/**
 * 덱 즐겨찾기 (localStorage, share_code 기준)
 */
(function initDeckFavorites() {
    const STORAGE_KEY = 'uadeck.deckFavorites';

    /**
     * @returns {Set<string>}
     */
    function readSet() {
        try {
            const raw = localStorage.getItem(STORAGE_KEY);
            const list = raw ? JSON.parse(raw) : [];
            return new Set(Array.isArray(list) ? list : []);
        } catch {
            return new Set();
        }
    }

    /**
     * @param {Set<string>} set
     */
    function writeSet(set) {
        localStorage.setItem(STORAGE_KEY, JSON.stringify([...set]));
    }

    /**
     * @param {string} shareCode
     * @returns {boolean}
     */
    function isFavorite(shareCode) {
        if (!shareCode) return false;
        return readSet().has(shareCode);
    }

    /**
     * @param {string} shareCode
     * @returns {boolean} 토글 후 즐겨찾기 여부
     */
    function toggle(shareCode) {
        if (!shareCode) return false;
        const set = readSet();
        if (set.has(shareCode)) {
            set.delete(shareCode);
        } else {
            set.add(shareCode);
        }
        writeSet(set);
        return set.has(shareCode);
    }

    /**
     * @returns {string[]}
     */
    function getAll() {
        return [...readSet()];
    }

    window.UaDeckFavorites = { isFavorite, toggle, getAll };
})();