<?php

/**

 * Canonical API to handle WordPress Redirecting

 *

 * Based on "Permalink Redirect" from Scott Yang and "Enforce www. Preference"

 * by Mark Jaquith

 *

 * @package WordPress

 * @since 2.3.0

 */

/**

 * Redirects incoming links to the proper URL based on the site url.

 *

 * Search engines consider www.somedomain.com and somedomain.com to be two

 * different URLs when they both go to the same location. This SEO enhancement

 * prevents penalty for duplicate content by redirecting all incoming links to

 * one or the other.

 *

 * Prevents redirection for feeds, trackbacks, searches, and

 * admin URLs. Does not redirect on non-pretty-permalink-supporting IIS 7+,

 * page/post previews, WP admin, Trackbacks, robots.txt, searches, or on POST

 * requests.

 *

 * Will also attempt to find the correct link when a user enters a URL that does

 * not exist based on exact WordPress query. Will instead try to parse the URL

 * or query in an attempt to figure the correct page to go to.

 *

 * @since 2.3.0

 *

 * @global WP_Rewrite $wp_rewrite

 * @global bool $is_IIS

 * @global WP_Query $wp_query

 * @global wpdb $wpdb WordPress database abstraction object.

 *

 * @param string $requested_url Optional. The URL that was requested, used to

 * @param bool $do_redirect Optional. Redirect to the new URL.

 * @return string|void The string of the URL, if redirect needed.

 */

function redirect_canonical( $requested_url = null, $do_redirect = true ) {

	global $wp_rewrite, $is_IIS, $wp_query, $wpdb, $wp;

	if ( isset( $_SERVER['REQUEST_METHOD'] ) && ! in_array( strtoupper( $_SERVER['REQUEST_METHOD'] ), array( 'GET', 'HEAD' ) ) ) {

		return;

	}

	// If we're not in wp-admin and the post has been published and preview nonce

	// is non-existent or invalid then no need for preview in query

	if ( is_preview() && get_query_var( 'p' ) && 'publish' == get_post_status( get_query_var( 'p' ) ) ) {

		if ( ! isset( $_GET['preview_id'] )

			|| ! isset( $_GET['preview_nonce'] )

			|| ! wp_verify_nonce( $_GET['preview_nonce'], 'post_preview_' . (int) $_GET['preview_id'] ) ) {

			$wp_query->is_preview = false;

		}

	}

		return;

	}

	if ( ! $requested_url && isset( $_SERVER['HTTP_HOST'] ) ) {

		// build the URL in the address bar

		$requested_url  = is_ssl() ? 'https://' : 'http://';

		$requested_url .= $_SERVER['HTTP_HOST'];

		$requested_url .= $_SERVER['REQUEST_URI'];

	}

	if ( false === $original ) {

		return;

	}

	$redirect_url = false;

	// Notice fixing

		$redirect['path'] = '';

		$redirect['query'] = '';

	// If the original URL ended with non-breaking spaces, they were almost

	// certainly inserted by accident. Let's remove them, so the reader doesn't

	// see a 404 error with no obvious cause.

	$redirect['path'] = preg_replace( '|(%C2%A0)+$|i', '', $redirect['path'] );

	// It's not a preview, so remove it from URL

	if ( get_query_var( 'preview' ) ) {

		$redirect['query'] = remove_query_arg( 'preview', $redirect['query'] );

	}

	if ( is_feed() && ( $id = get_query_var( 'p' ) ) ) {

		if ( $redirect_url = get_post_comments_feed_link( $id, get_query_var( 'feed' ) ) ) {

		}

	}

				$id = $vars->post_parent;

				$redirect['query'] = _remove_qs_args_if_not_in_url( $redirect['query'], array( 'p', 'page_id', 'attachment_id', 'pagename', 'name', 'post_type' ), $redirect_url );

		}

	}

	// These tests give us a WP-generated permalink

	if ( is_404() ) {

		// Redirect ?page_id, ?p=, ?attachment_id= to their respective url's

			if ( $post_type_obj->public && 'auto-draft' != $redirect_post->post_status ) {

				$redirect['query'] = _remove_qs_args_if_not_in_url( $redirect['query'], array( 'p', 'page_id', 'attachment_id', 'pagename', 'name', 'post_type' ), $redirect_url );

			}

		}

		if ( get_query_var( 'day' ) && get_query_var( 'monthnum' ) && get_query_var( 'year' ) ) {

			$year  = get_query_var( 'year' );

			$month = get_query_var( 'monthnum' );

			$day   = get_query_var( 'day' );

			$date  = sprintf( '%04d-%02d-%02d', $year, $month, $day );

			if ( ! wp_checkdate( $month, $day, $year, $date ) ) {

				$redirect['query'] = _remove_qs_args_if_not_in_url( $redirect['query'], array( 'year', 'monthnum', 'day' ), $redirect_url );

			}

		} elseif ( get_query_var( 'monthnum' ) && get_query_var( 'year' ) && 12 < get_query_var( 'monthnum' ) ) {

			$redirect['query'] = _remove_qs_args_if_not_in_url( $redirect['query'], array( 'year', 'monthnum' ), $redirect_url );

		}

		if ( ! $redirect_url ) {

			if ( $redirect_url = redirect_guess_404_permalink() ) {

				$redirect['query'] = _remove_qs_args_if_not_in_url( $redirect['query'], array( 'page', 'feed', 'p', 'page_id', 'attachment_id', 'pagename', 'name', 'post_type' ), $redirect_url );

			}

		}

		if ( get_query_var( 'page' ) && $wp_query->post &&

			false !== strpos( $wp_query->post->post_content, '<!--nextpage-->' ) ) {

			$redirect['query'] = remove_query_arg( 'page', $redirect['query'] );

		}

		// rewriting of old ?p=X, ?m=2004, ?m=200401, ?m=20040101

		if ( is_attachment() &&

			! array_diff( array_keys( $wp->query_vars ), array( 'attachment', 'attachment_id' ) ) &&

			! $redirect_url ) {

			if ( ! empty( $_GET['attachment_id'] ) ) {

				$redirect_url = get_attachment_link( get_query_var( 'attachment_id' ) );

				if ( $redirect_url ) {

					$redirect['query'] = remove_query_arg( 'attachment_id', $redirect['query'] );

				}

			} else {

				$redirect_url = get_attachment_link();

			}

				case 4: // Yearly

					break;

				case 6: // Monthly

					break;

				case 8: // Daily

					break;

			}

			if ( ( false !== $author ) && $wpdb->get_var( $wpdb->prepare( "SELECT ID FROM $wpdb->posts WHERE $wpdb->posts.post_author = %d AND $wpdb->posts.post_status = 'publish' LIMIT 1", $author->ID ) ) ) {

			}

		} elseif ( is_category() || is_tag() || is_tax() ) { // Terms (Tags/categories)

			$term_count = 0;

				$term_count += count( $tax_query['terms'] );

			$obj = $wp_query->get_queried_object();

					// Strip taxonomy query vars off the url.

					if ( is_category() ) {

						$qv_remove[] = 'category_name';

						$qv_remove[] = 'cat';

					} elseif ( is_tag() ) {

						$qv_remove[] = 'tag';

						$qv_remove[] = 'tag_id';

					} else { // Custom taxonomies will have a custom query var, remove those too:

						$tax_obj = get_taxonomy( $obj->taxonomy );

							$qv_remove[] = $tax_obj->query_var;

					}

						// Create the destination url for this taxonomy

						} else { // Taxonomy is accessible via a "pretty-URL"

							$redirect['path'] = $tax_url['path'];

						}

					} else { // Some query vars are set via $_GET. Unset those from $_GET that exist via the rewrite

						foreach ( $qv_remove as $_qv ) {

						}

					}

				}

			}

			$category = get_category_by_path( $cat );

			if ( ( ! $category || is_wp_error( $category ) ) || ! has_term( $category->term_id, 'category', $wp_query->get_queried_object_id() ) ) {

			}

		}

				$redirect_url = get_permalink( get_queried_object_id() );

			$page = get_query_var( 'page' );

			if ( $page > 1 ) {

				if ( is_front_page() ) {

					$redirect_url = trailingslashit( $redirect_url ) . user_trailingslashit( "$wp_rewrite->pagination_base/$page", 'paged' );

				} else {

					$redirect_url = trailingslashit( $redirect_url ) . user_trailingslashit( $page, 'single_paged' );

				}

			}

		}

			while ( preg_match( "#/$wp_rewrite->pagination_base/?[0-9]+?(/+)?$#", $redirect['path'] ) || preg_match( '#/(comments/?)?(feed|rss|rdf|atom|rss2)(/+)?$#', $redirect['path'] ) || preg_match( "#/{$wp_rewrite->comments_pagination_base}-[0-9]+(/+)?$#", $redirect['path'] ) ) {

				// Strip off paging and feed

			}

			$addl_path = '';

					$addl_path .= 'comments/';

					$addl_path .= user_trailingslashit( 'feed/' . ( ( get_default_feed() == 'rss2' ) ? '' : 'rss2' ), 'feed' );

				$redirect['query'] = remove_query_arg( 'feed', $redirect['query'] );

				$old_feed_files = array(

					'wp-atom.php'         => 'atom',

					'wp-commentsrss2.php' => 'comments_rss2',

					'wp-feed.php'         => get_default_feed(),

					'wp-rdf.php'          => 'rdf',

					'wp-rss.php'          => 'rss2',

					'wp-rss2.php'         => 'rss2',

				);

				if ( isset( $old_feed_files[ basename( $redirect['path'] ) ] ) ) {

					$redirect_url = get_feed_link( $old_feed_files[ basename( $redirect['path'] ) ] );

					wp_redirect( $redirect_url, 301 );

					die();

				}

			}

				$redirect['query'] = remove_query_arg( 'paged', $redirect['query'] );