Нужна критика кода переключателя темы на React

import React, {useEffect, useState, useMemo, useCallback} from "react";
import DarkStyles from "../DarkStyles/DarkStyles";
 
export const ThemeSwitcherApp = () => {
    const key = "DARK_THEME";
    const saveJSON = (key, data) => {
        if (window[`localStorage`] === null) return
        return localStorage.setItem(key, JSON.stringify(data));
    };
    const loadJSON = key => {
        if (window[`localStorage`] === null) return
        return key && JSON.parse(localStorage.getItem(key));
    };
 
    const [themeIsActive, setThemeIsActive] = useState(loadJSON(key) ?
        loadJSON(key).darkMode : false);
    const [button_text_value, setButton_text_value] = useState(themeIsActive ? "Turn off" : "Turn on");
 
    const theme_data_false = useMemo(() => ({darkMode: false}), []);
    const theme_data_true = useMemo(() => ({darkMode: true}), []);
 
    const insertDarkStyles = (where) => {
        const style = document.createElement(`style`);
        style.setAttribute(`id`, `dark-mode`);
        style.innerHTML = DarkStyles;
        where.append(style);
    };
 
    const ActiveDarkTheme = useCallback(
        () => {
            insertDarkStyles(document.getElementsByTagName(`head`)[0]);
            setButton_text_value("Turn off");
            saveJSON(key, theme_data_true);
        }, [theme_data_true]
    )
    const DeactivateDarkTheme = useCallback(
        () => {
            const isDarkModeExist = !!document.getElementById(`dark-mode`);
            if (isDarkModeExist) {
                document.getElementById(`dark-mode`).remove();
                setButton_text_value("Turn on");
                saveJSON(key, theme_data_false);
            }
        }, [theme_data_false]
    )
 
    const ThemeStorageLoading = useCallback(
        (key, data) => {
            if (!localStorage.getItem(key)) {
                saveJSON(key, data);
            } else {
                if (loadJSON(key).darkMode) {
                    ActiveDarkTheme();
                } else {
                    DeactivateDarkTheme();
                }
            }
        }, [ActiveDarkTheme, DeactivateDarkTheme]);
 
    useEffect(() => { // Once Loading
        ThemeStorageLoading(key, theme_data_false);
    }, [theme_data_false, ThemeStorageLoading]);
 
    const ButtonAction = (bool_value) => {
        setThemeIsActive(bool_value);
        if (bool_value) ActiveDarkTheme();
        else DeactivateDarkTheme();
    };
 
    return (
        <div>
            <input type="button"
                   onClick={() => ButtonAction(!themeIsActive)}
                   defaultValue={button_text_value}
                   style={{cursor: "pointer"}}
            />
        </div>
    );
}