/*******************************************************************************
* SAT4J: a SATisfiability library for Java Copyright (C) 2004-2008 Daniel Le Berre
*
* All rights reserved. This program and the accompanying materials
* are made available under the terms of the Eclipse Public License v1.0
* which accompanies this distribution, and is available at
* http://www.eclipse.org/legal/epl-v10.html
*
* Alternatively, the contents of this file may be used under the terms of
* either the GNU Lesser General Public License Version 2.1 or later (the
* "LGPL"), in which case the provisions of the LGPL are applicable instead
* of those above. If you wish to allow use of your version of this file only
* under the terms of the LGPL, and not to allow others to use your version of
* this file under the terms of the EPL, indicate your decision by deleting
* the provisions above and replace them with the notice and other provisions
* required by the LGPL. If you do not delete the provisions above, a recipient
* may use your version of this file under the terms of the EPL or the LGPL.
* 
* Based on the original MiniSat specification from:
* 
* An extensible SAT solver. Niklas Een and Niklas Sorensson. Proceedings of the
* Sixth International Conference on Theory and Applications of Satisfiability
* Testing, LNCS 2919, pp 502-518, 2003.
*
* See www.minisat.se for the original solver in C++.
* 
*******************************************************************************/
package org.sat4j.reader;

import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.net.URL;
import java.util.zip.GZIPInputStream;

import org.sat4j.specs.ContradictionException;
import org.sat4j.specs.IProblem;

/**
 * A reader is responsible to feed an ISolver from a text file and to convert
 * the model found by the solver to a textual representation.
 * 
 * @author leberre
 */
public abstract class Reader {

	public IProblem parseInstance(final String filename)
			throws FileNotFoundException, ParseFormatException, IOException,
			ContradictionException {
		InputStream in = null;
		try {
			if (filename.startsWith("http://")) {
				in = (new URL(filename)).openStream();
			} else {
				in = new FileInputStream(filename);
			}
			if (filename.endsWith(".gz")) {
				in = new GZIPInputStream(in);
			}
			IProblem problem;
			problem = parseInstance(in);
			return problem;
		} catch (FileNotFoundException e) {
			throw e;
		} catch (ParseFormatException e) {
			throw e;
		} catch (IOException e) {
			throw e;
		} catch (ContradictionException e) {
			throw e;
		} finally {
			if (in != null) {
				in.close();
			}
		}
	}

    public IProblem parseInstance(final InputStream in)
            throws ParseFormatException, ContradictionException, IOException {
        return parseInstance(new InputStreamReader(in));
    }

    public abstract IProblem parseInstance(final java.io.Reader in)
            throws ParseFormatException, ContradictionException, IOException;

    /**
     * Produce a model using the reader format.
     * 
     * @param model
     *            a model using the Dimacs format.
     * @return a human readable view of the model.
     */
    @Deprecated
    public abstract String decode(int[] model);

    /**
     * Produce a model using the reader format on a provided printwriter.
     * 
     * @param model
     *            a model using the Dimacs format.
     * @param out
     *            the place where to display the model
     */
    public abstract void decode(int[] model, PrintWriter out);

    public boolean isVerbose() {
        return verbose;
    }

    public void setVerbosity(boolean b) {
        verbose = b;
    }

    private boolean verbose = false;
}