/********************************************************
  Xpress-BCL Java Example Problems
  ================================

  file xbgoalobj.java
  ```````````````````
  Archimedian and pre-emptive goal programming
  using objective functions.

  (c) 2008-2023 Fair Isaac Corporation
      author: S.Heipcke, 2005, rev. Mar. 2011
********************************************************/

import java.lang.*;
import com.dashoptimization.*;

public class xbgoalobj {
    static final int NGOALS = 3;

    /**** Data ****/
    static final String[] Type = {"perc", "abs", "perc"};
    static final String[] Sense = {"max", "min", "max"};
    static final double[] Weight = {100, 1, 0.1};
    static final double[] Deviation = {10, 4, 20};

    public static void main(String[] args) throws XPRSprobException, XPRSexception {
        XPRBvar x,y;
        XPRBexpr[] goal;
        XPRBexpr wobj;
        XPRBctr[] goalCtr;
        XPRBctr aCtr;
        double[] Target;
        int i,g;

        try (XPRBprob prob = new XPRBprob("Goal"); /* Initialize BCL and create a new problem */
             XPRS xprs = new XPRS()) {             /* Initialize Xpress-Optimizer */

            Target = new double[NGOALS];
            goalCtr = new XPRBctr[NGOALS];
            goal = new XPRBexpr[NGOALS];
            wobj = new XPRBexpr();

            /* Adding the variables */
            x = prob.newVar("x",XPRB.PL);
            y = prob.newVar("y",XPRB.PL);

            /* Adding a constraint */
            aCtr = prob.newCtr("Limit", x.mul(42) .add(y.mul(13)) .lEql(100) );

            /* Goals */
            goal[0] = x.mul(5) .add(y.mul(2)) .add(-20);
            goal[1] = x.mul(-3) .add(y.mul(15)) .add(-48);
            goal[2] = x.mul(1.5) .add(y.mul(21)) .add(-3.8);
            for(g=0;g<NGOALS;g++)
                goalCtr[g] = prob.newCtr("Goal"+(g+1), goal[g]);

            /**** Archimedian GP ****/
            System.out.println("Archimedian:");
            for(g=0;g<NGOALS;g++) {
                if (Sense[g]=="max")
                    wobj.add(((XPRBexpr)goal[g].clone()).mul(-Weight[g]));
                else
                    wobj.add(((XPRBexpr)goal[g].clone()).mul(Weight[g]));
            }
            prob.setObj(wobj);
            prob.getXPRSprob().setIntControl(XPRS.OUTPUTLOG, 0);
            prob.lpOptimize("");

            /* Solution printout */
            System.out.println(" Solution: x: " + x.getSol() + ", y: " + y.getSol());
            System.out.println(" Goal   Target     Value");
            for(g=0;g<NGOALS;g++)
                System.out.println("  " + (g+1) + "       " + Sense[g] + "      " +
                                   (goalCtr[g].getAct() - goalCtr[g].getRHS()));


            /**** Prememptive GP ****/
            System.out.println("Prememptive:");
            i=-1;
            while (i<NGOALS-1) {
                i+=1;
                if (Sense[i]=="max") {
                    prob.setObj(goal[i]);
                    prob.setSense(XPRB.MAXIM);
                    prob.lpOptimize("");
                    if (prob.getLPStat() != XPRB.LP_OPTIMAL) {
                        System.out.println("Cannot satisfy goal " + (i+1));
                        break;
                    }
                    else {
                        Target[i]=prob.getObjVal();
                        if (Type[i]=="perc")
                            Target[i]-= Math.abs(Target[i])*Deviation[i]/100;
                        else
                            Target[i]-= Deviation[i];
                        if (i<NGOALS-1) goalCtr[i].add(Target[i]);
                        goalCtr[i].setType(XPRB.G);
                    }
                }
                else {
                    prob.setObj(goal[i]);
                    prob.setSense(XPRB.MINIM);
                    prob.lpOptimize("");
                    if (prob.getLPStat() != XPRB.LP_OPTIMAL) {
                        System.out.println("Cannot satisfy goal " + i);
                        break;
                    }
                    else {
                        Target[i]=prob.getObjVal();
                        if (Type[i]=="perc")
                            Target[i]+= Math.abs(Target[i])*Deviation[i]/100;
                        else
                            Target[i]+= Deviation[i];
                        if (i<NGOALS-1) goalCtr[i].add(Target[i]);
                        goalCtr[i].setType(XPRB.L);
                    }
                }
                System.out.println("Solution(" + (i+1) + "):  x: " + x.getSol() +
                                   ", y: " + y.getSol());
            }

            /* Solution printout */
            System.out.println(" Goal        Target                Value");
            for(g=0;g<=i;g++) {
                System.out.print("  " + (g+1) + "    " +
                                 (goalCtr[g].getType()==XPRB.G?" >=  ":" <=  ") + Target[g]);
                if(g==NGOALS-1)
                    System.out.println("   " + prob.getObjVal());
                else
                    System.out.println("   " + (goalCtr[g].getAct() - goalCtr[g].getRHS()
                                                + Target[g]));
            }
        }
    }
}