/*
 * @param int $user id
 * @param string $meta_key
 * @param string $new_value - the new value to be added to the array
 */
function meta_update($user_id, $meta_key, $new_value) {
    // Get the existing meta for 'meta_key'
    $meta = get_user_meta($user_id, $meta_key, true);
    // Do some defensive coding - if it's not an array, set it up
    if ( ! is_array($meta) ) {
        $meta = array();
    }
    // Push a new value onto the array
    $meta[] = $new_value;
    // Write the user meta record with the new value in it
    update_user_meta($user_id, $meta_key, $meta);
}

/*
 * @param int $user_id
 * @param int $certification_id - certifications post_id
 * @param string $name - TODO: auto pull post title
 * @param string $renewal_date - user provided date
 */
function cpe_enroll_user( $user_id, $certification_id, $name, $renewal_date ) {

    // $meta = get_user_meta( $user_id, 'certifications', false)[0];
    $meta = get_user_meta( $user_id, 'certifications', true);

    if ( !array($meta) ) {
        $meta = array();
    }

    $enrollment_data = array(array(
        'certification_id'          =>  $certification_id,
        'certification_name'        =>  $name,
        'cpes_required'             =>  $cpes_required,
        'renewal_date'              =>  $renewal_date,
        ),
    );

    if(!empty($meta)) {
        // foreach($meta as $key => $value) {
            if(!in_array($enrollment_data[0]['certification_id'], array_column($meta, 'certification_id'))) {
                $meta_update = array_merge($meta, $enrollment_data);
                update_user_meta( $user_id, 'certifications', $meta_update);
            }
        // }
    } else {
        update_user_meta( $user_id, 'certifications', $enrollment_data);
    }
}