<?php
/**
 * @package Frontend
 */

if ( ! defined( 'WPSEO_VERSION' ) ) {
	header( 'Status: 403 Forbidden' );
	header( 'HTTP/1.1 403 Forbidden' );
	exit();
}


if ( ! class_exists( 'WPSEO_Rewrite' ) ) {
	/**
	 * This code handles the category rewrites.
	 */
	class WPSEO_Rewrite {

		/**
		 * Class constructor
		 */
		function __construct() {
			add_filter( 'query_vars', array( $this, 'query_vars' ) );
			add_filter( 'category_link', array( $this, 'no_category_base' ) );
			add_filter( 'request', array( $this, 'request' ) );
			add_filter( 'category_rewrite_rules', array( $this, 'category_rewrite_rules' ) );

			add_action( 'created_category', array( $this, 'schedule_flush' ) );
			add_action( 'edited_category', array( $this, 'schedule_flush' ) );
			add_action( 'delete_category', array( $this, 'schedule_flush' ) );

			add_action( 'init', array( $this, 'flush' ), 999 );
		}

		/**
		 * Save an option that triggers a flush on the next init.
		 *
		 * @since 1.2.8
		 */
		function schedule_flush() {
			update_option( 'wpseo_flush_rewrite', 1 );
		}

		/**
		 * If the flush option is set, flush the rewrite rules.
		 *
		 * @since 1.2.8
		 * @return bool
		 */
		function flush() {
			if ( get_option( 'wpseo_flush_rewrite' ) ) {

				add_action( 'shutdown', 'flush_rewrite_rules' );
				delete_option( 'wpseo_flush_rewrite' );

				return true;
			}

			return false;
		}

		/**
		 * Override the category link to remove the category base.
		 *
		 * @param string $link Unused, overridden by the function.
		 *
		 * @return string
		 */
		function no_category_base( $link ) {
			$category_base = get_option( 'category_base' );

			if ( '' == $category_base ) {
				$category_base = 'category';
			}

			// Remove initial slash, if there is one (we remove the trailing slash in the regex replacement and don't want to end up short a slash)
			if ( '/' == substr( $category_base, 0, 1 ) ) {
				$category_base = substr( $category_base, 1 );
			}

			$category_base .= '/';

			return preg_replace( '`' . preg_quote( $category_base, '`' ) . '`u', '', $link, 1 );
		}

		/**
		 * Update the query vars with the redirect var when stripcategorybase is active
		 *
		 * @param $query_vars
		 *
		 * @return array
		 */
		function query_vars( $query_vars ) {
			$options = WPSEO_Options::get_all();

			if ( $options['stripcategorybase'] === true ) {
				$query_vars[] = 'wpseo_category_redirect';
			}

			return $query_vars;
		}

		/**
		 * Redirect the "old" category URL to the new one.
		 *
		 * @param array $query_vars Query vars to check for existence of redirect var
		 *
		 * @return array
		 */
		function request( $query_vars ) {
			if ( isset( $query_vars['wpseo_category_redirect'] ) ) {
				$catlink = trailingslashit( get_option( 'home' ) ) . user_trailingslashit( $query_vars['wpseo_category_redirect'], 'category' );

				wp_redirect( $catlink, 301 );
				exit;
			}

			return $query_vars;
		}

		/**
		 * This function taken and only slightly adapted from WP No Category Base plugin by Saurabh Gupta
		 *
		 * @return array
		 */
		function category_rewrite_rules() {
			global $wp_rewrite;

			$category_rewrite = array();

			$taxonomy = get_taxonomy( 'category' );

			$blog_prefix = '';
			if ( function_exists( 'is_multisite' ) && is_multisite() && ! is_subdomain_install() && is_main_site() ) {
				$blog_prefix = 'blog/';
			}

			$categories = get_categories( array( 'hide_empty' => false ) );
			if ( is_array( $categories ) && $categories !== array() ) {
				foreach ( $categories as $category ) {
					$category_nicename = $category->slug;
					if ( $category->parent == $category->cat_ID ) {
						// recursive recursion
						$category->parent = 0;
					} elseif ( $taxonomy->rewrite['hierarchical'] != 0 && $category->parent != 0 ) {
						$parents = get_category_parents( $category->parent, false, '/', true );
						if ( ! is_wp_error( $parents ) ) {
							$category_nicename = $parents . $category_nicename;
						}
						unset( $parents );
					}

					$category_rewrite[ $blog_prefix . '(' . $category_nicename . ')/(?:feed/)?(feed|rdf|rss|rss2|atom)/?$' ]                = 'index.php?category_name=$matches[1]&feed=$matches[2]';
					$category_rewrite[ $blog_prefix . '(' . $category_nicename . ')/' . $wp_rewrite->pagination_base . '/?([0-9]{1,})/?$' ] = 'index.php?category_name=$matches[1]&paged=$matches[2]';
					$category_rewrite[ $blog_prefix . '(' . $category_nicename . ')/?$' ]                                                   = 'index.php?category_name=$matches[1]';
				}
			}

			// Redirect support from Old Category Base
			$old_base                            = $wp_rewrite->get_category_permastruct();
			$old_base                            = str_replace( '%category%', '(.+)', $old_base );
			$old_base                            = trim( $old_base, '/' );
			$category_rewrite[ $old_base . '$' ] = 'index.php?wpseo_category_redirect=$matches[1]';

			return $category_rewrite;
		}
	} /* End of class */

} /* End of class-exists wrapper */
