Initial commit: OmniAI Web Frontend

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

src/features/canvas/useCanvasHistory.ts

@@ -0,0 +1,65 @@
+import { useCallback, useRef } from "react";
+
+export interface CanvasHistorySnapshot {
+  textNodes: unknown[];
+  imageNodes: unknown[];
+  videoNodes: unknown[];
+  manualLinks: unknown[];
+  nodePackages: unknown[];
+}
+
+interface CanvasHistoryState {
+  past: CanvasHistorySnapshot[];
+  future: CanvasHistorySnapshot[];
+}
+
+const MAX_HISTORY = 50;
+
+export function useCanvasHistory() {
+  const historyRef = useRef<CanvasHistoryState>({ past: [], future: [] });
+  const lastPushRef = useRef<number>(0);
+
+  const pushSnapshot = useCallback((snapshot: CanvasHistorySnapshot) => {
+    const now = Date.now();
+    // Debounce: skip if pushed within 300ms (e.g. rapid drag moves)
+    if (now - lastPushRef.current < 300) return;
+    lastPushRef.current = now;
+
+    const history = historyRef.current;
+    history.past = [...history.past.slice(-(MAX_HISTORY - 1)), snapshot];
+    history.future = [];
+  }, []);
+
+  const undo = useCallback(
+    (currentSnapshot: CanvasHistorySnapshot): CanvasHistorySnapshot | null => {
+      const history = historyRef.current;
+      if (!history.past.length) return null;
+      const previous = history.past[history.past.length - 1];
+      history.past = history.past.slice(0, -1);
+      history.future = [...history.future, currentSnapshot];
+      return previous;
+    },
+    []
+  );
+
+  const redo = useCallback(
+    (currentSnapshot: CanvasHistorySnapshot): CanvasHistorySnapshot | null => {
+      const history = historyRef.current;
+      if (!history.future.length) return null;
+      const next = history.future[history.future.length - 1];
+      history.future = history.future.slice(0, -1);
+      history.past = [...history.past, currentSnapshot];
+      return next;
+    },
+    []
+  );
+
+  const canUndo = useCallback(() => historyRef.current.past.length > 0, []);
+  const canRedo = useCallback(() => historyRef.current.future.length > 0, []);
+
+  const clear = useCallback(() => {
+    historyRef.current = { past: [], future: [] };
+  }, []);
+
+  return { pushSnapshot, undo, redo, canUndo, canRedo, clear };
+}