import React, { FunctionComponent, ReactNode, useEffect, useRef, useState } from 'react';
import { useTranslation } from 'react-i18next';
import WalletLib from '../../lib/wallet';
import { WalletInfo } from '../wallet-info';
import { FabModal, ModalSize } from '../base/fab-modal';
import { HtmlTranslate } from '../base/html-translate';
import { CustomAsset, CustomAssetName } from '../../models/custom-asset';
import { ShoppingCart } from '../../models/payment';
import { PaymentSchedule } from '../../models/payment-schedule';
import { User } from '../../models/user';
import CustomAssetAPI from '../../api/custom-asset';
import PriceAPI from '../../api/price';
import WalletAPI from '../../api/wallet';
import { Invoice } from '../../models/invoice';
import SettingAPI from '../../api/setting';
import { SettingName } from '../../models/setting';
import { GoogleTagManager } from '../../models/gtm';
import { ComputePriceResult } from '../../models/price';
import { Wallet } from '../../models/wallet';
import FormatLib from '../../lib/format';

export interface GatewayFormProps {
  onSubmit: () => void,
  onSuccess: (result: Invoice|PaymentSchedule) => void,
  onError: (message: string) => void,
  customer: User,
  operator: User,
  className?: string,
  paymentSchedule?: PaymentSchedule,
  cart?: ShoppingCart,
  updateCart?: (cart: ShoppingCart) => void,
  formId: string,
}

interface AbstractPaymentModalProps {
  isOpen: boolean,
  toggleModal: () => void,
  afterSuccess: (result: Invoice|PaymentSchedule) => void,
  onError: (message: string) => void,
  cart: ShoppingCart,
  updateCart?: (cart: ShoppingCart) => void,
  currentUser: User,
  schedule?: PaymentSchedule,
  customer: User,
  logoFooter: ReactNode,
  GatewayForm: FunctionComponent<GatewayFormProps>,
  formId: string,
  className?: string,
  formClassName?: string,
  title?: string,
  preventCgv?: boolean,
  preventScheduleInfo?: boolean,
  modalSize?: ModalSize,
}

declare const GTM: GoogleTagManager;

/**
 * This component is an abstract modal that must be extended by each payment gateway to include its payment form.
 *
 * This component must not be called directly but must be extended for each implemented payment gateway.
 * @see https://reactjs.org/docs/composition-vs-inheritance.html
 */
export const AbstractPaymentModal: React.FC<AbstractPaymentModalProps> = ({ isOpen, toggleModal, afterSuccess, onError, cart, updateCart, currentUser, schedule, customer, logoFooter, GatewayForm, formId, className, formClassName, title, preventCgv, preventScheduleInfo, modalSize }) => {
  // customer's wallet
  const [wallet, setWallet] = useState<Wallet>(null);
  // server-computed price with all details
  const [price, setPrice] = useState<ComputePriceResult>(null);
  // remaining price = total price - wallet amount
  const [remainingPrice, setRemainingPrice] = useState<number>(0);
  // is the component ready to display?
  const [ready, setReady] = useState<boolean>(false);
  // errors to display in the UI (gateway errors mainly)
  const [errors, setErrors] = useState<string>(null);
  // are we currently processing the payment (ie. the form was submit, but the process is still running)?
  const [submitState, setSubmitState] = useState<boolean>(false);
  // did the user accepts the terms of services (CGV)?
  const [tos, setTos] = useState<boolean>(false);
  // currently active payment gateway
  const [gateway, setGateway] = useState<string>(null);
  // the sales conditions
  const [cgv, setCgv] = useState<CustomAsset>(null);
  // is the component mounted
  const mounted = useRef(false);

  const { t } = useTranslation('shared');

  /**
   * When the component loads first, get the name of the currently active payment modal
   */
  useEffect(() => {
    mounted.current = true;
    CustomAssetAPI.get(CustomAssetName.CgvFile).then(asset => setCgv(asset));
    SettingAPI.get(SettingName.PaymentGateway).then((setting) => {
      // we capitalize the first letter of the name
      if (setting.value) {
        setGateway(setting.value.replace(/^\w/, (c) => c.toUpperCase()));
      }
    });

    return () => { mounted.current = false; };
  }, []);

  /**
   * On each display:
   * - Refresh the wallet
   * - Refresh the price
   * - Refresh the remaining price
   */
  useEffect(() => {
    if (!cart) return;
    WalletAPI.getByUser(cart.customer_id).then((wallet) => {
      setWallet(wallet);
      PriceAPI.compute(cart).then((res) => {
        setPrice(res);
        setRemainingPrice(new WalletLib(wallet).computeRemainingPrice(res.price));
        setReady(true);
      });
    });
  }, [cart]);

  /**
   * Check if there is currently an error to display
   */
  const hasErrors = (): boolean => {
    return errors !== null;
  };

  /**
   * Check if the user accepts the Terms of Sales document
   */
  const hasCgv = (): boolean => {
    return cgv != null && !preventCgv;
  };

  /**
   * Triggered when the user accepts or declines the Terms of Sales
   */
  const toggleTos = (): void => {
    setTos(!tos);
  };

  /**
   * Check if we must display the info box about the payment schedule
   */
  const hasPaymentScheduleInfo = (): boolean => {
    return schedule !== undefined && !preventScheduleInfo;
  };

  /**
   * Set the component as 'currently submitting'
   */
  const handleSubmit = (): void => {
    setSubmitState(true);
  };

  /**
   * After sending the form with success, process the resulting payment method
   */
  const handleFormSuccess = async (result: Invoice|PaymentSchedule): Promise<void> => {
    setSubmitState(false);
    GTM.trackPurchase(result.id, result.total);
    afterSuccess(result);
  };

  /**
   * When the payment form raises an error, it is handled by this callback which display it in the modal.
   */
  const handleFormError = (message: string): void => {
    if (mounted.current) {
      setSubmitState(false);
      setErrors(message);
    } else {
      onError(message);
    }
  };

  /**
   * Check the form can be submitted.
   * => We're not currently already submitting the form, and, if the terms of service are enabled, the user must agree with them.
   */
  const canSubmit = (): boolean => {
    let terms = true;
    if (hasCgv()) { terms = tos; }
    return !submitState && terms;
  };

  /**
   * Build the modal title. If the provided title is a shared translation key, interpolate it through the
   * translation service. Otherwise, just display the provided string.
   */
  const getTitle = (): string => {
    if (title.match(/^app\.shared\./)) {
      return t(title);
    }
    return title;
  };

  return (
    <FabModal title={getTitle()}
      isOpen={isOpen}
      toggleModal={toggleModal}
      width={modalSize}
      closeButton={false}
      customFooter={logoFooter}
      className={`payment-modal ${className || ''}`}>
      {ready && <div>
        <WalletInfo cart={cart} currentUser={currentUser} wallet={wallet} price={price?.price} />
        <GatewayForm onSubmit={handleSubmit}
          onSuccess={handleFormSuccess}
          onError={handleFormError}
          operator={currentUser}
          className={`gateway-form ${formClassName || ''}`}
          formId={formId}
          cart={cart}
          updateCart={updateCart}
          customer={customer}
          paymentSchedule={schedule}>
          {hasErrors() && <div className="payment-errors">
            {errors}
          </div>}
          {hasPaymentScheduleInfo() && <div className="payment-schedule-info">
            <HtmlTranslate trKey="app.shared.payment.payment_schedule_html" options={{ DEADLINES: `${schedule.items.length}`, GATEWAY: gateway }} />
          </div>}
          {hasCgv() && <div className="terms-of-sales">
            <input type="checkbox" id="acceptToS" name="acceptCondition" checked={tos} onChange={toggleTos} required />
            <label htmlFor="acceptToS">{ t('app.shared.payment.i_have_read_and_accept_') }
              <a href={cgv.custom_asset_file_attributes.attachment_url} target="_blank" rel="noreferrer">
                { t('app.shared.payment._the_general_terms_and_conditions') }
              </a>
            </label>
          </div>}
        </GatewayForm>
        {!submitState && <button type="submit"
          disabled={!canSubmit()}
          form={formId}
          className="validate-btn">
          {remainingPrice > 0 && t('app.shared.payment.confirm_payment_of_', { AMOUNT: FormatLib.price(remainingPrice) })}
          {remainingPrice === 0 && t('app.shared.payment.validate')}
        </button>}
        {submitState && <div className="payment-pending">
          <div className="fa-2x">
            <i className="fas fa-circle-notch fa-spin" />
          </div>
        </div>}
      </div>}
    </FabModal>
  );
};

AbstractPaymentModal.defaultProps = {
  title: 'app.shared.payment.online_payment',
  preventCgv: false,
  preventScheduleInfo: false,
  modalSize: ModalSize.medium
};