[Init] Initial commit - NetMesh terminal manager

application/state/useTreeExpandedState.ts

@@ -0,0 +1,59 @@
+import { useCallback, useEffect, useState } from "react";
+import { localStorageAdapter } from "../../infrastructure/persistence/localStorageAdapter";
+
+export const useTreeExpandedState = (storageKey: string) => {
+  const [expandedPaths, setExpandedPaths] = useState<Set<string>>(() => {
+    const stored = localStorageAdapter.readString(storageKey);
+    if (stored) {
+      try {
+        const paths = JSON.parse(stored) as string[];
+        return new Set(paths);
+      } catch {
+        return new Set();
+      }
+    }
+    return new Set();
+  });
+
+  useEffect(() => {
+    const pathsArray = Array.from(expandedPaths);
+    localStorageAdapter.writeString(storageKey, JSON.stringify(pathsArray));
+  }, [storageKey, expandedPaths]);
+
+  const togglePath = useCallback((path: string) => {
+    setExpandedPaths((current) => {
+      const next = new Set(current);
+      if (next.has(path)) {
+        next.delete(path);
+      } else {
+        next.add(path);
+      }
+      return next;
+    });
+  }, []);
+
+  const expandAll = useCallback((allPaths: string[]) => {
+    setExpandedPaths(new Set(allPaths));
+  }, []);
+
+  const collapseAll = useCallback(() => {
+    setExpandedPaths(new Set());
+  }, []);
+
+  const ensurePathExpanded = useCallback((path: string) => {
+    setExpandedPaths((current) => {
+      if (current.has(path)) return current;
+      const next = new Set(current);
+      next.add(path);
+      return next;
+    });
+  }, []);
+
+  return {
+    expandedPaths,
+    togglePath,
+    expandAll,
+    collapseAll,
+    ensurePathExpanded,
+  };
+};