refactor xmr rate module to exchange rate module for multi crypto support

backend/src/modules/exchangeRate/utils/extractCoinPaprikaTickerPrice.ts

@@ -0,0 +1,25 @@
+import Decimal from 'decimal.js';
+import type { ShopFiatCurrency } from '../../../types/ShopFiatCurrency';
+
+export const extractCoinPaprikaTickerPrice = (
+    response: { quotes: Record<string, { price: number }> },
+    shopFiatCurrency: ShopFiatCurrency
+): number | null => {
+    const quote = response.quotes[shopFiatCurrency];
+
+    if (!quote) {
+        return null;
+    }
+
+    const rate = quote.price;
+
+    if (typeof rate !== 'number' || !Number.isFinite(rate) || rate <= 0) {
+        return null;
+    }
+
+    try {
+        return new Decimal(rate).toDecimalPlaces(2).toNumber();
+    } catch {
+        return null;
+    }
+};