// C Sc 127B. Spring 2007 Project due 10-April-2007 @ 10:00pm
//
// Complete this game tree class according to the specification
// found as Project9: Game of 20 Questions
//
import java.io.File;
import java.io.FileNotFoundException;
import java.util.Scanner;

public class GameTree {
  public static void main(String[] args) {

    String fileWithQandA = "animals.txt";
    System.out.println("You are to answer questions until you find an answer");
    System.out.println("that you seek. If you don't find it, enter a new");
    System.out.println("question and the answer. Current file with");
    System.out.println("game questions and answers: " + fileWithQandA);

    // Create the game tree using the input files
    GameTree aGame = new GameTree(fileWithQandA);

    // And show the new tree sideways
    aGame.printSideways();
  }

  private class BinaryTreeNode { // instance variables
    private String data;

    private BinaryTreeNode left;

    private BinaryTreeNode right;

    BinaryTreeNode() {
      data = null;
      left = null;
      right = null;
    }

    BinaryTreeNode(String theData) {
      data = theData;
      left = null;
      right = null;
    }

    BinaryTreeNode(String theData, BinaryTreeNode leftLink,
        BinaryTreeNode rightLink) {
      data = theData;
      left = leftLink;
      right = rightLink;
    }
  } // end class BinaryTreeNode

  private BinaryTreeNode root;

  private Scanner my_inputFile;

  public GameTree(String fileName) {
    try {
      my_inputFile = new Scanner(new File(fileName));
    } catch (FileNotFoundException e) {
      // TODO Auto-generated catch block
      e.printStackTrace();
    }
    root = build();
  }

  private BinaryTreeNode build() {
    // pre: input readable (Based on the C++
    // version by Owen Astrachan)
    // post: returns tree constructed from reading file
    String s = null;
    BinaryTreeNode tree = null;
    BinaryTreeNode left = null;
    BinaryTreeNode right = null;

    if (my_inputFile.hasNextLine()) {
      s = my_inputFile.nextLine().trim();
      if (s.indexOf("?") > 0) { // add a question
        left = build(); // process yes branch
        right = build(); // process no branch
        tree = new BinaryTreeNode(s, left, right);
      } else { // Call one argument constructor
        tree = new BinaryTreeNode(s); // add an answer
      }
    }
    return tree;
  }

  public void printSideways() {
    int depth = 0;
    System.out.println();
    printSideways(root, depth);
  }

  private void printSideways(BinaryTreeNode t, int depth) {
    if (t != null) {
      printSideways(t.right, depth + 1);
      for (int j = 1; j <= depth; j++)
        System.out.print("     ");
      System.out.println(t.data.toString());
      printSideways(t.left, depth + 1);
    }
  }
}