package exercise.situation;

import java.io.*;
import java.util.*;

public class SituationSolution {
    public static final int	UNSPECIFIED_NUM_REQUIRED =
				SituationExercise.UNSPECIFIED_NUM_REQUIRED;

    public static final int	ALL_REQUIRED =
				SituationExercise.ALL_REQUIRED;

    protected String		exerciseID;
    protected int		numRequired;

    // Outer index ranges over situations, inner index ranges over variables.
    // The array elements give the variable values.  The set of situations
    // is exhaustive.  Right now all situations must be totally-specified.
    // At some point it might be nice to allow for "don't care" variables.
    protected int[][]		situations;

    public SituationSolution(String exerciseID,
			     int numRequired,
			     int[][] situations) {

	this.exerciseID = exerciseID;
	this.numRequired = numRequired;
	this.situations = situations;
    }

    public String getExerciseID() { return exerciseID; }
    public int getNumRequired() { return numRequired; }
    public int[][] getSituations() { return situations; }

    public static SituationSolution loadSolution(String exerciseID)
	throws IOException {

	// Open a buffered reader to the Solution file.
	Class cl = SituationSolution.class;
	String resourceName = "solutions/" + exerciseID + ".txt";
	InputStream is = cl.getResourceAsStream(resourceName);
	InputStreamReader isr = new InputStreamReader(is);
	BufferedReader br = new BufferedReader(isr);

	// Get the number of situations required of the student.
	int numRequired = Integer.parseInt(br.readLine());

	// Get the solution situations.
	Vector lines = new Vector();
	String line;
	while ((line = br.readLine()) != null) { lines.add(line); }
	int numLines = lines.size();
	int[][] situations = new int[numLines][];
	for (int i = 0; i < numLines; i++) {
	    String s = (String)lines.get(i);
	    int numVars = s.length();
	    situations[i] = new int[numVars];
	    for (int j = 0; j < numVars; j++) {
		situations[i][j] = Integer.parseInt(s.substring(j, j+1));
	    }
	}

	// Close the buffered reader.
	br.close();

	// Return a Solution object.
	return new SituationSolution(exerciseID, numRequired, situations);
    }
}