import { useQuery } from '@tanstack/react-query';
import { Node } from '@tiptap/core';
import { NodeViewWrapper, ReactNodeViewRenderer } from '@tiptap/react';
import type { NodeViewProps } from '@tiptap/react';
import { useTranslation } from 'react-i18next';
import { Link } from 'react-router-dom';

import { apiGet } from '../../lib/api';
import { attributesFromSpec, nodeSpec } from '../spec-utils';
import { useWikilinks } from '../wikilink-context';

interface RenderedContent {
  title: string;
  html: string;
}

/**
 * Renders a `![[page embed]]` (issue #135). In edit mode — and while loading or
 * when the target is missing/unreadable — it shows a compact placeholder card
 * (title + open link) so writing stays fast. In read mode it fetches the
 * target's server-rendered HTML (`/read/:pond/:slug`, permission-checked, with
 * nested embeds already expanded) and shows it inline.
 */
function TransclusionView({ node, editor }: NodeViewProps): React.JSX.Element {
  const { t } = useTranslation('editor');
  const { resolve, pondSlug } = useWikilinks();

  const slug = node.attrs.targetSlug as string;
  const display = node.attrs.displayText as string | null;
  const bare = node.attrs.bare as boolean;
  const { title, exists } = resolve(slug);
  const label = display ?? title ?? slug;
  const editable = editor.isEditable;

  const content = useQuery({
    queryKey: ['rendered', pondSlug, slug],
    queryFn: () => apiGet<RenderedContent>(`/read/${pondSlug}/${slug}`),
    enabled: !editable && exists,
    retry: false,
  });

  if (editable || !exists || content.isError) {
    return (
      <NodeViewWrapper className="dt-transclusion-card" contentEditable={false}>
        <span className="dt-transclusion-card__icon" aria-hidden>
          ⧉
        </span>
        <span className="dt-transclusion-card__label">
          {t(bare ? 'transclusion.embeddedBare' : 'transclusion.embedded', { title: label })}
        </span>
        <Link className="dt-transclusion-card__open" to={`/p/${pondSlug}/${slug}`}>
          {t('transclusion.open')}
        </Link>
      </NodeViewWrapper>
    );
  }

  if (bare) {
    // `$[[…]]` (#146): the embed reads as part of the host page — no frame,
    // no title, just the target's rendered content.
    return (
      <NodeViewWrapper className="dt-embed-bare" contentEditable={false}>
        {content.data ? (
          <div dangerouslySetInnerHTML={{ __html: content.data.html }} />
        ) : (
          <div aria-busy="true" />
        )}
      </NodeViewWrapper>
    );
  }

  return (
    <NodeViewWrapper className="dt-embed" contentEditable={false}>
      <div className="dt-embed__title">
        <Link className="wikilink" to={`/p/${pondSlug}/${slug}`}>
          {content.data?.title ?? label}
        </Link>
      </div>
      {content.data ? (
        // Server-sanitized read HTML (shared docToHtml pipeline) — safe by
        // contract, same as the public view.
        <div className="dt-embed__body" dangerouslySetInnerHTML={{ __html: content.data.html }} />
      ) : (
        <div className="dt-embed__body" aria-busy="true" />
      )}
    </NodeViewWrapper>
  );
}

const transclusionSpec = nodeSpec('transclusion');
export const Transclusion = Node.create({
  name: 'transclusion',
  group: transclusionSpec.group,
  atom: transclusionSpec.atom,
  addAttributes() {
    return attributesFromSpec(transclusionSpec);
  },
  parseHTML: () => transclusionSpec.parseDOM,
  renderHTML: ({ node }) => transclusionSpec.toDOM!(node),
  addNodeView() {
    return ReactNodeViewRenderer(TransclusionView);
  },
});