Custom avatar in Algolia plugin for WordPress

custom-avatar.php

<?php
/**
 * Plugin Name: Customize data pushed to Algolia.
 */

/**
 * @param int $user_id
 * @param string $fallback_avatar_url
 *
 * @return string
 */
function ca_get_user_avatar_url( $user_id, $fallback_avatar_url ) {
	$user_id = (int) $user_id;
	$avatar_override = get_user_option( 'metronet_avatar_override', $user_id );
	if ( ! $avatar_override || $avatar_override != 'on' ) {
		return $fallback_avatar_url;
	}

	$post_id = (int) get_user_option( 'metronet_post_id', $user_id );

	$avatar_url = '';
	$post_thumbnail_id = get_post_thumbnail_id( $post_id );
	if ( $post_thumbnail_id ) {
		$avatar_url = wp_get_attachment_thumb_url( $post_thumbnail_id );
	}

	if ( ! $avatar_url ) {
		return $fallback_avatar_url;
	}

	return $avatar_url;
}

/**
 * @param int $post_id
 * @param string $post_thumbnail_fallback_url
 *
 * @return mixed
 */
function ca_get_post_thumbnail_url( $post_id, $post_thumbnail_fallback_url ) {
	$post_id = (int) $post_id;
	$thumbnail_id = get_post_thumbnail_id( $post_id );

	if ( ! $thumbnail_id ) {
		return $post_thumbnail_fallback_url;
	}

	$thumb = wp_get_attachment_image_src( get_post_thumbnail_id( $post_id ), 'main-block' );
	if ( ! $thumb ) {
		return $post_thumbnail_fallback_url;
	}

	return $thumb[0];
}

/**
 * Push the overridden profile image provided by metronet-profile-picture plugin.
 *
 * @param array   $record
 * @param WP_User $user
 *
 * @return array
 */
function ca_algolia_user_record( array $record, WP_User $user ) {

	$record['avatar_url'] = ca_get_user_avatar_url( $user->ID, $record['avatar_url'] );

	return $record;
}

add_filter( 'algolia_user_record', 'ca_algolia_user_record', 10, 2 );

/**
 * @param array   $record
 * @param WP_Post $post
 *
 * @return array
 */
function ca_algolia_post_shared_attributes( array $record, WP_Post $post ) {
	$record['thumbnail_url'] = ca_get_post_thumbnail_url( $post->ID, $record['thumbnail_url'] );
	$record['post_author']['display_name'] = ca_get_user_avatar_url( $record['post_author']['user_id'], get_avatar_url( $record['post_author']['user_id'] ) ) . '|' . $record['post_author']['display_name'];
	$record['date_formatted'] = get_the_date( '', $post );

	return $record;
}

add_filter( 'algolia_post_shared_attributes', 'ca_algolia_post_shared_attributes', 10, 2 );
add_filter( 'algolia_searchable_post_shared_attributes', 'ca_algolia_post_shared_attributes', 10, 2 );