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/**
 * Copyright (c) 2015, Ecole des Mines de Nantes
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *    This product includes software developed by the .
 * 4. Neither the name of the  nor the
 *    names of its contributors may be used to endorse or promote products
 *    derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY  ''AS IS'' AND ANY
 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL  BE LIABLE FOR ANY
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 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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package org.chocosolver.samples.integer;

import org.chocosolver.samples.AbstractProblem;
import org.chocosolver.solver.ResolutionPolicy;
import org.chocosolver.solver.Solver;
import org.chocosolver.solver.constraints.IntConstraintFactory;
import org.chocosolver.solver.search.strategy.IntStrategyFactory;
import org.chocosolver.solver.variables.BoolVar;
import org.chocosolver.solver.variables.IntVar;
import org.chocosolver.solver.variables.VariableFactory;
import org.chocosolver.util.tools.StringUtils;
import org.kohsuke.args4j.Option;

import static org.chocosolver.solver.constraints.IntConstraintFactory.*;
import static org.chocosolver.solver.constraints.LogicalConstraintFactory.ifThenElse;

/**
 * gecode:

 * "A group of people wants to take a group photo. Each person can give
 * preferences next to whom he or she wants to be placed on the
 * photo. The problem to be solved is to find a placement that
 * violates as few preferences as possible."
 * 

 *
 * @author Charles Prud'homme
 * @since 03/08/11
 */
public class Photo extends AbstractProblem {

    @Option(name = "-d", aliases = "--data", usage = "Photo preferences .", required = false)
    Data data = Data.small;

    IntVar[] positions;
    IntVar[] dist;
    BoolVar[] viols;
    IntVar violations;

    @Override
    public void createSolver() {
        solver = new Solver("Photo");
    }

    @Override
    public void buildModel() {
        positions = VariableFactory.boundedArray("pos", data.people(), 0, data.people() - 1, solver);
        violations = VariableFactory.bounded("viol", 0, data.preferences().length, solver);

        viols = VariableFactory.boolArray("b", data.prefPerPeople(), solver);
        dist = new IntVar[data.prefPerPeople()];
        for (int i = 0; i < data.prefPerPeople(); i++) {
            int pa = data.preferences()[(2 * i)];
            int pb = data.preferences()[2 * i + 1];


			IntVar k = VariableFactory.bounded(StringUtils.randomName(),-20000,20000,solver);
			solver.post(IntConstraintFactory.sum(new IntVar[]{positions[pb], k}, positions[pa]));
			dist[i] = VariableFactory.abs(k);

            ifThenElse(viols[i],
                            arithm(dist[i], ">", 1),
                            arithm(dist[i], "<=", 1));
        }
        solver.post(sum(viols, violations));
        solver.post(alldifferent(positions, "BC"));
        solver.post(arithm(positions[1], ">", positions[0]));
    }

    @Override
    public void configureSearch() {
        solver.set(IntStrategyFactory.minDom_LB(positions));
    }

    @Override
    public void solve() {
        solver.findOptimalSolution(ResolutionPolicy.MINIMIZE, violations);
//        solver.findAllSolutions();
    }

    @Override
    public void prettyOut() {
        System.out.println(String.format("Photo -- %s", data.name()));
        StringBuilder st = new StringBuilder();
        st.append("\tPositions: ");
        for (int i = 0; i < data.people(); i++) {
            st.append(String.format("%d ", positions[i].getValue()));
        }
        st.append(String.format("\n\tViolations: %d", violations.getValue()));
        System.out.println(st.toString());
    }

    public static void main(String[] args) {
        new Photo().execute(args);
    }

    /////////////////////////////////// DATA //////////////////////////////////////////////////
    static enum Data {
        small {
            @Override
            int[] preferences() {
                return new int[]{
                        0, 2,
                        1, 4,
                        2, 3,
                        2, 4,
                        3, 0,
                        4, 3,
                        4, 0,
                        4, 1
                };
            }

            @Override
            int people() {
                return 5;
            }

            @Override
            int prefPerPeople() {
                return 8;
            }
        },
        large {
            @Override
            int[] preferences() {
                return new int[]{
                        0, 2, 0, 4, 0, 7, 1, 4, 1, 8, 2, 3, 2, 4, 3, 0, 3, 4,
                        4, 5, 4, 0, 5, 0, 5, 8, 6, 2, 6, 7, 7, 8, 7, 6
                };
            }

            @Override
            int people() {
                return 9;
            }

            @Override
            int prefPerPeople() {
                return 17;
            }
        };

        abstract int[] preferences();

        abstract int people();

        abstract int prefPerPeople();
    }

}