<?php

/**
 * @file classes/metadata/MetadataRecord.php
 *
 * Copyright (c) 2014-2021 Simon Fraser University
 * Copyright (c) 2000-2021 John Willinsky
 * Distributed under the GNU GPL v3. For full terms see the file docs/COPYING.
 *
 * @class MetadataRecord
 *
 * @ingroup metadata
 *
 * @see MetadataProperty
 * @see MetadataDescription
 *
 * @brief Class modeling a meta-data record (DCMI abstract model: an instance
 *  of a description set, RDF: a graph of several subject nodes with associated
 *  object nodes).
 */

namespace PKP\metadata;

class MetadataRecord
{
    /** @var array the MetadataDescriptions in this record */
    public $_descriptions = [];

    //
    // Get/set methods
    //
    /**
     * Add a meta-data description.
     *
     * @param MetadataDescription $metadataDescription
     * @param bool $replace whether to replace a description if a description for
     *  the same application entity instance already exists.
     *
     * @return bool true if a valid description was added, otherwise false
     */
    public function addDescription($metadataDescription, $replace = true)
    {
        assert($metadataDescription instanceof \PKP\metadata\MetadataDescription);

        // Check that the description complies with the meta-data schema
        $descriptionMetadataSchema = $metadataDescription->getMetadataSchema();
        $recordMetadataSchema = $this->getMetadataSchema();
        if ($descriptionMetadataSchema->getName() != $recordMetadataSchema->getName()) {
            return false;
        }

        // Check whether we already have a description for the same
        // application entity instance.
        $applicationEntityId = $this->getApplicationEntityIdFromMetadataDescription($metadataDescription);
        if (isset($this->_descriptions[$applicationEntityId]) && !$replace) {
            return false;
        }

        // Add the description
        $this->_descriptions[$applicationEntityId] = & $metadataDescription;
    }

    /**
     * Remove description.
     *
     * @param string $applicationEntityId consisting of 'assocType:assocId'
     *
     * @return bool true if the description was found and removed, otherwise false
     *
     * @see MetadataRecord::getApplicationEntityIdFromMetadataDescription()
     */
    public function removeDescription($applicationEntityId)
    {
        // Remove the description if it exists
        if (isset($applicationEntityId) && isset($this->_descriptions[$applicationEntityId])) {
            unset($this->_descriptions[$applicationEntityId]);
            return true;
        }

        return false;
    }

    /**
     * Get all descriptions
     *
     * @return array statements
     */
    public function &getDescriptions()
    {
        return $this->_descriptions;
    }

    /**
     * Get a specific description
     *
     * @param string $applicationEntityId consisting of 'assocType:assocId'
     *
     * @return ?bool true if the description was found and removed, otherwise false
     *
     * @see MetadataRecord::getApplicationEntityIdFromMetadataDescription()
     */
    public function &getDescription($applicationEntityId)
    {
        assert(isset($applicationEntityId));

        // Retrieve the description
        if (isset($this->_descriptions[$applicationEntityId])) {
            return $this->_descriptions[$applicationEntityId];
        } else {
            $nullValue = null;
            return $nullValue;
        }
    }

    /**
     * Replace all descriptions at once. If one of the descriptions
     * is invalid then the meta-data record will be empty after this
     * operation.
     *
     * @param array $descriptions descriptions
     *
     * @return bool true if all descriptions could be added, false otherwise
     */
    public function setDescriptions(&$descriptions)
    {
        // Delete existing statements
        $this->_descriptions = [];

        // Add descriptions one by one to validate them.
        foreach ($descriptions as $description) {
            if (!($this->addDescription($description, false))) {
                $this->_descriptions = [];
            }
        }
        return true;
    }
}

if (!PKP_STRICT_MODE) {
    class_alias('\PKP\metadata\MetadataRecord', '\MetadataRecord');
}