Library Switching functionality

frontend/src/hooks/useLibrarySwitch.ts

@@ -0,0 +1,118 @@
+'use client';
+
+import { useState, useCallback } from 'react';
+
+interface LibrarySwitchState {
+  isLoading: boolean;
+  targetLibraryName: string | null;
+  error: string | null;
+}
+
+interface LibrarySwitchResult {
+  state: LibrarySwitchState;
+  switchLibrary: (password: string) => Promise<boolean>;
+  clearError: () => void;
+  reset: () => void;
+}
+
+export function useLibrarySwitch(): LibrarySwitchResult {
+  const [state, setState] = useState<LibrarySwitchState>({
+    isLoading: false,
+    targetLibraryName: null,
+    error: null,
+  });
+
+  const switchLibrary = useCallback(async (password: string): Promise<boolean> => {
+    setState({
+      isLoading: true,
+      targetLibraryName: null,
+      error: null,
+    });
+
+    try {
+      const response = await fetch('/api/libraries/switch', {
+        method: 'POST',
+        headers: {
+          'Content-Type': 'application/json',
+        },
+        body: JSON.stringify({ password }),
+      });
+
+      const data = await response.json();
+
+      if (!response.ok) {
+        setState(prev => ({
+          ...prev,
+          isLoading: false,
+          error: data.error || 'Failed to switch library',
+        }));
+        return false;
+      }
+
+      if (data.status === 'already_active') {
+        setState(prev => ({
+          ...prev,
+          isLoading: false,
+          error: data.message,
+        }));
+        return false;
+      }
+
+      if (data.status === 'switching') {
+        // Get library name if available
+        try {
+          const librariesResponse = await fetch('/api/libraries');
+          if (librariesResponse.ok) {
+            const libraries = await librariesResponse.json();
+            const targetLibrary = libraries.find((lib: any) => lib.id === data.targetLibrary);
+            setState(prev => ({
+              ...prev,
+              targetLibraryName: targetLibrary?.name || data.targetLibrary,
+            }));
+          }
+        } catch (e) {
+          // Continue without library name
+        }
+        
+        return true; // Switch initiated successfully
+      }
+
+      setState(prev => ({
+        ...prev,
+        isLoading: false,
+        error: 'Unexpected response from server',
+      }));
+      return false;
+
+    } catch (error) {
+      setState(prev => ({
+        ...prev,
+        isLoading: false,
+        error: 'Network error occurred',
+      }));
+      return false;
+    }
+  }, []);
+
+  const clearError = useCallback(() => {
+    setState(prev => ({
+      ...prev,
+      error: null,
+    }));
+  }, []);
+
+  const reset = useCallback(() => {
+    setState({
+      isLoading: false,
+      targetLibraryName: null,
+      error: null,
+    });
+  }, []);
+
+  return {
+    state,
+    switchLibrary,
+    clearError,
+    reset,
+  };
+}