1 files changed, 82 insertions, 62 deletions

diff --git a/packages/aml-backoffice-ui/src/hooks/useCases.ts b/packages/aml-backoffice-ui/src/hooks/useCases.ts
index 68deb7db9..d3a1c1018 100644
--- a/packages/aml-backoffice-ui/src/hooks/useCases.ts
+++ b/packages/aml-backoffice-ui/src/hooks/useCases.ts
@@ -1,95 +1,115 @@
+/*
+ This file is part of GNU Taler
+ (C) 2022-2024 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 { useState } from "preact/hooks";
 
 // FIX default import https://github.com/microsoft/TypeScript/issues/49189
-import { AmountString, HttpStatusCode, OfficerAccount, OperationFail, TalerExchangeApi, TalerExchangeResultByMethod, TalerHttpError } from "@gnu-taler/taler-util";
+import {
+  OfficerAccount,
+  OperationOk,
+  TalerExchangeApi,
+  TalerExchangeResultByMethod,
+  TalerHttpError,
+} from "@gnu-taler/taler-util";
 import _useSWR, { SWRHook } from "swr";
-import { useExchangeApiContext } from "../context/config.js";
-import { useOfficer } from "./useOfficer.js";
-import { AmlExchangeBackend } from "../utils/types.js";
+import { useOfficer } from "./officer.js";
+import { useExchangeApiContext } from "@gnu-taler/web-util/browser";
 const useSWR = _useSWR as unknown as SWRHook;
 
-const PAGE_SIZE = 10;
+export const PAGINATED_LIST_SIZE = 10;
+// when doing paginated request, ask for one more
+// and use it to know if there are more to request
+export const PAGINATED_LIST_REQUEST = PAGINATED_LIST_SIZE + 1;
+
 /**
  * FIXME: mutate result when balance change (transaction )
  * @param account
  * @param args
  * @returns
  */
-export function useCases(state: AmlExchangeBackend.AmlState) {
+export function useCases(state: TalerExchangeApi.AmlState) {
   const officer = useOfficer();
   const session = officer.state === "ready" ? officer.account : undefined;
-  const { api } = useExchangeApiContext();
+  const {
+    lib: { exchange: api },
+  } = useExchangeApiContext();
 
   const [offset, setOffset] = useState<string>();
 
-  async function fetcher([officer, state, offset]: [OfficerAccount, AmlExchangeBackend.AmlState, string | undefined]) {
+  async function fetcher([officer, state, offset]: [
+    OfficerAccount,
+    TalerExchangeApi.AmlState,
+    string | undefined,
+  ]) {
     return await api.getDecisionsByState(officer, state, {
-      order: "asc", offset, limit: PAGE_SIZE + 1
-    })
+      order: "asc",
+      offset,
+      limit: PAGINATED_LIST_REQUEST,
+    });
   }
 
-  const { data, error } = useSWR<TalerExchangeResultByMethod<"getDecisionsByState">, TalerHttpError>(
-    !session ? undefined : [session, state, offset],
+  const { data, error } = useSWR<
+    TalerExchangeResultByMethod<"getDecisionsByState">,
+    TalerHttpError
+  >(
+    !session ? undefined : [session, state, offset, "getDecisionsByState"],
     fetcher,
   );
 
-  // const [lastAfter, setLastAfter] = useState<
-  //   HttpResponse<AmlExchangeBackend.AmlRecords, AmlExchangeBackend.AmlError>
-  // >({ loading: true });
+  if (error) return error;
+  if (data === undefined) return undefined;
+  if (data.type !== "ok") return data;
 
-  // useEffect(() => {
-  //   if (afterData) setLastAfter(afterData);
-  // }, [afterData]);
+  return buildPaginatedResult(data.body.records, offset, setOffset, (d) =>
+    String(d.rowid),
+  );
+}
 
-  // if (afterError) {
-  //   return afterError.cause;
-  // }
+type PaginatedResult<T> = OperationOk<T> & {
+  isLastPage: boolean;
+  isFirstPage: boolean;
+  loadNext(): void;
+  loadFirst(): void;
+};
 
-  // if the query returns less that we ask, then we have reach the end or beginning
-  const isLastPage =
-    data && data.type === "ok" && data.body.records.length <= PAGE_SIZE;
-  const isFirstPage = !offset;
+//TODO: consider sending this to web-util
+export function buildPaginatedResult<R, OffId>(
+  data: R[],
+  offset: OffId | undefined,
+  setOffset: (o: OffId | undefined) => void,
+  getId: (r: R) => OffId,
+): PaginatedResult<R[]> {
+  const isLastPage = data.length < PAGINATED_LIST_REQUEST;
+  const isFirstPage = offset === undefined;
 
-  const pagination = {
+  const result = structuredClone(data);
+  if (result.length == PAGINATED_LIST_REQUEST) {
+    result.pop();
+  }
+  return {
+    type: "ok",
+    body: result,
     isLastPage,
     isFirstPage,
-    loadMore: () => {
-      if (isLastPage || data?.type !== "ok") return;
-      const list = data.body.records
-      setOffset(String(list[list.length - 1].rowid));
+    loadNext: () => {
+      if (!result.length) return;
+      const id = getId(result[result.length - 1]);
+      setOffset(id);
     },
-    reset: () => {
-      setOffset(undefined)
+    loadFirst: () => {
+      setOffset(undefined);
     },
   };
-
-  // const public_accountslist = data?.type !== "ok" ? [] : data.body.public_accounts;
-  if (!session) {
-    return {
-      data: {
-        type: "fail",
-        case: HttpStatusCode.Unauthorized,
-        detail: {}
-      } as OperationFail<never>
-    }
-  }
-
-  if (data) {
-    if (data.type === "fail") {
-      return { data }
-    }
-    const records = isLastPage ? data.body.records : removeLastElement(data.body.records)
-    return { data: { type: "ok" as const, body: { records } }, pagination }
-  }
-  if (error) {
-    return error;
-  }
-  return undefined;
 }
-
-function removeLastElement<T>(list: Array<T>): Array<T> {
-  if (list.length === 0) {
-    return list;
-  }
-  return list.slice(0, -1)
-}
\ No newline at end of file