///////////////////////////////////////////////////////////////////////////////
// For information as to what this class does, see the Javadoc, below.       //
// Copyright (C) 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006,       //
// 2007, 2008, 2009, 2010, 2014, 2015 by Peter Spirtes, Richard Scheines, Joseph   //
// Ramsey, and Clark Glymour.                                                //
//                                                                           //
// 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 2 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, write to the Free Software               //
// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA //
///////////////////////////////////////////////////////////////////////////////

package edu.cmu.tetrad.search;

import edu.cmu.tetrad.data.IKnowledge;
import edu.cmu.tetrad.data.Knowledge2;
import edu.cmu.tetrad.graph.EdgeListGraphSingleConnections;
import edu.cmu.tetrad.graph.Endpoint;
import edu.cmu.tetrad.graph.Graph;
import edu.cmu.tetrad.graph.Node;
import edu.cmu.tetrad.util.TetradLogger;

import java.util.ArrayList;
import java.util.List;


/**
 * Extends Erin Korber's implementation of the Fast Causal Inference algorithm (found in FCI.java) with Jiji Zhang's
 * Augmented FCI rules (found in sec. 4.1 of Zhang's 2006 PhD dissertation, "Causal Inference and Reasoning in Causally
 * Insufficient Systems").
 * <p/>
 * This class is based off a copy of FCI.java taken from the repository on 2008/12/16, revision 7306. The extension is
 * done by extending doFinalOrientation() with methods for Zhang's rules R5-R10 which implements the augmented search.
 * (By a remark of Zhang's, the rule applications can be staged in this way.)
 * </p>
 * Converts a MAG to a PAG. (Not well-tested.)
 *
 * @author Erin Korber, June 2004
 * @author Alex Smith, December 2008
 * @author Joseph Ramsey
 * @author Choh-Man Teng
 */
public final class MagToPag {

    private final EdgeListGraphSingleConnections mag;
    private final IndTestDSep dsep;
    /**
     * The PAG being constructed.
     */
    private Graph graph;

    /**
     * The background knowledge.
     */
    private IKnowledge knowledge = new Knowledge2();

    /**
     * The variables to search over (optional)
     */
    private List<Node> variables = new ArrayList<>();

    /**
     * flag for complete rule set, true if should use complete rule set, false otherwise.
     */
    private boolean completeRuleSetUsed = false;

    /**
     * The maximum length for any discriminating path. -1 if unlimited; otherwise, a positive integer.
     */
    private int maxPathLength = -1;

    /**
     * The depth for the fast adjacency search.
     */
    private int depth = -1;

    /**
     * The logger to use.
     */
    private TetradLogger logger = TetradLogger.getInstance();

    /**
     * True iff verbose output should be printed.
     */
    private boolean verbose = false;

    //============================CONSTRUCTORS============================//

    /**
     * Constructs a new FCI search for the given independence test and background knowledge.
     */
    public MagToPag(Graph mag) {
        this.mag = new EdgeListGraphSingleConnections(mag);
        this.variables.addAll(mag.getNodes());
        this.dsep = new IndTestDSep(mag);
    }

    //========================PUBLIC METHODS==========================//

    public int getDepth() {
        return depth;
    }

    public void setDepth(int depth) {
        if (depth < -1) {
            throw new IllegalArgumentException(
                    "Depth must be -1 (unlimited) or >= 0: " + depth);
        }

        this.depth = depth;
    }

    public Graph convert() {
        logger.log("info", "Starting DAG to PAG.");

        setMaxPathLength(maxPathLength);

        Graph graph = new EdgeListGraphSingleConnections(mag);
        graph.reorientAllWith(Endpoint.CIRCLE);

        FciOrient fciOrient = new FciOrient(new DagSepsets(mag));
        fciOrient.setCompleteRuleSetUsed(completeRuleSetUsed);
        return fciOrient.orient(graph);
    }


    public IKnowledge getKnowledge() {
        return knowledge;
    }

    public void setKnowledge(IKnowledge knowledge) {
        if (knowledge == null) {
            throw new NullPointerException();
        }

        this.knowledge = knowledge;
    }

    /**
     * @return true if Zhang's complete rule set should be used, false if only R1-R4 (the rule set of the original FCI)
     * should be used. False by default.
     */
    public boolean isCompleteRuleSetUsed() {
        return completeRuleSetUsed;
    }

    /**
     * @param completeRuleSetUsed set to true if Zhang's complete rule set should be used, false if only R1-R4 (the rule
     *                            set of the original FCI) should be used. False by default.
     */
    public void setCompleteRuleSetUsed(boolean completeRuleSetUsed) {
        this.completeRuleSetUsed = completeRuleSetUsed;
    }

    public void setMaxPathLength(int maxPathLength) {
        if (maxPathLength < -1) {
            throw new IllegalArgumentException("Max path length must be -1 (unlimited) or >= 0: " + maxPathLength);
        }

        this.maxPathLength = maxPathLength == -1
                ? Integer.MAX_VALUE : maxPathLength;
    }

    /**
     * True iff verbose output should be printed.
     */
    public boolean isVerbose() {
        return verbose;
    }

    public void setVerbose(boolean verbose) {
        this.verbose = verbose;
    }

}