<?php
defined( 'ABSPATH' ) || die( 'Cheatin\' uh?' );

class SQ_Models_Services_PrevNext extends SQ_Models_Abstract_Seo {

	public function __construct() {
		parent::__construct();

		if ( isset( $this->_post->sq->doseo ) && $this->_post->sq->doseo ) {
			if ( ! $this->_post->sq->do_metas ) {
				add_filter( 'sq_prevnext', array( $this, 'returnFalse' ) );

				return;
			}

			add_filter( 'sq_prevnext', array( $this, 'generateMeta' ) );
			add_filter( 'sq_prevnext', array( $this, 'packMeta' ), 99 );
		} else {
			add_filter( 'sq_prevnext', array( $this, 'returnFalse' ) );
		}

	}

	public function generateMeta( $meta ) {
		global $paged;

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

		if ( ! $this->isHomePage() ) {
			if ( get_previous_posts_link() ) {
				$meta['prev'] = get_pagenum_link( $paged - 1 );
			}
			if ( get_next_posts_link() ) {
				$meta['next'] = get_pagenum_link( $paged + 1 );
			}
		}

		return $meta;
	}

	public function packMeta( $metas = array() ) {
		if ( ! empty( $metas ) ) {
			foreach ( $metas as $key => &$value ) {
				$value = '<link rel="' . $key . '" href="' . $value . '" />';
			}

			return "\n" . join( "\n", array_values( $metas ) );
		}

		return false;
	}

}