root, rootTarget, false, false, ancestors);

  const rootText = getTextContent(root);

  targetParent.children.push({
    type: 'tag',
    name: 'm:rad',
    attribs: {},
    children: [
      {
        type: 'tag',
        name: 'm:radPr',
        attribs: {},
        children: [
          {
            type: 'tag',
            name: 'm:degHide',
            attribs: { 'm:val': rootText.length ? 'off' : 'on' },
            children: []
          }
        ]
      },
      rootTarget,
      baseTarget
    ]
  });
}

function text(element, targetParent, previousSibling, nextSibling, ancestors) {
  let text = element.data.replace(/[\u2062]|[\u200B]/g, '');
  if (ancestors.find((element) => ['mi', 'mn', 'mo'].includes(element.name))) {
    text = text.replace(/\s/g, '');
  } else {
    const ms = ancestors.find((element) => element.name === 'ms');
    if (ms) {
      text = (ms.attribs?.lquote || '"') + text + (ms.attribs?.rquote || '"');
    }
  }
  if (text.length) {
    if (
      targetParent.children.length &&
      targetParent.children[targetParent.children.length - 1].type === 'text'
    ) {
      targetParent.children[targetParent.children.length - 1].data += text;
    } else {
      targetParent.children.push({
        type: 'text',
        data: text
      });
    }
  }
  return targetParent
}

var mathmlHandlers = /*#__PURE__*/Object.freeze({
    __proto__: null,
    math: math,
    menclose: menclose,
    mfrac: mfrac,
    mglyph: mglyph,
    mi: mi,
    mmultiscripts: mmultiscripts,
    mn: mn,
    mo: mo,
    mover: mover,
    mroot: mroot,
    mrow: mrow,
    ms: ms,
    mspace: mspace,
    msqrt: msqrt,
    mstyle: mstyle,
    msub: msub,
    msubsup: msubsup,
    msup: msup,
    mtable: mtable,
    mtd: mtd,
    mtext: mtext,
    mtr: mtr,
    munder: munder,
    munderover: munderover,
    semantics: semantics,
    text: text
});

function walker(
  element,
  targetParent,
  previousSibling = false,
  nextSibling = false,
  ancestors = []
) {
  if (
    !previousSibling &&
    ['m:deg', 'm:den', 'm:e', 'm:fName', 'm:lim', 'm:num', 'm:sub', 'm:sup'].includes(
      targetParent.name
    )
  ) {
    // We are walking through the first element within one of the
    // elements where an <m:argPr> might occur. The <m:argPr> can specify
    // the scriptlevel, but it only makes sense if there is some content.
    // The fact that we are here means that there is at least one content item.
    // So we will check whether to add the m:rPr.
    // For possible parent types, see
    // https://docs.microsoft.com/en-us/dotnet/api/documentformat.openxml.math.argumentproperties?view=openxml-2.8.1#remarks
    addScriptlevel(targetParent, ancestors);
  }
  let targetElement;
  const nameOrType = element.name || element.type;
  if (mathmlHandlers[nameOrType]) {
    targetElement = mathmlHandlers[nameOrType](
      element,
      targetParent,
      previousSibling,
      nextSibling,
      ancestors
    );
  } else {
    if (nameOrType && nameOrType !== 'root') {
      console.warn(`Type not supported: ${nameOrType}`);
    }

    targetElement = targetParent;
  }

  if (!targetElement) {
    // Target element hasn't been assigned, so don't handle children.
    return
  }
  if (element.children?.length) {
    ancestors = [...ancestors];
    ancestors.unshift(element);
    // Track nary body redirect: after a nary operator, redirect subsequent
    // siblings into its <m:e> until a relational operator (=, <, >, etc.) is
    // encountered.  Chains through nested nary operators (e.g. double
    // integrals ∫∫).
    let naryBodyTarget = null;
    // Track prescript redirect: after a msubsup with empty base (e.g.
    // {}^{14}_{6}C), redirect the next sibling into <m:sPre>'s <m:e>.
    let prescriptTarget = null;
    for (let i = 0; i < element.children.length; i++) {
      const child = element.children[i];
      if (child.skipInWalker) continue

      // A relational/separator <mo> or <mtext> stops the nary redirect so
      // that content after the operand stays outside the nary body.
      // Examples: ∑ aᵢ = S  →  operand is aᵢ  (stopped by =)
      //           ∑ aᵢ, bⱼ  →  operand is aᵢ  (stopped by ,)
      //           ∑ aᵢ \text{ for } i  →  operand is aᵢ  (stopped by mtext)
      if (naryBodyTarget) {
        if (child.name === 'mo') {
          const txt = child.children?.[0]?.data;
          if (txt && /^[=<>≤≥≠≈≡∼≲≳≪≫∈∉⊂⊃⊆⊇⊄⊅≺≻⪯⪰∝≅≃≍≎∥⊥⊢⊣⊨⊩,;:∣]$/.test(txt)) {
            naryBodyTarget = null;
          }
        } else if (child.name === 'mtext') {
          naryBodyTarget = null;
        }
      }

      const effectiveTarget = prescriptTarget || naryBodyTarget || targetElement;
      walker(
        child,
        effectiveTarget,
        element.children[i - 1],
        element.children[i + 1],
        ancestors
      );
      if (child.isNary) {
        // Chain into the new nary's <m:e>
        const naryNode = effectiveTarget.children[effectiveTarget.children.length - 1];
        naryBodyTarget = naryNode.children[naryNode.children.length - 1];
      }
      if (child.isPrescript) {
        // Redirect next sibling into <m:sPre>'s <m:e>
        const preNode = effectiveTarget.children[effectiveTarget.children.length - 1];
        prescriptTarget = preNode.children[preNode.children.length - 1];
      } else if (prescriptTarget) {
        // One element consumed; stop prescript redirect
        prescriptTarget = null;
      }
    }
  }
}

class MML2OMML {
  constructor(mmlString, options = {}) {
    this.inString = mmlString;
    this.inXML = parse(mmlString, options);
    this.outXML = false;
    this.outString = false;
  }

  run() {
    const outXML = {};
    walker({ children: this.inXML, type: 'root' }, outXML);
    this.outXML = outXML;
  }

  getResult() {
    this.outString = stringifyDoc([this.outXML]);
    return this.outString
  }
}

const mml2omml = (mmlString, options) => {
  const converter = new MML2OMML(mmlString, options);
  converter.run();
  return converter.getResult()
};

exports.mml2omml = mml2omml;
//# sourceMappingURL=index.cjs.map