/*
 This file is part of GNU Taler
 (C) 2021 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/>
 */

/**
 * Imports.
 */
import { ExchangeRecord, Stores } from "../db.js";
import { Logger } from "../util/logging";
import { getExchangeDetails } from "./exchanges.js";
import { InternalWalletState } from "./state.js";

const logger = new Logger("currencies.ts");

export interface TrustInfo {
  isTrusted: boolean;
  isAudited: boolean;
}

/**
 * Check if and how an exchange is trusted and/or audited.
 */
export async function getExchangeTrust(
  ws: InternalWalletState,
  exchangeInfo: ExchangeRecord,
): Promise<TrustInfo> {
  let isTrusted = false;
  let isAudited = false;
  const exchangeDetails = await ws.db.runWithReadTransaction(
    [Stores.exchangeDetails, Stores.exchanges],
    async (tx) => {
      return getExchangeDetails(tx, exchangeInfo.baseUrl);
    },
  );
  if (!exchangeDetails) {
    throw Error(`exchange ${exchangeInfo.baseUrl} details not available`);
  }
  const exchangeTrustRecord = await ws.db.getIndexed(
    Stores.exchangeTrustStore.exchangeMasterPubIndex,
    exchangeDetails.masterPublicKey,
  );
  if (
    exchangeTrustRecord &&
    exchangeTrustRecord.uids.length > 0 &&
    exchangeTrustRecord.currency === exchangeDetails.currency
  ) {
    isTrusted = true;
  }

  for (const auditor of exchangeDetails.auditors) {
    const auditorTrustRecord = await ws.db.getIndexed(
      Stores.auditorTrustStore.auditorPubIndex,
      auditor.auditor_pub,
    );
    if (auditorTrustRecord && auditorTrustRecord.uids.length > 0) {
      isAudited = true;
      break;
    }
  }

  return { isTrusted, isAudited };
}