Metacat

/**

 * This work was created by participants in the DataONE project, and is

 * jointly copyrighted by participating institutions in DataONE. For 

 * more information on DataONE, see our web site at http://dataone.org.

 *

 *   Copyright ${year}

 *

 * Licensed under the Apache License, Version 2.0 (the "License");

 * you may not use this file except in compliance with the License.

 * You may obtain a copy of the License at

 *

 *   http://www.apache.org/licenses/LICENSE-2.0

 *

 * Unless required by applicable law or agreed to in writing, software

 * distributed under the License is distributed on an "AS IS" BASIS,

 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

 * See the License for the specific language governing permissions and 

 * limitations under the License.

 * 

 * $Id: MetacatDocumentDeleteSubprocessor.java 9060 2015-01-07 20:02:25Z leinfelder $

 */

package edu.ucsb.nceas.metacat.index;

import java.io.IOException;

import java.util.ArrayList;

import java.util.HashSet;

import java.util.List;

import java.util.Map;

import java.util.Set;

import javax.xml.xpath.XPathExpressionException;

import org.apache.commons.codec.EncoderException;

import org.apache.commons.lang.StringUtils;

import org.dataone.cn.indexer.parser.IDocumentDeleteSubprocessor;

import org.dataone.cn.indexer.solrhttp.SolrDoc;

import org.dataone.cn.indexer.solrhttp.SolrElementField;

import edu.ucsb.nceas.metacat.index.resourcemap.ResourceMapSubprocessor;

public class MetacatDocumentDeleteSubprocessor implements IDocumentDeleteSubprocessor {

    private String relationSourceFormatId;

    private String relationSourceField;

    private List<String> biDirectionalRelationFields;

    private List<String> uniDirectionalRelationFields;

    public MetacatDocumentDeleteSubprocessor() {

    }

    public Map<String, SolrDoc> processDocForDelete(String identifier, Map<String, SolrDoc> docs)

            throws Exception {

        SolrDoc indexedDoc = ResourceMapSubprocessor.getSolrDoc(identifier);

        if (indexedDoc != null) {

            if (hasRelationsBySource(indexedDoc)) {

                docs.putAll(removeBiDirectionalRelationsForDoc(identifier, indexedDoc, docs));

            }

            if (isRelationshipSource(indexedDoc)) {

                docs.putAll(removeRelationsBySourceDoc(identifier, indexedDoc, docs));

            }

        }

        return docs;

    }

    private Map<String, SolrDoc> removeRelationsBySourceDoc(String relationSourceId,

            SolrDoc indexedDoc, Map<String, SolrDoc> docs) throws Exception {

        // gather all docs with relations from self source

        List<SolrDoc> relatedDocs = ResourceMapSubprocessor.getDocumentsByQuery(

                "q=" + relationSourceField + ":\"" + relationSourceId + "\"");

        Set<String> otherSourceDocs = new HashSet<String>();

        for (SolrDoc relatedDoc : relatedDocs) {

            // gather other relation source docs from modified list

            otherSourceDocs.addAll(relatedDoc.getAllFieldValues(relationSourceField));

            // remove relation fields (uni and bi-directional)

            // add modified docs to update list

            String docId = relatedDoc.getFirstFieldValue(SolrElementField.FIELD_ID);

            if (docs.get(docId) != null) {

                relatedDoc = docs.get(docId);

            }

            relatedDoc.removeAllFields(relationSourceField);

            for (String relationField : getBiDirectionalRelationFields()) {

                relatedDoc.removeAllFields(relationField);

            }

            for (String relationField : getUniDirectionalRelationFields()) {

                relatedDoc.removeAllFields(relationField);

            }

            docs.put(docId, relatedDoc);

        }

        for (String otherRelatedDoc : otherSourceDocs) {

            if (!otherRelatedDoc.equals(relationSourceId)) {

                docs.put(otherRelatedDoc, null);

            }

        }

        return docs;

    }

    private boolean isRelationshipSource(SolrDoc indexedDoc) throws Exception {

        String formatId = indexedDoc.getFirstFieldValue(SolrElementField.FIELD_OBJECTFORMAT);

        return relationSourceFormatId.equals(formatId);

    }

    private boolean hasRelationsBySource(SolrDoc indexedDoc) throws XPathExpressionException,

            IOException, EncoderException {

        String relationSourceId = indexedDoc.getFirstFieldValue(relationSourceField);

        return StringUtils.isNotEmpty(relationSourceId);

    }

    private Map<String, SolrDoc> removeBiDirectionalRelationsForDoc(String identifier,

            SolrDoc indexedDoc, Map<String, SolrDoc> docs) throws Exception {

        for (String relationField : getBiDirectionalRelationFields()) {

            List<SolrDoc> inverseDocs = ResourceMapSubprocessor.getDocumentsByQuery(

                    "q=" + relationField + ":\"" + identifier + "\"");

            for (SolrDoc inverseDoc : inverseDocs) {

                String inverseDocId = inverseDoc.getFirstFieldValue(SolrElementField.FIELD_ID);

                if (docs.get(inverseDocId) != null) {

                    inverseDoc = docs.get(inverseDocId);

                }

                inverseDoc.removeFieldsWithValue(relationField, identifier);

                docs.put(inverseDocId, inverseDoc);

            }

        }

        return docs;

    }

    private List<String> getBiDirectionalRelationFields() {

        if (biDirectionalRelationFields == null) {

            biDirectionalRelationFields = new ArrayList<String>();

        }

        return biDirectionalRelationFields;

    }

    private List<String> getUniDirectionalRelationFields() {

        if (uniDirectionalRelationFields == null) {

            uniDirectionalRelationFields = new ArrayList<String>();

        }

        return uniDirectionalRelationFields;

    }

    public String getRelationSourceFormatId() {

        return relationSourceFormatId;

    }

    public void setRelationSourceFormatId(String relationSourceFormatId) {

        this.relationSourceFormatId = relationSourceFormatId;

    }

    public String getRelationSourceField() {

        return relationSourceField;

    }

    public void setRelationSourceField(String relationSourceField) {

        this.relationSourceField = relationSourceField;

    }

    public void setBiDirectionalRelationFields(List<String> biDirectionalRelationFields) {

        this.biDirectionalRelationFields = biDirectionalRelationFields;

    }

    public void setUniDirectionalRelationFields(List<String> uniDirectionalRelationFields) {

        this.uniDirectionalRelationFields = uniDirectionalRelationFields;

    }

}