// @flow
import { URL, SITE_NAME } from 'config';
import React, { useEffect, useState } from 'react';
import Button from 'component/button';
import { Form, FormField } from 'component/common/form';
import CopyableText from 'component/copyableText';
import Card from 'component/common/card';
import SelectChannel from 'component/selectChannel';
import analytics from 'analytics';
import I18nMessage from 'component/i18nMessage';
import LbcSymbol from 'component/common/lbc-symbol';

type Props = {
  errorMessage: ?string,
  inviteNew: string => void,
  isPending: boolean,
  referralLink: string,
  referralCode: string,
  channels: ?Array<ChannelClaim>,
};

function InviteNew(props: Props) {
  const { inviteNew, errorMessage, isPending, referralCode = '', channels } = props;
  const noChannels = !channels || !(channels.length > 0);

  // Email
  const [email, setEmail] = useState('');
  function handleSubmit() {
    inviteNew(email);
  }

  function handleEmailChanged(event: any) {
    setEmail(event.target.value);
  }

  // Referral link
  const [referralSource, setReferralSource] = useState(referralCode);

  const handleReferralChange = React.useCallback(
    code => {
      setReferralSource(code);
      // TODO: keep track of this in an array?
      const matchingChannel = channels && channels.find(ch => ch.name === code);
      if (matchingChannel) {
        analytics.apiLogPublish(matchingChannel);
      }
    },
    [setReferralSource]
  );

  const topChannel =
    channels &&
    channels.reduce((top, channel) => {
      const topClaimCount = (top && top.meta && top.meta.claims_in_channel) || 0;
      const currentClaimCount = (channel && channel.meta && channel.meta.claims_in_channel) || 0;
      return topClaimCount >= currentClaimCount ? top : channel;
    });
  const referralString =
    channels && channels.length && referralSource !== referralCode
      ? lookupUrlByClaimName(referralSource, channels)
      : referralSource;

  const referral = `${URL}/$/invite/${referralString.replace('#', ':')}`;

  useEffect(() => {
    // set default channel
    if (topChannel) {
      handleReferralChange(topChannel.name);
    }
  }, [topChannel, handleReferralChange]);

  function lookupUrlByClaimName(name, channels) {
    const claim = channels.find(channel => channel.name === name);
    return claim && claim.canonical_url ? claim.canonical_url.replace('lbry://', '') : name;
  }

  return (
    <div className={'columns'}>
      <Card
        title={__('Invites')}
        subtitle={
          <I18nMessage tokens={{ SITE_NAME, lbc: <LbcSymbol /> }}>
            Earn %lbc% for inviting subscribers, followers, fans, friends, etc. to join and follow you on %SITE_NAME%.
            You can use invites just like affiliate links.
          </I18nMessage>
        }
        actions={
          <React.Fragment>
            <CopyableText label={__('Your invite link')} copyable={referral} />
            {!noChannels && (
              <SelectChannel
                channel={referralSource}
                onChannelChange={channel => handleReferralChange(channel)}
                label={__('Customize link')}
                hideAnon
                injected={[referralCode]}
              />
            )}
          </React.Fragment>
        }
      />

      <Card
        title={__('Invite by email')}
        subtitle={
          <I18nMessage tokens={{ SITE_NAME, lbc: <LbcSymbol /> }}>
            Invite someone you know by email and earn %lbc% when they join %SITE_NAME%.
          </I18nMessage>
        }
        actions={
          <React.Fragment>
            <Form onSubmit={handleSubmit}>
              <FormField
                type="text"
                label={__('Email')}
                placeholder="youremail@example.org"
                name="email"
                value={email}
                error={errorMessage}
                inputButton={
                  <Button button="secondary" type="submit" label={__('Invite')} disabled={isPending || !email} />
                }
                onChange={event => {
                  handleEmailChanged(event);
                }}
              />
              <p className="help">
                <I18nMessage
                  tokens={{
                    rewards_link: <Button button="link" navigate="/$/rewards" label={__('rewards')} />,
                    referral_faq_link: <Button button="link" label={__('FAQ')} href="https://lbry.com/faq/referrals" />,
                  }}
                >
                  Read our %referral_faq_link% to learn more about rewards.
                </I18nMessage>
              </p>
            </Form>
          </React.Fragment>
        }
      />
    </div>
  );
}

export default InviteNew;