<?php
/**
 * COPS (Calibre OPDS PHP Server) class file
 *
 * @license    GPL 2 (http://www.gnu.org/licenses/gpl.html)
 * @author     Sébastien Lucas <sebastien@slucas.fr>
 */

require_once ("base.php");

class OPDSRenderer
{
    private $xmlStream = NULL;
    private $updated = NULL;

    private function getUpdatedTime () {
        if (is_null ($this->updated)) {
            $this->updated = time();
        }
        return date (DATE_ATOM, $this->updated);
    }

    private function getXmlStream () {
        if (is_null ($this->xmlStream)) {
            $this->xmlStream = new XMLWriter();
            $this->xmlStream->openMemory();
            $this->xmlStream->setIndent (true);
        }
        return $this->xmlStream;
    }

    public function getOpenSearch () {
        global $config;
        $xml = new XMLWriter ();
        $xml->openMemory ();
        $xml->setIndent (true);
        $xml->startDocument('1.0','UTF-8');
            $xml->startElement ("OpenSearchDescription");
                $xml->writeAttribute ("xmlns", "http://a9.com/-/spec/opensearch/1.1/");
                $xml->startElement ("ShortName");
                    $xml->text ("My catalog");
                $xml->endElement ();
                $xml->startElement ("Description");
                    $xml->text ("Search for ebooks");
                $xml->endElement ();
                $xml->startElement ("InputEncoding");
                    $xml->text ("UTF-8");
                $xml->endElement ();
                $xml->startElement ("OutputEncoding");
                    $xml->text ("UTF-8");
                $xml->endElement ();
                $xml->startElement ("Image");
                    $xml->writeAttribute ("type", "image/x-icon");
                    $xml->writeAttribute ("width", "16");
                    $xml->writeAttribute ("height", "16");
                    $xml->text ($config['cops_icon']);
                $xml->endElement ();
                $xml->startElement ("Url");
                    $xml->writeAttribute ("type", 'application/atom+xml');
                    $urlparam = "?query={searchTerms}";
                    if (!is_null (GetUrlParam (DB))) $urlparam = addURLParameter ($urlparam, DB, GetUrlParam (DB));
                    $urlparam = str_replace ("%7B", "{", $urlparam);
                    $urlparam = str_replace ("%7D", "}", $urlparam);
                    $xml->writeAttribute ("template", $config['cops_full_url'] . 'feed.php' . $urlparam);
                $xml->endElement ();
                $xml->startElement ("Query");
                    $xml->writeAttribute ("role", "example");
                    $xml->writeAttribute ("searchTerms", "robot");
                $xml->endElement ();
            $xml->endElement ();
        $xml->endDocument();
        return $xml->outputMemory(true);
    }

    private function startXmlDocument ($page) {
        global $config;
        self::getXmlStream ()->startDocument('1.0','UTF-8');
        self::getXmlStream ()->startElement ("feed");
            self::getXmlStream ()->writeAttribute ("xmlns", "http://www.w3.org/2005/Atom");
            self::getXmlStream ()->writeAttribute ("xmlns:xhtml", "http://www.w3.org/1999/xhtml");
            self::getXmlStream ()->writeAttribute ("xmlns:opds", "http://opds-spec.org/2010/catalog");
            self::getXmlStream ()->writeAttribute ("xmlns:opensearch", "http://a9.com/-/spec/opensearch/1.1/");
            self::getXmlStream ()->writeAttribute ("xmlns:dcterms", "http://purl.org/dc/terms/");
            self::getXmlStream ()->startElement ("title");
                self::getXmlStream ()->text ($page->title);
            self::getXmlStream ()->endElement ();
            if ($page->subtitle != "")
            {
                self::getXmlStream ()->startElement ("subtitle");
                    self::getXmlStream ()->text ($page->subtitle);
                self::getXmlStream ()->endElement ();
            }
            self::getXmlStream ()->startElement ("id");
                if ($page->idPage)
                {
                    $idPage = $page->idPage;
                    if (!is_null (GetUrlParam (DB))) $idPage = str_replace ("cops:", "cops:" . GetUrlParam (DB) . ":", $idPage);
                    self::getXmlStream ()->text ($idPage);
                }
                else
                {
                    self::getXmlStream ()->text ($_SERVER['REQUEST_URI']);
                }
            self::getXmlStream ()->endElement ();
            self::getXmlStream ()->startElement ("updated");
                self::getXmlStream ()->text (self::getUpdatedTime ());
            self::getXmlStream ()->endElement ();
            self::getXmlStream ()->startElement ("icon");
                self::getXmlStream ()->text ($page->favicon);
            self::getXmlStream ()->endElement ();
            self::getXmlStream ()->startElement ("author");
                self::getXmlStream ()->startElement ("name");
                    self::getXmlStream ()->text ($page->authorName);
                self::getXmlStream ()->endElement ();
                self::getXmlStream ()->startElement ("uri");
                    self::getXmlStream ()->text ($page->authorUri);
                self::getXmlStream ()->endElement ();
                self::getXmlStream ()->startElement ("email");
                    self::getXmlStream ()->text ($page->authorEmail);
                self::getXmlStream ()->endElement ();
            self::getXmlStream ()->endElement ();
            $link = new LinkNavigation ("", "start", "Home");
            self::renderLink ($link);
            $link = new LinkNavigation ("?" . getQueryString (), "self");
            self::renderLink ($link);
            $urlparam = "?";
            if (!is_null (GetUrlParam (DB))) $urlparam = addURLParameter ($urlparam, DB, GetUrlParam (DB));
            if ($config['cops_generate_invalid_opds_stream'] == 0 || preg_match("/(MantanoReader|FBReader)/", $_SERVER['HTTP_USER_AGENT'])) {
                // Good and compliant way of handling search
                $urlparam = addURLParameter ($urlparam, "page", Base::PAGE_OPENSEARCH);
                $link = new Link ("feed.php" . $urlparam, "application/opensearchdescription+xml", "search", "Search here");
            }
            else
            {
                // Bad way, will be removed when OPDS client are fixed
                $urlparam = addURLParameter ($urlparam, "query", "{searchTerms}");
                $urlparam = str_replace ("%7B", "{", $urlparam);
                $urlparam = str_replace ("%7D", "}", $urlparam);
                $link = new Link ($config['cops_full_url'] . 'feed.php' . $urlparam, "application/atom+xml", "search", "Search here");
            }
            self::renderLink ($link);
            if ($page->containsBook () && !is_null ($config['cops_books_filter']) && count ($config['cops_books_filter']) > 0) {
                $Urlfilter = getURLParam ("tag", "");
                foreach ($config['cops_books_filter'] as $lib => $filter) {
                    $link = new LinkFacet ("?" . addURLParameter (getQueryString (), "tag", $filter), $lib, localize ("tagword.title"), $filter == $Urlfilter);
                    self::renderLink ($link);
                }
            }
    }

    private function endXmlDocument () {
        self::getXmlStream ()->endElement ();
        self::getXmlStream ()->endDocument ();
        return self::getXmlStream ()->outputMemory(true);
    }

    private function renderLink ($link) {
        self::getXmlStream ()->startElement ("link");
            self::getXmlStream ()->writeAttribute ("href", $link->href);
            self::getXmlStream ()->writeAttribute ("type", $link->type);
            if (!is_null ($link->rel)) {
                self::getXmlStream ()->writeAttribute ("rel", $link->rel);
            }
            if (!is_null ($link->title)) {
                self::getXmlStream ()->writeAttribute ("title", $link->title);
            }
            if (!is_null ($link->facetGroup)) {
                self::getXmlStream ()->writeAttribute ("opds:facetGroup", $link->facetGroup);
            }
            if ($link->activeFacet) {
                self::getXmlStream ()->writeAttribute ("opds:activeFacet", "true");
            }
        self::getXmlStream ()->endElement ();
    }

    private function getPublicationDate($book) {
        $dateYmd = substr($book->pubdate, 0, 10);
        $pubdate = \DateTime::createFromFormat('Y-m-d', $dateYmd);
        if ($pubdate === false ||
            $pubdate->format ("Y") == "0101" ||
            $pubdate->format ("Y") == "0100") {
            return "";
        }
        return $pubdate->format("Y-m-d");
    }

    private function renderEntry ($entry) {
        self::getXmlStream ()->startElement ("title");
            self::getXmlStream ()->text ($entry->title);
        self::getXmlStream ()->endElement ();
        self::getXmlStream ()->startElement ("updated");
            self::getXmlStream ()->text (self::getUpdatedTime ());
        self::getXmlStream ()->endElement ();
        self::getXmlStream ()->startElement ("id");
            self::getXmlStream ()->text ($entry->id);
        self::getXmlStream ()->endElement ();
        self::getXmlStream ()->startElement ("content");
            self::getXmlStream ()->writeAttribute ("type", $entry->contentType);
            if ($entry->contentType == "text") {
                self::getXmlStream ()->text ($entry->content);
            } else {
                self::getXmlStream ()->writeRaw ($entry->content);
            }
        self::getXmlStream ()->endElement ();
        foreach ($entry->linkArray as $link) {
            self::renderLink ($link);
        }

        if (get_class ($entry) != "EntryBook") {
            return;
        }

        foreach ($entry->book->getAuthors () as $author) {
            self::getXmlStream ()->startElement ("author");
                self::getXmlStream ()->startElement ("name");
                    self::getXmlStream ()->text ($author->name);
                self::getXmlStream ()->endElement ();
                self::getXmlStream ()->startElement ("uri");
                    self::getXmlStream ()->text ("feed.php" . $author->getUri ());
                self::getXmlStream ()->endElement ();
            self::getXmlStream ()->endElement ();
        }
        foreach ($entry->book->getTags () as $category) {
            self::getXmlStream ()->startElement ("category");
                self::getXmlStream ()->writeAttribute ("term", $category->name);
                self::getXmlStream ()->writeAttribute ("label", $category->name);
            self::getXmlStream ()->endElement ();
        }
        if ($entry->book->getPubDate () != "") {
            self::getXmlStream ()->startElement ("dcterms:issued");
                self::getXmlStream ()->text (self::getPublicationDate($entry->book));
            self::getXmlStream ()->endElement ();
            self::getXmlStream ()->startElement ("published");
                self::getXmlStream ()->text (self::getPublicationDate($entry->book) . "T08:08:08Z");
            self::getXmlStream ()->endElement ();
        }

        $lang = $entry->book->getLanguages ();
        if (!empty ($lang)) {
            self::getXmlStream ()->startElement ("dcterms:language");
                self::getXmlStream ()->text ($lang);
            self::getXmlStream ()->endElement ();
        }

    }

    public function render ($page) {
        global $config;
        self::startXmlDocument ($page);
        if ($page->isPaginated ())
        {
            self::getXmlStream ()->startElement ("opensearch:totalResults");
                self::getXmlStream ()->text ($page->totalNumber);
            self::getXmlStream ()->endElement ();
            self::getXmlStream ()->startElement ("opensearch:itemsPerPage");
                self::getXmlStream ()->text ($config['cops_max_item_per_page']);
            self::getXmlStream ()->endElement ();
            self::getXmlStream ()->startElement ("opensearch:startIndex");
                self::getXmlStream ()->text (($page->n - 1) * $config['cops_max_item_per_page'] + 1);
            self::getXmlStream ()->endElement ();
            $prevLink = $page->getPrevLink ();
            $nextLink = $page->getNextLink ();
            if (!is_null ($prevLink)) {
                self::renderLink ($prevLink);
            }
            if (!is_null ($nextLink)) {
                self::renderLink ($nextLink);
            }
        }
        foreach ($page->entryArray as $entry) {
            self::getXmlStream ()->startElement ("entry");
                self::renderEntry ($entry);
            self::getXmlStream ()->endElement ();
        }
        return self::endXmlDocument ();
    }
}