/**
 * Simple extension of class Board that provides a textual representation of
 * the MineSweeper game board on System.out.
 */
public class TextBoard extends Board {

  // Maximum length of string to hold column/row numbers
  private int colLength, rowLength;

  // Printable versions of column and row numbers
  private String[] colNums, rowNums;

  // Spacing for column-header lines
  private String spacer;


  /**
   * Create a new TextBoard of size width*height and containing numMines
   * mines.
   */
  public TextBoard(int width, int height, int numMines) {
    // Don't forget to initialise the superclass!
    super(width, height, numMines);

    // Allocate storage for column and row number, and work out how long the
    // respective strings need to be.  Note that the largest column/row number 
    // is actually one less than width/height, respectivaly.
    colLength = Integer.toString(width-1).length();
    rowLength = Integer.toString(height-1).length();
    colNums = new String[width];
    rowNums = new String[height];

    // Generate column numbers.  These are all padded out to colLength for
    // ease of printing later on.  The numbers are right-justified within the
    // string.
    for (int i = 0; i < width; i++) {
      StringBuffer col = new StringBuffer(Integer.toString(i));
      while (col.length() < colLength) {
	col.insert(0, ' ');
      }
      colNums[i] = col.toString();
    }

    // Generate a spacer for column numbers.  Just a string of spaces that
    // takes up the same space as a row number, for aligning the column
    // headers correctly.
    StringBuffer spaces = new StringBuffer();
    for (int i = 0; i < rowLength + 2; i++) {
      spaces.append(' ');
    }
    spacer = spaces.toString();

    // Generate row numbers.  Exactly the same procedure as the column
    // numbers, except that we are extra spaces around the number to make the
    // display more readable.
    for (int i = 0; i < height; i++) {
      StringBuffer row = new StringBuffer(Integer.toString(i));
      while (row.length() <= rowLength) {
	row.insert(0, ' ');
      }
      row.append(' ');
      rowNums[i] = row.toString();
    }
  }


  /**
   * Draw the current state of the board on System.out, as follows:
   *    - An unknown cell is indicated by '#'
   *    - A marked cell is indicated by 'X'
   *    - A revealed mine is indicated by '*'
   *    - A revealed empty cell contains a digit indicating the number of
   *      immediate neighbours containing mines, or '.' if there are no such
   *      neighbours.
   */
  public void draw() {

    // Some space
    System.out.println();

    // Do column numbers.  We print these out vertically, 'bottom-justified'.
    // Note the use of the spacer defined in the constructor.
    for (int i = 0; i < colLength; i++) {
      System.out.print(spacer);
      for (int j = 0; j < width; j++) {
	System.out.print(colNums[j].charAt(i));
      }
      System.out.println();
    }

    // Some more space
    System.out.println();

    // Do rows, complete with numbers
    for (int i = 0; i < height; i++) {
      // Print row number.  We do this again at the end of the row in case the 
      // board is huge and hard to read.
      System.out.print(rowNums[i]);

      // Print something appropriate for the cell
      for (int j = 0; j < width; j++) {
	switch (board[j][i]) {
	 case UNKNOWN:
	  System.out.print("#");
	  break;
	 case MARKED:
	  System.out.print("X");
	  break;
	 case MINE:
	  System.out.print("*");
	  break;
	 case 1:
	 case 2:
	 case 3:
	 case 4:
	 case 5:
	 case 6:
	 case 7:
	 case 8:
	 case 9:
	  System.out.print(board[j][i]);
	  break;
	 case 0:
	  System.out.print(".");
	  break;
	}
      }
      System.out.println(rowNums[i]);
    }

    // Some more space
    System.out.println();

    // Do column numbers, again in case the board is humongous and hard to
    // read.
    for (int i = 0; i < colLength; i++) {
      System.out.print(spacer);
      for (int j = 0; j < width; j++) {
	System.out.print(colNums[j].charAt(i));
      }
      System.out.println();
    }

    // Some more space (surprise)
    System.out.println();

    // Display the number of mines left to find.  This number reflects the
    // number of marked mines, any of which might of course be wrong!
    System.out.println("Mines remaining: " + (getMines() - getMarked()));

    // Yet more spacing
    System.out.println();
  }
}