<?php
/*
Plugin Name: SIOC Plugin
Plugin URI: http://sioc-project.org/wordpress/
Description: Adds <a href="http://sioc-project.org/">SIOC metadata</a> export to WordPress blog. 
Author: Uldis Bojars
Version: 1.25
Author URI: http://captsolo.net/info/
*/ 

require_once "sioc-include.php";

// This displays a link to SIOC metadata profile 
function sioc_get_link() {
	global $posts;
	
	# TODO - Use WP_Rewrite to get correct pathname
	$base_mid = "http://$_SERVER[HTTP_HOST]$_SERVER[PHP_SELF]"; # '/wp-sioc.php';
	
	if ( is_home() ) $base_mid .= '?sioc_type=site'; 
	if ( is_single() ) $base_mid .= '?sioc_type=post&sioc_id=' . $posts[0]->ID;
	if ( is_author() ) {
		// TODO - Check if getting author won't break if there is more than one author queried for
		$user_id = get_query_var('author');
		$base_mid .= '?sioc_type=user&sioc_id=' . $user_id; 
	}

	/* Types of pages we don't do special processing for */
	if ( is_category() ||
	     is_page() ||
	     is_archive() ||
	     is_paged() ) {
		// No auto-discovery link
	     	return '';
	} else {
		return $base_mid;
	}
}

function sioc_link() {
	global $posts;
	
	if ( is_feed() ) return;

	// Form the template link to SIOC metadata
	$base_url = '<link rel="meta" type="application/rdf+xml" title="SIOC" href="';
	$base_end = '" />' . "\n\n";
		# TODO - Use WP_Rewrite to get correct pathname
	$base_mid = sioc_get_link();

	if ( !empty($base_mid) )
		echo $base_url . htmlentities($base_mid) . $base_end;
}

// Add sioc_link function to execute during a page HEAD section
add_action('wp_head', 'sioc_link');

function is_sioc() {
	if ( !empty($_GET['sioc_type']) ) return true;
	return false;
}

function is_rdf_request() {
	if ( $_SERVER['HTTP_ACCEPT'] == 'application/rdf+xml' ) {
		return true;
	}
	return false;
}
// ************* Get control from WordPress *************
function sioc_get_control() {
	global $aaa;

	if ( is_sioc() ) {
		$aaa = $_GET['sioc_type'];
		# @header("Custom-header: PING");
		# @header('Content-type: application/rdf+xml');
		sioc_main();
		die();
	}
	
	if ( is_rdf_request() ) {
		$redir = sioc_get_link();
		if ( !empty($redir) ) {
			@header( "Location: " . sioc_get_link() );
			die();
		}
	}
}

add_action('template_redirect', 'sioc_get_control');

?>