/* This file is part of the OWL API.
 * The contents of this file are subject to the LGPL License, Version 3.0.
 * Copyright 2011, Clark & Parsia, LLC
 * 
 * This program is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.
 * This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for more details.
 * You should have received a copy of the GNU General Public License along with this program.  If not, see http://www.gnu.org/licenses/.
 *
 * Alternatively, the contents of this file may be used under the terms of the Apache License, Version 2.0 in which case, the provisions of the Apache License Version 2.0 are applicable instead of those above.
 * 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. */
package com.clarkparsia.owlapi.explanation;

import static org.semanticweb.owlapi.util.OWLAPIPreconditions.checkNotNull;

import org.semanticweb.owlapi.model.OWLOntology;
import org.semanticweb.owlapi.model.OWLOntologyManager;
import org.semanticweb.owlapi.model.OWLRuntimeException;
import org.semanticweb.owlapi.reasoner.OWLReasoner;
import org.semanticweb.owlapi.reasoner.OWLReasonerFactory;

import com.clarkparsia.owlapi.explanation.util.DefinitionTracker;

/**
 * The Class SingleExplanationGeneratorImpl.
 */
public abstract class SingleExplanationGeneratorImpl implements TransactionAwareSingleExpGen {

    private final OWLOntologyManager owlOntologyManager;
    private final OWLOntology ontology;
    private final OWLReasoner reasoner;
    private final OWLReasonerFactory reasonerFactory;
    private final DefinitionTracker definitionTracker;
    private boolean inTransaction;

    /**
     * Instantiates a new single explanation generator impl.
     *
     * @param ontology the ontology
     * @param reasonerFactory the reasoner factory
     * @param reasoner the reasoner
     */
    public SingleExplanationGeneratorImpl(OWLOntology ontology, OWLReasonerFactory reasonerFactory,
        OWLReasoner reasoner) {
        this.ontology = checkNotNull(ontology, "ontology cannot be null");
        this.reasonerFactory = checkNotNull(reasonerFactory, "reasonerFactory cannot be null");
        this.reasoner = checkNotNull(reasoner, "reasoner cannot be null");
        owlOntologyManager = ontology.getOWLOntologyManager();
        definitionTracker = new DefinitionTracker(ontology);
    }

    @Override
    public OWLOntologyManager getOntologyManager() {
        return owlOntologyManager;
    }

    @Override
    public OWLReasoner getReasoner() {
        return reasoner;
    }

    /**
     * @return the definition tracker
     */
    public DefinitionTracker getDefinitionTracker() {
        return definitionTracker;
    }

    @Override
    public OWLOntology getOntology() {
        return ontology;
    }

    @Override
    public OWLReasonerFactory getReasonerFactory() {
        return reasonerFactory;
    }

    /**
     * @return true, if is first explanation
     */
    protected boolean isFirstExplanation() {
        return !inTransaction;
    }

    @Override
    public void beginTransaction() {
        if (inTransaction) {
            throw new OWLRuntimeException("Already in transaction");
        }
        inTransaction = true;
    }

    @Override
    public void endTransaction() {
        if (!inTransaction) {
            throw new OWLRuntimeException("Cannot end transaction");
        }
        inTransaction = false;
    }
}