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diff --git a/packages/taler-wallet-core/src/operations/balance.ts b/packages/taler-wallet-core/src/operations/balance.ts
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+++ b/packages/taler-wallet-core/src/operations/balance.ts
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+/*
+ This file is part of GNU Taler
+ (C) 2019 GNUnet e.V.
+
+ GNU Taler is free software; you can redistribute it and/or modify it under the
+ terms of the GNU General Public License as published by the Free Software
+ Foundation; either version 3, or (at your option) any later version.
+
+ GNU Taler is distributed in the hope that it will be useful, but WITHOUT ANY
+ WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
+ A PARTICULAR PURPOSE.  See the GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License along with
+ GNU Taler; see the file COPYING.  If not, see <http://www.gnu.org/licenses/>
+ */
+
+/**
+ * Imports.
+ */
+import { BalancesResponse } from "../types/walletTypes";
+import { TransactionHandle } from "../util/query";
+import { InternalWalletState } from "./state";
+import { Stores, CoinStatus } from "../types/dbTypes";
+import * as Amounts from "../util/amounts";
+import { AmountJson } from "../util/amounts";
+import { Logger } from "../util/logging";
+
+const logger = new Logger("withdraw.ts");
+
+interface WalletBalance {
+  available: AmountJson;
+  pendingIncoming: AmountJson;
+  pendingOutgoing: AmountJson;
+}
+
+/**
+ * Get balance information.
+ */
+export async function getBalancesInsideTransaction(
+  ws: InternalWalletState,
+  tx: TransactionHandle,
+): Promise<BalancesResponse> {
+  const balanceStore: Record<string, WalletBalance> = {};
+
+  /**
+   * Add amount to a balance field, both for
+   * the slicing by exchange and currency.
+   */
+  const initBalance = (currency: string): WalletBalance => {
+    const b = balanceStore[currency];
+    if (!b) {
+      balanceStore[currency] = {
+        available: Amounts.getZero(currency),
+        pendingIncoming: Amounts.getZero(currency),
+        pendingOutgoing: Amounts.getZero(currency),
+      };
+    }
+    return balanceStore[currency];
+  };
+
+  // Initialize balance to zero, even if we didn't start withdrawing yet.
+  await tx.iter(Stores.reserves).forEach((r) => {
+    const b = initBalance(r.currency);
+    if (!r.initialWithdrawalStarted) {
+      b.pendingIncoming = Amounts.add(
+        b.pendingIncoming,
+        r.initialDenomSel.totalCoinValue,
+      ).amount;
+    }
+  });
+
+  await tx.iter(Stores.coins).forEach((c) => {
+    // Only count fresh coins, as dormant coins will
+    // already be in a refresh session.
+    if (c.status === CoinStatus.Fresh) {
+      const b = initBalance(c.currentAmount.currency);
+      b.available = Amounts.add(b.available, c.currentAmount).amount;
+    }
+  });
+
+  await tx.iter(Stores.refreshGroups).forEach((r) => {
+    // Don't count finished refreshes, since the refresh already resulted
+    // in coins being added to the wallet.
+    if (r.timestampFinished) {
+      return;
+    }
+    for (let i = 0; i < r.oldCoinPubs.length; i++) {
+      const session = r.refreshSessionPerCoin[i];
+      if (session) {
+        const b = initBalance(session.amountRefreshOutput.currency);
+        // We are always assuming the refresh will succeed, thus we
+        // report the output as available balance.
+        b.available = Amounts.add(session.amountRefreshOutput).amount;
+      }
+    }
+  });
+
+  await tx.iter(Stores.withdrawalGroups).forEach((wds) => {
+    if (wds.timestampFinish) {
+      return;
+    }
+    const b = initBalance(wds.denomsSel.totalWithdrawCost.currency);
+    b.pendingIncoming = Amounts.add(
+      b.pendingIncoming,
+      wds.denomsSel.totalCoinValue,
+    ).amount;
+  });
+
+  const balancesResponse: BalancesResponse = {
+    balances: [],
+  };
+
+  Object.keys(balanceStore)
+    .sort()
+    .forEach((c) => {
+      const v = balanceStore[c];
+      balancesResponse.balances.push({
+        available: Amounts.stringify(v.available),
+        pendingIncoming: Amounts.stringify(v.pendingIncoming),
+        pendingOutgoing: Amounts.stringify(v.pendingOutgoing),
+        hasPendingTransactions: false,
+        requiresUserInput: false,
+      });
+    });
+
+  return balancesResponse;
+}
+
+/**
+ * Get detailed balance information, sliced by exchange and by currency.
+ */
+export async function getBalances(
+  ws: InternalWalletState,
+): Promise<BalancesResponse> {
+  logger.trace("starting to compute balance");
+
+  const wbal = await ws.db.runWithReadTransaction(
+    [
+      Stores.coins,
+      Stores.refreshGroups,
+      Stores.reserves,
+      Stores.purchases,
+      Stores.withdrawalGroups,
+    ],
+    async (tx) => {
+      return getBalancesInsideTransaction(ws, tx);
+    },
+  );
+
+  logger.trace("finished computing wallet balance");
+
+  return wbal;
+}