// @flow
import * as ICONS from 'constants/icons';
import React from 'react';
import Page from 'component/page';
import Spinner from 'component/spinner';
import { FormField } from 'component/common/form';
import Notification from 'component/notification';
import Button from 'component/button';
import usePersistedState from 'effects/use-persisted-state';
import Yrbl from 'component/yrbl';
import * as NOTIFICATIONS from 'constants/notifications';

type Props = {
  notifications: Array<Notification>,
  fetching: boolean,
  unreadCount: number,
  unseenCount: number,
  doSeeAllNotifications: () => void,
  doReadNotifications: () => void,
};

const ALL_NOTIFICATIONS = 'all';

export default function NotificationsPage(props: Props) {
  const { notifications, fetching, unreadCount, unseenCount, doSeeAllNotifications, doReadNotifications } = props;
  const hasNotifications = notifications.length > 0;
  const [filterBy, setFilterBy] = usePersistedState('notifications--filter-by', 'all');
  const [filteredNotifications, setFilteredNotifications] = React.useState(notifications);
  const isFiltered = filterBy !== ALL_NOTIFICATIONS;

  const NOTIFICATION_FILTER_TYPES = [
    ALL_NOTIFICATIONS,
    NOTIFICATIONS.NOTIFICATION_CREATOR_SUBSCRIBER,
    NOTIFICATIONS.NOTIFICATION_COMMENT,
    NOTIFICATIONS.NOTIFICATION_REPLY,
    NOTIFICATIONS.DAILY_WATCH_AVAILABLE,
    NOTIFICATIONS.DAILY_WATCH_REMIND,
    NOTIFICATIONS.NEW_CONTENT,
  ];

  React.useEffect(() => {
    if (unseenCount > 0 || unreadCount > 0) {
      // If there are unread notifications when entering the page, reset to All.
      setFilterBy(ALL_NOTIFICATIONS);
    }
  }, []);

  React.useEffect(() => {
    if (notifications && filterBy !== ALL_NOTIFICATIONS) {
      setFilteredNotifications(notifications.filter((n) => n.notification_rule === filterBy));
    } else {
      setFilteredNotifications(notifications);
    }
  }, [notifications, filterBy]);

  React.useEffect(() => {
    if (unseenCount > 0) {
      doSeeAllNotifications();
    }
  }, [unseenCount, doSeeAllNotifications]);

  return (
    <Page>
      {fetching && !hasNotifications && (
        <div className="main--empty">
          <Spinner delayed />
        </div>
      )}
      {!fetching && (
        <>
          <div className="claim-list__header">
            <h1 className="card__title">{__('Notifications')}</h1>
            <div className="claim-list__alt-controls--wrap">
              {fetching && <Spinner type="small" />}

              {unreadCount > 0 && (
                <Button
                  icon={ICONS.EYE}
                  onClick={doReadNotifications}
                  button="secondary"
                  label={__('Mark all as read')}
                />
              )}
              <FormField
                className="notification__filter"
                type="select"
                name="filter"
                value={filterBy || ALL_NOTIFICATIONS}
                onChange={(e) => setFilterBy(e.target.value)}
              >
                {NOTIFICATION_FILTER_TYPES.map((type) => (
                  <option key={type} value={type}>
                    {/* i18fixme */}
                    {type === ALL_NOTIFICATIONS && __('All')}
                    {type === NOTIFICATIONS.NOTIFICATION_CREATOR_SUBSCRIBER && __('Followers')}
                    {type === NOTIFICATIONS.NOTIFICATION_COMMENT && __('Comments')}
                    {type === NOTIFICATIONS.NOTIFICATION_REPLY && __('Comment replies')}
                    {type === NOTIFICATIONS.DAILY_WATCH_AVAILABLE && __('Daily watch availability')}
                    {type === NOTIFICATIONS.DAILY_WATCH_REMIND && __('Daily watch reminders')}
                    {type === NOTIFICATIONS.NEW_CONTENT && __('New content')}
                  </option>
                ))}
              </FormField>
            </div>
          </div>
          {filteredNotifications && filteredNotifications.length > 0 ? (
            <div className="card">
              <div className="notification_list">
                {filteredNotifications.map((notification, index) => {
                  return <Notification key={notification.id} notification={notification} />;
                })}
              </div>
            </div>
          ) : (
            <div className="main--empty">
              <Yrbl
                title={__('No notifications')}
                subtitle={
                  <p>
                    {isFiltered
                      ? __('Try selecting another filter.')
                      : __("You don't have any notifications yet, but they will be here when you do!")}
                  </p>
                }
                actions={
                  <div className="section__actions">
                    <Button button="primary" icon={ICONS.HOME} label={__('Go Home')} navigate="/" />
                  </div>
                }
              />
            </div>
          )}
        </>
      )}
    </Page>
  );
}