package exercise.choice;

import java.io.*;
import java.util.*;
import widget.*;	// Uses widget.ChoicePane to provide model constants.

public class ChoiceExercise {
    public static final int	CHOOSE_ONE = ChoicePane.CHOOSE_ONE;
    public static final int	CHOOSE_ALL = ChoicePane.CHOOSE_ALL;

    protected String		exerciseID;
    protected String		instructions;
    protected int		type;
    protected String[]		choices;

    public ChoiceExercise(String exerciseID,
			  String instructions,
			  int type,
			  String[] choices) {

	this.exerciseID = exerciseID;
	this.type = type;
	this.instructions = instructions;
	this.choices = choices;
    }

    public String getExerciseID() { return exerciseID; }

    // For now this just returns the exercise ID.  Ultimately it should
    // derive the exercise name from the id and return the derived name.
    public String getExerciseName() { return exerciseID; }

    public String getInstructions() { return instructions; }
    public int getType() { return type; }
    public String[] getChoices() { return choices; }

    public static ChoiceExercise loadExercise(String exerciseID)
	throws IOException {

	// Load the contents of the Exercise file.
	Class cl = ChoiceExercise.class;
	String resourceName = "exercises/" + exerciseID + ".txt";
	InputStream is = cl.getResourceAsStream(resourceName);
	InputStreamReader isr = new InputStreamReader(is);
	BufferedReader br = new BufferedReader(isr);

	// Get the instructions and type.
	String instr = br.readLine();
	int type = Integer.parseInt(br.readLine());

	// Get the choices.
	Vector choiceLines = new Vector();
	String line;
	while ((line = br.readLine()) != null) { choiceLines.add(line); }
	int numChoices = choiceLines.size();
	String[] choices = new String[numChoices];
	for (int i = 0; i < numChoices; i++) {
	    choices[i] = (String)choiceLines.get(i);
	}

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

	// Return an Exercise object.
	return new ChoiceExercise(exerciseID, instr, type, choices);
    }
}