/* exported LocalStorageTools */
/* globals BookWyrm */

let LocalStorageTools = new class {
    constructor() {
        document.querySelectorAll('[data-hide]')
            .forEach(t => this.setDisplay(t));

        document.querySelectorAll('.set-display')
            .forEach(t => t.addEventListener('click', this.updateDisplay.bind(this)));
    }

    /**
     * Update localStorage, then display content based on keys in localStorage.
     *
     * @param  {Event} event
     *
     * @return {undefined}
     */
    updateDisplay(event) {
        // used in set reading goal
        let key = event.target.dataset.id;
        let value = event.target.dataset.value;

        window.localStorage.setItem(key, value);

        document.querySelectorAll('[data-hide="' + key + '"]')
            .forEach(node => this.setDisplay(node));
    }

    /**
     * Toggle display of a DOM node based on its value in the localStorage.
     *
     * @param {object} node - DOM node to toggle.
     *
     * @return {undefined}
     */
    setDisplay(node) {
        // used in set reading goal
        let key = node.dataset.hide;
        let value = window.localStorage.getItem(key);

        BookWyrm.addRemoveClass(node, 'hidden', value);
    }
}