// Referee.java
// Class for the state of a game of Chips.
// Written by THC for Lab #1.

// This version uses dialog boxes.

import javax.swing.JOptionPane;

public class Referee {
  // Instance variables.
  private int chips; // Number of chips left
  private Player currentPlayer, otherPlayer; // The two players
  private int maxMove; // Max number of chips in next legal move

  // Initialize the state of the game:
  // * the names of the players and how many chips each has
  // * the number of chips in the pile
  // * max number of chips that may be taken in the first move
  public Referee() {
    // Start by creating the two Player objects.
    String message;
    message = "What is the name of the first player?";
    currentPlayer = new Player(JOptionPane.showInputDialog(message));

    message = "What is the name of the second player?";
    otherPlayer = new Player(JOptionPane.showInputDialog(message));

    // Make sure that the two players have different names.
    while (currentPlayer.getName().equalsIgnoreCase(otherPlayer.getName())) {
      message = "Both players cannot be named " + otherPlayer.getName() + 
          ".\nEnter a different name.";
      otherPlayer = new Player(JOptionPane.showInputDialog(message));
    }
  
    // Get the initial number of chips in the pile.
    final int MIN_CHIPS = 3; // Have to start with at least 3 chips

    message = "How many chips does the initial pile contain?";
    chips = Integer.parseInt(JOptionPane.showInputDialog(message));
    while (chips < MIN_CHIPS || chips % 2 == 0) {
      if (chips < MIN_CHIPS)
        message = "You have to start with at least " + MIN_CHIPS
            + " chips.\nChoose another number.";
      else
        message = "You have to start with an odd number of chips.\n"
                + "Choose another number.";
      chips = Integer.parseInt(JOptionPane.showInputDialog(message));
    }

    // It's easy to determine the maximum number of chips that may be taken
    // in the first move.
    maxMove = chips / 2;

    // Print a blank line to separate this dialog from the rest of the game.
    System.out.println();
  }

  // Return whether the game is over.
  public boolean saysGameIsOver() {
    return chips == 0;
  }

  // Return a String containing the state of the game: 
  // * How many chips each player has.
  // * Whose turn it is.
  // * How many chips remain.
  public String describeState() {
    String message = describePlayers();

    message += "It is your turn, " + currentPlayer.getName() + ".\n";

    if (chips == 1)
      message += "There is 1 chip remaining.\n";
    else
      message += "There are " + chips + " chips remaining.\n";
    
    return message;
  }
  
  // Return a String saying how many chips each player has.
  public String describePlayers() {
    return currentPlayer.describe() + "\n" + otherPlayer.describe() + "\n";
  }

  // Return whether a given move is legal.
  private boolean isLegal(int move) {
    return move >= 1 && move <= maxMove;
  }
  
  private String getIllegalMoveMessage(int move) {
    String message = "";
    
    if (move < 1)
      message = "Illegal move: you must take at least one chip.\n";
    else if (move > maxMove) {
      message = "Illegal move: you may not take more than " +
                         maxMove + " chip";
      if (maxMove != 1)
        message += "s";
      message += ".\n";
    }
    
    return message;
  }

  // Get a legal move from a player, prompting until a legal move is given.
  public int getLegalMove(String message) {
    int move; // The player's move

    // Tell the player the range of how many chips may be taken.
    message += "You may take any number of chips from 1 to " + maxMove + ".\n";

    do {
      message += "How many will you take, " + currentPlayer.getName() + "?";
      move = Integer.parseInt(JOptionPane.showInputDialog(message));
      message = getIllegalMoveMessage(move);
    }
    while (!isLegal(move));

    // At this point, we have a legal move, so return it.
    return move;
  }

  // Update the state of the game based on a move.
  public void updateState(int move) {
    chips -= move; // Remove the chips taken from the pile

    // Put the chips on the current player's pile.
    currentPlayer.addChips(move);
    
    // Switch between the two players.
    Player temp = currentPlayer;
    currentPlayer = otherPlayer;
    otherPlayer = temp;
  
    // And update the max legal move for the next turn.
    maxMove = Math.min(chips, 2 * move);
  }

  // Determine who won the game, and announce it.
  public void announceWinner() {
    String message = describePlayers();

    // The winner is the player with an even number of chips.
    String winner;
    if (currentPlayer.getChips() % 2 == 0)
      winner = currentPlayer.getName();
    else
      winner = otherPlayer.getName();
    
    message += winner + " wins!";
    JOptionPane.showMessageDialog(null, message);
  }
}