index.js

const markAfterNum = '[A-Z0-9]{1,6}(?:[.-][A-Z0-9]{1,6}){0,5}';
const joint = '[.:．。：　]';
const jointFullWidth = '[．。：　]';
const jointHalfWidth = '[.:]';

const markAfterEn = '(?:' +
  ' *(?:' +
    jointHalfWidth + '(?:(?=[ ]+)|$)|' +
    jointFullWidth + '|' +
    '(?=[ ]+[^0-9a-zA-Z])' +
  ')|' +
  ' *(' + markAfterNum + ')(?:' +
    jointHalfWidth + '(?:(?=[ ]+)|$)|' +
    jointFullWidth + '|' +
    '(?=[ ]+[^a-z])|$' +
  ')|' +
  '[.](' + markAfterNum + ')(?:' +
    joint + '|(?=[ ]+[^a-z])|$' +
  ')' +
')';

const markAfterJa = '(?:' +
  ' *(?:' +
    jointHalfWidth + '(?:(?=[ ]+)|$)|' +
    jointFullWidth + '|' +
    '(?=[ ]+)' +
  ')|' +
  ' *(' + markAfterNum + ')(?:' +
    jointHalfWidth + '(?:(?=[ ]+)|$)|' +
    jointFullWidth + '|' +
    '(?=[ ]+)|$' +
  ')' +
')';

const markReg = {
  //fig(ure)?, illust, photo
  "img": new RegExp('^(?:' +
    '(?:[fF][iI][gG](?:[uU][rR][eE])?|[iI][lL]{2}[uU][sS][tT]|[pP][hH][oO][tT][oO])'+ markAfterEn + '|' +
    '(?:図|イラスト|写真)' + markAfterJa +
  ')'),
  //movie, video
  "video": new RegExp('^(?:' +
    '(?:[mM][oO][vV][iI][eE]|[vV][iI][dD][eE][oO])'+ markAfterEn + '|' +
    '(?:動画|ビデオ)' + markAfterJa +
  ')'),
  //table
  "table": new RegExp('^(?:' +
    '(?:[tT][aA][bB][lL][eE])'+ markAfterEn + '|' +
    '(?:表)' + markAfterJa +
  ')'),
  //code(block)?, program
  "pre-code": new RegExp('^(?:' +
    '(?:[cC][oO][dD][eE](?:[bB][lL][oO][cC][kK])?|[pP][rR][oO][gG][rR][aA][mM]|[aA][lL][gG][oO][rR][iI][tT][hH][mM])'+ markAfterEn + '|' +
    '(?:(?:ソース)?コード|リスト|命令|プログラム|算譜|アルゴリズム|算法)' + markAfterJa +
  ')'),
  //terminal, prompt, command
  "pre-samp": new RegExp('^(?:' +
    '(?:[cC][oO][nN][sS][oO][lL][eE]|[tT][eE][rR][mM][iI][nN][aA][lL]|[pP][rR][oO][mM][pP][tT]|[cC][oO][mM]{2}[aA][nN][dD])'+ markAfterEn + '|' +
    '(?:端末|リスト|ターミナル|コマンド|(?:コマンド)?プロンプト)' + markAfterJa +
  ')'),
  //quote, blockquote, source
  "blockquote": new RegExp('^(?:' +
    '(?:(?:[bB][lL][oO][cC][kK])?[qQ][uU][oO][tT][eE]|[sS][oO][uU][rR][cC][eE])'+ markAfterEn + '|' +
    '(?:引用(?:元)?|出典)' + markAfterJa +
  ')'),
  //slide
  "slide": new RegExp('^(?:' +
    '(?:[sS][lL][iI][dD][eE])'+ markAfterEn + '|' +
    '(?:スライド)' + markAfterJa +
  ')')
};

/* Notice: the label only caption such as "Figure." and "図。" can be converted, but double-byte space caption i.e. `図　` only  cannot be converted. (This happens because the full-width spaces at the end of the paragraph have been trimmed.) */

const setCaptionParagraph = (n, state, caption, sp, opt) => {
  const token = state.tokens[n];
  const nextToken = state.tokens[n+1];
  const isParagraphStartTag = token.type === 'paragraph_open';
  if (!isParagraphStartTag)  return caption
  if (n > 1) {
    const isList = state.tokens[n-1].type === 'list_item_open';
    if (isList) return caption
  }

  let actualLabel = '';
  let actualNum = '';
  let actualLabelJoint = '';
  for (let mark of Object.keys(markReg)) {
    if (caption.name) {
      if (/^pre/.test(mark)) {
        if (caption.name !== mark) {
          continue
        }
      }
    }
    const hasMarkLabel = nextToken.content.match(markReg[mark]);
    if (hasMarkLabel) {
      let i = 1;
      while (i < 6) {
        if (hasMarkLabel[i] !== undefined) {
          actualNum = hasMarkLabel[i];
          break;
        }
        i++;
      }
      //console.log('mark: ' + mark + ', caption.name: ' + caption.name + ', sp.isIframeTypeBlockquote: ' + sp.isIframeTypeBlockquote, ', sp.isVideoIframe: ' + sp.isVideoIframe)
      if (sp.isIframeTypeBlockquote) {
        if (mark !== 'blockquote' && caption.name !== 'blockquote') return caption
      } else if (sp.isVideoIframe) {
        if (mark !== 'video' && caption.name !== 'iframe') return caption
      } else if (caption.name) {
        if(caption.name !== 'iframe' && caption.name !== mark) return caption
      }

      token.attrJoin('class', opt.classPrefix + '-' + mark);
      actualLabel = hasMarkLabel[0];
      actualLabelJoint = actualLabel.match(new RegExp('(' + joint + '|)$'));
      if(actualLabelJoint) {
        actualLabelJoint = actualLabelJoint[1];
      }
      actualLabel = actualLabel.replace(/ *$/, '');
      let convertJointSpaceFullWith = false;
      if (opt.jointSpaceUseHalfWidth && actualLabelJoint === '　') {
        actualLabelJoint = ''
        convertJointSpaceFullWith = true;
      }
      /*
      console.log('=============================');
      console.log('actualLabel: ' + actualLabel + ', actualNum: ' + actualNum + ', actualLabelJoint: ' + actualLabelJoint);
      */
      addLabel(state, nextToken, mark, actualLabel, actualNum, actualLabelJoint, convertJointSpaceFullWith, opt);
      return caption
    }
  }
  return caption
}

const actualLabelContent = (actualLabel, actualLabelJoint, convertJointSpaceFullWith, opt) => {
  actualLabel = actualLabel.replace(new RegExp('\\\\' + actualLabelJoint + '$'), '');
  if (convertJointSpaceFullWith) {
    actualLabel = actualLabel.replace(/　$/, '');
  }
  return actualLabel;
}

const markFilename = (state, nextToken, mark, opt) => {

  let filename = nextToken.children[0].content.match(/^([ 　]*?)"(\S.*?)"(?:[ 　]+|$)/);
  nextToken.children[0].content = nextToken.children[0].content.replace(/^[ 　]*?"\S.*?"([ 　]+|$)/, '$1');

  const beforeFilenameToken = new state.Token('text', '', 0)
  beforeFilenameToken.content = filename[1];
  const filenameTokenOpen = new state.Token('strong_open', 'strong', 1);
  filenameTokenOpen.attrSet('class', opt.classPrefix + '-' + mark + '-filename');
  const filenameTokenContent = new state.Token('text', '', 0);
  filenameTokenContent.content = filename[2];
  const filenameTokenClose = new state.Token('strong_close', 'strong', -1);

  nextToken.children.splice(0, 0, beforeFilenameToken, filenameTokenOpen, filenameTokenContent, filenameTokenClose);
  return;
}

const addLabel = (state, nextToken, mark, actualLabel, actualNum, actualLabelJoint, convertJointSpaceFullWith, opt) => {

  let labelTag = 'span';
  if (opt.bLabel) labelTag = 'b';
  if (opt.strongLabel) labelTag = 'strong';

  const labelToken = {
    first: new state.Token('text', '', 0),
    open: new state.Token(labelTag + '_open', labelTag, 1),
    content: new state.Token('text', '', 0),
    close: new state.Token(labelTag + '_close', labelTag, -1),
  };

  labelToken.open.attrSet('class', opt.classPrefix + '-' + mark + '-label');
  if (opt.hasNumClass && actualNum) {
    labelToken.open.attrJoin('class', 'label-has-num');
  }
  labelToken.content.content = actualLabelContent(actualLabel, actualLabelJoint, convertJointSpaceFullWith, opt);

  nextToken.children[0].content = nextToken.children[0].content.replace(actualLabel, '');
  if (convertJointSpaceFullWith) {
    nextToken.children[0].content = ' ' + nextToken.children[0].content;
  }

  if (opt.strongFilename) {
    if (nextToken.children.length > 4) {
      if(nextToken.children[1].type === 'strong_open'
        && nextToken.children[3].type === 'strong_close'
        && /^(?:[ 　]|$)/.test(nextToken.children[4].content)) {
        nextToken.children[1].attrJoin('class', opt.classPrefix + '-' + mark + '-filename');
      }
    }
  }

  if (opt.dquoteFilename) {
    if (nextToken.children[0].content.match(/^[ 　]*?"\S.*?"(?:[ 　]+|$)/)) {
      markFilename(state, nextToken, mark, opt);
    }
  }

  if (actualNum) {
    modifyLabel(state, nextToken, mark, labelToken, actualLabelJoint, opt);
  } else {
    if (opt.removeUnnumberedLabel) {
      if (opt.removeUnnumberedLabelExceptMarks.length > 0) {
        let isExceptMark = false
        for (let exceptMark of opt.removeUnnumberedLabelExceptMarks) {
          if (exceptMark === mark) {
            isExceptMark = true
            break
          }
        }
        if (isExceptMark) {
          modifyLabel(state, nextToken, mark, labelToken, actualLabelJoint, opt);
        } else {
          nextToken.children[0].content = nextToken.children[0].content.replace(new RegExp('^ *'), '');
        }
      } else {
        nextToken.children[0].content = nextToken.children[0].content.replace(new RegExp('^ *'), '');
      }
    } else {
      modifyLabel(state, nextToken, mark, labelToken, actualLabelJoint, opt);
    }
  }
  return true;
}

const modifyLabel = (state, nextToken, mark, labelToken, actualLabelJoint, opt) => {
  nextToken.children.splice(0, 0, labelToken.first, labelToken.open, labelToken.content, labelToken.close);
  if (!actualLabelJoint) { return; }
  nextToken.children[2].content = nextToken.children[2].content.replace(new RegExp(actualLabelJoint + ' *$'), '');

  const labelJointToken = {
    open: new state.Token('span_open', 'span', 1),
    content: new state.Token('text', '', 0),
    close: new state.Token('span_close', 'span', -1),
  };
  labelJointToken.open.attrSet('class', opt.classPrefix + '-' + mark + '-label-joint');
  labelJointToken.content.content = actualLabelJoint;

  nextToken.children.splice(3, 0, labelJointToken.open, labelJointToken.content, labelJointToken.close);
  return;
}

const mditPCaption = (md, option) => {
  const opt = {
    classPrefix: 'caption',
    dquoteFilename: false,
    strongFilename: false,
    hasNumClass: false,
    bLabel: false,
    strongLabel: false,
    jointSpaceUseHalfWidth: false,
    removeUnnumberedLabel: false,
    removeUnnumberedLabelExceptMarks: [],
  };
  if (option !== undefined) {
    for (let o in option) {
        opt[o] = option[o]
    }
  }

  const caption = {
    mark: '',
    name: '',
    nameSuffix: '',
    isPrev: false,
    isNext: false,
  }

  const sp = {
    isIframeTypeBlockquote: false,
    isVideoIframe: false,
  }

  md.core.ruler.after('inline', 'p-caption', (state) => {
    let n = 0;
    while (n < state.tokens.length - 1) {
      setCaptionParagraph(n, state, caption, sp, opt)
      n++
    }
  })
}

export default mditPCaption
export { setCaptionParagraph, markAfterNum, joint, jointFullWidth, jointHalfWidth, markAfterEn, markAfterJa, markReg }