refactor: unify agent session persistence

src/sessions/uiStateStore.ts

@@ -0,0 +1,46 @@
+import { join } from "node:path";
+
+import { config } from "../config.js";
+import {
+  atomicWriteJson,
+  ensureDirectory,
+  readJsonFile,
+  removeFileIfExists,
+  slugify,
+} from "../utils/fileStore.js";
+
+export type SessionUiStateRecord = {
+  sessionId: string;
+  isTitleManuallyEdited?: boolean;
+  messages: unknown[];
+  branchGroups: unknown[];
+};
+
+type SessionUiStateContext = {
+  sessionId: string;
+};
+
+export class SessionUiStateStore {
+  constructor(private readonly baseDir = config.SESSION_UI_STATE_STORAGE_DIR) {}
+
+  async initialize() {
+    await ensureDirectory(this.baseDir);
+  }
+
+  async read(context: SessionUiStateContext) {
+    return await readJsonFile<SessionUiStateRecord>(this.filePath(context));
+  }
+
+  async write(context: SessionUiStateContext, state: SessionUiStateRecord) {
+    await atomicWriteJson(this.filePath(context), state);
+    return state;
+  }
+
+  async remove(context: SessionUiStateContext) {
+    await removeFileIfExists(this.filePath(context));
+  }
+
+  private filePath(context: SessionUiStateContext) {
+    return join(this.baseDir, `${slugify(context.sessionId)}.json`);
+  }
+}