1 files changed, 185 insertions, 0 deletions
diff --git a/packages/taler-wallet-webextension/src/cta/TransferCreate/state.ts b/packages/taler-wallet-webextension/src/cta/TransferCreate/state.ts
new file mode 100644
index 000000000..f092801ed
--- /dev/null
+++ b/packages/taler-wallet-webextension/src/cta/TransferCreate/state.ts
@@ -0,0 +1,185 @@
+/*
+ This file is part of GNU Taler
+ (C) 2022 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 {
+  AmountString,
+  Amounts,
+  TalerErrorCode,
+  TalerProtocolTimestamp,
+} from "@gnu-taler/taler-util";
+import { WalletApiOperation } from "@gnu-taler/taler-wallet-core";
+import { useTranslationContext } from "@gnu-taler/web-util/browser";
+import { isFuture, parse } from "date-fns";
+import { useState } from "preact/hooks";
+import { alertFromError, useAlertContext } from "../../context/alert.js";
+import { useBackendContext } from "../../context/backend.js";
+import { useAsyncAsHook } from "../../hooks/useAsyncAsHook.js";
+import { BackgroundError, WxApiType } from "../../wxApi.js";
+import { Props, State } from "./index.js";
+
+export function useComponentState({
+  amount: amountStr,
+  onClose,
+  onSuccess,
+}: Props): State {
+  const api = useBackendContext();
+  const { pushAlertOnError } = useAlertContext();
+  const amount = Amounts.parseOrThrow(amountStr);
+  const { i18n } = useTranslationContext();
+
+  const [subject, setSubject] = useState<string | undefined>();
+  const [timestamp, setTimestamp] = useState<string | undefined>();
+
+  const hook = useAsyncAsHook(async () => {
+    const resp = await checkPeerPushDebitAndCheckMax(api, amountStr);
+    return resp;
+  });
+
+  if (!hook) {
+    return {
+      status: "loading",
+      error: undefined,
+    };
+  }
+  if (hook.hasError) {
+    return {
+      status: "error",
+      error: alertFromError(
+        i18n,
+        i18n.str`Could not load the max amount to transfer`,
+        hook,
+      ),
+    };
+  }
+
+  const { amountEffective, amountRaw } = hook.response;
+  const debitAmount = Amounts.parseOrThrow(amountEffective);
+  const toBeReceived = Amounts.parseOrThrow(amountRaw);
+
+  let purse_expiration: TalerProtocolTimestamp | undefined = undefined;
+  let timestampError: string | undefined = undefined;
+
+  const t =
+    timestamp === undefined
+      ? undefined
+      : parse(timestamp, "dd/MM/yyyy", new Date());
+
+  if (t !== undefined) {
+    if (Number.isNaN(t.getTime())) {
+      timestampError = 'Should have the format "dd/MM/yyyy"';
+    } else {
+      if (!isFuture(t)) {
+        timestampError = "Should be in the future";
+      } else {
+        purse_expiration = {
+          t_s: t.getTime() / 1000,
+        };
+      }
+    }
+  }
+
+  async function accept(): Promise<void> {
+    if (!subject || !purse_expiration) return;
+    const resp = await api.wallet.call(
+      WalletApiOperation.InitiatePeerPushDebit,
+      {
+        partialContractTerms: {
+          summary: subject,
+          amount: amountStr,
+          purse_expiration,
+        },
+      },
+    );
+    onSuccess(resp.transactionId);
+  }
+
+  const unableToCreate =
+    !subject || Amounts.isZero(amount) || !purse_expiration;
+
+  return {
+    status: "ready",
+    cancel: {
+      onClick: pushAlertOnError(onClose),
+    },
+    subject: {
+      error:
+        subject === undefined
+          ? undefined
+          : !subject
+            ? "Can't be empty"
+            : undefined,
+      value: subject ?? "",
+      onInput: pushAlertOnError(async (e) => setSubject(e)),
+    },
+    expiration: {
+      error: timestampError,
+      value: timestamp === undefined ? "" : timestamp,
+      onInput: pushAlertOnError(async (e) => {
+        setTimestamp(e);
+      }),
+    },
+    create: {
+      onClick: unableToCreate ? undefined : pushAlertOnError(accept),
+    },
+    debitAmount,
+    toBeReceived,
+    error: undefined,
+  };
+}
+
+async function checkPeerPushDebitAndCheckMax(
+  api: WxApiType,
+  amountState: AmountString,
+) {
+  // FIXME : https://bugs.gnunet.org/view.php?id=7872
+  try {
+    return await api.wallet.call(WalletApiOperation.CheckPeerPushDebit, {
+      amount: amountState,
+    });
+  } catch (e) {
+    if (!(e instanceof BackgroundError)) {
+      throw e;
+    }
+    if (
+      !e.hasErrorCode(
+        TalerErrorCode.WALLET_PEER_PUSH_PAYMENT_INSUFFICIENT_BALANCE,
+      )
+    ) {
+      throw e;
+    }
+    const material = Amounts.parseOrThrow(
+      e.errorDetail.insufficientBalanceDetails.balanceMaterial,
+    );
+    const amount = Amounts.parseOrThrow(amountState);
+    const gap = Amounts.sub(
+      amount,
+      Amounts.parseOrThrow(
+        e.errorDetail.insufficientBalanceDetails.maxEffectiveSpendAmount,
+      ),
+    ).amount;
+    const newAmount = Amounts.sub(material, gap).amount;
+    if (Amounts.cmp(newAmount, amount) === 0) {
+      //insufficient balance and the exception didn't give
+      //a good response that allow us to try again
+      throw e;
+    }
+    if (Amounts.cmp(newAmount, amount) === 1) {
+      //how can this happen?
+      throw e;
+    }
+    return checkPeerPushDebitAndCheckMax(api, Amounts.stringify(newAmount));
+  }
+}