// @flow

import { getFeatureFlag, FILMSTRIP_ENABLED } from '../base/flags';
import { getParticipantCountWithFake } from '../base/participants';
import { toState } from '../base/redux';

/**
 * Returns true if the filmstrip on mobile is visible, false otherwise.
 *
 * NOTE: Filmstrip on mobile behaves differently to web, and is only visible
 * when there are at least 2 participants.
 *
 * @param {Object | Function} stateful - The Object or Function that can be
 * resolved to a Redux state object with the toState function.
 * @returns {boolean}
 */
export function isFilmstripVisible(stateful: Object | Function) {
    const state = toState(stateful);

    const enabled = getFeatureFlag(state, FILMSTRIP_ENABLED, true);

    if (!enabled) {
        return false;
    }

    return getParticipantCountWithFake(state) > 1;
}