/*
 * @(#)SetBuilderExerciseServlet.java	0.0.0 99/08/10
 *
 * Copyright (c) 1999 by Willie Wheeler.  All rights reserved.
 */
package stats.exercises;

import java.util.*;
import javax.servlet.*;
import javax.servlet.http.*;
import javax.swing.*;
import exercise.*;
import stats.*;

/**
 * @version     0.0.0 08/10/99
 * @author      Willie Wheeler
 */
public class SetBuilderExerciseServlet extends ExerciseServlet {
    protected static final String	ATOM_PATH =
	"e:/courseware/classes/resources/images/atoms/";

    protected static Map		exercises = new HashMap();

    static {

	//
	// This is just a temporary way of handling the exercises.  Ultimately
	// we should read them from a database.
	//


	//
	// Exercise 0.
	//

	Vector vars = new Vector();
	vars.add(new TextVariable("Sex",
				  new String[] { "Male", "Female" }));
	vars.add(new TextVariable("Hair color",
				  new String[] { "Blond", "Brown" }));
	vars.add(new TextVariable("Smoker?",
				  new String[] { "Yes", "No" }));

	Vector atoms = new Vector();
	ImageIcon atom = null;

	atom = new ImageIcon(ATOM_PATH + "white_male_blond_smoker.gif");
	atom.setDescription("0,0,0");
	atoms.add(atom);

	atom = new ImageIcon(ATOM_PATH + "white_male_blond_nonsmoker.gif");
	atom.setDescription("0,0,1");
	atoms.add(atom);

	atom = new ImageIcon(ATOM_PATH + "white_male_black_smoker.gif");
	atom.setDescription("0,1,0");
	atoms.add(atom);

	atom = new ImageIcon(ATOM_PATH + "white_male_black_nonsmoker.gif");
	atom.setDescription("0,1,1");
	atoms.add(atom);

	atom = new ImageIcon(ATOM_PATH + "white_female_blond_smoker.gif");
	atom.setDescription("1,0,0");
	atoms.add(atom);

	atom = new ImageIcon(ATOM_PATH + "white_female_blond_nonsmoker.gif");
	atom.setDescription("1,0,1");
	atoms.add(atom);

	atom = new ImageIcon(ATOM_PATH + "white_female_black_smoker.gif");
	atom.setDescription("1,1,0");
	atoms.add(atom);

	atom = new ImageIcon(ATOM_PATH + "white_female_black_nonsmoker.gif");
	atom.setDescription("1,1,1");
	atoms.add(atom);

	SetBuilderExercise sbe = new SetBuilderExercise(vars, atoms);
	Vector constraints = new Vector();
	int[] state = { -1, -1, 0 };
	int[] condState = { 0, -1, -1 };
	constraints.add(sbe.new Constraint(state, condState, .50));
	sbe.setConstraints(constraints);
	exercises.put("0", sbe);
    }

    public Exercise createExercise(String exerciseID) {
	return (Exercise)exercises.get(exerciseID);
    }

    public Grade evaluateSolution(Exercise exercise, Solution solution) {

	// Get exercise constraints.
	SetBuilderExercise sbe = (SetBuilderExercise)exercise;
	Vector constraints = sbe.getConstraints();

	// Get solution relative frequencies.
	SetBuilderSolution sbs = (SetBuilderSolution)solution;
	ContingencyTableModel model = sbs.getModel();
	int depIndex = ContingencyTableModel.ESTIMATE_OFFSET;

	// Evaluate the solution.
	boolean correct = true;
	for (int i = 0; i < constraints.size(); i++) {
	    SetBuilderExercise.Constraint constraint =
		(SetBuilderExercise.Constraint)constraints.get(i);
	    int[] state = constraint.getState();
	    int[] conditioningState = constraint.getConditioningState();
	    double target = constraint.getTarget();
	    double actual = model.getEstimate(state, conditioningState);
	    if (Math.abs(target - actual) > 0.01) {	// tolerance = 0.01
		correct = false;
		break;
	    }
	}

	// Return the results.
	double score = (correct ? 100.0 : 0.0);
	double maxScore = 100.0;
	return new SetBuilderGrade(score, maxScore);
    }
}