src/lib/prosemirror/utils.ts

import type { Node, NodeType, ResolvedPos, Mark, MarkType, Schema } from 'prosemirror-model';
import type { EditorState, Selection } from 'prosemirror-state';
import type { EditorView } from 'prosemirror-view';
import { selectAll } from 'prosemirror-commands';

export const isList = (node: Node, schema: Schema) => {
  return node.type === schema.nodes.bullet_list || node.type === schema.nodes.ordered_list;
};

export const autoSelectAll = (view: EditorView) => {
  const { empty } = view.state.selection;
  if (empty) selectAll(view.state, view.dispatch);
};

export const addMark = (
  editorView: EditorView,
  mark: Mark,
  selection?: { from: number; to: number },
) => {
  if (selection) {
    editorView.dispatch(editorView.state.tr.addMark(selection.from, selection.to, mark));
  } else {
    const { $from, $to } = editorView.state.selection;
    editorView.dispatch(editorView.state.tr.addMark($from.pos, $to.pos, mark));
  }
};

export const findNodesWithSameMark = (doc: Node, from: number, to: number, markType: MarkType) => {
  let ii = from;
  const finder = (mark: Mark) => mark.type === markType;
  let firstMark = null;
  let fromNode = null;
  let toNode = null;

  while (ii <= to) {
    const node = doc.nodeAt(ii);
    if (!node || !node.marks) return null;

    const mark = node.marks.find(finder);
    if (!mark) return null;

    if (firstMark && mark !== firstMark) return null;

    fromNode = fromNode || node;
    firstMark = firstMark || mark;
    toNode = node;
    ii++;
  }

  let fromPos = from;
  let toPos = to;

  let jj = 0;
  ii = from - 1;
  while (ii > jj) {
    const node = doc.nodeAt(ii);
    const mark = node && node.marks.find(finder);
    if (!mark || mark !== firstMark) break;
    fromPos = ii;
    fromNode = node;
    ii--;
  }

  ii = to + 1;
  jj = doc.nodeSize - 2;
  while (ii < jj) {
    const node = doc.nodeAt(ii);
    const mark = node && node.marks.find(finder);
    if (!mark || mark !== firstMark) break;
    toPos = ii;
    toNode = node;
    ii++;
  }

  return {
    mark: firstMark,
    from: {
      node: fromNode,
      pos: fromPos,
    },
    to: {
      node: toNode,
      pos: toPos,
    },
  };
};

const equalNodeType = (nodeType: NodeType, node: Node) => {
  return (Array.isArray(nodeType) && nodeType.indexOf(node.type) > -1) || node.type === nodeType;
};

const findParentNodeClosestToPos = ($pos: ResolvedPos, predicate: (node: Node) => boolean) => {
  for (let i = $pos.depth; i > 0; i--) {
    const node = $pos.node(i);
    if (predicate(node)) {
      return {
        pos: i > 0 ? $pos.before(i) : 0,
        start: $pos.start(i),
        depth: i,
        node,
      };
    }
  }
};

export const findParentNode = (predicate: (node: Node) => boolean) => {
  return (_ref: Selection) => findParentNodeClosestToPos(_ref.$from, predicate);
};

export const findParentNodeOfType = (nodeType: NodeType) => {
  return (selection: Selection) => {
    return findParentNode((node: Node) => {
      return equalNodeType(nodeType, node);
    })(selection);
  };
};

export const isActiveOfParentNodeType = (nodeType: string, state: EditorState) => {
  const node = state.schema.nodes[nodeType];
  return !!findParentNodeOfType(node)(state.selection);
};

export const getLastTextNode = (node: Node | null): Node | null => {
  if (!node) return null;
  if (node.type.name === 'text') return node;
  if (!node.lastChild) return null;

  return getLastTextNode(node.lastChild);
};

export const getMarkAttrs = (view: EditorView) => {
  const { selection, doc } = view.state;
  const { from } = selection;

  let node = doc.nodeAt(from) || doc.nodeAt(from - 1);
  node = getLastTextNode(node);

  return node?.marks || [];
};

export const getAttrValue = (
  marks: readonly Mark[],
  markType: string,
  attr: string,
): string | null => {
  for (const mark of marks) {
    if (mark.type.name === markType && mark.attrs[attr]) return mark.attrs[attr];
  }
  return null;
};

export const isActiveMark = (marks: readonly Mark[], markType: string) => {
  for (const mark of marks) {
    if (mark.type.name === markType) return true;
  }
  return false;
};

export const markActive = (state: EditorState, type: MarkType) => {
  const { from, $from, to, empty } = state.selection;
  if (empty) return type.isInSet(state.storedMarks || $from.marks());
  return state.doc.rangeHasMark(from, to, type);
};

export const getAttrValueInSelection = (view: EditorView, attr: string) => {
  const { selection, doc } = view.state;
  const { from, to } = selection;

  let keepChecking = true;
  let value = '';
  doc.nodesBetween(from, to, (node) => {
    if (keepChecking && node.attrs[attr]) {
      keepChecking = false;
      value = node.attrs[attr];
    }
    return keepChecking;
  });
  return value;
};

type Align = 'left' | 'right' | 'center';

interface DefaultAttrs {
  color: string;
  backcolor: string;
  fontsize: string;
  fontname: string;
  align: Align;
}
const _defaultAttrs: DefaultAttrs = {
  color: '#000000',
  backcolor: '',
  fontsize: '16px',
  fontname: '',
  align: 'left',
};
export const getTextAttrs = (view: EditorView, attrs: Partial<DefaultAttrs> = {}) => {
  const defaultAttrs: DefaultAttrs = { ..._defaultAttrs, ...attrs };

  const marks = getMarkAttrs(view);

  const isBold = isActiveMark(marks, 'strong');
  const isEm = isActiveMark(marks, 'em');
  const isUnderline = isActiveMark(marks, 'underline');
  const isStrikethrough = isActiveMark(marks, 'strikethrough');
  const isSuperscript = isActiveMark(marks, 'superscript');
  const isSubscript = isActiveMark(marks, 'subscript');
  const isCode = isActiveMark(marks, 'code');
  const color = getAttrValue(marks, 'forecolor', 'color') || defaultAttrs.color;
  const backcolor = getAttrValue(marks, 'backcolor', 'backcolor') || defaultAttrs.backcolor;
  const fontsize = getAttrValue(marks, 'fontsize', 'fontsize') || defaultAttrs.fontsize;
  const fontname = getAttrValue(marks, 'fontname', 'fontname') || defaultAttrs.fontname;
  const link = getAttrValue(marks, 'link', 'href') || '';
  const align = (getAttrValueInSelection(view, 'align') || defaultAttrs.align) as Align;
  const isBulletList = isActiveOfParentNodeType('bullet_list', view.state);
  const isOrderedList = isActiveOfParentNodeType('ordered_list', view.state);
  const isBlockquote = isActiveOfParentNodeType('blockquote', view.state);

  return {
    bold: isBold,
    em: isEm,
    underline: isUnderline,
    strikethrough: isStrikethrough,
    superscript: isSuperscript,
    subscript: isSubscript,
    code: isCode,
    color: color,
    backcolor: backcolor,
    fontsize: fontsize,
    fontname: fontname,
    link: link,
    align: align,
    bulletList: isBulletList,
    orderedList: isOrderedList,
    blockquote: isBlockquote,
  };
};

export type TextAttrs = ReturnType<typeof getTextAttrs>;

export const getFontsize = (view: EditorView) => {
  const marks = getMarkAttrs(view);
  const fontsize = getAttrValue(marks, 'fontsize', 'fontsize') || _defaultAttrs.fontsize;
  return parseInt(fontsize);
};

export const defaultRichTextAttrs: TextAttrs = {
  bold: false,
  em: false,
  underline: false,
  strikethrough: false,
  superscript: false,
  subscript: false,
  code: false,
  color: '#000000',
  backcolor: '',
  fontsize: '16px',
  fontname: '',
  link: '',
  align: 'left',
  bulletList: false,
  orderedList: false,
  blockquote: false,
};