/*
 This file is part of GNU Taler
 (C) 2022 Taler Systems SA

 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.

 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
 TALER; see the file COPYING.  If not, see <http://www.gnu.org/licenses/>
 */

/**
 * Implementation of dev experiments, i.e. scenarios
 * triggered by taler://dev-experiment URIs.
 *
 * @author Florian Dold <dold@taler.net>
 */

/**
 * Imports.
 */

import {
  DenomLossEventType,
  Logger,
  RefreshReason,
  TalerPreciseTimestamp,
  encodeCrock,
  getRandomBytes,
  parseDevExperimentUri,
} from "@gnu-taler/taler-util";
import {
  HttpRequestLibrary,
  HttpRequestOptions,
  HttpResponse,
} from "@gnu-taler/taler-util/http";
import { PendingTaskType, constructTaskIdentifier } from "./common.js";
import {
  DenomLossEventRecord,
  DenomLossStatus,
  RefreshGroupRecord,
  RefreshOperationStatus,
  timestampPreciseToDb,
} from "./db.js";
import { WalletExecutionContext } from "./wallet.js";

const logger = new Logger("dev-experiments.ts");

/**
 * Apply a dev experiment to the wallet database / state.
 */
export async function applyDevExperiment(
  wex: WalletExecutionContext,
  uri: string,
): Promise<void> {
  logger.info(`applying dev experiment ${uri}`);
  const parsedUri = parseDevExperimentUri(uri);
  if (!parsedUri) {
    logger.info("unable to parse dev experiment URI");
    return;
  }
  if (!wex.ws.config.testing.devModeActive) {
    throw Error("can't handle devmode URI unless devmode is active");
  }

  switch (parsedUri.devExperimentId) {
    case "start-block-refresh": {
      wex.ws.devExperimentState.blockRefreshes = true;
      return;
    }
    case "stop-block-refresh": {
      wex.ws.devExperimentState.blockRefreshes = false;
      return;
    }
    case "insert-pending-refresh": {
      const refreshGroupId = encodeCrock(getRandomBytes(32));
      await wex.db.runReadWriteTx(
        { storeNames: ["refreshGroups"] },
        async (tx) => {
          const newRg: RefreshGroupRecord = {
            currency: "TESTKUDOS",
            expectedOutputPerCoin: [],
            inputPerCoin: [],
            oldCoinPubs: [],
            operationStatus: RefreshOperationStatus.Pending,
            reason: RefreshReason.Manual,
            refreshGroupId,
            statusPerCoin: [],
            timestampCreated: timestampPreciseToDb(TalerPreciseTimestamp.now()),
            timestampFinished: undefined,
            originatingTransactionId: undefined,
            infoPerExchange: {},
          };
          await tx.refreshGroups.put(newRg);
        },
      );
      wex.taskScheduler.startShepherdTask(
        constructTaskIdentifier({
          tag: PendingTaskType.Refresh,
          refreshGroupId,
        }),
      );
      return;
    }
    case "insert-denom-loss": {
      await wex.db.runReadWriteTx(
        { storeNames: ["denomLossEvents"] },
        async (tx) => {
          const eventId = encodeCrock(getRandomBytes(32));
          const newRg: DenomLossEventRecord = {
            amount: "TESTKUDOS:42",
            currency: "TESTKUDOS",
            exchangeBaseUrl: "https://exchange.test.taler.net/",
            denomLossEventId: eventId,
            denomPubHashes: [
              encodeCrock(getRandomBytes(64)),
              encodeCrock(getRandomBytes(64)),
            ],
            eventType: DenomLossEventType.DenomExpired,
            status: DenomLossStatus.Done,
            timestampCreated: timestampPreciseToDb(TalerPreciseTimestamp.now()),
          };
          await tx.denomLossEvents.put(newRg);
        },
      );
      return;
    }
  }

  throw Error(`dev-experiment id not understood ${parsedUri.devExperimentId}`);
}

export class DevExperimentHttpLib implements HttpRequestLibrary {
  _isDevExperimentLib = true;
  underlyingLib: HttpRequestLibrary;

  constructor(lib: HttpRequestLibrary) {
    this.underlyingLib = lib;
  }

  fetch(
    url: string,
    opt?: HttpRequestOptions | undefined,
  ): Promise<HttpResponse> {
    logger.trace(`devexperiment httplib ${url}`);
    return this.underlyingLib.fetch(url, opt);
  }
}