const CurrencyManager = (function () {
    const STORAGE_KEY = 'app_currency_payload';
    const CACHE_MINUTES = 5;
    let COOKIE_NAME = 'Preference_ShowUsd_';
    let _activePromise = null;
    let currencyCache = null;

    return {
        setPreference(showUsd) {
            const date = new Date();
            date.setTime(date.getTime() + (30 * 24 * 60 * 60 * 1000));
            document.cookie = `${COOKIE_NAME}=${showUsd}; expires=${date.toUTCString()}; path=/`;
        },

        getPreference() {
            const value = `; ${document.cookie}`;
            const parts = value.split(`; ${COOKIE_NAME}=`);
            if (parts.length === 2) return parts.pop().split(';').shift() === 'true';
            return false;
        },

        async init(userId) {
            
            if (!isNaN(userId) && COOKIE_NAME == 'Preference_ShowUsd_') {
                COOKIE_NAME += userId;
            }
            const cachedStr = localStorage.getItem(STORAGE_KEY);
            const now = Date.now();
            let needsUpdate = true;

            if (cachedStr) {
                const cache = JSON.parse(cachedStr);
                currencyCache = cache.data;
                if (now < cache.expiresAt) {
                    needsUpdate = false;
                }
            }

            if (needsUpdate) {
                await this.sync();
            }
        },

        async sync() {
            if (_activePromise) return _activePromise;

            _activePromise = (async () => {
                try {
                    const response = await fetch('/Wallet/GetCurrencySettings', {
                        method: 'POST',
                        headers: {
                            'Content-Type': 'application/json',
                        },
                    });
                    const freshData = await response.json();
                    if (freshData && freshData.Success) {
                        localStorage.setItem(STORAGE_KEY, JSON.stringify({
                            expiresAt: Date.now() + (CACHE_MINUTES * 60 * 1000),
                            data: freshData.Data
                        }));
                        currencyCache = freshData.Data;
                        return freshData.Data;
                    }
                } finally { _activePromise = null; }
            })();
            return _activePromise;
        },

        async refreshUI() {

            if (currencyCache == null) return;

            const elements = document.querySelectorAll('.js_display_currency');

            elements.forEach(el => {
                const amount = parseFloat(el.dataset.amount);
                const currencyId = el.dataset.id;
                const formatted = this.format(amount, currencyId);
                el.innerText = `$ ${formatted}`;
            });
        },

        format(amount, currencyId) {
            if (currencyCache == null) {
                return amount;
            }
            const isUsd = this.getPreference(); 

            const currentCfg = currencyCache.find(c => c.CurrencyId === currencyId);

            const cfg = isUsd
                ? currencyCache.find(c => c.CurrencyId === "USD")
                : currentCfg;

            if (!cfg) return amount;

            let val = amount;
            if (isUsd && currentCfg) {
                val = amount * currentCfg.CurrentRate;
            }

            const digits = cfg.DigitsAfterPoint || 0;
            const multiplier = Math.pow(10, digits);

            const truncatedVal = Math.trunc(val * multiplier) / multiplier;


            let str = truncatedVal.toFixed(digits);


            if (cfg.ExcludeZeros && str.includes('.')) {
                str = str.replace(/\.?0+$/, "");
            }

            const sep = cfg.AmountFormatType === 2 ? " " : ","; 
            const parts = str.split(".");

            parts[0] = parts[0].replace(/\B(?=(\d{3})+(?!\d))/g, sep);

            return parts.join(".");
        },

        getCurrencyIcon(currencyId) {
            if (currencyCache == null) {
                return amount;
            }
            const currentCfg = currencyCache.find(c => c.CurrencyId === currencyId);
            if (!currentCfg) return "";

            return currentCfg.IconUrl;
        }
    };
})();