refactor: migrate plain text adapter to extension (#8831)

[BS-1855](https://linear.app/affine-design/issue/BS-1855/migrate-plain-text-adapter)

- [x] Migrate PlainTextAdapter to extension
- [x] Handle inline delta: reference, link, inline code
- [x] Add unit test

packages/affine/block-list/src/adapters/index.ts

@@ -0,0 +1,2 @@
+export * from './markdown.js';
+export * from './plain-text.js';

packages/affine/block-list/src/adapters/plain-text.ts

@@ -0,0 +1,28 @@
+import type { DeltaInsert } from '@blocksuite/inline';
+
+import { ListBlockSchema } from '@blocksuite/affine-model';
+import {
+  BlockPlainTextAdapterExtension,
+  type BlockPlainTextAdapterMatcher,
+} from '@blocksuite/affine-shared/adapters';
+
+export const listBlockPlainTextAdapterMatcher: BlockPlainTextAdapterMatcher = {
+  flavour: ListBlockSchema.model.flavour,
+  toMatch: () => false,
+  fromMatch: o => o.node.flavour === ListBlockSchema.model.flavour,
+  toBlockSnapshot: {},
+  fromBlockSnapshot: {
+    enter: (o, context) => {
+      const text = (o.node.props.text ?? { delta: [] }) as {
+        delta: DeltaInsert[];
+      };
+      const { deltaConverter } = context;
+      const buffer = deltaConverter.deltaToAST(text.delta).join('');
+      context.textBuffer.content += buffer;
+      context.textBuffer.content += '\n';
+    },
+  },
+};
+
+export const ListBlockPlainTextAdapterExtension =
+  BlockPlainTextAdapterExtension(listBlockPlainTextAdapterMatcher);

packages/affine/block-list/src/index.ts

@@ -1,4 +1,4 @@
-export * from './adapters/markdown.js';
+export * from './adapters/index.js';
 export * from './list-block.js';
 export * from './list-service.js';
 export * from './list-spec.js';

packages/affine/block-paragraph/src/adapters/index.ts

@@ -0,0 +1,2 @@
+export * from './markdown.js';
+export * from './plain-text.js';

packages/affine/block-paragraph/src/adapters/plain-text.ts

@@ -0,0 +1,29 @@
+import type { DeltaInsert } from '@blocksuite/inline';
+
+import { ParagraphBlockSchema } from '@blocksuite/affine-model';
+import {
+  BlockPlainTextAdapterExtension,
+  type BlockPlainTextAdapterMatcher,
+} from '@blocksuite/affine-shared/adapters';
+
+export const paragraphBlockPlainTextAdapterMatcher: BlockPlainTextAdapterMatcher =
+  {
+    flavour: ParagraphBlockSchema.model.flavour,
+    toMatch: () => false,
+    fromMatch: o => o.node.flavour === ParagraphBlockSchema.model.flavour,
+    toBlockSnapshot: {},
+    fromBlockSnapshot: {
+      enter: (o, context) => {
+        const text = (o.node.props.text ?? { delta: [] }) as {
+          delta: DeltaInsert[];
+        };
+        const { deltaConverter } = context;
+        const buffer = deltaConverter.deltaToAST(text.delta).join('');
+        context.textBuffer.content += buffer;
+        context.textBuffer.content += '\n';
+      },
+    },
+  };
+
+export const ParagraphBlockPlainTextAdapterExtension =
+  BlockPlainTextAdapterExtension(paragraphBlockPlainTextAdapterMatcher);

packages/affine/block-paragraph/src/index.ts

@@ -1,4 +1,4 @@
-export * from './adapters/markdown.js';
+export * from './adapters/index.js';
 export * from './paragraph-block.js';
 export * from './paragraph-service.js';
 export * from './paragraph-spec.js';

packages/affine/shared/src/adapters/index.ts

@@ -11,11 +11,22 @@ export {
   type MarkdownASTToDeltaMatcher,
   MarkdownASTToDeltaMatcherIdentifier,
 } from './markdown/index.js';
+export * from './plain-text/index.js';
+export {
+  BlockPlainTextAdapterExtension,
+  type BlockPlainTextAdapterMatcher,
+  BlockPlainTextAdapterMatcherIdentifier,
+  type InlineDeltaToPlainTextAdapterMatcher,
+  InlineDeltaToPlainTextAdapterMatcherIdentifier,
+  type PlainText,
+  PlainTextDeltaConverter,
+} from './plain-text/index.js';
 export {
   type AdapterContext,
   type BlockAdapterMatcher,
   DeltaASTConverter,
   isBlockSnapshotNode,
+  type TextBuffer,
 } from './type.js';
 export {
   createText,

packages/affine/shared/src/adapters/plain-text/block-adapter.ts

@@ -0,0 +1,29 @@
+import type { ExtensionType } from '@blocksuite/block-std';
+
+import {
+  createIdentifier,
+  type ServiceIdentifier,
+} from '@blocksuite/global/di';
+
+import type { BlockAdapterMatcher } from '../type.js';
+
+export type BlockPlainTextAdapterMatcher = BlockAdapterMatcher;
+
+export const BlockPlainTextAdapterMatcherIdentifier =
+  createIdentifier<BlockPlainTextAdapterMatcher>(
+    'BlockPlainTextAdapterMatcher'
+  );
+
+export function BlockPlainTextAdapterExtension(
+  matcher: BlockPlainTextAdapterMatcher
+): ExtensionType & {
+  identifier: ServiceIdentifier<BlockPlainTextAdapterMatcher>;
+} {
+  const identifier = BlockPlainTextAdapterMatcherIdentifier(matcher.flavour);
+  return {
+    setup: di => {
+      di.addImpl(identifier, () => matcher);
+    },
+    identifier,
+  };
+}

packages/affine/shared/src/adapters/plain-text/delta-converter.ts

@@ -0,0 +1,63 @@
+import type { DeltaInsert } from '@blocksuite/inline';
+
+import { createIdentifier } from '@blocksuite/global/di';
+
+import type { AffineTextAttributes } from '../../types/index.js';
+
+import {
+  type ASTToDeltaMatcher,
+  DeltaASTConverter,
+  type InlineDeltaMatcher,
+  type TextBuffer,
+} from '../type.js';
+
+export type InlineDeltaToPlainTextAdapterMatcher =
+  InlineDeltaMatcher<TextBuffer>;
+
+export const InlineDeltaToPlainTextAdapterMatcherIdentifier =
+  createIdentifier<InlineDeltaToPlainTextAdapterMatcher>(
+    'InlineDeltaToPlainTextAdapterMatcher'
+  );
+
+export type PlainTextASTToDeltaMatcher = ASTToDeltaMatcher<string>;
+
+export class PlainTextDeltaConverter extends DeltaASTConverter<
+  AffineTextAttributes,
+  string
+> {
+  constructor(
+    readonly configs: Map<string, string>,
+    readonly inlineDeltaMatchers: InlineDeltaToPlainTextAdapterMatcher[],
+    readonly plainTextASTToDeltaMatchers: PlainTextASTToDeltaMatcher[]
+  ) {
+    super();
+  }
+
+  astToDelta(ast: string) {
+    const context = {
+      configs: this.configs,
+      toDelta: (ast: string) => this.astToDelta(ast),
+    };
+    for (const matcher of this.plainTextASTToDeltaMatchers) {
+      if (matcher.match(ast)) {
+        return matcher.toDelta(ast, context);
+      }
+    }
+    return [];
+  }
+
+  deltaToAST(deltas: DeltaInsert<AffineTextAttributes>[]): string[] {
+    return deltas.map(delta => {
+      const context = {
+        configs: this.configs,
+        current: { content: delta.insert },
+      };
+      for (const matcher of this.inlineDeltaMatchers) {
+        if (matcher.match(delta)) {
+          context.current = matcher.toAST(delta, context);
+        }
+      }
+      return context.current.content;
+    });
+  }
+}

packages/affine/shared/src/adapters/plain-text/index.ts

@@ -0,0 +1,3 @@
+export * from './block-adapter.js';
+export * from './delta-converter.js';
+export * from './type.js';

packages/affine/shared/src/adapters/plain-text/type.ts

@@ -0,0 +1 @@
+export type PlainText = string;

packages/affine/shared/src/adapters/type.ts

@@ -15,16 +15,21 @@ import type { AffineTextAttributes } from '../types/index.js';
 export const isBlockSnapshotNode = (node: unknown): node is BlockSnapshot =>
   BlockSnapshotSchema.safeParse(node).success;
 
+export type TextBuffer = {
+  content: string;
+};
+
 export type AdapterContext<
   ONode extends object,
-  TNode extends object,
-  TConverter extends DeltaASTConverter,
+  TNode extends object = never,
+  TConverter extends DeltaASTConverter = DeltaASTConverter,
 > = {
   walker: ASTWalker<ONode, TNode>;
   walkerContext: ASTWalkerContext<TNode>;
   configs: Map<string, string>;
   job: Job;
   deltaConverter: TConverter;
+  textBuffer: TextBuffer;
   assets?: AssetsManager;
   updateAssetIds?: (assetsId: string) => void;
 };
@@ -37,8 +42,8 @@ export type AdapterContext<
  * @template TConverter - The converter used for handling delta format conversions
  */
 export type BlockAdapterMatcher<
-  TNode extends object,
-  TConverter extends DeltaASTConverter,
+  TNode extends object = never,
+  TConverter extends DeltaASTConverter = DeltaASTConverter,
 > = {
   /** The block flavour identifier */
   flavour: string;
@@ -126,7 +131,7 @@ export abstract class DeltaASTConverter<
   ): AST[];
 }
 
-export type InlineDeltaMatcher<TNode extends object> = {
+export type InlineDeltaMatcher<TNode extends object = never> = {
   name: keyof AffineTextAttributes | string;
   match: (delta: DeltaInsert<AffineTextAttributes>) => boolean;
   toAST: (