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

import java.util.Scanner;

public class Referee {
  // Instance variables.
  private int chips; // Number of chips left
  private Player currentPlayer, nextPlayer, previousPlayer; // The three 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() {
    Scanner input = new Scanner(System.in);
    
    // Start by creating the two Player objects.
    System.out.print("What is the name of the first player?  ");
    currentPlayer = new Player(input.nextLine());
    
    System.out.print("What is the name of the second player? ");
    nextPlayer = new Player(input.nextLine());
    
    // Make sure that the first two players have different names.
    while (currentPlayer.getName().equalsIgnoreCase(nextPlayer.getName())) {
      System.out.print("Both players cannot be named " + nextPlayer.getName()
      + ".  Enter a different name: ");
      nextPlayer = new Player(input.nextLine());
    }
    
    System.out.print("What is the name of the third player?  ");
    previousPlayer = new Player(input.nextLine());
    
    // Make sure that the third player has a different name from the first two.
    while (currentPlayer.getName().equalsIgnoreCase(previousPlayer.getName()) ||
        nextPlayer.getName().equalsIgnoreCase(previousPlayer.getName())) {
      System.out.println("There cannot be more than one player named " +
          previousPlayer.getName() + ".  Enter a different name: ");
      previousPlayer = new Player(input.nextLine());
    }
    
    // Get the initial number of chips in the pile.
    final int MIN_CHIPS = 7; // Smallest odd number > 1 that is congruent to 1 (mod 3)

    System.out.print("How many chips does the initial pile contain? ");
    chips = input.nextInt();
    while (chips < MIN_CHIPS || chips % 2 == 0 || chips % 3 != 1) {
      if (chips < MIN_CHIPS)
        System.out.print("You have to start with at least " + MIN_CHIPS
            + " chips.  Choose another number: ");
      else
        System.out.print("You have to start with an odd number of chips " +
             "that is one greater than a multiple of 3.\n" +
             "Choose another number: ");
      chips = input.nextInt();
    }

    // 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;
  }

  // Print out the state of the game: 
  // * How many chips each player has.
  // * Whose turn it is.
  // * How many chips remain.
  public void describeState() {
    describePlayers();

    System.out.println("It is your turn, " + currentPlayer.getName() + ".");

    if (chips == 1)
      System.out.println("There is 1 chip remaining.");
    else
      System.out.println("There are " + chips + " chips remaining.");
  }
  
  // Print out how many chips each player has.
  public void describePlayers() {
    System.out.println(currentPlayer.describe());
    System.out.println(nextPlayer.describe());
    System.out.println(previousPlayer.describe());
  }

  // Return whether a given move is legal and, if it's not legal, tell
  // the player why.
  private boolean isLegal(int move) {
    if (move < 1) {
      System.out.println("Illegal move: you must take at least one chip.");
      return false;
    }
    else if (move > maxMove) {
      System.out.print("Illegal move: you may not take more than "
          + maxMove + " chip");
      if (maxMove != 1)
        System.out.print("s");
      System.out.println(".");

      return false;
    }
    else
      return true;
  }

  // Get a legal move from a player, prompting until a legal move is given.
  public int getLegalMove() {
    int move; // The player's move
    Scanner input = new Scanner(System.in);

    // Tell the player the range of how many chips may be taken.
    System.out.print("You may take any number of chips from 1 to "
        + maxMove + ".  ");

    do {
      System.out.print("How many will you take, " + currentPlayer.getName()
          + "? ");
      move = input.nextInt();
    }
    while (!isLegal(move));

    // At this point, we have a legal move, so return it.  First, put out a blank
    // line to separate the dialog that just occurred from what will follow.
    System.out.println();
    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);
    
    // Rotate among the three players.
    Player temp = currentPlayer;
    currentPlayer = nextPlayer;
    nextPlayer = previousPlayer;
    previousPlayer = 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() {
    System.out.println("* * * * * * * * * * * * * * * * * * * * * * * * * * *");
    describePlayers();

    // First, determine if one is odd and two are even.  We do so by taking
    // the remainders and adding them up.  They're either all 1 (adding to 3)
    // or only one is 1.
    int currentRem = currentPlayer.getChips() % 2;
    int nextRem = nextPlayer.getChips() % 2;
    int previousRem = previousPlayer.getChips() % 2;
    String winner;
    
    if (currentRem + nextRem + previousRem == 1) {
      // One is odd, two are even.  The winner is the odd one.
      if (currentRem == 1)
        winner = currentPlayer.getName();
      else if (nextRem == 1)
        winner = nextPlayer.getName();
      else
        winner = previousPlayer.getName();
      
      System.out.println(winner + " has an odd number of chips, " 
          + "and the other two players have an even number.");
    }
    else {
      // All three are odd.  Find the one with the different remainder when
      // we divide by 3.
      currentRem = currentPlayer.getChips() % 3;
      nextRem = nextPlayer.getChips() % 3;
      previousRem = previousPlayer.getChips() % 3;
      
      if (currentRem == nextRem)
        winner = previousPlayer.getName();
      else if (currentRem == previousRem)
        winner = nextPlayer.getName();
      else
        winner = currentPlayer.getName();
      
      // Say why we have our winner.
      System.out.println("All three players have an odd number of chips.");
      System.out.println("Remainders when we divide chips by 3:");
      System.out.println("  " + currentPlayer.getName() + ": " + currentRem);
      System.out.println("  " + nextPlayer.getName() + ": " + nextRem);
      System.out.println("  " + previousPlayer.getName() + ": " + previousRem);
    }
    
    System.out.println(winner + " wins!");
  }
}