/*
 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/>
 */

/**
 *
 * @author Sebastian Javier Marchano (sebasjm)
 */

import {
  AmountJson,
  Amounts,
  BalancesResponse,
  ConfirmPayResult,
  ConfirmPayResultType,
  NotificationType,
  PreparePayResult,
  PreparePayResultType,
} from "@gnu-taler/taler-util";
import { expect } from "chai";
import { mountHook } from "../../test-utils.js";
import { useComponentState } from "./state.js";
import * as wxApi from "../../wxApi.js";

const nullFunction: any = () => null;
type VoidFunction = () => void;

type Subs = {
  [key in NotificationType]?: VoidFunction;
};

export class SubsHandler {
  private subs: Subs = {};

  constructor() {
    this.saveSubscription = this.saveSubscription.bind(this);
  }

  saveSubscription(
    messageTypes: NotificationType[],
    callback: VoidFunction,
  ): VoidFunction {
    messageTypes.forEach((m) => {
      this.subs[m] = callback;
    });
    return nullFunction;
  }

  notifyEvent(event: NotificationType): void {
    const cb = this.subs[event];
    if (cb === undefined)
      expect.fail(`Expected to have a subscription for ${event}`);
    cb();
  }
}

describe("Payment CTA states", () => {
  it("should tell the user that the URI is missing", async () => {
    const { getLastResultOrThrow, waitNextUpdate, assertNoPendingUpdate } =
      mountHook(() =>
        useComponentState({ talerPayUri: undefined, goBack: nullFunction, goToWalletManualWithdraw: nullFunction }, {
          onUpdateNotification: nullFunction,
        } as Partial<typeof wxApi> as any),
      );

    {
      const { status, error } = getLastResultOrThrow();
      expect(status).equals("loading");
      expect(error).undefined;
    }

    await waitNextUpdate();

    {
      const { status, error } = getLastResultOrThrow();

      expect(status).equals("loading-uri");
      if (error === undefined) expect.fail();
      expect(error.hasError).true;
      expect(error.operational).false;
    }

    await assertNoPendingUpdate();
  });

  it("should response with no balance", async () => {
    const { getLastResultOrThrow, waitNextUpdate, assertNoPendingUpdate } =
      mountHook(() =>
        useComponentState({ talerPayUri: "taller://pay", goBack: nullFunction, goToWalletManualWithdraw: nullFunction }, {
          onUpdateNotification: nullFunction,
          preparePay: async () =>
          ({
            amountRaw: "USD:10",
            status: PreparePayResultType.InsufficientBalance,
          } as Partial<PreparePayResult>),
          getBalance: async () =>
          ({
            balances: [],
          } as Partial<BalancesResponse>),
        } as Partial<typeof wxApi> as any),
      );

    {
      const { status, error } = getLastResultOrThrow();
      expect(status).equals("loading");
      expect(error).undefined;
    }

    await waitNextUpdate();

    {
      const r = getLastResultOrThrow();
      if (r.status !== "no-balance-for-currency") expect.fail();
      expect(r.balance).undefined;
      expect(r.amount).deep.equal(Amounts.parseOrThrow("USD:10"));
    }

    await assertNoPendingUpdate();
  });

  it("should not be able to pay if there is no enough balance", async () => {
    const { getLastResultOrThrow, waitNextUpdate, assertNoPendingUpdate } =
      mountHook(() =>
        useComponentState({ talerPayUri: "taller://pay", goBack: nullFunction, goToWalletManualWithdraw: nullFunction }, {
          onUpdateNotification: nullFunction,
          preparePay: async () =>
          ({
            amountRaw: "USD:10",
            status: PreparePayResultType.InsufficientBalance,
          } as Partial<PreparePayResult>),
          getBalance: async () =>
          ({
            balances: [
              {
                available: "USD:5",
              },
            ],
          } as Partial<BalancesResponse>),
        } as Partial<typeof wxApi> as any),
      );

    {
      const { status, error } = getLastResultOrThrow();
      expect(status).equals("loading");
      expect(error).undefined;
    }

    await waitNextUpdate();

    {
      const r = getLastResultOrThrow();
      if (r.status !== "no-enough-balance") expect.fail();
      expect(r.balance).deep.equal(Amounts.parseOrThrow("USD:5"));
      expect(r.amount).deep.equal(Amounts.parseOrThrow("USD:10"));
    }

    await assertNoPendingUpdate();
  });

  it("should be able to pay (without fee)", async () => {
    const { getLastResultOrThrow, waitNextUpdate, assertNoPendingUpdate } =
      mountHook(() =>
        useComponentState({ talerPayUri: "taller://pay", goBack: nullFunction, goToWalletManualWithdraw: nullFunction }, {
          onUpdateNotification: nullFunction,
          preparePay: async () =>
          ({
            amountRaw: "USD:10",
            amountEffective: "USD:10",
            status: PreparePayResultType.PaymentPossible,
          } as Partial<PreparePayResult>),
          getBalance: async () =>
          ({
            balances: [
              {
                available: "USD:15",
              },
            ],
          } as Partial<BalancesResponse>),
        } as Partial<typeof wxApi> as any),
      );

    {
      const { status, error } = getLastResultOrThrow();
      expect(status).equals("loading");
      expect(error).undefined;
    }

    await waitNextUpdate();

    {
      const r = getLastResultOrThrow();
      if (r.status !== "ready") expect.fail();
      expect(r.balance).deep.equal(Amounts.parseOrThrow("USD:15"));
      expect(r.amount).deep.equal(Amounts.parseOrThrow("USD:10"));
      // expect(r.totalFees).deep.equal(Amounts.parseOrThrow("USD:0"));
      expect(r.payHandler.onClick).not.undefined;
    }

    await assertNoPendingUpdate();
  });

  it("should be able to pay (with fee)", async () => {
    const { getLastResultOrThrow, waitNextUpdate, assertNoPendingUpdate } =
      mountHook(() =>
        useComponentState({ talerPayUri: "taller://pay", goBack: nullFunction, goToWalletManualWithdraw: nullFunction }, {
          onUpdateNotification: nullFunction,
          preparePay: async () =>
          ({
            amountRaw: "USD:9",
            amountEffective: "USD:10",
            status: PreparePayResultType.PaymentPossible,
          } as Partial<PreparePayResult>),
          getBalance: async () =>
          ({
            balances: [
              {
                available: "USD:15",
              },
            ],
          } as Partial<BalancesResponse>),
        } as Partial<typeof wxApi> as any),
      );

    {
      const { status, error } = getLastResultOrThrow();
      expect(status).equals("loading");
      expect(error).undefined;
    }

    await waitNextUpdate();

    {
      const r = getLastResultOrThrow();
      if (r.status !== "ready") expect.fail();
      expect(r.balance).deep.equal(Amounts.parseOrThrow("USD:15"));
      expect(r.amount).deep.equal(Amounts.parseOrThrow("USD:9"));
      // expect(r.totalFees).deep.equal(Amounts.parseOrThrow("USD:1"));
      expect(r.payHandler.onClick).not.undefined;
    }

    await assertNoPendingUpdate();
  });

  it("should get confirmation done after pay successfully", async () => {
    const { getLastResultOrThrow, waitNextUpdate, assertNoPendingUpdate } =
      mountHook(() =>
        useComponentState({ talerPayUri: "taller://pay", goBack: nullFunction, goToWalletManualWithdraw: nullFunction }, {
          onUpdateNotification: nullFunction,
          preparePay: async () =>
          ({
            amountRaw: "USD:9",
            amountEffective: "USD:10",
            status: PreparePayResultType.PaymentPossible,
          } as Partial<PreparePayResult>),
          getBalance: async () =>
          ({
            balances: [
              {
                available: "USD:15",
              },
            ],
          } as Partial<BalancesResponse>),
          confirmPay: async () =>
          ({
            type: ConfirmPayResultType.Done,
            contractTerms: {},
          } as Partial<ConfirmPayResult>),
        } as Partial<typeof wxApi> as any),
      );

    {
      const { status, error } = getLastResultOrThrow();
      expect(status).equals("loading");
      expect(error).undefined;
    }

    await waitNextUpdate();

    {
      const r = getLastResultOrThrow();
      if (r.status !== "ready") expect.fail();
      expect(r.balance).deep.equal(Amounts.parseOrThrow("USD:15"));
      expect(r.amount).deep.equal(Amounts.parseOrThrow("USD:9"));
      // expect(r.totalFees).deep.equal(Amounts.parseOrThrow("USD:1"));
      if (r.payHandler.onClick === undefined) expect.fail();
      r.payHandler.onClick();
    }

    await waitNextUpdate();

    {
      const r = getLastResultOrThrow();
      if (r.status !== "completed") expect.fail();
      expect(r.balance).deep.equal(Amounts.parseOrThrow("USD:15"));
      expect(r.amount).deep.equal(Amounts.parseOrThrow("USD:9"));
      // expect(r.totalFees).deep.equal(Amounts.parseOrThrow("USD:1"));
      // if (r.payResult.type !== ConfirmPayResultType.Done) expect.fail();
      // expect(r.payResult.contractTerms).not.undefined;
      // expect(r.payHandler.onClick).undefined;
    }

    await assertNoPendingUpdate();
  });

  it("should not stay in ready state after pay with error", async () => {
    const { getLastResultOrThrow, waitNextUpdate, assertNoPendingUpdate } =
      mountHook(() =>
        useComponentState({ talerPayUri: "taller://pay", goBack: nullFunction, goToWalletManualWithdraw: nullFunction }, {
          onUpdateNotification: nullFunction,
          preparePay: async () =>
          ({
            amountRaw: "USD:9",
            amountEffective: "USD:10",
            status: PreparePayResultType.PaymentPossible,
          } as Partial<PreparePayResult>),
          getBalance: async () =>
          ({
            balances: [
              {
                available: "USD:15",
              },
            ],
          } as Partial<BalancesResponse>),
          confirmPay: async () =>
          ({
            type: ConfirmPayResultType.Pending,
            lastError: { code: 1 },
          } as Partial<ConfirmPayResult>),
        } as Partial<typeof wxApi> as any),
      );

    {
      const { status, error } = getLastResultOrThrow();
      expect(status).equals("loading");
      expect(error).undefined;
    }

    await waitNextUpdate();

    {
      const r = getLastResultOrThrow();
      if (r.status !== "ready") expect.fail();
      expect(r.balance).deep.equal(Amounts.parseOrThrow("USD:15"));
      expect(r.amount).deep.equal(Amounts.parseOrThrow("USD:9"));
      // expect(r.totalFees).deep.equal(Amounts.parseOrThrow("USD:1"));
      if (r.payHandler.onClick === undefined) expect.fail();
      r.payHandler.onClick();
    }

    await waitNextUpdate();

    {
      const r = getLastResultOrThrow();
      if (r.status !== "ready") expect.fail();
      expect(r.balance).deep.equal(Amounts.parseOrThrow("USD:15"));
      expect(r.amount).deep.equal(Amounts.parseOrThrow("USD:9"));
      // expect(r.totalFees).deep.equal(Amounts.parseOrThrow("USD:1"));
      expect(r.payHandler.onClick).undefined;
      if (r.payHandler.error === undefined) expect.fail();
      //FIXME: error message here is bad
      expect(r.payHandler.error.errorDetail.hint).eq(
        "could not confirm payment",
      );
      expect(r.payHandler.error.errorDetail.payResult).deep.equal({
        type: ConfirmPayResultType.Pending,
        lastError: { code: 1 },
      });
    }

    await assertNoPendingUpdate();
  });

  it("should update balance if a coins is withdraw", async () => {
    const subscriptions = new SubsHandler();
    let availableBalance = Amounts.parseOrThrow("USD:10");

    function notifyCoinWithdrawn(newAmount: AmountJson): void {
      availableBalance = Amounts.add(availableBalance, newAmount).amount;
      subscriptions.notifyEvent(NotificationType.CoinWithdrawn);
    }

    const { getLastResultOrThrow, waitNextUpdate, assertNoPendingUpdate } =
      mountHook(() =>
        useComponentState({ talerPayUri: "taller://pay", goBack: nullFunction, goToWalletManualWithdraw: nullFunction }, {
          onUpdateNotification: subscriptions.saveSubscription,
          preparePay: async () =>
          ({
            amountRaw: "USD:9",
            amountEffective: "USD:10",
            status: PreparePayResultType.PaymentPossible,
          } as Partial<PreparePayResult>),
          getBalance: async () =>
          ({
            balances: [
              {
                available: Amounts.stringify(availableBalance),
              },
            ],
          } as Partial<BalancesResponse>),
        } as Partial<typeof wxApi> as any),
      );

    {
      const { status, error } = getLastResultOrThrow();
      expect(status).equals("loading");
      expect(error).undefined;
    }

    await waitNextUpdate();

    {
      const r = getLastResultOrThrow();
      if (r.status !== "ready") expect.fail();
      expect(r.balance).deep.equal(Amounts.parseOrThrow("USD:10"));
      expect(r.amount).deep.equal(Amounts.parseOrThrow("USD:9"));
      // expect(r.totalFees).deep.equal(Amounts.parseOrThrow("USD:1"));
      expect(r.payHandler.onClick).not.undefined;

      notifyCoinWithdrawn(Amounts.parseOrThrow("USD:5"));
    }

    await waitNextUpdate();

    {
      const r = getLastResultOrThrow();
      if (r.status !== "ready") expect.fail();
      expect(r.balance).deep.equal(Amounts.parseOrThrow("USD:15"));
      expect(r.amount).deep.equal(Amounts.parseOrThrow("USD:9"));
      // expect(r.totalFees).deep.equal(Amounts.parseOrThrow("USD:1"));
      expect(r.payHandler.onClick).not.undefined;
    }

    await assertNoPendingUpdate();
  });
});