<?php   
/**
 * functions/inc-blog.php
 * 
 * Blog & Posts: Related Posts, Blog Home Page Posts Offset
 * 
 * @author JJROD Framework
 * @see https://docs.jjrod.com
 * @version 1.0
 */

/****************************************************************************************************************/
/****************************************************************************************************************/
/****************************************************************************************************************/
/* Related Posts */
/****************************************************************************************************************/
/****************************************************************************************************************/
/****************************************************************************************************************/

function joints_related_posts() {
    global $post;
    $tag_arr = '';
    $tags = wp_get_post_tags( $post->ID );
    if($tags) {
        foreach( $tags as $tag ) {
            $tag_arr .= $tag->slug . ',';
        }
        $args = array(
            'tag' => $tag_arr,
            'numberposts' => 3, /* you can change this to show more */
            'post__not_in' => array($post->ID)
        );
        $related_posts = get_posts( $args );
        if($related_posts) {
        echo __( '<h4>Related Posts</h4>', 'jointswp' );
        echo '<ul class="joints-related-posts">';
            foreach ( $related_posts as $post ) : setup_postdata( $post ); ?>
                <li class="related_post">
                    <a href="<?php the_permalink() ?>" title="<?php the_title_attribute(); ?>"><?php the_title(); ?></a>
                    <?php get_template_part( 'parts/content', 'byline' ); ?>
                </li>
            <?php endforeach; }
            }
    wp_reset_postdata();
    echo '</ul>';
}

/****************************************************************************************************************/
/****************************************************************************************************************/
/****************************************************************************************************************/
/* Offset the main query on blog home page */
/****************************************************************************************************************/
/****************************************************************************************************************/
/****************************************************************************************************************/

function myprefix_query_offset(&$query) {

    // Before anything else, make sure this query is on our
    // blog's home page, and that it's the main query...
    if ( $query->is_home() && $query->is_main_query() ) {

        // First, define your desired offset...
        $offset = 1;

        // Next, determine how many posts per page you want (we'll use WordPress's settings)
        $ppp = get_option('posts_per_page');

        // Next, detect and handle pagination...
        if ( $query->is_paged ) {

            // Manually determine page query offset (offset + current page (minus one) x posts per page)
            $page_offset = $offset + ( ($query->query_vars['paged']-1) * $ppp );

            // Apply adjust page offset
            $query->set('offset', $page_offset );

        }
        else {

            // This is the first page. Just use the offset...
            $query->set('offset',$offset);

        }

    } else {

        return;

    }
}
add_action('pre_get_posts', 'myprefix_query_offset', 1 );

/**
 *
 * Adjust the found_posts according to our offset.
 * Used for our pagination calculation.
 *
 */
function myprefix_adjust_offset_pagination($found_posts, $query) {

    // Define our offset again...
    $offset = 1;

    // Ensure we're modifying the right query object...
    if ( $query->is_home() && $query->is_main_query() ) {
        // Reduce WordPress's found_posts count by the offset... 
        return $found_posts - $offset;
    }
    return $found_posts;
}
add_filter('found_posts', 'myprefix_adjust_offset_pagination', 1, 2 );