/*******************************************************************************
 * Copyright (c) 2016 Parasoft.
 *
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v2.0
 * which accompanies this distribution, and is available at
 * https://www.eclipse.org/org/documents/epl-2.0/EPL-2.0.html
 *
 * SPDX-License-Identifier: EPL-2.0
 *
 * Contributors:
 *   Janusz Studzizba - initial API and implementation
 *   Dariusz Oszczedlowski - initial API and implementation
 *   Magdalena Gniewek - initial API and implementation
 *   Michal Wlodarczyk - initial API and implementation
 *******************************************************************************/
package org.eclipse.opencert.impactanalysis;

import java.util.ArrayList;
import java.util.HashSet;
import java.util.List;
import java.util.Set;

import org.eclipse.emf.cdo.transaction.CDOTransaction;
import org.eclipse.emf.cdo.view.CDOQuery;
import org.eclipse.opencert.apm.assuranceassets.assuranceasset.AssuranceAssetEvent;
import org.eclipse.opencert.apm.assuranceassets.assuranceasset.EventKind;
import org.eclipse.opencert.infra.general.general.ChangeEffectKind;
import org.eclipse.opencert.evm.evidspec.evidence.Artefact;
import org.eclipse.opencert.impactanalysis.eventcreators.ChangeDrivenEventsCreatorsFactory;
import org.eclipse.opencert.impactanalysis.eventcreators.IChangeDrivenEventsCreator;
import org.eclipse.opencert.impactanalysis.relations.ArtefactRelationType;
import org.eclipse.opencert.impactanalysis.relations.IArtefactRelationImpact;
import org.eclipse.opencert.impactanalysis.relations.RelationVisitationRecord;
import org.eclipse.opencert.impactanalysis.relations.traverse.DirectAndBaseRelationsTraverser;
import org.eclipse.opencert.impactanalysis.relations.traverse.DirectArtefactsRelationsTraverser;
import org.eclipse.opencert.impactanalysis.relations.traverse.IArtefactsRelationsTraverser;
import org.eclipse.opencert.storage.cdo.CDOStorageUtil;
import org.eclipse.opencert.storage.cdo.executors.SessionNotClosingInTransactionExecutor;
import org.eclipse.opencert.storage.cdo.property.IOpencertClientConfigurationAdapter;
import org.eclipse.opencert.storage.cdo.property.OpencertPropertiesReader;
import org.eclipse.opencert.storage.cdo.session.ICDOSessionProvider;
import org.eclipse.opencert.storage.cdo.session.SimpleCDOSessionProvider;

public class ImpactAnalyser
{
    private final ICDOSessionProvider cdoSessionProvider;

    
    public ImpactAnalyser(IOpencertClientConfigurationAdapter clientConfigurationAdapter)
    {
        cdoSessionProvider = new SimpleCDOSessionProvider(clientConfigurationAdapter);
    }
    
    
    public ImpactAnalyser(ICDOSessionProvider icdoSessionProvider)
    {
        cdoSessionProvider = icdoSessionProvider;
    }
    
    
    public List<IArtefactRelationImpact> listArtefactsRelationImpacts(final List<ImpactSource> impactSources)
    {
        final List<IArtefactRelationImpact> artefactsRelationImpacts = new ArrayList<IArtefactRelationImpact>();
        final Set<RelationVisitationRecord> artefactRelVisitationRecords = new HashSet<>();
        
        new SessionNotClosingInTransactionExecutor(cdoSessionProvider)
        {
            @Override
            public void executeInTransaction(CDOTransaction cdoTransaction)
            {
                for (ImpactSource impactSource : impactSources) {
                
                    recurseAllImpactedArtefactRelations(
                            impactSource.getImpactingArtefactCdoId(),
                            null,
                            impactSource.getImpactingEventKind(), 
                            artefactsRelationImpacts, artefactRelVisitationRecords, cdoTransaction, 0);
                }
            }

        }.executeReadOnlyOperation();
        
        return artefactsRelationImpacts;
    }
    
    
    public String visualizeArtefactsRelationImpacts(List<IArtefactRelationImpact> artefactsRelationImpacts)
    {
        return visualizeArtefactsRelationImpacts(artefactsRelationImpacts, "\t", "\n");
    }
    
    
    public String visualizeArtefactsRelationImpacts(List<IArtefactRelationImpact> artefactsRelationImpacts, String indendationString, String nextLineString)
    {
        StringBuilder stringBuilder = new StringBuilder();
        
        for (IArtefactRelationImpact artefactsRelationImpact : artefactsRelationImpacts) {
            
            for (int nr = 0; nr < artefactsRelationImpact.getRecursionDepth(); nr++) {
                stringBuilder.append(indendationString);
            }
            
            stringBuilder.append(artefactsRelationImpact.toString());
            
            stringBuilder.append(nextLineString);
        }
        
        return stringBuilder.toString();
    }
    
    
    public void close()
    {
        cdoSessionProvider.close();
    }
    
    
    public void executeArtefactsRelationImpacts(final List<IArtefactRelationImpact> artefactsRelationImpacts)
    {
        new SessionNotClosingInTransactionExecutor(cdoSessionProvider)
        {
            @Override
            public void executeInTransaction(CDOTransaction cdoTransaction)
            {
                for (IArtefactRelationImpact artefactsRelationImpact : artefactsRelationImpacts) {
                    
                    //we execute only these two types
                    if (!ArtefactRelationType.DIRECT_EVIDENCE_RELATION.equals(artefactsRelationImpact.getArtefactRelationType())
                            && !ArtefactRelationType.BASELINE_TO_EVIDENCE_VIA_MAP_RELATION.equals(artefactsRelationImpact.getArtefactRelationType())) {
                        continue;
                    }
                    
                    ChangeEffectKind impactedChangeEffectKind = artefactsRelationImpact.getImpactedChangeEffectKind();
                    
                    IChangeDrivenEventsCreator changeDrivenEventsCreator = ChangeDrivenEventsCreatorsFactory.
                            getProperChangeDrivenEventsCreator(impactedChangeEffectKind);
                    //none found, abort
                    if (changeDrivenEventsCreator == null) {
                        continue;
                    }
                    
                    AssuranceAssetEvent newEvent = changeDrivenEventsCreator.produceEvent(artefactsRelationImpact, impactedChangeEffectKind);
                    
                    Artefact impactedArtefact = queryForArtefact(artefactsRelationImpact.getImpactedArtefactCDOId(), cdoTransaction);
                    if (impactedArtefact == null) {
                        throw new RuntimeException("IA execution called for impactedArtefact which doesn't exist in database"); 
                    }
                    
                    impactedArtefact.getLifecycleEvent().add(newEvent);       
                }
            }

        }.executeReadWriteOperation();
    }
    
    
    private void recurseAllImpactedArtefactRelations(
            Long impactSourceCdoId,
            IArtefactRelationImpact sourceArtefactRelationImpact,
            EventKind impactingEventKind,
            List<IArtefactRelationImpact> artefactsRelationImpacts,
            Set<RelationVisitationRecord> artefactRelVisitationRecords,
            CDOTransaction cdoTransaction,
            int recursionDepth)
    {
        final boolean isImpactAnalysisViaBaselineElementsEnabled = OpencertPropertiesReader.getInstance().isImpactAnalysisViaBaselineElementsEnabled();
        
        IArtefactsRelationsTraverser relationsTraverser = isImpactAnalysisViaBaselineElementsEnabled ?
                                                        new DirectAndBaseRelationsTraverser() :
                                                        new DirectArtefactsRelationsTraverser();
        
        List<IArtefactRelationImpact> artefactRelationImpacts = 
                relationsTraverser.generateArtefactRelationImpactsList(cdoTransaction, impactSourceCdoId, sourceArtefactRelationImpact, recursionDepth,
                        impactingEventKind);
        
        for (IArtefactRelationImpact artefactRelationImpact : artefactRelationImpacts) {
            
            EventKind newImpactingEventKind = null;
            
            newImpactingEventKind = artefactRelationImpact.generateNewEventBasedOnChangeEffectKindOrForwardCurrent(impactingEventKind);
            
            if (newImpactingEventKind == null) {
                continue;
            }
                        
            
            //check and skip if already visited this relation WITH THIS EXACT impactedChangeEffectKind
            //this skips cycles
            RelationVisitationRecord artefactRelVisitationRecord = new RelationVisitationRecord(artefactRelationImpact);
            if (artefactRelVisitationRecords.contains(artefactRelVisitationRecord)) {
                continue;
            }
            artefactRelVisitationRecords.add(artefactRelVisitationRecord);
            
            artefactsRelationImpacts.add(artefactRelationImpact);
            
            recurseAllImpactedArtefactRelations(artefactRelationImpact.getImpactedArtefactCDOId(), artefactRelationImpact,
                    newImpactingEventKind, artefactsRelationImpacts, artefactRelVisitationRecords,
                    cdoTransaction, recursionDepth + 1);
        }
    }
    
    
    private Artefact queryForArtefact(
            Long impactingArtefactCdoId,
            CDOTransaction cdoTransaction)
    {
        CDOQuery query = cdoTransaction.createQuery("sql", "select * from evidence_artefact where cdo_id = " 
                + impactingArtefactCdoId + CDOStorageUtil.getMandatoryCDOQuerySuffix());
        
        return query.getResultValue(Artefact.class);
    }
    
    
    
}