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diff --git a/packages/taler-wallet-core/src/instructedAmountConversion.ts b/packages/taler-wallet-core/src/instructedAmountConversion.ts
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+++ b/packages/taler-wallet-core/src/instructedAmountConversion.ts
@@ -0,0 +1,872 @@
+/*
+ This file is part of GNU Taler
+ (C) 2023 Taler Systems S.A.
+
+ 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/>
+ */
+
+import { GlobalIDB } from "@gnu-taler/idb-bridge";
+import {
+  AbsoluteTime,
+  AgeRestriction,
+  AmountJson,
+  AmountResponse,
+  Amounts,
+  ConvertAmountRequest,
+  Duration,
+  GetAmountRequest,
+  GetPlanForOperationRequest,
+  TransactionAmountMode,
+  TransactionType,
+  checkDbInvariant,
+  parsePaytoUri,
+  strcmp,
+} from "@gnu-taler/taler-util";
+import { DenominationRecord, timestampProtocolFromDb } from "./db.js";
+import { getExchangeWireDetailsInTx } from "./exchanges.js";
+import { WalletExecutionContext } from "./wallet.js";
+
+export interface CoinInfo {
+  id: string;
+  value: AmountJson;
+  denomDeposit: AmountJson;
+  denomWithdraw: AmountJson;
+  denomRefresh: AmountJson;
+  totalAvailable: number | undefined;
+  exchangeWire: AmountJson | undefined;
+  exchangePurse: AmountJson | undefined;
+  duration: Duration;
+  exchangeBaseUrl: string;
+  maxAge: number;
+}
+
+/**
+ * If the operation going to be plan subtracts
+ * or adds amount in the wallet db
+ */
+export enum OperationType {
+  Credit = "credit",
+  Debit = "debit",
+}
+
+// FIXME: Name conflict ...
+interface ExchangeInfo {
+  wireFee: AmountJson | undefined;
+  purseFee: AmountJson | undefined;
+  creditDeadline: AbsoluteTime;
+  debitDeadline: AbsoluteTime;
+}
+
+function getOperationType(txType: TransactionType): OperationType {
+  const operationType =
+    txType === TransactionType.Withdrawal
+      ? OperationType.Credit
+      : txType === TransactionType.Deposit
+        ? OperationType.Debit
+        : undefined;
+  if (!operationType) {
+    throw Error(`operation type ${txType} not yet supported`);
+  }
+  return operationType;
+}
+
+interface SelectedCoins {
+  totalValue: AmountJson;
+  coins: { info: CoinInfo; size: number }[];
+  refresh?: RefreshChoice;
+}
+
+function getCoinsFilter(req: GetPlanForOperationRequest): CoinsFilter {
+  switch (req.type) {
+    case TransactionType.Withdrawal: {
+      return {
+        exchanges:
+          req.exchangeUrl === undefined ? undefined : [req.exchangeUrl],
+      };
+    }
+    case TransactionType.Deposit: {
+      const payto = parsePaytoUri(req.account);
+      if (!payto) {
+        throw Error(`wrong payto ${req.account}`);
+      }
+      return {
+        wireMethod: payto.targetType,
+      };
+    }
+  }
+}
+
+interface RefreshChoice {
+  /**
+   * Amount that need to be covered
+   */
+  gap: AmountJson;
+  totalFee: AmountJson;
+  selected: CoinInfo;
+  totalChangeValue: AmountJson;
+  refreshEffective: AmountJson;
+  coins: { info: CoinInfo; size: number }[];
+
+  // totalValue: AmountJson;
+  // totalDepositFee: AmountJson;
+  // totalRefreshFee: AmountJson;
+  // totalChangeContribution: AmountJson;
+  // totalChangeWithdrawalFee: AmountJson;
+}
+
+interface CoinsFilter {
+  shouldCalculatePurseFee?: boolean;
+  exchanges?: string[];
+  wireMethod?: string;
+  ageRestricted?: number;
+}
+
+interface AvailableCoins {
+  list: CoinInfo[];
+  exchanges: Record<string, ExchangeInfo>;
+}
+
+/**
+ * Get all the denoms that can be used for a operation that is limited
+ * by the following restrictions.
+ * This function is costly (by the database access) but with high chances
+ * of being cached
+ */
+async function getAvailableDenoms(
+  wex: WalletExecutionContext,
+  op: TransactionType,
+  currency: string,
+  filters: CoinsFilter = {},
+): Promise<AvailableCoins> {
+  const operationType = getOperationType(TransactionType.Deposit);
+
+  return await wex.db.runReadOnlyTx(
+    {
+      storeNames: [
+        "exchanges",
+        "exchangeDetails",
+        "denominations",
+        "coinAvailability",
+      ],
+    },
+    async (tx) => {
+      const list: CoinInfo[] = [];
+      const exchanges: Record<string, ExchangeInfo> = {};
+
+      const databaseExchanges = await tx.exchanges.iter().toArray();
+      const filteredExchanges =
+        filters.exchanges ?? databaseExchanges.map((e) => e.baseUrl);
+
+      for (const exchangeBaseUrl of filteredExchanges) {
+        const exchangeDetails = await getExchangeWireDetailsInTx(
+          tx,
+          exchangeBaseUrl,
+        );
+        // 1.- exchange has same currency
+        if (exchangeDetails?.currency !== currency) {
+          continue;
+        }
+
+        let deadline = AbsoluteTime.never();
+        // 2.- exchange supports wire method
+        let wireFee: AmountJson | undefined;
+        if (filters.wireMethod) {
+          const wireMethodWithDates =
+            exchangeDetails.wireInfo.feesForType[filters.wireMethod];
+
+          if (!wireMethodWithDates) {
+            throw Error(
+              `exchange ${exchangeBaseUrl} doesn't have wire method ${filters.wireMethod}`,
+            );
+          }
+          const wireMethodFee = wireMethodWithDates.find((x) => {
+            return AbsoluteTime.isBetween(
+              AbsoluteTime.now(),
+              AbsoluteTime.fromProtocolTimestamp(x.startStamp),
+              AbsoluteTime.fromProtocolTimestamp(x.endStamp),
+            );
+          });
+
+          if (!wireMethodFee) {
+            throw Error(
+              `exchange ${exchangeBaseUrl} doesn't have wire fee defined for this period`,
+            );
+          }
+          wireFee = Amounts.parseOrThrow(wireMethodFee.wireFee);
+          deadline = AbsoluteTime.min(
+            deadline,
+            AbsoluteTime.fromProtocolTimestamp(wireMethodFee.endStamp),
+          );
+        }
+        // exchanges[exchangeBaseUrl].wireFee = wireMethodFee;
+
+        // 3.- exchange supports wire method
+        let purseFee: AmountJson | undefined;
+        if (filters.shouldCalculatePurseFee) {
+          const purseFeeFound = exchangeDetails.globalFees.find((x) => {
+            return AbsoluteTime.isBetween(
+              AbsoluteTime.now(),
+              AbsoluteTime.fromProtocolTimestamp(x.startDate),
+              AbsoluteTime.fromProtocolTimestamp(x.endDate),
+            );
+          });
+          if (!purseFeeFound) {
+            throw Error(
+              `exchange ${exchangeBaseUrl} doesn't have purse fee defined for this period`,
+            );
+          }
+          purseFee = Amounts.parseOrThrow(purseFeeFound.purseFee);
+          deadline = AbsoluteTime.min(
+            deadline,
+            AbsoluteTime.fromProtocolTimestamp(purseFeeFound.endDate),
+          );
+        }
+
+        let creditDeadline = AbsoluteTime.never();
+        let debitDeadline = AbsoluteTime.never();
+        //4.- filter coins restricted by age
+        if (operationType === OperationType.Credit) {
+          // FIXME: Use denom groups instead of querying all denominations!
+          const ds =
+            await tx.denominations.indexes.byExchangeBaseUrl.getAll(
+              exchangeBaseUrl,
+            );
+          for (const denom of ds) {
+            const expiresWithdraw = AbsoluteTime.fromProtocolTimestamp(
+              timestampProtocolFromDb(denom.stampExpireWithdraw),
+            );
+            const expiresDeposit = AbsoluteTime.fromProtocolTimestamp(
+              timestampProtocolFromDb(denom.stampExpireDeposit),
+            );
+            creditDeadline = AbsoluteTime.min(deadline, expiresWithdraw);
+            debitDeadline = AbsoluteTime.min(deadline, expiresDeposit);
+            list.push(
+              buildCoinInfoFromDenom(
+                denom,
+                purseFee,
+                wireFee,
+                AgeRestriction.AGE_UNRESTRICTED,
+                Number.MAX_SAFE_INTEGER, // Max withdrawable from single denom
+              ),
+            );
+          }
+        } else {
+          const ageLower = filters.ageRestricted ?? 0;
+          const ageUpper = AgeRestriction.AGE_UNRESTRICTED;
+
+          const myExchangeCoins =
+            await tx.coinAvailability.indexes.byExchangeAgeAvailability.getAll(
+              GlobalIDB.KeyRange.bound(
+                [exchangeDetails.exchangeBaseUrl, ageLower, 1],
+                [
+                  exchangeDetails.exchangeBaseUrl,
+                  ageUpper,
+                  Number.MAX_SAFE_INTEGER,
+                ],
+              ),
+            );
+          //5.- save denoms with how many coins are available
+          // FIXME: Check that the individual denomination is audited!
+          // FIXME: Should we exclude denominations that are
+          // not spendable anymore?
+          for (const coinAvail of myExchangeCoins) {
+            const denom = await tx.denominations.get([
+              coinAvail.exchangeBaseUrl,
+              coinAvail.denomPubHash,
+            ]);
+            checkDbInvariant(!!denom);
+            if (denom.isRevoked || !denom.isOffered) {
+              continue;
+            }
+            const expiresWithdraw = AbsoluteTime.fromProtocolTimestamp(
+              timestampProtocolFromDb(denom.stampExpireWithdraw),
+            );
+            const expiresDeposit = AbsoluteTime.fromProtocolTimestamp(
+              timestampProtocolFromDb(denom.stampExpireDeposit),
+            );
+            creditDeadline = AbsoluteTime.min(deadline, expiresWithdraw);
+            debitDeadline = AbsoluteTime.min(deadline, expiresDeposit);
+            list.push(
+              buildCoinInfoFromDenom(
+                denom,
+                purseFee,
+                wireFee,
+                coinAvail.maxAge,
+                coinAvail.freshCoinCount,
+              ),
+            );
+          }
+        }
+
+        exchanges[exchangeBaseUrl] = {
+          purseFee,
+          wireFee,
+          debitDeadline,
+          creditDeadline,
+        };
+      }
+
+      return { list, exchanges };
+    },
+  );
+}
+
+function buildCoinInfoFromDenom(
+  denom: DenominationRecord,
+  purseFee: AmountJson | undefined,
+  wireFee: AmountJson | undefined,
+  maxAge: number,
+  total: number,
+): CoinInfo {
+  return {
+    id: denom.denomPubHash,
+    denomWithdraw: Amounts.parseOrThrow(denom.fees.feeWithdraw),
+    denomDeposit: Amounts.parseOrThrow(denom.fees.feeDeposit),
+    denomRefresh: Amounts.parseOrThrow(denom.fees.feeRefresh),
+    exchangePurse: purseFee,
+    exchangeWire: wireFee,
+    exchangeBaseUrl: denom.exchangeBaseUrl,
+    duration: AbsoluteTime.difference(
+      AbsoluteTime.now(),
+      AbsoluteTime.fromProtocolTimestamp(
+        timestampProtocolFromDb(denom.stampExpireDeposit),
+      ),
+    ),
+    totalAvailable: total,
+    value: Amounts.parseOrThrow(denom.value),
+    maxAge,
+  };
+}
+
+export async function convertDepositAmount(
+  wex: WalletExecutionContext,
+  req: ConvertAmountRequest,
+): Promise<AmountResponse> {
+  const amount = Amounts.parseOrThrow(req.amount);
+  // const filter = getCoinsFilter(req);
+
+  const denoms = await getAvailableDenoms(
+    wex,
+    TransactionType.Deposit,
+    amount.currency,
+    {},
+  );
+  const result = convertDepositAmountForAvailableCoins(
+    denoms,
+    amount,
+    req.type,
+  );
+
+  return {
+    effectiveAmount: Amounts.stringify(result.effective),
+    rawAmount: Amounts.stringify(result.raw),
+  };
+}
+
+const LOG_REFRESH = false;
+const LOG_DEPOSIT = false;
+export function convertDepositAmountForAvailableCoins(
+  denoms: AvailableCoins,
+  amount: AmountJson,
+  mode: TransactionAmountMode,
+): AmountAndRefresh {
+  const zero = Amounts.zeroOfCurrency(amount.currency);
+  if (!denoms.list.length) {
+    // no coins in the database
+    return { effective: zero, raw: zero };
+  }
+  const depositDenoms = rankDenominationForDeposit(denoms.list, mode);
+
+  //FIXME: we are not taking into account
+  // * exchanges with multiple accounts
+  // * wallet with multiple exchanges
+  const wireFee = Object.values(denoms.exchanges)[0]?.wireFee ?? zero;
+  const adjustedAmount = Amounts.add(amount, wireFee).amount;
+
+  const selected = selectGreedyCoins(depositDenoms, adjustedAmount);
+
+  const gap = Amounts.sub(amount, selected.totalValue).amount;
+
+  const result = getTotalEffectiveAndRawForDeposit(
+    selected.coins,
+    amount.currency,
+  );
+  result.raw = Amounts.sub(result.raw, wireFee).amount;
+
+  if (Amounts.isZero(gap)) {
+    // exact amount founds
+    return result;
+  }
+
+  if (LOG_DEPOSIT) {
+    const logInfo = selected.coins.map((c) => {
+      return `${Amounts.stringifyValue(c.info.id)} x ${c.size}`;
+    });
+    console.log(
+      "deposit used:",
+      logInfo.join(", "),
+      "gap:",
+      Amounts.stringifyValue(gap),
+    );
+  }
+
+  const refreshDenoms = rankDenominationForRefresh(denoms.list);
+  /**
+   * FIXME: looking for refresh AFTER selecting greedy is not optimal
+   */
+  const refreshCoin = searchBestRefreshCoin(
+    depositDenoms,
+    refreshDenoms,
+    gap,
+    mode,
+  );
+
+  if (refreshCoin) {
+    const fee = Amounts.sub(result.effective, result.raw).amount;
+    const effective = Amounts.add(
+      result.effective,
+      refreshCoin.refreshEffective,
+    ).amount;
+    const raw = Amounts.sub(effective, fee, refreshCoin.totalFee).amount;
+    //found with change
+    return {
+      effective,
+      raw,
+      refresh: refreshCoin,
+    };
+  }
+
+  // there is a gap, but no refresh coin was found
+  return result;
+}
+
+export async function getMaxDepositAmount(
+  wex: WalletExecutionContext,
+  req: GetAmountRequest,
+): Promise<AmountResponse> {
+  // const filter = getCoinsFilter(req);
+
+  const denoms = await getAvailableDenoms(
+    wex,
+    TransactionType.Deposit,
+    req.currency,
+    {},
+  );
+
+  const result = getMaxDepositAmountForAvailableCoins(denoms, req.currency);
+  return {
+    effectiveAmount: Amounts.stringify(result.effective),
+    rawAmount: Amounts.stringify(result.raw),
+  };
+}
+
+export function getMaxDepositAmountForAvailableCoins(
+  denoms: AvailableCoins,
+  currency: string,
+) {
+  const zero = Amounts.zeroOfCurrency(currency);
+  if (!denoms.list.length) {
+    // no coins in the database
+    return { effective: zero, raw: zero };
+  }
+
+  const result = getTotalEffectiveAndRawForDeposit(
+    denoms.list.map((info) => {
+      return { info, size: info.totalAvailable ?? 0 };
+    }),
+    currency,
+  );
+
+  const wireFee = Object.values(denoms.exchanges)[0]?.wireFee ?? zero;
+  result.raw = Amounts.sub(result.raw, wireFee).amount;
+
+  return result;
+}
+
+export async function convertPeerPushAmount(
+  wex: WalletExecutionContext,
+  req: ConvertAmountRequest,
+): Promise<AmountResponse> {
+  throw Error("to be implemented after 1.0");
+}
+
+export async function getMaxPeerPushAmount(
+  wex: WalletExecutionContext,
+  req: GetAmountRequest,
+): Promise<AmountResponse> {
+  throw Error("to be implemented after 1.0");
+}
+
+export async function convertWithdrawalAmount(
+  wex: WalletExecutionContext,
+  req: ConvertAmountRequest,
+): Promise<AmountResponse> {
+  const amount = Amounts.parseOrThrow(req.amount);
+
+  const denoms = await getAvailableDenoms(
+    wex,
+    TransactionType.Withdrawal,
+    amount.currency,
+    {},
+  );
+
+  const result = convertWithdrawalAmountFromAvailableCoins(
+    denoms,
+    amount,
+    req.type,
+  );
+
+  return {
+    effectiveAmount: Amounts.stringify(result.effective),
+    rawAmount: Amounts.stringify(result.raw),
+  };
+}
+
+export function convertWithdrawalAmountFromAvailableCoins(
+  denoms: AvailableCoins,
+  amount: AmountJson,
+  mode: TransactionAmountMode,
+) {
+  const zero = Amounts.zeroOfCurrency(amount.currency);
+  if (!denoms.list.length) {
+    // no coins in the database
+    return { effective: zero, raw: zero };
+  }
+  const withdrawDenoms = rankDenominationForWithdrawals(denoms.list, mode);
+
+  const selected = selectGreedyCoins(withdrawDenoms, amount);
+
+  return getTotalEffectiveAndRawForWithdrawal(selected.coins, amount.currency);
+}
+
+/** *****************************************************
+ * HELPERS
+ * *****************************************************
+ */
+
+/**
+ *
+ * @param depositDenoms
+ * @param refreshDenoms
+ * @param amount
+ * @param mode
+ * @returns
+ */
+function searchBestRefreshCoin(
+  depositDenoms: SelectableElement[],
+  refreshDenoms: Record<string, SelectableElement[]>,
+  amount: AmountJson,
+  mode: TransactionAmountMode,
+): RefreshChoice | undefined {
+  let choice: RefreshChoice | undefined = undefined;
+  let refreshIdx = 0;
+  refreshIteration: while (refreshIdx < depositDenoms.length) {
+    const d = depositDenoms[refreshIdx];
+
+    const denomContribution =
+      mode === TransactionAmountMode.Effective
+        ? d.value
+        : Amounts.sub(d.value, d.info.denomRefresh, d.info.denomDeposit).amount;
+
+    const changeAfterDeposit = Amounts.sub(denomContribution, amount).amount;
+    if (Amounts.isZero(changeAfterDeposit)) {
+      //this coin is not big enough to use for refresh
+      //since the list is sorted, we can break here
+      break refreshIteration;
+    }
+
+    const withdrawDenoms = refreshDenoms[d.info.exchangeBaseUrl];
+    const change = selectGreedyCoins(withdrawDenoms, changeAfterDeposit);
+
+    const zero = Amounts.zeroOfCurrency(amount.currency);
+    const withdrawChangeFee = change.coins.reduce((cur, prev) => {
+      return Amounts.add(
+        cur,
+        Amounts.mult(prev.info.denomWithdraw, prev.size).amount,
+      ).amount;
+    }, zero);
+
+    const withdrawChangeValue = change.coins.reduce((cur, prev) => {
+      return Amounts.add(cur, Amounts.mult(prev.info.value, prev.size).amount)
+        .amount;
+    }, zero);
+
+    const totalFee = Amounts.add(
+      d.info.denomDeposit,
+      d.info.denomRefresh,
+      withdrawChangeFee,
+    ).amount;
+
+    if (!choice || Amounts.cmp(totalFee, choice.totalFee) === -1) {
+      //found cheaper change
+      choice = {
+        gap: amount,
+        totalFee: totalFee,
+        totalChangeValue: change.totalValue, //change after refresh
+        refreshEffective: Amounts.sub(d.info.value, withdrawChangeValue).amount, // what of the denom used is not recovered
+        selected: d.info,
+        coins: change.coins,
+      };
+    }
+    refreshIdx++;
+  }
+  if (choice) {
+    if (LOG_REFRESH) {
+      const logInfo = choice.coins.map((c) => {
+        return `${Amounts.stringifyValue(c.info.id)} x ${c.size}`;
+      });
+      console.log(
+        "refresh used:",
+        Amounts.stringifyValue(choice.selected.value),
+        "change:",
+        logInfo.join(", "),
+        "fee:",
+        Amounts.stringifyValue(choice.totalFee),
+        "refreshEffective:",
+        Amounts.stringifyValue(choice.refreshEffective),
+        "totalChangeValue:",
+        Amounts.stringifyValue(choice.totalChangeValue),
+      );
+    }
+  }
+  return choice;
+}
+
+/**
+ * Returns a copy of the list sorted for the best denom to withdraw first
+ *
+ * @param denoms
+ * @returns
+ */
+function rankDenominationForWithdrawals(
+  denoms: CoinInfo[],
+  mode: TransactionAmountMode,
+): SelectableElement[] {
+  const copyList = [...denoms];
+  /**
+   * Rank coins
+   */
+  copyList.sort((d1, d2) => {
+    // the best coin to use is
+    // 1.- the one that contrib more and pay less fee
+    // 2.- it takes more time before expires
+
+    //different exchanges may have different wireFee
+    //ranking should take the relative contribution in the exchange
+    //which is (value - denomFee / fixedFee)
+    const rate1 = Amounts.divmod(d1.value, d1.denomWithdraw).quotient;
+    const rate2 = Amounts.divmod(d2.value, d2.denomWithdraw).quotient;
+    const contribCmp = rate1 === rate2 ? 0 : rate1 < rate2 ? 1 : -1;
+    return (
+      contribCmp ||
+      Duration.cmp(d1.duration, d2.duration) ||
+      strcmp(d1.id, d2.id)
+    );
+  });
+
+  return copyList.map((info) => {
+    switch (mode) {
+      case TransactionAmountMode.Effective: {
+        //if the user instructed "effective" then we need to selected
+        //greedy total coin value
+        return {
+          info,
+          value: info.value,
+          total: Number.MAX_SAFE_INTEGER,
+        };
+      }
+      case TransactionAmountMode.Raw: {
+        //if the user instructed "raw" then we need to selected
+        //greedy total coin raw amount (without fee)
+        return {
+          info,
+          value: Amounts.add(info.value, info.denomWithdraw).amount,
+          total: Number.MAX_SAFE_INTEGER,
+        };
+      }
+    }
+  });
+}
+
+/**
+ * Returns a copy of the list sorted for the best denom to deposit first
+ *
+ * @param denoms
+ * @returns
+ */
+function rankDenominationForDeposit(
+  denoms: CoinInfo[],
+  mode: TransactionAmountMode,
+): SelectableElement[] {
+  const copyList = [...denoms];
+  /**
+   * Rank coins
+   */
+  copyList.sort((d1, d2) => {
+    // the best coin to use is
+    // 1.- the one that contrib more and pay less fee
+    // 2.- it takes more time before expires
+
+    //different exchanges may have different wireFee
+    //ranking should take the relative contribution in the exchange
+    //which is (value - denomFee / fixedFee)
+    const rate1 = Amounts.divmod(d1.value, d1.denomDeposit).quotient;
+    const rate2 = Amounts.divmod(d2.value, d2.denomDeposit).quotient;
+    const contribCmp = rate1 === rate2 ? 0 : rate1 < rate2 ? 1 : -1;
+    return (
+      contribCmp ||
+      Duration.cmp(d1.duration, d2.duration) ||
+      strcmp(d1.id, d2.id)
+    );
+  });
+
+  return copyList.map((info) => {
+    switch (mode) {
+      case TransactionAmountMode.Effective: {
+        //if the user instructed "effective" then we need to selected
+        //greedy total coin value
+        return {
+          info,
+          value: info.value,
+          total: info.totalAvailable ?? 0,
+        };
+      }
+      case TransactionAmountMode.Raw: {
+        //if the user instructed "raw" then we need to selected
+        //greedy total coin raw amount (without fee)
+        return {
+          info,
+          value: Amounts.sub(info.value, info.denomDeposit).amount,
+          total: info.totalAvailable ?? 0,
+        };
+      }
+    }
+  });
+}
+
+/**
+ * Returns a copy of the list sorted for the best denom to withdraw first
+ *
+ * @param denoms
+ * @returns
+ */
+function rankDenominationForRefresh(
+  denoms: CoinInfo[],
+): Record<string, SelectableElement[]> {
+  const groupByExchange: Record<string, CoinInfo[]> = {};
+  for (const d of denoms) {
+    if (!groupByExchange[d.exchangeBaseUrl]) {
+      groupByExchange[d.exchangeBaseUrl] = [];
+    }
+    groupByExchange[d.exchangeBaseUrl].push(d);
+  }
+
+  const result: Record<string, SelectableElement[]> = {};
+  for (const d of denoms) {
+    result[d.exchangeBaseUrl] = rankDenominationForWithdrawals(
+      groupByExchange[d.exchangeBaseUrl],
+      TransactionAmountMode.Raw,
+    );
+  }
+  return result;
+}
+
+interface SelectableElement {
+  total: number;
+  value: AmountJson;
+  info: CoinInfo;
+}
+
+function selectGreedyCoins(
+  coins: SelectableElement[],
+  limit: AmountJson,
+): SelectedCoins {
+  const result: SelectedCoins = {
+    totalValue: Amounts.zeroOfCurrency(limit.currency),
+    coins: [],
+  };
+  if (!coins.length) return result;
+
+  let denomIdx = 0;
+  iterateDenoms: while (denomIdx < coins.length) {
+    const denom = coins[denomIdx];
+    // let total = denom.total;
+    const left = Amounts.sub(limit, result.totalValue).amount;
+
+    if (Amounts.isZero(denom.value)) {
+      // 0 contribution denoms should be the last
+      break iterateDenoms;
+    }
+
+    //use Amounts.divmod instead of iterate
+    const div = Amounts.divmod(left, denom.value);
+    const size = Math.min(div.quotient, denom.total);
+    if (size > 0) {
+      const mul = Amounts.mult(denom.value, size).amount;
+      const progress = Amounts.add(result.totalValue, mul).amount;
+
+      result.totalValue = progress;
+      result.coins.push({ info: denom.info, size });
+      denom.total = denom.total - size;
+    }
+
+    //go next denom
+    denomIdx++;
+  }
+
+  return result;
+}
+
+type AmountWithFee = { raw: AmountJson; effective: AmountJson };
+type AmountAndRefresh = AmountWithFee & { refresh?: RefreshChoice };
+
+export function getTotalEffectiveAndRawForDeposit(
+  list: { info: CoinInfo; size: number }[],
+  currency: string,
+): AmountWithFee {
+  const init = {
+    raw: Amounts.zeroOfCurrency(currency),
+    effective: Amounts.zeroOfCurrency(currency),
+  };
+  return list.reduce((prev, cur) => {
+    const ef = Amounts.mult(cur.info.value, cur.size).amount;
+    const rw = Amounts.mult(
+      Amounts.sub(cur.info.value, cur.info.denomDeposit).amount,
+      cur.size,
+    ).amount;
+
+    prev.effective = Amounts.add(prev.effective, ef).amount;
+    prev.raw = Amounts.add(prev.raw, rw).amount;
+    return prev;
+  }, init);
+}
+
+function getTotalEffectiveAndRawForWithdrawal(
+  list: { info: CoinInfo; size: number }[],
+  currency: string,
+): AmountWithFee {
+  const init = {
+    raw: Amounts.zeroOfCurrency(currency),
+    effective: Amounts.zeroOfCurrency(currency),
+  };
+  return list.reduce((prev, cur) => {
+    const ef = Amounts.mult(cur.info.value, cur.size).amount;
+    const rw = Amounts.mult(
+      Amounts.add(cur.info.value, cur.info.denomWithdraw).amount,
+      cur.size,
+    ).amount;
+
+    prev.effective = Amounts.add(prev.effective, ef).amount;
+    prev.raw = Amounts.add(prev.raw, rw).amount;
+    return prev;
+  }, init);
+}