feat: add subdoc migration script (#2820)

Co-authored-by: himself65 <himself65@outlook.com>

packages/env/src/blocksuite/index.ts

@@ -14,3 +14,5 @@ export function initEmptyPage(page: Page): void {
   const frameId = page.addBlock('affine:frame', {}, pageBlockId);
   page.addBlock('affine:paragraph', {}, frameId);
 }
+
+export * from './subdoc-migration';

packages/env/src/blocksuite/subdoc-migration.ts

@@ -0,0 +1,94 @@
+import * as Y from 'yjs';
+
+function runBlockMigration(
+  flavour: string,
+  data: Y.Map<unknown>,
+  version: number
+) {
+  if (flavour === 'affine:frame') {
+    data.set('sys:flavour', 'affine:note');
+    return;
+  }
+  if (flavour === 'affine:surface' && version <= 3 && data.has('elements')) {
+    const elements = data.get('elements') as Y.Map<unknown>;
+    data.set('prop:elements', elements.clone());
+    data.delete('elements');
+  }
+  if (flavour === 'affine:embed') {
+    data.set('sys:flavour', 'affine:image');
+    data.delete('prop:type');
+  }
+}
+
+function updateBlockVersions(versions: Y.Map<number>) {
+  const frameVersion = versions.get('affine:frame');
+  if (frameVersion !== undefined) {
+    versions.set('affine:note', frameVersion);
+    versions.delete('affine:frame');
+  }
+  const embedVersion = versions.get('affine:embed');
+  if (embedVersion !== undefined) {
+    versions.set('affine:image', embedVersion);
+    versions.delete('affine:embed');
+  }
+}
+
+function migrateMeta(oldDoc: Y.Doc, newDoc: Y.Doc) {
+  const originalMeta = oldDoc.getMap('space:meta');
+  const originalVersions = originalMeta.get('versions') as Y.Map<number>;
+  const originalPages = originalMeta.get('pages') as Y.Array<Y.Map<unknown>>;
+  const meta = newDoc.getMap('meta');
+  const pages = new Y.Array();
+  const blockVersions = originalVersions.clone();
+
+  meta.set('workspaceVersion', 1);
+  meta.set('blockVersions', blockVersions);
+  meta.set('pages', pages);
+
+  updateBlockVersions(blockVersions);
+  const mapList = originalPages.map(page => {
+    const map = new Y.Map();
+    Array.from(page.entries())
+      .filter(([key]) => key !== 'subpageIds')
+      .forEach(([key, value]) => {
+        map.set(key, value);
+      });
+    return map;
+  });
+  pages.push(mapList);
+}
+
+function migrateBlocks(oldDoc: Y.Doc, newDoc: Y.Doc) {
+  const spaces = newDoc.getMap('spaces');
+  const originalMeta = oldDoc.getMap('space:meta');
+  const originalVersions = originalMeta.get('versions') as Y.Map<number>;
+  const originalPages = originalMeta.get('pages') as Y.Array<Y.Map<unknown>>;
+  originalPages.forEach(page => {
+    const id = page.get('id') as string;
+    const spaceId = id.startsWith('space:') ? id : `space:${id}`;
+    const originalBlocks = oldDoc.getMap(spaceId) as Y.Map<unknown>;
+    const subdoc = new Y.Doc();
+    spaces.set(spaceId, subdoc);
+    const blocks = subdoc.getMap('blocks');
+    Array.from(originalBlocks.entries()).forEach(([key, value]) => {
+      const blockData = value.clone();
+      blocks.set(key, blockData);
+      const flavour = blockData.get('sys:flavour') as string;
+      const version = originalVersions.get(flavour);
+      if (version !== undefined) {
+        runBlockMigration(flavour, blockData, version);
+      }
+    });
+  });
+}
+
+export function migrateToSubdoc(doc: Y.Doc): Y.Doc {
+  const needMigration = Array.from(doc.getMap('space:meta').keys()).length > 0;
+  if (!needMigration) {
+    return doc;
+  }
+  const output = new Y.Doc();
+  migrateMeta(doc, output);
+  migrateBlocks(doc, output);
+  return output;
+}