<?php
// 全ページ数を取得
$max_pages = $wp_query->max_num_pages;

if($max_pages > 1):
	?>
	<div id="pager">
		<?php
		// 現在のページ番号を取得
		$current_page = get_query_var( 'paged' );
		$current_page = $current_page === 0 ? '1' : $current_page;

    if($max_pages <= 5){
	    $start_page = 1;
	    $end_page = $max_pages;
    }else{
	    if($current_page - 2 <= 1){
		    $start_page = 1;
	      $end_page = $start_page + 4;
	    }else{
		    $start_page = $current_page - 2;
	      $end_page = $start_page + 4;
	    }

	    if($current_page + 2 > $max_pages){
		    $end_page = $max_pages;
        $start_page = $max_pages - 4;
	    }
    }

		if($current_page > 1){ ?>
			<div><a href="<?php echo get_pagenum_link($current_page - 1); ?>" class="prev"></a></div>
		<?php } ?>

		<div class="page_num"><?php echo $current_page . '/' . $max_pages; ?></div>

	  <?php if($start_page - 1 >= 1){ ?>
        <div><a href="<?php echo get_pagenum_link(1); ?>">1</a></div>
        <div>...</div>
	  <?php } ?>

		<?php for ($i = $start_page; $i <= $end_page; $i++){ ?>
			<?php if((int)$i === (int)$current_page): ?>
				<div><span><?php echo $i; ?></span></div>
			<?php else: ?>
				<div><a href="<?php echo get_pagenum_link($i); ?>"><?php echo $i; ?></a></div>
			<?php endif; ?>
		<?php } ?>

    <?php if($end_page + 1 <= $max_pages){ ?>
      <div>...</div>
      <div><a href="<?php echo get_pagenum_link($max_pages); ?>"><?php echo $max_pages; ?></a></div>
    <?php } ?>

		<?php if($current_page < $max_pages){ ?>
			<div><a href="<?php echo get_pagenum_link($current_page + 1); ?>" class="next"></a></div>
		<?php } ?>
	</div>

<?php endif; ?>