<?php

namespace CorpusParole\Libraries\Mergers;

use EasyRdf\RdfNamespace;

use EasyRdf\Graph;

RdfNamespace::set('edm', 'http://www.europeana.eu/schemas/edm/');

RdfNamespace::set('ore', 'http://www.openarchives.org/ore/terms/');

RdfNamespace::set('crdo', 'http://crdo.risc.cnrs.fr/schemas/');

RdfNamespace::set('olac', 'http://www.language-archives.org/OLAC/1.1/');

RdfNamespace::set('skos', 'http://www.w3.org/2004/02/skos/core#');

abstract class CocoonAbstractRdfMerger implements RdfMerger {

    const ORIGIN_BASE = 0;

    const ORIGIN_SRC = 1;

    abstract protected function getTypeMergeMethodMap();

    /**

     * Merge an Rdf Graph from one model to another

     *

     * @param EasyRdf\Graph $baseGraph The graph used as base for the merge

     * @param EasyRdf\Graph $srcGraph The source graph with the new triples to add

     *

     * @return EasyRdf\Graph The new merged graph

     */

    function mergeGraph($baseGraph, $srcGraph, $uri = null) {

        $uri = is_null($uri)?$baseGraph->getUri():$uri;

        $this->mergedArray = [];

        $this->resGraph = new Graph($uri);

        $this->bnodeMerge = [];

        $this->baseGraph = $baseGraph;

        $this->srcGraph = $srcGraph;

        $typeMergeMethodMap = $this->getTypeMergeMethodMap();

        foreach ( $typeMergeMethodMap as $nodeType => $mergeMethod) {

            foreach($baseGraph->allOfType($nodeType) as $baseResource) {

                if($baseResource->isBNode()) {

                    continue;

                }

                $this->mergedArray[$baseResource->getUri()] = $baseGraph->toRdfPhp()[$baseResource->getUri()];

            }

            foreach($srcGraph->allOfType($nodeType) as $srcResource) {

                if($srcResource->isBNode()) {

                    continue;

                }

                if(empty($baseGraph->propertyUris($srcResource->getUri()))) {

                    $this->mergedArray[$srcResource->getUri()] = $srcGraph->toRdfPhp()[$srcResource->getUri()];

                }

                else {

                    $baseResource = $baseGraph->resource($srcResource->getUri());

                    $this->mergedArray[$srcResource->getUri()] = $baseGraph->toRdfPhp()[$baseResource->getUri()];

                    call_user_func(array($this, $mergeMethod), $baseResource, $srcResource);

                }

            }

        }

        // merge blank node

        reset($this->bnodeMerge);

        while(list($bnodeId, $bnodeDef) = each($this->bnodeMerge)) {

            $srcUrl = isset($bnodeDef['src_url'])?$bnodeDef['src_url']:null;

            $baseUrl = isset($bnodeDef['base_url'])?$bnodeDef['base_url']:null;

            if(is_null($srcUrl) && !is_null($baseUrl)) {

                $copyResource = $this->copyResource($baseGraph->toRdfPhp()[$baseUrl],CocoonAbstractRdfMerger::ORIGIN_BASE);

                $this->mergedArray[$bnodeId] = $copyResource;

            }

            elseif (is_null($baseUrl) && !is_null($srcUrl)) {

                $copyResource = $this->copyResource($srcGraph->toRdfPhp()[$srcUrl],CocoonAbstractRdfMerger::ORIGIN_SRC);

                $this->mergedArray[$bnodeId] = $copyResource;

            }

            elseif (!is_null($baseUrl) && !is_null($srcUrl)) {

                $baseResource = $baseGraph->resource($baseUrl);

                $srcResource = $srcGraph->resource($srcUrl);

                if(!is_null($baseResource->typeAsResource()) && array_key_exists($baseResource->typeAsResource()->getUri(), $typeMergeMethodMap)) {

                    $mergeMethod = $typeMergeMethodMap[$baseResource->typeAsResource()->getUri()];

                    $this->mergedArray[$bnodeId] = [];

                    call_user_func(array($this, $mergeMethod), $baseResource, $srcResource, $bnodeId);

                }

            }

        }

        //echo "MERGED ARRAY:\n";

        $this->resGraph->parse($this->mergedArray);

        return $this->resGraph;

    }

    /**

     * Copy a full resource node

     *

     */

    protected function copyResource($origArray, $origin) {

        $resArray = [];

        foreach($origArray as $prop => $propValues) {

            $resArray[$prop] = $this->buildValueList($propValues, $origin);

        }

        return $resArray;

    }

    /**

     * Build a value list. replace the blank node reference.

     * @param $srcValues array The original values

     * @param $origin int values are 'ORIGIN_BASE' if bnode from base graph or 'ORIGIN_SRC' from source graph

     */

    protected function buildValueList($srcValues, $origin) {

        $srcArrayProps = [];

        foreach ($srcValues as $propValue) {

            if(is_array($propValue) && array_key_exists('type', $propValue) && $propValue['type'] == 'bnode') {

                $newBNodeId = $this->resGraph->newBNodeId();

                if($origin == CocoonAbstractRdfMerger::ORIGIN_SRC) {

                    $this->bnodeMerge[$newBNodeId] = ['src_url' => $propValue['value'], 'base_url' => null];

                }

                else {

                    $this->bnodeMerge[$newBNodeId] = ['base_url' => $propValue['value'], 'src_url' => null];

                }

                $propValue['value'] = $newBNodeId;

            }

            $srcArrayProps[] = $propValue;

        }

        return $srcArrayProps;

    }

    protected function mergePropertySingleValue($prop, &$targetArray, $baseArray, $srcArray) {

        if(isset($baseArray[$prop])) {

            $targetArray[$prop] = $this->buildValueList($baseArray[$prop], CocoonAbstractRdfMerger::ORIGIN_BASE);

        }

        elseif(isset($srcArray[$prop])) {

            $targetArray[$prop] = $this->buildValueList($srcArray[$prop], CocoonAbstractRdfMerger::ORIGIN_SRC);

        }

    }

    protected function mergePropertyMultiplevalue($prop, &$targetArray, $baseArray, $srcArray) {

        $propArray = $this->buildValueList(isset($baseArray[$prop])?$baseArray[$prop]:[], CocoonAbstractRdfMerger::ORIGIN_BASE);

        if(isset($srcArray[$prop])) {

            $mergedArray = array_merge($propArray, $this->buildValueList($srcArray[$prop], CocoonAbstractRdfMerger::ORIGIN_BASE));

            //yes, this is real. Array_unique does not work on multidimentional arrays. Most work-around suggest the use of serialize to compare sub arrays...

            $propArray = array_values(array_intersect_key($mergedArray, array_unique(array_map('md5',array_map('serialize', $mergedArray)))));

        }

        if(!empty($propArray)) {

            $targetArray[$prop] = $propArray;

        }

    }

    protected function mergePropertySingleBNode($prop, &$targetArray, $baseArray, $srcArray) {

        $newBNodeId = $this->resGraph->newBNodeId();

        $srcUrl = null;

        $baseUrl = null;

        // in src but not in base

        if(array_key_exists($prop, $baseArray) &&

            !empty($baseArray[$prop]) &&

            array_key_exists('type',$baseArray[$prop][0]) &&

            array_key_exists('value',$baseArray[$prop][0]) &&

            $baseArray[$prop][0]['type'] === 'bnode') {

            $baseUrl = $baseArray[$prop][0]['value'];

        }

        if(array_key_exists($prop, $srcArray) &&

            !empty($srcArray[$prop]) &&

            array_key_exists('type',$srcArray[$prop][0]) &&

            array_key_exists('value',$srcArray[$prop][0]) &&

            $srcArray[$prop][0]['type'] === 'bnode') {

            $srcUrl = $srcArray[$prop][0]['value'];

        }

        $this->bnodeMerge[$newBNodeId] = ['src_url' => $srcUrl, 'base_url' => $baseUrl];

        $targetArray[$prop] = [ [ 'type' => 'bnode', 'value' => $newBNodeId], ];

    }

    protected function mergeProperties($singleBNodeProperties, $singleProperties, &$targetArray, $baseRes, $srcRes) {

        $srcRdfPhp = $this->srcGraph->toRdfPhp();

        $srcArray = array_key_exists($srcRes->getUri(), $srcRdfPhp)?$srcRdfPhp[$srcRes->getUri()]:[];

        $baseRdfPhp = $this->baseGraph->toRdfPhp();

        $baseArray = array_key_exists($baseRes->getUri(), $baseRdfPhp)?$baseRdfPhp[$baseRes->getUri()]:[];

        foreach(array_unique(array_merge($srcRes->propertyUris(), $baseRes->propertyUris())) as $prop) {

            if(in_array($prop, $singleBNodeProperties)) {

                $this->mergePropertySingleBNode($prop, $targetArray, $baseArray, $srcArray);

            }

            elseif(in_array($prop, $singleProperties)) {

                $this->mergePropertySingleValue($prop, $targetArray, $baseArray, $srcArray);

            }

            else {

                $this->mergePropertyMultiplevalue($prop, $targetArray, $baseArray, $srcArray);

            }

        }

    }

}