///////////////////////////////////////////////////////////////////////////////
// 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.DataSet;
import edu.cmu.tetrad.data.ICovarianceMatrix;
import edu.cmu.tetrad.graph.Node;
import edu.cmu.tetrad.graph.NodeType;
import edu.cmu.tetrad.util.TetradLogger;
import edu.cmu.tetrad.util.TetradMatrix;

import java.util.*;


/**
 * Checks independence facts for variables associated associated with a sepset by simply querying the sepset
 *
 * @author Robert Tillman
 */
public class IndTestSepset implements IndependenceTest {

    /**
     * The sepset being queried
     */
    private SepsetMapDci sepset;

    /**
     * The map from nodes to variables.
     */
    private Map<Node, Node> nodesToVariables;

    /**
     * The map from variables to nodes.
     */
    private Map<Node, Node> variablesToNodes;

    /**
     * The list of observed variables (i.e. variables for observed nodes).
     */
    private List<Node> observedVars;
    private boolean verbose = false;

    /**
     * Constructs a new independence test that returns d-separation facts for the given graph as independence results.
     */
    public IndTestSepset(SepsetMapDci sepset, List<Node> nodes) {
        if (sepset == null) {
            throw new NullPointerException();
        }

        this.sepset = sepset;
        this.nodesToVariables = new HashMap<>();
        this.variablesToNodes = new HashMap<>();

        for (Node node : nodes) {
            this.nodesToVariables.put(node, node);
            this.variablesToNodes.put(node, node);
        }

        this.observedVars = calcObservedVars(nodes);
    }

    /**
     * Required by IndependenceTest.
     */
    public IndependenceTest indTestSubset(List<Node> vars) {
        if (vars.isEmpty()) {
            throw new IllegalArgumentException("Subset may not be empty.");
        }

        for (Node var : vars) {
            if (!getVariables().contains(var)) {
                throw new IllegalArgumentException(
                        "All vars must be original vars");
            }
        }

        return this;
    }

    /**
     * @return the list of observed nodes in the given graph.
     */
    private List<Node> calcObservedVars(List<Node> nodes) {
        List<Node> observedVars = new ArrayList<>();

        for (Node node : nodes) {
            if (node.getNodeType() == NodeType.MEASURED) {
                observedVars.add(getVariable(node));
            }
        }

        return observedVars;
    }

    /**
     * Checks the indicated independence fact.
     *
     * @param x one node.
     * @param y a second node.
     * @param z a List of nodes (conditioning variables)
     * @return true iff x _||_ y | z
     */
    public boolean isIndependent(Node x, Node y, List<Node> z) {
        if (z == null) {
            throw new NullPointerException();
        }

        for (Node node : z) {
            if (node == null) {
                throw new NullPointerException();
            }
        }

        boolean independent = false;

        if (sepset.get(x, y) != null) {
            List<List<Node>> condSets = sepset.getSet(x, y);
            for (List<Node> condSet : condSets) {
                if (condSet.size() == z.size() && condSet.containsAll(z)) {
                    double pValue = 1.0;

                    if (verbose) {
                        TetradLogger.getInstance().log("independencies", SearchLogUtils.independenceFactMsg(x, y, z, pValue));
                    }
                    independent = true;
                    break;
//                    return true;
                }
            }
        }

        if (verbose) {
            if (independent) {
                TetradLogger.getInstance().log("independencies", SearchLogUtils.independenceFactMsg(x, y, z, getPValue()));
            } else {
                TetradLogger.getInstance().log("dependencies", SearchLogUtils.dependenceFactMsg(x, y, z, getPValue()));
            }
        }

        return independent;

//        return false;
    }

    public boolean isIndependent(Node x, Node y, Node... z) {
        List<Node> zList = Arrays.asList(z);
        return isIndependent(x, y, zList);
    }

    public boolean isDependent(Node x, Node y, List<Node> z) {
        return !isIndependent(x, y, z);
    }

    public boolean isDependent(Node x, Node y, Node... z) {
        List<Node> zList = Arrays.asList(z);
        return isDependent(x, y, zList);
    }

    /**
     * Needed for IndependenceTest interface. P value is not meaningful here.
     */
    public double getPValue() {
        return Double.NaN;
    }

    /**
     * @return the list of TetradNodes over which this independence checker is capable of determinine independence
     * relations-- that is, all the variables in the given graph or the given data set.
     */
    public List<Node> getVariables() {
        return Collections.unmodifiableList(observedVars);
    }

    /**
     * @return the list of variable varNames.
     */
    public List<String> getVariableNames() {
        List<Node> nodes = getVariables();
        List<String> nodeNames = new ArrayList<>();
        for (Node var : nodes) {
            nodeNames.add(var.getName());
        }
        return nodeNames;
    }

    public boolean determines(List z, Node x1) {
        return z.contains(x1);
    }

    public double getAlpha() {
        throw new UnsupportedOperationException();
    }

    public void setAlpha(double alpha) {
        throw new UnsupportedOperationException();
    }

    public Node getVariable(String name) {
        for (int i = 0; i < getVariables().size(); i++) {
            Node variable = getVariables().get(i);

            if (variable.getName().equals(name)) {
                return variable;
            }
        }

        return null;
    }

    /**
     * @return the variable associated with the given node in the graph.
     */
    public Node getVariable(Node node) {
        return nodesToVariables.get(node);
    }

    /**
     * @return the node associated with the given variable in the graph.
     */
    public Node getNode(Node variable) {
        return variablesToNodes.get(variable);
    }

    public String toString() {
        return "D-separation";
    }

    public DataSet getData() {
        return null;  //To change body of implemented methods use File | Settings | File Templates.
    }

    @Override
    public ICovarianceMatrix getCov() {
        return null;
    }

    @Override
    public List<DataSet> getDataSets() {
        return null;
    }

    @Override
    public int getSampleSize() {
        return 0;
    }

    @Override
    public List<TetradMatrix> getCovMatrices() {
        return null;
    }

    @Override
    public double getScore() {
        return getPValue();
    }

    public boolean isVerbose() {
        return verbose;
    }

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