export function insertMarkdownText()

in app/assets/javascripts/lib/utils/text_markdown.js [124:263]
117 lines of code
38 McCabe index (conditional complexity)

export function insertMarkdownText({
  textArea,
  text,
  tag,
  cursorOffset,
  blockTag,
  selected = '',
  wrap,
  select,
  editor,
}) {
  var textToInsert,
    selectedSplit,
    startChar,
    removedLastNewLine,
    removedFirstNewLine,
    currentLineEmpty,
    lastNewLine,
    editorSelectionStart,
    editorSelectionEnd;
  removedLastNewLine = false;
  removedFirstNewLine = false;
  currentLineEmpty = false;

  if (editor) {
    const selectionRange = editor.getSelectionRange();

    editorSelectionStart = selectionRange.start;
    editorSelectionEnd = selectionRange.end;
  }

  // check for link pattern and selected text is an URL
  // if so fill in the url part instead of the text part of the pattern.
  if (tag === LINK_TAG_PATTERN) {
    if (URL) {
      try {
        const ignoredUrl = new URL(selected);
        // valid url
        tag = '[text]({text})';
        select = 'text';
      } catch (e) {
        // ignore - no valid url
      }
    }
  }

  // Remove the first newline
  if (selected.indexOf('\n') === 0) {
    removedFirstNewLine = true;
    selected = selected.replace(/\n+/, '');
  }

  // Remove the last newline
  if (textArea) {
    if (textArea.selectionEnd - textArea.selectionStart > selected.replace(/\n$/, '').length) {
      removedLastNewLine = true;
      selected = selected.replace(/\n$/, '');
    }
  } else if (editor) {
    if (editorSelectionStart.row !== editorSelectionEnd.row) {
      removedLastNewLine = true;
      selected = selected.replace(/\n$/, '');
    }
  }

  selectedSplit = selected.split('\n');

  if (editor && !wrap) {
    lastNewLine = editor.getValue().split('\n')[editorSelectionStart.row];

    if (/^\s*$/.test(lastNewLine)) {
      currentLineEmpty = true;
    }
  } else if (textArea && !wrap) {
    lastNewLine = textArea.value.substr(0, textArea.selectionStart).lastIndexOf('\n');

    // Check whether the current line is empty or consists only of spaces(=handle as empty)
    if (/^\s*$/.test(textArea.value.substring(lastNewLine, textArea.selectionStart))) {
      currentLineEmpty = true;
    }
  }

  const isBeginning =
    (textArea && textArea.selectionStart === 0) ||
    (editor && editorSelectionStart.column === 0 && editorSelectionStart.row === 0);

  startChar = !wrap && !currentLineEmpty && !isBeginning ? '\n' : '';

  const textPlaceholder = '{text}';

  if (selectedSplit.length > 1 && (!wrap || (blockTag != null && blockTag !== ''))) {
    if (blockTag != null && blockTag !== '') {
      textToInsert = editor
        ? editorBlockTagText(text, blockTag, selected, editor)
        : blockTagText(text, textArea, blockTag, selected);
    } else {
      textToInsert = selectedSplit
        .map(function(val) {
          if (tag.indexOf(textPlaceholder) > -1) {
            return tag.replace(textPlaceholder, val);
          }
          if (val.indexOf(tag) === 0) {
            return String(val.replace(tag, ''));
          } else {
            return String(tag) + val;
          }
        })
        .join('\n');
    }
  } else if (tag.indexOf(textPlaceholder) > -1) {
    textToInsert = tag.replace(textPlaceholder, selected);
  } else {
    textToInsert = String(startChar) + tag + selected + (wrap ? tag : ' ');
  }

  if (removedFirstNewLine) {
    textToInsert = '\n' + textToInsert;
  }

  if (removedLastNewLine) {
    textToInsert += '\n';
  }

  if (editor) {
    editor.insert(textToInsert);
  } else {
    insertText(textArea, textToInsert);
  }
  return moveCursor({
    textArea,
    tag: tag.replace(textPlaceholder, selected),
    cursorOffset,
    positionBetweenTags: wrap && selected.length === 0,
    removedLastNewLine,
    select,
    editor,
    editorSelectionStart,
    editorSelectionEnd,
  });
}