feat: add initial balance support to accounts, enhancing account management and balance calculations across components

app/statistics/page.tsx

@@ -10,6 +10,7 @@ import {
   TopExpensesList,
 } from "@/components/statistics";
 import { useBankingData } from "@/lib/hooks";
+import { getAccountBalance } from "@/lib/account-utils";
 import {
   Select,
   SelectContent,
@@ -231,7 +232,19 @@ export default function StatisticsPage() {
       (a, b) => new Date(a.date).getTime() - new Date(b.date).getTime()
     );
 
+    // Start with sum of initial balances for filtered accounts
     let runningBalance = 0;
+    if (selectedAccounts.includes("all")) {
+      runningBalance = data.accounts.reduce(
+        (sum, acc) => sum + (acc.initialBalance || 0),
+        0,
+      );
+    } else {
+      runningBalance = data.accounts
+        .filter((acc) => selectedAccounts.includes(acc.id))
+        .reduce((sum, acc) => sum + (acc.initialBalance || 0), 0);
+    }
+
     const aggregatedBalanceByDate = new Map<string, number>();
     sortedFilteredTransactions.forEach((t) => {
       runningBalance += t.amount;
@@ -254,10 +267,10 @@ export default function StatisticsPage() {
       accountBalances.set(account.id, new Map());
     });
 
-    // Calculate running balance per account
+    // Calculate running balance per account (start with initialBalance)
     const accountRunningBalances = new Map<string, number>();
     data.accounts.forEach((account) => {
-      accountRunningBalances.set(account.id, 0);
+      accountRunningBalances.set(account.id, account.initialBalance || 0);
     });
 
     sortedFilteredTransactions.forEach((t) => {
@@ -280,7 +293,7 @@ export default function StatisticsPage() {
     const sortedDates = Array.from(allDates).sort();
     const lastBalances = new Map<string, number>();
     data.accounts.forEach((account) => {
-      lastBalances.set(account.id, 0);
+      lastBalances.set(account.id, account.initialBalance || 0);
     });
 
     const perAccountBalanceData = sortedDates.map((date) => {