<?php

namespace CorpusParole\Models;

use CorpusParole\Libraries\RdfModel\RdfModelResource;

use JsonSerializable;

use Log;

/**

 * Model class for Document. Inherit from EasyRd\Resource

 * SELECT DISTINCT ?g WHERE {GRAPH ?g {?s ?p ?o}}

 */

abstract class WebResource extends RdfModelResource implements JsonSerializable {

    public function __construct(...$args) {

        list($uri, $graph) = $args;

        parent::__construct($uri, $graph);

    }

    private $format = false;

    abstract protected function doClearMemoizationCache();

    public function clearMemoizationCache() {

        $this->format = false;

        $this->doClearMemoizationCache();

    }

    public function getFormat() {

        if($this->format === false) {

            $format = $this->getLiteral("<http://purl.org/dc/elements/1.1/format>");

            $this->format = is_null($format)?null:$format->getValue();

        }

        return $this->format;

    }

    public function getUrl() {

        return $this->getUri();

    }

    abstract protected function jsonSerializeExtra();

    public function jsonSerialize() {

        return array_merge(

            [

                'url' => $this->getUrl(),

                'format' => $this->getFormat()

            ],

            $this->jsonSerializeExtra()

        );

    }

}