Initial commit

api-wiaas/client/js/components/financing/financing.service.js

@@ -0,0 +1,56 @@
+(function () {
+    global.dashModule.service('finanncingService', [finanncingService]);
+
+    function finanncingService() {
+        return {
+            calculateFinancing
+        };
+
+        /**
+         * Copy of Excel's PMT function.
+         * Credit: http://stackoverflow.com/questions/2094967/excel-pmt-function-in-js
+         *
+         * @param ratePerPeriod       The interest rate for the loan.
+         * @param numberOfPayments    The total number of payments for the loan in months.
+         * @param presentValue         The present value, or the total amount that a series of future payments is worth now;
+         *                              Also known as the principal.
+         * @param futureValue          The future value, or a cash balance you want to attain after the last payment is made.
+         *                              If fv is omitted, it is assumed to be 0 (zero), that is, the future value of a loan is 0.
+         * @param type                  Optional, defaults to 0. The number 0 (zero) or 1 and indicates when payments are due.
+         *                              0 = At the end of period
+         *                              1 = At the beginning of the period
+         * @returns {number}
+         */
+        function calculateFinancing(ratePerPeriod, numberOfPayments, presentValue, futureValue = 0, type = 0) {
+            /*var q = 0;
+            var c = 0;
+            const monthlyRatePerPeriod = ratePerPeriod / 12;
+
+            if (monthlyRatePerPeriod !== 0.0) {
+                // Interest rate exists
+                q = Math.pow(1 + monthlyRatePerPeriod, numberOfPayments);
+                c = (monthlyRatePerPeriod * (futureValue + (q * presentValue))) / ((-1 + q) * (1 + monthlyRatePerPeriod * (type)));
+                return c.toFixed(2);
+
+            } else if (numberOfPayments !== 0.0) {
+                // No interest rate, but number of payments exists
+                return -(futureValue + presentValue) / numberOfPayments;
+            }
+
+            return 0;*/
+            const rates = {
+                24 : 4.282,
+                30 : 3.451,
+                36 : 2.896,
+                42 : 2.500,
+                48 : 2.223,
+                54 : 2.025,
+                60 : 1.834
+            };
+
+            const interest = rates[numberOfPayments] || 10;
+
+            return presentValue * (interest / 100);
+        }
+    }
+})();