/*
 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 {
  AbsoluteTime,
  Codec,
  TalerCorebankApi,
  buildCodecForObject,
  buildCodecForUnion,
  codecForAbsoluteTime,
  codecForAny,
  codecForConstString,
  codecForString,
  codecForTanTransmission,
  codecOptional
} from "@gnu-taler/taler-util";
import { buildStorageKey, useLocalStorage } from "@gnu-taler/web-util/browser";

export type ChallengeInProgess =
  DeleteAccountChallenge |
  UpdateAccountChallenge |
  UpdatePasswordChallenge |
  CreateTransactionChallenge |
  ConfirmWithdrawalChallenge |
  CashoutChallenge;

type BaseChallenge<OpType extends string, ReqType> = {
  id: string,
  operation: OpType,
  sent: AbsoluteTime,
  info?: TalerCorebankApi.TanTransmission,
  request: ReqType
}

type DeleteAccountChallenge = BaseChallenge<"delete-account", string>
type UpdateAccountChallenge = BaseChallenge<"update-account", TalerCorebankApi.AccountReconfiguration>
type UpdatePasswordChallenge = BaseChallenge<"update-password", TalerCorebankApi.AccountPasswordChange>
type CreateTransactionChallenge = BaseChallenge<"create-transaction", TalerCorebankApi.CreateTransactionRequest>
type ConfirmWithdrawalChallenge = BaseChallenge<"confirm-withdrawal", string>
type CashoutChallenge = BaseChallenge<"create-cashout", TalerCorebankApi.CashoutRequest>

const codecForChallengeUpdatePassword = (): Codec<UpdatePasswordChallenge> =>
  buildCodecForObject<UpdatePasswordChallenge>()
    .property("operation", codecForConstString("update-password"))
    .property("id", codecForString())
    .property("sent", codecForAbsoluteTime)
    .property("info", codecOptional(codecForTanTransmission()))
    .property("request", codecForAny())
    .build("UpdatePasswordChallenge");

const codecForChallengeDeleteAccount = (): Codec<DeleteAccountChallenge> =>
  buildCodecForObject<DeleteAccountChallenge>()
    .property("operation", codecForConstString("delete-account"))
    .property("id", codecForString())
    .property("sent", codecForAbsoluteTime)
    .property("request", codecForString())
    .property("info", codecOptional(codecForTanTransmission()))
    .build("DeleteAccountChallenge");

const codecForChallengeUpdateAccount = (): Codec<UpdateAccountChallenge> =>
  buildCodecForObject<UpdateAccountChallenge>()
    .property("operation", codecForConstString("update-account"))
    .property("id", codecForString())
    .property("sent", codecForAbsoluteTime)
    .property("info", codecOptional(codecForTanTransmission()))
    .property("request", codecForAny())
    .build("UpdateAccountChallenge");

const codecForChallengeCreateTransaction = (): Codec<CreateTransactionChallenge> =>
  buildCodecForObject<CreateTransactionChallenge>()
    .property("operation", codecForConstString("create-transaction"))
    .property("id", codecForString())
    .property("sent", codecForAbsoluteTime)
    .property("info", codecOptional(codecForTanTransmission()))
    .property("request", codecForAny())
    .build("CreateTransactionChallenge");

const codecForChallengeConfirmWithdrawal = (): Codec<ConfirmWithdrawalChallenge> =>
  buildCodecForObject<ConfirmWithdrawalChallenge>()
    .property("operation", codecForConstString("confirm-withdrawal"))
    .property("id", codecForString())
    .property("sent", codecForAbsoluteTime)
    .property("info", codecOptional(codecForTanTransmission()))
    .property("request", codecForString())
    .build("ConfirmWithdrawalChallenge");

const codecForChallengeCashout = (): Codec<CashoutChallenge> =>
  buildCodecForObject<CashoutChallenge>()
    .property("operation", codecForConstString("create-cashout"))
    .property("id", codecForString())
    .property("sent", codecForAbsoluteTime)
    .property("info", codecOptional(codecForTanTransmission()))
    .property("request", codecForAny())
    .build("CashoutChallenge");

const codecForChallenge = (): Codec<ChallengeInProgess> =>
  buildCodecForUnion<ChallengeInProgess>()
    .discriminateOn("operation")
    .alternative("confirm-withdrawal", codecForChallengeConfirmWithdrawal())
    .alternative("create-cashout", codecForChallengeCashout())
    .alternative("create-transaction", codecForChallengeCreateTransaction())
    .alternative("delete-account", codecForChallengeDeleteAccount())
    .alternative("update-account", codecForChallengeUpdateAccount())
    .alternative("update-password", codecForChallengeUpdatePassword())
    .build("ChallengeInProgess");


interface BankState {
  currentWithdrawalOperationId: string | undefined;
  currentChallenge: ChallengeInProgess | undefined;
}

export const codecForBankState = (): Codec<BankState> =>
  buildCodecForObject<BankState>()
    .property("currentWithdrawalOperationId", codecOptional(codecForString()))
    .property("currentChallenge", codecOptional(codecForChallenge()))
    .build("BankState");

const defaultBankState: BankState = {
  currentWithdrawalOperationId: undefined,
  currentChallenge: undefined,
};

const BANK_STATE_KEY = buildStorageKey(
  "bank-app-state",
  codecForBankState(),
);

export function useBankState(): [
  Readonly<BankState>,
  <T extends keyof BankState>(key: T, value: BankState[T]) => void,
  () => void,
] {
  const { value, update } = useLocalStorage(
    BANK_STATE_KEY,
    defaultBankState,
  );

  function updateField<T extends keyof BankState>(k: T, v: BankState[T]) {
    const newValue = { ...value, [k]: v };
    update(newValue);
  }
  function reset() {
    update(defaultBankState)
  }
  return [value, updateField, reset];
}