/*******************************************************************************
 * SAT4J: a SATisfiability library for Java Copyright (C) 2004, 2012 Artois University and CNRS
 *
 * 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++.
 *
 * Contributors:
 *   CRIL - initial API and implementation
 *******************************************************************************/
package org.sat4j.pb;

import java.math.BigInteger;
import java.util.Map;

import org.sat4j.specs.ContradictionException;
import org.sat4j.specs.FakeConstr;
import org.sat4j.specs.IConstr;
import org.sat4j.specs.IVec;
import org.sat4j.specs.IVecInt;
import org.sat4j.specs.IteratorInt;
import org.sat4j.tools.DimacsStringSolver;

/**
 * Solver to display SAT instances using domain objects names instead of Dimacs
 * numbers.
 * 
 * @author leberre
 */
public class UserFriendlyPBStringSolver<T> extends DimacsStringSolver
        implements IPBSolver {

    /**
     * 
     */
    private static final long serialVersionUID = 1L;

    private int indxConstrObj;

    private int nbOfConstraints;

    private ObjectiveFunction obj;

    private boolean inserted = false;

    private Map<Integer, T> mapping;

    /**
     * 
     */
    public UserFriendlyPBStringSolver() {
    }

    /**
     * @param initSize
     */
    public UserFriendlyPBStringSolver(int initSize) {
        super(initSize);
    }

    public void setMapping(Map<Integer, T> mapping) {
        this.mapping = mapping;
    }

    public IConstr addPseudoBoolean(IVecInt lits, IVec<BigInteger> coeffs,
            boolean moreThan, BigInteger d) throws ContradictionException {
        StringBuilder out = getOut();
        assert lits.size() == coeffs.size();
        this.nbOfConstraints++;
        if (moreThan) {
            for (int i = 0; i < lits.size(); i++) {
                out.append(coeffs.get(i) + " " + this.mapping.get(lits.get(i))
                        + " + ");
            }
            out.append(">= " + d + " ;\n");
        } else {
            for (int i = 0; i < lits.size(); i++) {
                out.append(coeffs.get(i) + " " + this.mapping.get(lits.get(i))
                        + " + ");
            }
            out.append("<= " + d + " ;\n");
        }
        return FakeConstr.instance();
    }

    public void setObjectiveFunction(ObjectiveFunction obj) {
        this.obj = obj;
    }

    @Override
    public IConstr addAtLeast(IVecInt literals, int degree)
            throws ContradictionException {
        StringBuilder out = getOut();
        this.nbOfConstraints++;
        for (IteratorInt iterator = literals.iterator(); iterator.hasNext();) {
            out.append(this.mapping.get(iterator.next()));
            out.append(" ");
            if (iterator.hasNext()) {
                out.append("+ ");
            }
        }
        out.append(">= " + degree + " ;\n");
        return FakeConstr.instance();
    }

    @Override
    public IConstr addAtMost(IVecInt literals, int degree)
            throws ContradictionException {
        StringBuilder out = getOut();
        this.nbOfConstraints++;
        for (IteratorInt iterator = literals.iterator(); iterator.hasNext();) {
            out.append(this.mapping.get(iterator.next()));
            out.append(" ");
            if (iterator.hasNext()) {
                out.append("+ ");
            }
        }
        out.append("<= " + degree + " ;\n");
        return FakeConstr.instance();
    }

    @Override
    public IConstr addClause(IVecInt literals) throws ContradictionException {
        StringBuilder out = getOut();
        this.nbOfConstraints++;
        int lit;
        boolean beginning = true;
        for (IteratorInt iterator = literals.iterator(); iterator.hasNext();) {
            lit = iterator.next();
            if (lit > 0) {
                if (beginning) {
                    out.append("-> ");
                    beginning = false;
                }
                out.append(this.mapping.get(lit));
            } else {
                if (!beginning) {
                    out.append(" NOT ");
                }
                out.append(this.mapping.get(-lit));
            }
            out.append(" ");
            if (iterator.hasNext() && !beginning) {
                out.append("OR ");
            }
        }
        if (beginning) {
            out.append("-> false");
        }
        out.append(" ;\n");
        return FakeConstr.instance();
    }

    /*
     * (non-Javadoc)
     * 
     * @see org.sat4j.pb.IPBSolver#getExplanation()
     */
    public String getExplanation() {
        return null;
    }

    /*
     * (non-Javadoc)
     * 
     * @see
     * org.sat4j.pb.IPBSolver#setListOfVariablesForExplanation(org.sat4j.specs
     * .IVecInt)
     */
    public void setListOfVariablesForExplanation(IVecInt listOfVariables) {
        // do nothing
    }

    @Override
    public String toString() {
        StringBuilder out = getOut();
        if (!this.inserted) {
            StringBuilder tmp = new StringBuilder();
            tmp.append("* #variable= ");
            tmp.append(nVars());
            tmp.append(" #constraint= ");
            tmp.append(this.nbOfConstraints);
            tmp.append(" \n");
            if (this.obj != null) {
                tmp.append("min: ");
                tmp.append(decode(this.obj));
                tmp.append(" ;\n");
            }
            out.insert(this.indxConstrObj, tmp.toString());
            this.inserted = true;
        }
        return out.toString();
    }

    private Object decode(ObjectiveFunction obj2) {
        StringBuilder stb = new StringBuilder();
        IVecInt vars = obj2.getVars();
        IVec<BigInteger> coeffs = obj2.getCoeffs();
        int lit;
        for (int i = 0; i < vars.size(); i++) {
            stb.append(coeffs.get(i));
            stb.append(" ");
            lit = vars.get(i);
            if (lit > 0) {
                stb.append(this.mapping.get(lit));
            } else {
                stb.append("~");
                stb.append(this.mapping.get(-lit));
            }
            stb.append(" ");
        }

        return stb.toString();
    }

    @Override
    public String toString(String prefix) {
        return "OPB output solver";
    }

    @Override
    public int newVar(int howmany) {
        StringBuilder out = getOut();
        setNbVars(howmany);
        // to add later the number of constraints
        this.indxConstrObj = out.length();
        out.append("\n");
        return howmany;
    }

    @Override
    public void setExpectedNumberOfClauses(int nb) {
    }

    public ObjectiveFunction getObjectiveFunction() {
        return this.obj;
    }

    public IConstr addAtMost(IVecInt literals, IVecInt coeffs, int degree)
            throws ContradictionException {
        StringBuilder out = getOut();
        assert literals.size() == coeffs.size();
        this.nbOfConstraints++;
        for (int i = 0; i < literals.size(); i++) {
            out.append(coeffs.get(i) + " " + this.mapping.get(literals.get(i))
                    + " + ");
        }
        out.append("<= " + degree + " ;\n");
        return FakeConstr.instance();
    }

    public IConstr addAtMost(IVecInt literals, IVec<BigInteger> coeffs,
            BigInteger degree) throws ContradictionException {
        StringBuilder out = getOut();
        assert literals.size() == coeffs.size();
        this.nbOfConstraints++;
        for (int i = 0; i < literals.size(); i++) {
            out.append(coeffs.get(i) + " " + this.mapping.get(literals.get(i))
                    + " + ");
        }
        out.append("<= " + degree + " ;\n");
        return FakeConstr.instance();
    }

    public IConstr addAtLeast(IVecInt literals, IVecInt coeffs, int degree)
            throws ContradictionException {
        StringBuilder out = getOut();
        assert literals.size() == coeffs.size();
        this.nbOfConstraints++;
        for (int i = 0; i < literals.size(); i++) {
            out.append(coeffs.get(i) + " " + this.mapping.get(literals.get(i))
                    + " + ");
        }
        out.append(">= " + degree + " ;\n");
        return FakeConstr.instance();
    }

    public IConstr addAtLeast(IVecInt literals, IVec<BigInteger> coeffs,
            BigInteger degree) throws ContradictionException {
        StringBuilder out = getOut();
        assert literals.size() == coeffs.size();
        this.nbOfConstraints++;
        for (int i = 0; i < literals.size(); i++) {
            out.append(coeffs.get(i) + " " + this.mapping.get(literals.get(i))
                    + " + ");
        }
        out.append(">= " + degree + " ;\n");
        return FakeConstr.instance();
    }

    public IConstr addExactly(IVecInt literals, IVecInt coeffs, int weight)
            throws ContradictionException {
        StringBuilder out = getOut();
        assert literals.size() == coeffs.size();
        this.nbOfConstraints++;
        for (int i = 0; i < literals.size(); i++) {
            out.append(coeffs.get(i) + " " + this.mapping.get(literals.get(i))
                    + " + ");
        }
        out.append("= " + weight + " ;\n");
        return FakeConstr.instance();
    }

    public IConstr addExactly(IVecInt literals, IVec<BigInteger> coeffs,
            BigInteger weight) throws ContradictionException {
        StringBuilder out = getOut();
        assert literals.size() == coeffs.size();
        this.nbOfConstraints++;
        for (int i = 0; i < literals.size(); i++) {
            out.append(coeffs.get(i) + " " + this.mapping.get(literals.get(i))
                    + " + ");
        }
        out.append("= " + weight + " ;\n");
        return FakeConstr.instance();
    }

}
