package EDU.gac.max.puzzle;

import java.awt.*;

public class Puzzle extends java.applet.Applet{
  private int size = 4;               // how many buttons wide and high
  private TileButton[][] buttons;
  private int blankRow, blankCol;     // position of the blank space

  public Puzzle(){
    setLayout(new BorderLayout());

    Panel controlPanel = new Panel();
    controlPanel.setLayout(new FlowLayout(FlowLayout.CENTER));
    add("North", controlPanel);
    controlPanel.add(new InitializeButton(this));
    controlPanel.add(new RandomizeButton(this));

    Panel mainPanel = new Panel();
    add("Center", mainPanel);
    mainPanel.setLayout(new GridLayout(size, size));
    buttons = new TileButton[size][size];
    for(int row = 0; row < size; row++){
      for(int col = 0; col < size; col++){
        TileButton b = new TileButton(this, row, col);
        buttons[row][col] = b;
        mainPanel.add(b);
      }
    }
    initialize();
  }

  void initialize(){
    for(int row = 0; row < size; row++){
      for(int col = 0; col < size; col++){
        int label = row * size + col + 1;
        buttons[row][col].setLabel("" + label);
      }
    }
    blankRow = size - 1;
    blankCol = size - 1;
    buttons[blankRow][blankCol].setLabel("");
  }

  void randomize(){
    for(int i = 0; i < 100; i++){
      pushRandomTile();
    }
  }

  void pushRandomTile(){
    int row = (int) (Math.random() * size);
    int col = (int) (Math.random() * size);
    pushTile(row, col);
  }
    
  void pushTile(int row, int col){
    if(row == blankRow){
      for( ; blankCol < col; blankCol++){
        buttons[blankRow][blankCol].setLabel
          (buttons[blankRow][blankCol+1].getLabel());
      }
      for( ; blankCol > col; blankCol--){
        buttons[blankRow][blankCol].setLabel
          (buttons[blankRow][blankCol-1].getLabel());
      }
    } else if(col == blankCol){
      for( ; blankRow < row; blankRow++){
        buttons[blankRow][blankCol].setLabel
          (buttons[blankRow+1][blankCol].getLabel());
      }
      for( ; blankRow > row; blankRow--){
        buttons[blankRow][blankCol].setLabel
          (buttons[blankRow-1][blankCol].getLabel());
      }
    }
    buttons[blankRow][blankCol].setLabel("");
  }
}