Series Progress for a Category of Lessons (No LMS Needed)

add_shortcode( 'wpide_series_progress', function ( $atts ) {
    $atts = shortcode_atts( array( 'category' => '', 'list' => 'yes' ), $atts, 'wpide_series_progress' );

    if ( '' === $atts['category'] ) {
        return '';
    }

    $lessons = get_posts( array(
        'category_name' => sanitize_title( $atts['category'] ),
        'numberposts'   => 100,
        'orderby'       => 'date',
        'order'         => 'ASC',
        'fields'        => 'ids',
        'no_found_rows' => true,
    ) );

    if ( ! $lessons ) {
        return '';
    }

    $done    = is_user_logged_in() ? array_map( 'intval', (array) get_user_meta( get_current_user_id(), 'wpide_completed_lessons', true ) ) : array();
    $count   = count( array_intersect( $lessons, $done ) );
    $percent = (int) round( $count / count( $lessons ) * 100 );

    $html = sprintf(
        '<div class="wpide-series"><div role="progressbar" aria-valuenow="%1$d" aria-valuemin="0" aria-valuemax="100" aria-label="Series progress" style="height:10px;border-radius:5px;background:rgba(127,127,127,.25);overflow:hidden"><div style="width:%1$d%%;height:100%%;background:currentColor"></div></div><p style="margin:.4em 0">%2$s</p>',
        $percent,
        esc_html( sprintf( '%1$d of %2$d lessons complete', $count, count( $lessons ) ) )
    );

    if ( 'yes' === $atts['list'] ) {
        $html .= '<ol class="wpide-series__list">';
        foreach ( $lessons as $id ) {
            $is_done = in_array( $id, $done, true );
            $html   .= '<li' . ( $is_done ? ' class="is-done"' : '' ) . '><a href="' . esc_url( get_permalink( $id ) ) . '">' . esc_html( get_the_title( $id ) ) . '</a>' . ( $is_done ? ' <span aria-label="completed">✓</span>' : '' ) . '</li>';
        }
        $html .= '</ol>';
    }

    return $html . '</div>';
} );