<?php

/**
 * Footer
 *
 * Main footer file for the theme.
 *
 * @category   Components
 * @package    ResearchRepository
 * @subpackage Publish
 * @author     Your Name <yourname@example.com>
 * @license    https://www.gnu.org/licenses/gpl-3.0.txt GNU/GPLv3
 * @link       https://gisgba.geologie.ac.at
 * @since      1.0.0
 */
namespace App\Library\Xml;

use App\Models\XmlCache;
use Illuminate\Support\Facades\Log;
use \Exception;

class XmlModel
{
    /**
     * Holds current configuration.
     * @var Conf
     */
    private $config = null;

    /**
     * Holds current xml strategy object.
     * @var Strategy
     */
    private $strategy = null;

    /**
     * TODO
     * @var XmlCache
     */
    private $cache = null;


    /**
     * Do some initial stuff like setting of a XML version and an empty
     * configuration.
     */
    public function __construct()
    {
        $this->strategy = new Strategy();// Opus_Model_Xml_Version1;
        $this->config = new Conf();
        $this->strategy->setup($this->config);
    }

    /**
     * Set a new XML version with current configuration up.
     *
     * @param Strategy $strategy Version of Xml to process
     *
     * @return XmlModel fluent interface.
     */
    public function setStrategy(Strategy $strategy)
    {
        $this->strategy = $strategy;
        $this->strategy->setup($this->config);
        return $this;
    }

    /**
     * Set a new XML version with current configuration up.
     *
     * @param XmlCache $cache cach table
     *
     * @return XmlModel fluent interface.
     */
    public function setXmlCache(XmlCache $cache)
    {
        $this->cache = $cache;
        return $this;
    }

    /**
     * Return cache table.
     *
     * @return XmlCache
     */
    public function getXmlCache()
    {
        return $this->cache;
    }

    /**
     * Set the Model for XML generation.
     *
     * @param \App\Models\Dataset $model Model to serialize.
     *
     * @return XmlModel Fluent interface.
     */
    public function setModel($model)
    {
        $this->config->model = $model;
        return $this;
    }

    /**
     * Define that empty fields (value===null) shall be excluded.
     *
     * @return XmlModel Fluent interface
     */
    public function excludeEmptyFields()
    {
        $this->config->excludeEmpty = true;
        return $this;
    }

    /**
     * If a model has been set this method generates and returnes
     * DOM representation of it.
     *
     * @return \DOMDocument DOM representation of the current Model.
     */
    public function getDomDocument()
    {
        $dataset = $this->config->model;

        $domDocument = $this->getDomDocumentFromXmlCache();
        if (!is_null($domDocument)) {
            return $domDocument;
        }

        //$domDocument == null -> create xml:
        $domDocument = $this->strategy->getDomDocument();
        //if caching is not desired, return domDocument
        if (is_null($this->cache)) {
            return $domDocument;
        } else {
            //create cache relation
            // $this->cache->updateOrCreate(array(
            //     'document_id' => $dataset->id,
            //     'xml_version' => (int)$this->strategy->getVersion(),
            //     'server_date_modified' => $dataset->server_date_modified,
            //     'xml_data' => $domDocument->saveXML()
            // ));
           
            if (!$this->cache->document_id) {
                $this->cache->document_id =  $dataset->id;
            }
            
            $this->cache->xml_version =  (int)$this->strategy->getVersion();
            $this->cache->server_date_modified =   $dataset->server_date_modified;
            $this->cache->xml_data =  $domDocument->saveXML();

            $this->cache->save();

            Log::debug(__METHOD__ . ' cache refreshed for ' . get_class($dataset) . '#' . $dataset->id);
            return $domDocument;
        }
    }

    /**
     * This method tries to load the current model from the xml cache.  Returns
     * null in case of an error/cache miss/cache disabled.  Returns DOMDocument
     * otherwise.
     *
     * @return \DOMDocument DOM representation of the current Model.
     */
    private function getDomDocumentFromXmlCache()
    {
        $dataset = $this->config->model;
        if (null === $this->cache) {
            //$logger->debug(__METHOD__ . ' skipping cache for ' . get_class($model));
            Log::debug(__METHOD__ . ' skipping cache for ' . get_class($dataset));
            return null;
        }
        $actuallyCached = $this->cache->hasValidEntry(
            $dataset->id,
            $dataset->server_date_modified
        );
        //no actual cache
        if (true !== $actuallyCached) {
            Log::debug(__METHOD__ . ' cache miss for ' . get_class($dataset) . '#' . $dataset->id);
            return null;
        }
        //cache is actual return it for oai:
        Log::debug(__METHOD__ . ' cache hit for ' . get_class($dataset) . '#' . $dataset->id);
        try {
            //return $this->_cache->get($model->getId(), (int) $this->_strategy->getVersion());
            $cache = XmlCache::where('document_id', $dataset->id)->first();
            return $cache->getDomDocument();
        } catch (Exception $e) {
            Log::warning(__METHOD__ . " Access to XML cache failed on " . get_class($dataset) .
            '#' . $dataset->id . ".  Trying to recover.");
        }

        return null;

       
        // // $cache = XmlCache::where('document_id', $dataset->id)
        // // ->first();// model or null
        // if (!$cache) {
        //     Log::debug(__METHOD__ . ' cache miss for ' . get_class($dataset) . '#' . $dataset->id);
        //     return null;
        // } else {
        //     return $cache->getDomDocument();
        // }
    }
}