import { MarkdownSerializer, MarkdownParser } from 'prosemirror-markdown';

/**
 * @type {NodeSpec}
 */
export const mentionNodeSpec = {
  attrs: {
    type: {},
    id: {},
    label: {},
  },

  group: 'inline',
  inline: true,
  selectable: false,
  atom: true,

  toDOM: node => ['span', {
    'class': 'mention',
    'data-mention-type': node.attrs.type,
    'data-mention-id': node.attrs.id,
  }, `@${node.attrs.label}`],

  parseDOM: [{
    tag: 'span[data-mention-type][data-mention-id]',

    /**
     * @param {Element} dom
     * @returns {{type: string, id: string, label: string}}
     */
    getAttrs: dom => {
      const type = dom.getAttribute('data-mention-type');
      const id = dom.getAttribute('data-mention-id');
      const label = dom.innerText;

      return { type, id, label };
    },
  }],
};

/**
 * @param {OrderedMap} nodes
 * @returns {OrderedMap}
 */
export function addMentionNodes(nodes) {
  return nodes.append({
    mention: mentionNodeSpec,
  });
}

export function markdownSerializer() {
  return (state, node) => {
    const label = state.esc(node.attrs.label || '');
    const uri = state.esc(`mention://${node.attrs.type}/${node.attrs.id}`);

    state.write(`@[${label}](${uri})`)
  };
}

export function addMentionsToMarkdownSerializer(serializer) {
  return new MarkdownSerializer({
    ...serializer.nodes,
    mention: markdownSerializer(),
  }, serializer.marks);
}

export function markdownParser() {
  return {
    node: 'mention',
    getAttrs: ({ mention: { type, id, label } }) => ({ type, id, label }),
  };
}

export function addMentionsToMarkdownParser(parser) {
  return new MarkdownParser(parser.schema, parser.tokenizer, {
    ...parser.tokens,
    mention: markdownParser(),
  });
}