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|
/*
This file is part of GNU Taler
(C) 2019-2019 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/>
*/
/**
* Implementation of the refund operation.
*
* @author Florian Dold
*/
/**
* Imports.
*/
import { InternalWalletState } from "./state";
import {
TalerErrorDetails,
RefreshReason,
CoinPublicKey,
ApplyRefundResponse,
} from "../types/walletTypes";
import {
Stores,
CoinStatus,
RefundReason,
RefundState,
PurchaseRecord,
AbortStatus,
} from "../types/dbTypes";
import { NotificationType } from "../types/notifications";
import { parseRefundUri } from "../util/taleruri";
import { createRefreshGroup, getTotalRefreshCost } from "./refresh";
import { Amounts, AmountJson } from "../util/amounts";
import {
MerchantCoinRefundStatus,
MerchantCoinRefundSuccessStatus,
MerchantCoinRefundFailureStatus,
codecForMerchantOrderRefundPickupResponse,
AbortRequest,
AbortingCoin,
codecForMerchantAbortPayRefundStatus,
codecForAbortResponse,
} from "../types/talerTypes";
import { guardOperationException } from "./errors";
import {
getTimestampNow,
Timestamp,
durationAdd,
timestampAddDuration,
} from "../util/time";
import { Logger } from "../util/logging";
import { readSuccessResponseJsonOrThrow } from "../util/http";
import { TransactionHandle } from "../util/query";
import { URL } from "../util/url";
import { updateRetryInfoTimeout, initRetryInfo } from "../util/retries";
import { checkDbInvariant } from "../util/invariants";
import { TalerErrorCode } from "../TalerErrorCode";
const logger = new Logger("refund.ts");
/**
* Retry querying and applying refunds for an order later.
*/
async function incrementPurchaseQueryRefundRetry(
ws: InternalWalletState,
proposalId: string,
err: TalerErrorDetails | undefined,
): Promise<void> {
await ws.db.runWithWriteTransaction([Stores.purchases], async (tx) => {
const pr = await tx.get(Stores.purchases, proposalId);
if (!pr) {
return;
}
if (!pr.refundStatusRetryInfo) {
return;
}
pr.refundStatusRetryInfo.retryCounter++;
updateRetryInfoTimeout(pr.refundStatusRetryInfo);
pr.lastRefundStatusError = err;
await tx.put(Stores.purchases, pr);
});
if (err) {
ws.notify({
type: NotificationType.RefundStatusOperationError,
error: err,
});
}
}
function getRefundKey(d: MerchantCoinRefundStatus): string {
return `${d.coin_pub}-${d.rtransaction_id}`;
}
async function applySuccessfulRefund(
tx: TransactionHandle,
p: PurchaseRecord,
refreshCoinsMap: Record<string, { coinPub: string }>,
r: MerchantCoinRefundSuccessStatus,
): Promise<void> {
// FIXME: check signature before storing it as valid!
const refundKey = getRefundKey(r);
const coin = await tx.get(Stores.coins, r.coin_pub);
if (!coin) {
logger.warn("coin not found, can't apply refund");
return;
}
const denom = await tx.get(Stores.denominations, [
coin.exchangeBaseUrl,
coin.denomPubHash,
]);
if (!denom) {
throw Error("inconsistent database");
}
refreshCoinsMap[coin.coinPub] = { coinPub: coin.coinPub };
const refundAmount = Amounts.parseOrThrow(r.refund_amount);
const refundFee = denom.feeRefund;
coin.status = CoinStatus.Dormant;
coin.currentAmount = Amounts.add(coin.currentAmount, refundAmount).amount;
coin.currentAmount = Amounts.sub(coin.currentAmount, refundFee).amount;
logger.trace(`coin amount after is ${Amounts.stringify(coin.currentAmount)}`);
await tx.put(Stores.coins, coin);
const allDenoms = await tx
.iterIndexed(
Stores.denominations.exchangeBaseUrlIndex,
coin.exchangeBaseUrl,
)
.toArray();
const amountLeft = Amounts.sub(
Amounts.add(coin.currentAmount, Amounts.parseOrThrow(r.refund_amount))
.amount,
denom.feeRefund,
).amount;
const totalRefreshCostBound = getTotalRefreshCost(
allDenoms,
denom,
amountLeft,
);
p.refunds[refundKey] = {
type: RefundState.Applied,
obtainedTime: getTimestampNow(),
executionTime: r.execution_time,
refundAmount: Amounts.parseOrThrow(r.refund_amount),
refundFee: denom.feeRefund,
totalRefreshCostBound,
};
}
async function storePendingRefund(
tx: TransactionHandle,
p: PurchaseRecord,
r: MerchantCoinRefundFailureStatus,
): Promise<void> {
const refundKey = getRefundKey(r);
const coin = await tx.get(Stores.coins, r.coin_pub);
if (!coin) {
logger.warn("coin not found, can't apply refund");
return;
}
const denom = await tx.get(Stores.denominations, [
coin.exchangeBaseUrl,
coin.denomPubHash,
]);
if (!denom) {
throw Error("inconsistent database");
}
const allDenoms = await tx
.iterIndexed(
Stores.denominations.exchangeBaseUrlIndex,
coin.exchangeBaseUrl,
)
.toArray();
const amountLeft = Amounts.sub(
Amounts.add(coin.currentAmount, Amounts.parseOrThrow(r.refund_amount))
.amount,
denom.feeRefund,
).amount;
const totalRefreshCostBound = getTotalRefreshCost(
allDenoms,
denom,
amountLeft,
);
p.refunds[refundKey] = {
type: RefundState.Pending,
obtainedTime: getTimestampNow(),
executionTime: r.execution_time,
refundAmount: Amounts.parseOrThrow(r.refund_amount),
refundFee: denom.feeRefund,
totalRefreshCostBound,
};
}
async function storeFailedRefund(
tx: TransactionHandle,
p: PurchaseRecord,
refreshCoinsMap: Record<string, { coinPub: string }>,
r: MerchantCoinRefundFailureStatus,
): Promise<void> {
const refundKey = getRefundKey(r);
const coin = await tx.get(Stores.coins, r.coin_pub);
if (!coin) {
logger.warn("coin not found, can't apply refund");
return;
}
const denom = await tx.get(Stores.denominations, [
coin.exchangeBaseUrl,
coin.denomPubHash,
]);
if (!denom) {
throw Error("inconsistent database");
}
const allDenoms = await tx
.iterIndexed(
Stores.denominations.exchangeBaseUrlIndex,
coin.exchangeBaseUrl,
)
.toArray();
const amountLeft = Amounts.sub(
Amounts.add(coin.currentAmount, Amounts.parseOrThrow(r.refund_amount))
.amount,
denom.feeRefund,
).amount;
const totalRefreshCostBound = getTotalRefreshCost(
allDenoms,
denom,
amountLeft,
);
p.refunds[refundKey] = {
type: RefundState.Failed,
obtainedTime: getTimestampNow(),
executionTime: r.execution_time,
refundAmount: Amounts.parseOrThrow(r.refund_amount),
refundFee: denom.feeRefund,
totalRefreshCostBound,
};
if (p.abortStatus === AbortStatus.AbortRefund) {
// Refund failed because the merchant didn't even try to deposit
// the coin yet, so we try to refresh.
if (r.exchange_code === TalerErrorCode.EXCHANGE_REFUND_DEPOSIT_NOT_FOUND) {
const coin = await tx.get(Stores.coins, r.coin_pub);
if (!coin) {
logger.warn("coin not found, can't apply refund");
return;
}
const denom = await tx.get(Stores.denominations, [
coin.exchangeBaseUrl,
coin.denomPubHash,
]);
if (!denom) {
logger.warn("denomination for coin missing");
return;
}
let contrib: AmountJson | undefined;
for (let i = 0; i < p.payCoinSelection.coinPubs.length; i++) {
if (p.payCoinSelection.coinPubs[i] === r.coin_pub) {
contrib = p.payCoinSelection.coinContributions[i];
}
}
if (contrib) {
coin.currentAmount = Amounts.add(coin.currentAmount, contrib).amount;
coin.currentAmount = Amounts.sub(coin.currentAmount, denom.feeRefund).amount;
}
refreshCoinsMap[coin.coinPub] = { coinPub: coin.coinPub };
await tx.put(Stores.coins, coin);
}
}
}
async function acceptRefunds(
ws: InternalWalletState,
proposalId: string,
refunds: MerchantCoinRefundStatus[],
reason: RefundReason,
): Promise<void> {
logger.trace("handling refunds", refunds);
const now = getTimestampNow();
await ws.db.runWithWriteTransaction(
[
Stores.purchases,
Stores.coins,
Stores.denominations,
Stores.refreshGroups,
],
async (tx) => {
const p = await tx.get(Stores.purchases, proposalId);
if (!p) {
logger.error("purchase not found, not adding refunds");
return;
}
const refreshCoinsMap: Record<string, CoinPublicKey> = {};
for (const refundStatus of refunds) {
const refundKey = getRefundKey(refundStatus);
const existingRefundInfo = p.refunds[refundKey];
const isPermanentFailure =
refundStatus.type === "failure" &&
refundStatus.exchange_status >= 400 && refundStatus.exchange_status < 500 ;
// Already failed.
if (existingRefundInfo?.type === RefundState.Failed) {
continue;
}
// Already applied.
if (existingRefundInfo?.type === RefundState.Applied) {
continue;
}
// Still pending.
if (
refundStatus.type === "failure" &&
!isPermanentFailure &&
existingRefundInfo?.type === RefundState.Pending
) {
continue;
}
// Invariant: (!existingRefundInfo) || (existingRefundInfo === Pending)
if (refundStatus.type === "success") {
await applySuccessfulRefund(tx, p, refreshCoinsMap, refundStatus);
} else if (isPermanentFailure) {
await storeFailedRefund(tx, p, refreshCoinsMap, refundStatus);
} else {
await storePendingRefund(tx, p, refundStatus);
}
}
const refreshCoinsPubs = Object.values(refreshCoinsMap);
if (refreshCoinsPubs.length > 0) {
await createRefreshGroup(
ws,
tx,
refreshCoinsPubs,
RefreshReason.Refund,
);
}
// Are we done with querying yet, or do we need to do another round
// after a retry delay?
let queryDone = true;
if (
p.timestampFirstSuccessfulPay &&
p.autoRefundDeadline &&
p.autoRefundDeadline.t_ms > now.t_ms
) {
queryDone = false;
}
let numPendingRefunds = 0;
for (const ri of Object.values(p.refunds)) {
switch (ri.type) {
case RefundState.Pending:
numPendingRefunds++;
break;
}
}
if (numPendingRefunds > 0) {
queryDone = false;
}
if (queryDone) {
p.timestampLastRefundStatus = now;
p.lastRefundStatusError = undefined;
p.refundStatusRetryInfo = initRetryInfo(false);
p.refundQueryRequested = false;
if (p.abortStatus === AbortStatus.AbortRefund) {
p.abortStatus = AbortStatus.AbortFinished;
}
logger.trace("refund query done");
} else {
// No error, but we need to try again!
p.timestampLastRefundStatus = now;
p.refundStatusRetryInfo.retryCounter++;
updateRetryInfoTimeout(p.refundStatusRetryInfo);
p.lastRefundStatusError = undefined;
logger.trace("refund query not done");
}
await tx.put(Stores.purchases, p);
},
);
ws.notify({
type: NotificationType.RefundQueried,
});
}
/**
* Summary of the refund status of a purchase.
*/
export interface RefundSummary {
pendingAtExchange: boolean;
amountEffectivePaid: AmountJson;
amountRefundGranted: AmountJson;
amountRefundGone: AmountJson;
}
/**
* Accept a refund, return the contract hash for the contract
* that was involved in the refund.
*/
export async function applyRefund(
ws: InternalWalletState,
talerRefundUri: string,
): Promise<ApplyRefundResponse> {
const parseResult = parseRefundUri(talerRefundUri);
logger.trace("applying refund", parseResult);
if (!parseResult) {
throw Error("invalid refund URI");
}
let purchase = await ws.db.getIndexed(Stores.purchases.orderIdIndex, [
parseResult.merchantBaseUrl,
parseResult.orderId,
]);
if (!purchase) {
throw Error(
`no purchase for the taler://refund/ URI (${talerRefundUri}) was found`,
);
}
const proposalId = purchase.proposalId;
logger.info("processing purchase for refund");
const success = await ws.db.runWithWriteTransaction(
[Stores.purchases],
async (tx) => {
const p = await tx.get(Stores.purchases, proposalId);
if (!p) {
logger.error("no purchase found for refund URL");
return false;
}
p.refundQueryRequested = true;
p.lastRefundStatusError = undefined;
p.refundStatusRetryInfo = initRetryInfo();
await tx.put(Stores.purchases, p);
return true;
},
);
if (success) {
ws.notify({
type: NotificationType.RefundStarted,
});
await processPurchaseQueryRefund(ws, proposalId);
}
purchase = await ws.db.get(Stores.purchases, proposalId);
if (!purchase) {
throw Error("purchase no longer exists");
}
const p = purchase;
let amountRefundGranted = Amounts.getZero(
purchase.contractData.amount.currency,
);
let amountRefundGone = Amounts.getZero(purchase.contractData.amount.currency);
let pendingAtExchange = false;
Object.keys(purchase.refunds).forEach((rk) => {
const refund = p.refunds[rk];
if (refund.type === RefundState.Pending) {
pendingAtExchange = true;
}
if (
refund.type === RefundState.Applied ||
refund.type === RefundState.Pending
) {
amountRefundGranted = Amounts.add(
amountRefundGranted,
Amounts.sub(
refund.refundAmount,
refund.refundFee,
refund.totalRefreshCostBound,
).amount,
).amount;
} else {
amountRefundGone = Amounts.add(amountRefundGone, refund.refundAmount)
.amount;
}
});
return {
contractTermsHash: purchase.contractData.contractTermsHash,
proposalId: purchase.proposalId,
amountEffectivePaid: Amounts.stringify(purchase.totalPayCost),
amountRefundGone: Amounts.stringify(amountRefundGone),
amountRefundGranted: Amounts.stringify(amountRefundGranted),
pendingAtExchange,
info: {
contractTermsHash: purchase.contractData.contractTermsHash,
merchant: purchase.contractData.merchant,
orderId: purchase.contractData.orderId,
products: purchase.contractData.products,
summary: purchase.contractData.summary,
fulfillmentMessage: purchase.contractData.fulfillmentMessage,
summary_i18n: purchase.contractData.summaryI18n,
fulfillmentMessage_i18n: purchase.contractData.fulfillmentMessageI18n,
}
};
}
export async function processPurchaseQueryRefund(
ws: InternalWalletState,
proposalId: string,
forceNow = false,
): Promise<void> {
const onOpErr = (e: TalerErrorDetails): Promise<void> =>
incrementPurchaseQueryRefundRetry(ws, proposalId, e);
await guardOperationException(
() => processPurchaseQueryRefundImpl(ws, proposalId, forceNow),
onOpErr,
);
}
async function resetPurchaseQueryRefundRetry(
ws: InternalWalletState,
proposalId: string,
): Promise<void> {
await ws.db.mutate(Stores.purchases, proposalId, (x) => {
if (x.refundStatusRetryInfo.active) {
x.refundStatusRetryInfo = initRetryInfo();
}
return x;
});
}
async function processPurchaseQueryRefundImpl(
ws: InternalWalletState,
proposalId: string,
forceNow: boolean,
): Promise<void> {
if (forceNow) {
await resetPurchaseQueryRefundRetry(ws, proposalId);
}
const purchase = await ws.db.get(Stores.purchases, proposalId);
if (!purchase) {
return;
}
if (!purchase.refundQueryRequested) {
return;
}
if (purchase.timestampFirstSuccessfulPay) {
const requestUrl = new URL(
`orders/${purchase.contractData.orderId}/refund`,
purchase.contractData.merchantBaseUrl,
);
logger.trace(`making refund request to ${requestUrl.href}`);
const request = await ws.http.postJson(requestUrl.href, {
h_contract: purchase.contractData.contractTermsHash,
});
logger.trace(
"got json",
JSON.stringify(await request.json(), undefined, 2),
);
const refundResponse = await readSuccessResponseJsonOrThrow(
request,
codecForMerchantOrderRefundPickupResponse(),
);
await acceptRefunds(
ws,
proposalId,
refundResponse.refunds,
RefundReason.NormalRefund,
);
} else if (purchase.abortStatus === AbortStatus.AbortRefund) {
const requestUrl = new URL(
`orders/${purchase.contractData.orderId}/abort`,
purchase.contractData.merchantBaseUrl,
);
const abortingCoins: AbortingCoin[] = [];
for (let i = 0; i < purchase.payCoinSelection.coinPubs.length; i++) {
const coinPub = purchase.payCoinSelection.coinPubs[i];
const coin = await ws.db.get(Stores.coins, coinPub);
checkDbInvariant(!!coin, "expected coin to be present");
abortingCoins.push({
coin_pub: coinPub,
contribution: Amounts.stringify(
purchase.payCoinSelection.coinContributions[i],
),
exchange_url: coin.exchangeBaseUrl,
});
}
const abortReq: AbortRequest = {
h_contract: purchase.contractData.contractTermsHash,
coins: abortingCoins,
};
logger.trace(`making order abort request to ${requestUrl.href}`);
const request = await ws.http.postJson(requestUrl.href, abortReq);
const abortResp = await readSuccessResponseJsonOrThrow(
request,
codecForAbortResponse(),
);
const refunds: MerchantCoinRefundStatus[] = [];
if (abortResp.refunds.length != abortingCoins.length) {
// FIXME: define error code!
throw Error("invalid order abort response");
}
for (let i = 0; i < abortResp.refunds.length; i++) {
const r = abortResp.refunds[i];
refunds.push({
...r,
coin_pub: purchase.payCoinSelection.coinPubs[i],
refund_amount: Amounts.stringify(
purchase.payCoinSelection.coinContributions[i],
),
rtransaction_id: 0,
execution_time: timestampAddDuration(purchase.contractData.timestamp, {
d_ms: 1000,
}),
});
}
await acceptRefunds(ws, proposalId, refunds, RefundReason.AbortRefund);
}
}
export async function abortFailedPayWithRefund(
ws: InternalWalletState,
proposalId: string,
): Promise<void> {
await ws.db.runWithWriteTransaction([Stores.purchases], async (tx) => {
const purchase = await tx.get(Stores.purchases, proposalId);
if (!purchase) {
throw Error("purchase not found");
}
if (purchase.timestampFirstSuccessfulPay) {
// No point in aborting it. We don't even report an error.
logger.warn(`tried to abort successful payment`);
return;
}
if (purchase.abortStatus !== AbortStatus.None) {
return;
}
purchase.refundQueryRequested = true;
purchase.paymentSubmitPending = false;
purchase.abortStatus = AbortStatus.AbortRefund;
purchase.lastPayError = undefined;
purchase.payRetryInfo = initRetryInfo(false);
await tx.put(Stores.purchases, purchase);
});
processPurchaseQueryRefund(ws, proposalId, true).catch((e) => {
logger.trace(`error during refund processing after abort pay: ${e}`);
});
}
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