<?
#
# Sparqlette 0.4 - A SPARQL demo query service
#
# (c) 2003-2005 Morten Frederiksen
# License: http://www.gnu.org/licenses/gpl
#
# Background, documentation, and changelog:
# http://www.wasab.dk/morten/blog/archives/2005/05/02/the-gargonza-experiment
#

#include_once('dbSwitcher.php');
#$dbs=new dbSwitcher();
#define('REDLANDURI','mysql://mysql/'.$dbs->get('photo', 'online').'/photos');
define('REDLANDURI','mysql://mysql/online/sparqlette');
include_once('service.php');

# Accept 'default-graph-uri' as alias for 'data'.
if (array_key_exists('default-graph-uri',$_REQUEST)
        && !array_key_exists('data',$_REQUEST))
    $_REQUEST['data']=$_REQUEST['default-graph-uri'];

# Initialization.
$base='http://www.wasab.dk/morten/2005/04/sparqlette/';
$service=new Service(array(
        'uri'=>$base,
#        'xslt'=>'morten-service.xsl',
        'defaults'=>array(''=>array(
            'format'=>'xml',
            'output-type'=>'text/html; charset=utf-8',
            'query-lang'=>'sparql'))));
$formats=array(
        'rdfxml'=>'application/rdf+xml; charset=utf-8',
        'xml'=>'application/xml; charset=utf-8',
        'turtle'=>'application/x-turtle',
        'ntriples'=>'text/plain; charset=utf-8');

# Parse and run query?
if ($service->match('',array('query'))
        && (!array_key_exists('execute',$_REQUEST) || 'no'!=$_REQUEST['execute'])) {
    # Get query options.
    $query=$service->input('','query');
    $querylang=$service->input('','query-lang');
    $data=$service->input('','data');
    $format=$service->input('','format');
    $outputxslt=$service->input('','output-xslt');
    $outputtype=$service->input('','output-type');
    # Check remote XSLT...
    if (!preg_match('|^http://|',$outputxslt))
        $outputxslt='';
    # Construct XML comment with query and options.
    $comment="<!--";
    foreach ($service->inputs() as $input)
        $comment.="\n".str_replace('--','- -',$input.': '.str_replace("\n","\n  ",$service->input('',$input)));
    $comment.="\n-->\n";
    # Construct array of XSLT parameters.
    $xsltparms=array(
            '_now'=>date('Y-m-d\TH:i:s').(date('Z')>0?'+':'').sprintf('%02d',date('Z')/3600).':00',
            '_id'=>md5($query),
            '_uri'=>'http://'.$_SERVER['SERVER_NAME'].
                    ($_SERVER['SERVER_PORT']!=80?$_SERVER['SERVER_PORT']:'').
                    $_SERVER['REQUEST_URI']);
    while (list($name,$value)=each($_REQUEST))
        $xsltparms['sparql-'.$name]=$value;
    # Create Redland objects and process request.
    $nulluri=librdf_new_uri($World, '-');
    if ('xml1'==$format) {
        $format='xml';
        $dawgxmluri=librdf_new_uri($World, 'http://www.w3.org/TR/2004/WD-rdf-sparql-XMLres-20041221');
    } else
        $dawgxmluri=librdf_new_uri($World, 'http://www.w3.org/2005/sparql-results#');
    $results='';
    $xslt_error_message='';
    $Storage=0;
    $Model=0;
    $Query=0;
    $CBDStorage=0;
    $CBDModel=0;
    if ($data && !($Storage=librdf_new_storage($World,
            'hashes','temp',"hash-type='memory',contexts='yes'")))
        $service->error('500 Internal Server Error [Unable to create temporary storage for model'.redland_error().']');
    elseif (!$data && !($Storage=librdf_new_storage($World,
            $redland_config['redland_storage_type'],
            $redland_config['redland_model_name'],
            $redland_config['redland_storage_options'])))
        $service->error('500 Internal Server Error [Unable to create storage for model'.redland_error().']');
    elseif (!($Model=librdf_new_model($World, $Storage, '')))
        $service->error('500 Internal Server Error [Unable to create model'.redland_error().']');
    elseif ($data && load_content($data,$Model))
        $service->error('500 Internal Server Error [Unable to load content'.redland_error().'');
    elseif (!($Query=librdf_new_query($World, $querylang, $nulluri, $query, $nulluri)))
        $service->error('500 Internal Server Error [Unable to create query'.redland_error().']');
    elseif (!($Results=librdf_query_execute($Query, $Model))
            || librdf_query_results_is_boolean($Results)
            && librdf_query_results_is_graph($Results)
            && librdf_query_results_is_bindings($Results))
        $service->error('500 Internal Server Error [Unable to execute query'.redland_error().']');
    elseif (($cbd=(librdf_query_results_is_bindings($Results)
            && 'xml'!=$format
            && 1==librdf_query_results_get_bindings_count($Results)
            && 'cbd'==librdf_query_results_get_binding_name($Results, 0)))
            && !($CBDStorage=librdf_new_storage($World,
            'hashes','cbd',"hash-type='memory',contexts='yes'")))
        $service->error('500 Internal Server Error [Unable to create temporary storage for CBD model'.redland_error().']');
    elseif ($cbd
            && !($CBDModel=librdf_new_model($World, $CBDStorage, '')))
        $service->error('500 Internal Server Error [Unable to create CBD model'.redland_error().']');
    elseif ($cbd
            && !librdfutil_mysql_query_results_to_model_with_cbd($Results,$CBDModel))
        $service->error('500 Internal Server Error [Unable to populate CBD model from query results'.redland_error().']');
    elseif ($cbd
            && !($result=librdfutil_model_to_string($CBDModel,'rdfxml'==$format?'r3x':$format)))
        $service->error('500 Internal Server Error [Unable to serialize CBD model from query results'.redland_error().']');
    elseif (librdf_query_results_is_graph($Results)
            && ($format=('xml'==$format?'rdfxml':$format))
            && !($result=librdfutil_stream_to_string(librdf_query_results_as_stream($Results),'rdfxml'==$format?'r3x':$format)))
        $service->error('500 Internal Server Error [Unable to serialise query results from graph'.redland_error().']');
    elseif ($cbd
            || librdf_query_results_is_graph($Results)) {
        header('Content-Type: '.$formats[$format]);
        print $result;
        if ('rdfxml'==$format)
            print $comment;
        $service->free();
    } elseif ((librdf_query_results_is_bindings($Results)
            || librdf_query_results_is_boolean($Results))
            && !($result=librdfutil_query_results_to_string($Results,$dawgxmluri,$nulluri,preg_match('|select\s+distinct|i',$query))))
        $service->error('500 Internal Server Error [Unable to serialise query results from bindings'.redland_error().']');
    elseif ((librdf_query_results_is_bindings($Results)
            || librdf_query_results_is_boolean($Results))
            && $outputxslt
            && (!($xslt=xslt_create())
            || xslt_set_error_handler($xslt, 'xslt_error_handler')
            || !($result=xslt_process($xslt, 'arg:/_xml', 'arg:/_xsl', NULL,
                array('/_xml'=>$result,'/_xsl'=>@join('',@file($outputxslt))),
                $xsltparms))
            || $xslt_error_message
            || xslt_free($xslt)))
        $service->error('500 Internal Server Error [Unable to transform query results with XSLT ('.$xslt_error_message.').]');
    elseif ((librdf_query_results_is_bindings($Results)
            || librdf_query_results_is_boolean($Results))
            && $outputxslt) {
        header('Content-Type: '.$outputtype);
        print $result;
        $service->free();
    } elseif ((librdf_query_results_is_bindings($Results)
            || librdf_query_results_is_boolean($Results))) {
        header('Content-Type: application/xml; charset=utf-8');
        print $result.$comment;
        $service->free();
    } else {
        $Node=librdfutil_new_node($World);
        $service->add($Node, 'content:encoded', '<pre class="results">'.htmlspecialchars($result).'</pre>');
        $service->result($Node);
        librdf_free_node($Node);
    }
    librdf_free_uri($nulluri);
    librdf_free_uri($dawgxmluri);
    if ($Query)
        librdf_free_query($Query);
    if ($Model)
        librdf_free_model($Model);
    if ($Storage)
        librdf_free_storage($Storage);
    if ($CBDModel)
        librdf_free_model($CBDModel);
    if ($CBDStorage)
        librdf_free_storage($CBDStorage);
}

# Finish.
$service->finish();

# Retrieve, parse and load content URIs into model.
function load_content($contenturis,$Model) {
    global $World, $nulluri;
    $uris=preg_split('/\s+/',$contenturis);
    foreach ($uris as $uri) {
        $uri=librdf_new_uri($World,$uri);
        if (librdf_model_load($Model,$uri,'','',$nulluri))
            return 1;
        librdf_free_uri($uri);
    }
    return 0;
}

# Handle XSLT errors.
function xslt_error_handler($x,$e,$l,$f) {
    global $xslt_error_message;
    $xslt_error_message='Sablotron XSLT transformation error';
    reset($f);
    while(list($key,$val)=each($f)) {
        if ($key=='line')
            $xslt_error_message.=' on line '.$val;
        if ($key=='msg')
            $xslt_error_message.=': <strong>'.$val.'</strong>';
    }
}

function redland_error() {
    global $World;
    $nulluri=librdf_new_uri($World,'-');
    $log=librdf_world_get_feature($World,$nulluri);
    librdf_free_uri($nulluri);
    if ($log)
        return ': <strong>'.librdf_log_message_message($log).'</strong>';
    else
        return '.';
}

?>