feat(core): add markdown preview for backlinks (#8883)

packages/frontend/core/src/components/blocksuite/block-suite-editor/bi-directional-link-panel.tsx

@@ -5,7 +5,7 @@ import {
 } from '@affine/core/modules/doc-link';
 import { useI18n } from '@affine/i18n';
 import { LiveData, useLiveData, useServices } from '@toeverything/infra';
-import { useCallback, useState } from 'react';
+import { Fragment, useCallback, useState } from 'react';
 
 import { AffinePageReference } from '../../affine/reference-link';
 import * as styles from './bi-directional-link-panel.css';
@@ -52,9 +52,14 @@ export const BiDirectionalLinkPanel = () => {
               {t['com.affine.page-properties.backlinks']()} · {backlinks.length}
             </div>
             {backlinks.map(link => (
-              <div key={link.docId} className={styles.link}>
-                <AffinePageReference key={link.docId} pageId={link.docId} />
-              </div>
+              <Fragment key={link.docId}>
+                <div className={styles.link}>
+                  <AffinePageReference key={link.docId} pageId={link.docId} />
+                </div>
+                <br />
+                <pre style={{ opacity: 0.5 }}>{link.markdownPreview}</pre>
+                <br />
+              </Fragment>
             ))}
           </div>
           <div className={styles.linksContainer}>

packages/frontend/core/src/modules/doc-info/views/database-properties/doc-database-backlink-info.tsx

@@ -122,7 +122,6 @@ const DatabaseBacklinkRow = ({
 
   return (
     <PropertyCollapsibleSection
-      // @ts-expect-error fix type
       title={
         <span className={styles.databaseNameWrapper}>
           <span className={styles.databaseName}>

packages/frontend/core/src/modules/doc-link/entities/doc-backlinks.ts

@@ -7,6 +7,7 @@ export interface Backlink {
   docId: string;
   blockId: string;
   title: string;
+  markdownPreview?: string;
 }
 
 export class DocBacklinks extends Entity {

packages/frontend/core/src/modules/docs-search/entities/docs-indexer.ts

@@ -36,7 +36,7 @@ export class DocsIndexer extends Entity {
   /**
    * increase this number to re-index all docs
    */
-  static INDEXER_VERSION = 6;
+  static INDEXER_VERSION = 10;
 
   private readonly jobQueue: JobQueue<IndexerJobPayload> =
     new IndexedDBJobQueue<IndexerJobPayload>(

packages/frontend/core/src/modules/docs-search/schema.ts

@@ -28,6 +28,7 @@ export const blockIndexSchema = defineSchema({
   // additional info
   // { "databaseName": "xxx" }
   additional: { type: 'String', index: false },
+  markdownPreview: { type: 'String', index: false },
 });
 
 export type BlockIndexSchema = typeof blockIndexSchema;

packages/frontend/core/src/modules/docs-search/services/docs-search.ts

@@ -478,7 +478,7 @@ export class DocsSearchService extends Service {
         'docId',
         {
           hits: {
-            fields: ['docId', 'blockId'],
+            fields: ['docId', 'blockId', 'markdownPreview'],
             pagination: {
               limit: 1,
             },
@@ -499,10 +499,16 @@ export class DocsSearchService extends Service {
               const title =
                 docData.find(doc => doc.id === bucket.key)?.get('title') ?? '';
               const blockId = bucket.hits.nodes[0]?.fields.blockId ?? '';
+              const markdownPreview =
+                bucket.hits.nodes[0]?.fields.markdownPreview ?? '';
               return {
                 docId: bucket.key,
                 blockId: typeof blockId === 'string' ? blockId : blockId[0],
                 title: typeof title === 'string' ? title : title[0],
+                markdownPreview:
+                  typeof markdownPreview === 'string'
+                    ? markdownPreview
+                    : markdownPreview[0],
               };
             });
           });

packages/frontend/core/src/modules/docs-search/worker/in-worker.ts

@@ -1,6 +1,16 @@
-import type { AffineTextAttributes } from '@blocksuite/affine/blocks';
+import {
+  type AffineTextAttributes,
+  MarkdownAdapter,
+} from '@blocksuite/affine/blocks';
+import {
+  createYProxy,
+  DocCollection,
+  type DraftModel,
+  Job,
+  type YBlock,
+} from '@blocksuite/affine/store';
 import type { DeltaInsert } from '@blocksuite/inline';
-import { Document } from '@toeverything/infra';
+import { Document, getAFFiNEWorkspaceSchema } from '@toeverything/infra';
 import { toHexString } from 'lib0/buffer.js';
 import { digest as lib0Digest } from 'lib0/hash/sha256';
 import { difference, uniq } from 'lodash-es';
@@ -20,6 +30,8 @@ import type {
   WorkerOutput,
 } from './types';
 
+const blocksuiteSchema = getAFFiNEWorkspaceSchema();
+
 const LRU_CACHE_SIZE = 5;
 
 // lru cache for ydoc instances, last used at the end of the array
@@ -61,6 +73,92 @@ async function getOrCreateCachedYDoc(data: Uint8Array) {
   }
 }
 
+function yblockToDraftModal(yblock: YBlock): DraftModel | null {
+  const flavour = yblock.get('sys:flavour');
+  const blockSchema = blocksuiteSchema.flavourSchemaMap.get(flavour);
+  if (!blockSchema) {
+    return null;
+  }
+  const keys = Array.from(yblock.keys())
+    .filter(key => key.startsWith('prop:'))
+    .map(key => key.substring(5));
+
+  const props = Object.fromEntries(
+    keys.map(key => [key, createYProxy(yblock.get(`prop:${key}`))])
+  );
+
+  return {
+    ...props,
+    id: yblock.get('sys:id'),
+    flavour,
+    children: [],
+    role: blockSchema.model.role,
+    version: (yblock.get('sys:version') as number) ?? blockSchema.version,
+    keys: Array.from(yblock.keys())
+      .filter(key => key.startsWith('prop:'))
+      .map(key => key.substring(5)),
+  };
+}
+
+const markdownAdapter = new MarkdownAdapter(
+  new Job({
+    collection: new DocCollection({
+      id: 'indexer',
+      schema: blocksuiteSchema,
+    }),
+  })
+);
+
+interface BlockDocumentInfo {
+  docId: string;
+  blockId: string;
+  content?: string | string[];
+  flavour: string;
+  blob?: string[];
+  refDocId?: string[];
+  ref?: string[];
+  parentFlavour?: string;
+  parentBlockId?: string;
+  additional?: { databaseName?: string };
+  yblock: YMap<any>;
+  markdownPreview?: string;
+}
+
+const markdownPreviewCache = new WeakMap<BlockDocumentInfo, string | null>();
+const generateMarkdownPreview = async (block: BlockDocumentInfo) => {
+  if (markdownPreviewCache.has(block)) {
+    return markdownPreviewCache.get(block);
+  }
+  const flavour = block.flavour;
+  let markdown: string | null = null;
+  if (
+    flavour === 'affine:paragraph' ||
+    flavour === 'affine:list' ||
+    flavour === 'affine:code'
+  ) {
+    const draftModel = yblockToDraftModal(block.yblock);
+    markdown =
+      block.parentFlavour === 'affine:database'
+        ? `database · ${block.additional?.databaseName}\n`
+        : ((draftModel ? await markdownAdapter.fromBlock(draftModel) : null)
+            ?.file ?? null);
+  }
+  if (
+    flavour === 'affine:embed-linked-doc' ||
+    flavour === 'affine:embed-synced-doc'
+  ) {
+    markdown = '🔗\n';
+  }
+  if (flavour === 'affine:attachment') {
+    markdown = '📃\n';
+  }
+  if (flavour === 'affine:image') {
+    markdown = '🖼️\n';
+  }
+  markdownPreviewCache.set(block, markdown);
+  return markdown;
+};
+
 async function crawlingDocData({
   docBuffer,
   storageDocId,
@@ -110,7 +208,7 @@ async function crawlingDocData({
     let docTitle = '';
     let summaryLenNeeded = 1000;
     let summary = '';
-    const blockDocuments: Document<BlockIndexSchema>[] = [];
+    const blockDocuments: BlockDocumentInfo[] = [];
 
     const blocks = ydoc.getMap<any>('blocks');
 
@@ -147,6 +245,7 @@ async function crawlingDocData({
       }
     };
 
+    // #region first loop - generate block base info
     while (queue.length) {
       const next = queue.pop();
       if (!next) {
@@ -167,14 +266,13 @@ async function crawlingDocData({
 
       if (flavour === 'affine:page') {
         docTitle = block.get('prop:title').toString();
-        blockDocuments.push(
-          Document.from(`${docId}:${blockId}`, {
-            docId,
-            flavour,
-            blockId,
-            content: docTitle,
-          })
-        );
+        blockDocuments.push({
+          docId,
+          flavour,
+          blockId,
+          content: docTitle,
+          yblock: block,
+        });
       }
 
       if (
@@ -183,6 +281,7 @@ async function crawlingDocData({
         flavour === 'affine:code'
       ) {
         const text = block.get('prop:text') as YText;
+
         if (!text) {
           continue;
         }
@@ -213,27 +312,24 @@ async function crawlingDocData({
             ? parentBlock?.get('prop:title')?.toString()
             : undefined;
 
-        blockDocuments.push(
-          Document.from<BlockIndexSchema>(`${docId}:${blockId}`, {
-            docId,
-            flavour,
-            blockId,
-            content: text.toString(),
-            ...refs.reduce<{ refDocId: string[]; ref: string[] }>(
-              (prev, curr) => {
-                prev.refDocId.push(curr.refDocId);
-                prev.ref.push(curr.ref);
-                return prev;
-              },
-              { refDocId: [], ref: [] }
-            ),
-            parentFlavour,
-            parentBlockId,
-            additional: databaseName
-              ? JSON.stringify({ databaseName })
-              : undefined,
-          })
-        );
+        blockDocuments.push({
+          docId,
+          flavour,
+          blockId,
+          content: text.toString(),
+          ...refs.reduce<{ refDocId: string[]; ref: string[] }>(
+            (prev, curr) => {
+              prev.refDocId.push(curr.refDocId);
+              prev.ref.push(curr.ref);
+              return prev;
+            },
+            { refDocId: [], ref: [] }
+          ),
+          parentFlavour,
+          parentBlockId,
+          additional: { databaseName },
+          yblock: block,
+        });
 
         if (summaryLenNeeded > 0) {
           summary += text.toString();
@@ -249,33 +345,31 @@ async function crawlingDocData({
         if (typeof pageId === 'string') {
           // reference info
           const params = block.get('prop:params') ?? {};
-          blockDocuments.push(
-            Document.from<BlockIndexSchema>(`${docId}:${blockId}`, {
-              docId,
-              flavour,
-              blockId,
-              refDocId: [pageId],
-              ref: [JSON.stringify({ docId: pageId, ...params })],
-              parentFlavour,
-              parentBlockId,
-            })
-          );
+          blockDocuments.push({
+            docId,
+            flavour,
+            blockId,
+            refDocId: [pageId],
+            ref: [JSON.stringify({ docId: pageId, ...params })],
+            parentFlavour,
+            parentBlockId,
+            yblock: block,
+          });
         }
       }
 
       if (flavour === 'affine:attachment' || flavour === 'affine:image') {
         const blobId = block.get('prop:sourceId');
         if (typeof blobId === 'string') {
-          blockDocuments.push(
-            Document.from<BlockIndexSchema>(`${docId}:${blockId}`, {
-              docId,
-              flavour,
-              blockId,
-              blob: [blobId],
-              parentFlavour,
-              parentBlockId,
-            })
-          );
+          blockDocuments.push({
+            docId,
+            flavour,
+            blockId,
+            blob: [blobId],
+            parentFlavour,
+            parentBlockId,
+            yblock: block,
+          });
         }
       }
 
@@ -308,16 +402,15 @@ async function crawlingDocData({
           texts.push(text.toString());
         }
 
-        blockDocuments.push(
-          Document.from<BlockIndexSchema>(`${docId}:${blockId}`, {
-            docId,
-            flavour,
-            blockId,
-            content: texts,
-            parentFlavour,
-            parentBlockId,
-          })
-        );
+        blockDocuments.push({
+          docId,
+          flavour,
+          blockId,
+          content: texts,
+          parentFlavour,
+          parentBlockId,
+          yblock: block,
+        });
       }
 
       if (flavour === 'affine:database') {
@@ -356,16 +449,81 @@ async function crawlingDocData({
           }
         }
 
-        blockDocuments.push(
-          Document.from<BlockIndexSchema>(`${docId}:${blockId}`, {
-            docId,
-            flavour,
-            blockId,
-            content: texts,
-          })
-        );
+        blockDocuments.push({
+          docId,
+          flavour,
+          blockId,
+          content: texts,
+          yblock: block,
+        });
       }
     }
+    // #endregion
+
+    // #region second loop - generate markdown preview
+    const TARGET_PREVIEW_CHARACTER = 500;
+    const TARGET_PREVIOUS_BLOCK = 1;
+    const TARGET_FOLLOW_BLOCK = 4;
+    for (let i = 0; i < blockDocuments.length; i++) {
+      const block = blockDocuments[i];
+      if (block.ref) {
+        // only generate markdown preview for reference blocks
+        let previewText = (await generateMarkdownPreview(block)) ?? '';
+        let previousBlock = 0;
+        let followBlock = 0;
+        let previousIndex = i;
+        let followIndex = i;
+
+        while (
+          !(
+            (
+              previewText.length > TARGET_PREVIEW_CHARACTER || // stop if preview text reaches the limit
+              ((previousBlock >= TARGET_PREVIOUS_BLOCK || previousIndex < 0) &&
+                (followBlock >= TARGET_FOLLOW_BLOCK ||
+                  followIndex >= blockDocuments.length))
+            ) // stop if no more blocks, or preview block reaches the limit
+          )
+        ) {
+          if (previousBlock < TARGET_PREVIOUS_BLOCK) {
+            previousIndex--;
+            const block =
+              previousIndex >= 0 ? blockDocuments.at(previousIndex) : null;
+            const markdown = block
+              ? await generateMarkdownPreview(block)
+              : null;
+            if (
+              markdown &&
+              !previewText.startsWith(
+                markdown
+              ) /* A small hack to skip blocks with the same content */
+            ) {
+              previewText = markdown + previewText;
+              previousBlock++;
+            }
+          }
+
+          if (followBlock < TARGET_FOLLOW_BLOCK) {
+            followIndex++;
+            const block = blockDocuments.at(followIndex);
+            const markdown = block
+              ? await generateMarkdownPreview(block)
+              : null;
+            if (
+              markdown &&
+              !previewText.endsWith(
+                markdown
+              ) /* A small hack to skip blocks with the same content */
+            ) {
+              previewText = previewText + markdown;
+              followBlock++;
+            }
+          }
+        }
+
+        block.markdownPreview = previewText;
+      }
+    }
+    // #endregion
 
     return {
       addedDoc: [
@@ -375,7 +533,23 @@ async function crawlingDocData({
             title: docTitle,
             summary,
           }),
-          blocks: blockDocuments,
+          blocks: blockDocuments.map(block =>
+            Document.from<BlockIndexSchema>(`${docId}:${block.blockId}`, {
+              docId: block.docId,
+              blockId: block.blockId,
+              content: block.content,
+              flavour: block.flavour,
+              blob: block.blob,
+              refDocId: block.refDocId,
+              ref: block.ref,
+              parentFlavour: block.parentFlavour,
+              parentBlockId: block.parentBlockId,
+              additional: block.additional
+                ? JSON.stringify(block.additional)
+                : undefined,
+              markdownPreview: block.markdownPreview,
+            })
+          ),
         },
       ],
     };