import java.util.ArrayList;
import java.util.Scanner;
/**
 * Console user interface for decision support application.
 *
 * @author Dr. Jody Paul
 * @version 4 April 2006
 */
public class ConsoleUserInterface extends UserInterface {

    public ArrayList<Choice> getChoices() {
        ArrayList<Choice> alchoice = new ArrayList<Choice>();
        Scanner sc = new Scanner(System.in);
        System.out.print("Please enter one of the alternatives"
                         + " that you are considering: ");
        String alternative = sc.nextLine();
        while (alternative != null && !("".equals(alternative))) {
            alchoice.add(new Choice(alternative));
            System.out.print("Please enter another alternative "
                            + "(blank if all have been entered): ");
            alternative = sc.nextLine();
        }
        return alchoice;
    }
    
    public ArrayList<Characteristic> getCharacteristics() {
        ArrayList<Characteristic> alchar = new ArrayList<Characteristic>();
        Scanner sc = new Scanner(System.in);
        System.out.print("Please enter one factor that would influence your choice"
            + " among alternatives: ");
        String characteristic = sc.nextLine();
        while (characteristic != null && !("".equals(characteristic))) {
            alchar.add(new Characteristic(characteristic));
            System.out.print("Please enter another attribute "
                            + "(blank if all have been entered): ");
            characteristic = sc.nextLine();
        }
        return alchar;
    }
    
    public void getCharacteristicRankings(ArrayList<Characteristic> alc, int standard) {
        Scanner sc = new Scanner(System.in);
        int firstAttribute = 0;
        alc.get(firstAttribute).setRank(standard);
        System.out.print("\nAssume that " + alc.get(firstAttribute).getName()
            + " has an importance of " + standard + ",\n"
            + "    and that higher values are more important.\n");
        for (int i = firstAttribute + 1; i < alc.size(); i++) {
             System.out.print("        How important is " + alc.get(i).getName() + "? ");
             String importance = sc.nextLine();
             if (importance == null || "".equals(importance)) {
                 alc.get(i).setRank(standard);
             } else {
                 alc.get(i).setRank(new Integer(importance));
             }
        }
    }

    public double[][] getCrossRankings(ArrayList<Choice> choices,
                                      ArrayList<Characteristic> characteristics,
                                      int standard) {
        Scanner sc = new Scanner(System.in);
        double[][] crossRankings = new double[choices.size()][characteristics.size()];
        for (int i = 0; i < characteristics.size(); i++) {
            int firstChoice = 0;
            crossRankings[firstChoice][i] = standard;
            System.out.println("\n\nConsidering " + characteristics.get(i).getName()
                + " only...");
            System.out.println("    if "
                    + choices.get(firstChoice).getName()
                    + " has a value of " + standard + "... ");
            for (int j = firstChoice + 1; j < choices.size(); j++) {
                System.out.print("        ...what value would you associate with "
                    + choices.get(j).getName() + ": ");
                String rank = sc.nextLine();
                if (rank == null || "".equals(rank)) {
                    crossRankings[j][i] = standard;
                } else {
                    crossRankings[j][i] = new Integer(rank);
                }
            }
        }
        return crossRankings;
    }

    public void showResults(ArrayList<Choice> choices) {
        Choice preferredChoice = choices.get(0);
        int max = 0;
        for (Choice c : choices) {
            if (max < c.getFinalScore()) max = c.getFinalScore();
        }
        for (Choice c : choices) {
            if (max == c.getFinalScore()) preferredChoice = c;
        }
        System.out.print("\n\n================\nPreferred choice: ");
        System.out.println(preferredChoice.getName());
        System.out.println("-----");
        for (Choice c : choices) {
            System.out.println(c.getName()
                 + " == "
                 + c.getFinalScore());
        }
    }
}