// @flow
import React from 'react';
import Page from 'component/page';
import Card from 'component/common/card';
import Spinner from 'component/spinner';
import hmacSHA256 from 'crypto-js/hmac-sha256';
import Base64 from 'crypto-js/enc-base64';
import { countries as countryData } from 'country-data';
import { FormField } from 'component/common/form';
import { SUPPORTED_MOONPAY_COUNTRIES } from 'constants/moonpay';
import { useHistory } from 'react-router';
import Button from 'component/button';
import Nag from 'component/common/nag';
import I18nMessage from 'component/i18nMessage';

const MOONPAY_KEY = process.env.MOONPAY_SECRET_KEY;
const COUNTRIES = Array.from(
  new Set(
    countryData.all
      .map(country => country.name)
      .sort((a, b) => {
        if (a > b) {
          return 1;
        }

        if (b > a) {
          return -1;
        }

        return 0;
      })
  )
);

type Props = {
  receiveAddress: ?string,
  gettingNewAddress: boolean,
  email: string,
  user: ?User,
  doGetNewAddress: () => void,
  doUserSetCountry: string => void,
};

export default function BuyPage(props: Props) {
  const { receiveAddress, gettingNewAddress, doGetNewAddress, email, user, doUserSetCountry } = props;
  const initialCountry = (user && user.country) || '';
  const [url, setUrl] = React.useState();
  const [country, setCountry] = React.useState(initialCountry);
  const [showPurchaseScreen, setShowPurchaseScreen] = React.useState(false);
  const isValid = SUPPORTED_MOONPAY_COUNTRIES.includes(country);
  const { goBack } = useHistory();

  React.useEffect(() => {
    if (country) {
      doUserSetCountry(country);
    }
  }, [country, doUserSetCountry, isValid, setShowPurchaseScreen]);

  React.useEffect(() => {
    if (!receiveAddress && !gettingNewAddress) {
      doGetNewAddress();
    }
  }, [doGetNewAddress, receiveAddress, gettingNewAddress]);

  React.useEffect(() => {
    if (MOONPAY_KEY && !url && receiveAddress) {
      let url = `https://buy.moonpay.io?apiKey=pk_live_xNFffrN5NWKy6fu0ggbV8VQIwRieRzy&colorCode=%23257761&currencyCode=lbc&showWalletAddressForm=true&walletAddress=${receiveAddress}`;
      if (email) {
        url += `&email=${encodeURIComponent(email)}`;
      }

      const query = new URL(url).search;
      const signature = Base64.stringify(hmacSHA256(query, MOONPAY_KEY));

      setUrl(`${url}&signature=${encodeURIComponent(signature)}`);
    }
  }, [url, setUrl, receiveAddress, email]);

  const title = __('Buy LBRY Credits');
  const subtitle = (
    <I18nMessage
      tokens={{
        learn_more: <Button button="link" label={__('Learn more')} href="https://lbry.com/faq/buy-lbc" />,
      }}
    >
      LBRY, Inc. partners with Moonpay to provide the option to purchase LBC. %learn_more%.
    </I18nMessage>
  );

  return (
    <Page noSideNavigation className="main--buy">
      {!user && (
        <div className="main--empty">
          <Spinner delayed />
        </div>
      )}

      {user && (
        <>
          {showPurchaseScreen ? (
            <Card
              title={title}
              subtitle={subtitle}
              actions={
                url ? (
                  <iframe
                    allow="accelerometer; autoplay; camera; gyroscope; payment"
                    frameBorder="0"
                    src={url}
                    width="100%"
                  >
                    <p>{__('Your browser does not support iframes.')}</p>
                  </iframe>
                ) : (
                  <div className="main--empty">
                    <Spinner delayed />
                  </div>
                )
              }
            />
          ) : (
            <Card
              title={title}
              subtitle={subtitle}
              nag={country && !isValid && <Nag relative type="helpful" message={"This country isn't supported yet."} />}
              actions={
                <div>
                  <div className="section">
                    <FormField
                      label={__('Country')}
                      type="select"
                      name="country-codes"
                      helper={__(
                        'Only some countries are eligible at this time. We are working to make this available to everyone.'
                      )}
                      value={country}
                      onChange={e => setCountry(e.target.value)}
                    >
                      <option value="" disabled defaultValue>
                        {__('Select your country')}
                      </option>
                      {COUNTRIES.map((country, index) => (
                        <option key={country} value={country}>
                          {country}
                        </option>
                      ))}
                    </FormField>
                  </div>
                  {country && (
                    <div className="section">
                      {isValid ? (
                        <div className="section__actions">
                          <Button button="primary" label={__('Continue')} onClick={() => setShowPurchaseScreen(true)} />
                        </div>
                      ) : (
                        <div className="section__actions">
                          <Button button="alt" label={__('Go Back')} onClick={() => goBack()} />
                          <Button button="link" label={__('Try Anyway')} onClick={() => setShowPurchaseScreen(true)} />
                        </div>
                      )}
                    </div>
                  )}
                </div>
              }
            />
          )}
        </>
      )}
    </Page>
  );
}
