so I'm getting an error saying cannot destructure property 'currentTheme' object as it is undefined

//Layout
const {currentTheme, cursorStyles} = useGlobalStateContext()
const dispatch = useGlobalDispatchContext()

//GlobalContext
const globalReducer = (state, action) => {
switch(action.type) {
case "TOGGLE_THEME": {
return {
...state,
currentTheme: action.theme,
}
}
case "CURSOR_TYPE": {
return {
...state,
cursorType: action.cursorType,
}
}
default : {
throw new Error(unhandled action type: ${action.type})
}
}
}

//Provider
export const GlobalProvider = ({children}) => {
const [state, dispatch] = useReducer(globalReducer, {
currentTheme: window.localStorage.getItem("theme") === null ? "dark" : window.localStorage.getItem("theme"),
cursorType: false,
cursorStyles: ["pointer", "hovered", "nav-open"]
})