refactoring: balance sheet report.

refactoring: trial balance sheet report.
refactoring: general ledger report.
refactoring: journal report.
refactoring: P&L report.

server/src/services/FinancialStatements/AgingSummary/AgingSummary.ts

@@ -0,0 +1,75 @@
+import moment from 'moment';
+import { omit, reverse } from 'lodash';
+import { IAgingPeriod, IAgingPeriodClosingBalance, IAgingPeriodTotal } from 'interfaces';
+import FinancialSheet from '../FinancialSheet';
+
+export default class AgingSummaryReport extends FinancialSheet{
+
+  /**
+   * 
+   * @param {Array} agingPeriods 
+   * @param {Numeric} customerBalance 
+   */
+  contactAgingBalance(
+    agingPeriods: IAgingPeriodClosingBalance[],
+    receivableTotalCredit: number,
+  ): IAgingPeriodTotal[] {
+    let prevAging = 0;
+    let receivableCredit = receivableTotalCredit;
+    let diff = receivableCredit;
+
+    const periods = reverse(agingPeriods).map((agingPeriod) => { 
+      const agingAmount = (agingPeriod.closingBalance - prevAging);
+      const subtract = Math.min(diff, agingAmount);
+      diff -= Math.min(agingAmount, diff);
+
+      const total = Math.max(agingAmount - subtract, 0);
+
+      const output = {
+        ...omit(agingPeriod, ['closingBalance']),
+        total,
+      };
+      prevAging = agingPeriod.closingBalance;
+      return output;
+    });
+    return reverse(periods);
+  }
+
+  /**
+   * 
+   * @param {*} asDay 
+   * @param {*} agingDaysBefore 
+   * @param {*} agingPeriodsFreq 
+   */
+  agingRangePeriods(asDay, agingDaysBefore, agingPeriodsFreq): IAgingPeriod[] {
+    const totalAgingDays = agingDaysBefore * agingPeriodsFreq;
+    const startAging = moment(asDay).startOf('day');
+    const endAging = startAging.clone().subtract('days', totalAgingDays).endOf('day');
+
+    const agingPeriods: IAgingPeriod[] = [];
+    const startingAging = startAging.clone();
+
+    let beforeDays = 1;
+    let toDays = 0;
+
+    while (startingAging > endAging) {
+      const currentAging = startingAging.clone();
+      startingAging.subtract('days', agingDaysBefore).endOf('day');
+      toDays += agingDaysBefore;
+
+      agingPeriods.push({
+        fromPeriod: moment(currentAging).toDate(),
+        toPeriod: moment(startingAging).toDate(),
+        beforeDays: beforeDays === 1 ? 0 : beforeDays,
+        toDays: toDays,
+        ...(startingAging.valueOf() === endAging.valueOf()) ? {
+          toPeriod: null,
+          toDays: null,
+        } : {},
+      });
+      beforeDays += agingDaysBefore;
+    }
+    return agingPeriods;
+  }
+
+}