chore: wip

projects/ngrx-extension/src/lib/with-history/with-history.ts

@@ -0,0 +1,60 @@
+import { effect } from '@angular/core';
+import {
+	getState,
+	signalStoreFeature,
+	withHooks,
+	withMethods,
+} from '@ngrx/signals';
+
+export const STATE_HISTORY = Symbol('STATE_HISTORY');
+
+export type TStateHistory<State> = {
+	stateVersions: State[][];
+	currentVersionIndex: number;
+	currentVersion: number;
+};
+
+export function withHistory<State extends object>({
+	sync = true,
+}: { sync: boolean }) {
+	/** このオブジェクトにstateの変更履歴を保存する */
+	const stateHistory: { [STATE_HISTORY]: TStateHistory<State> } = {
+		[STATE_HISTORY]: {
+			stateVersions: [],
+			currentVersion: 0,
+			currentVersionIndex: 0,
+		},
+	};
+
+	/** この関数内でstateを書き換え場合trueとする */
+	let dirty = false;
+
+	return signalStoreFeature(
+		withMethods((store) => ({
+			undo({ cnt = 1 }: { cnt: number }) {},
+
+			redo() {
+				// todo
+			},
+		})),
+		withHooks({
+			onInit(store) {
+				// initialize
+				stateHistory[STATE_HISTORY].currentVersion++;
+				stateHistory[STATE_HISTORY].stateVersions.push([]);
+
+				if (sync) {
+					effect(() =>
+						((state) => {
+							// todo
+							if (dirty) {
+								dirty = true;
+								return;
+							}
+						})(getState(store)),
+					);
+				}
+			},
+		}),
+	);
+}