AI.java

import java.util.*;

public class AI extends Player {


  public AI(String name, char playerChar, Board boardIplayOn) {
    super(name, playerChar, boardIplayOn, false);
  }

  public int canMoveWin(char characterToPlace, Board boardIplayOn) {
    // creates virtual board, loops through all moves, if there is win return 1 else
    // return 0
    for (int i = 1; i <= this.board.getBoardX(); i++) {
      Board temporaryHelper = new Board(this.board.getBoardX(), this.board.getBoardY(), this.board.getconnectN());
      temporaryHelper.setBoardChars(this.board.getBoardChars());
      this.board.placeCounter(characterToPlace, i, temporaryHelper.getBoardChars());
      if (this.board.searchForPairs(characterToPlace, temporaryHelper.getBoardChars(),
          temporaryHelper.getconnectN()) >= 1) {
        return i;
      }
    }
    return 0;
  }

  public ArrayList<Integer> moveValue(char friendlyCharacter, Board boardToCheck) {
    ArrayList<Integer> listOfMoves = new ArrayList<Integer>(); // store all possible moves
    for (int positionToPlay = 1; positionToPlay < 1 + boardToCheck.getBoardX(); positionToPlay++) { // start making all possible moves
      Board temporaryHelper = new Board(this.board.getBoardX(), this.board.getBoardY(), this.board.getconnectN()); // create temp board
      temporaryHelper.setBoardChars(boardToCheck.getBoardChars());
      if (this.board.placeCounter(friendlyCharacter, positionToPlay, temporaryHelper.getBoardChars())) { // If theoretical play is valid, check for the value
        int thisMove = 0;
        for (int i = 0; i < temporaryHelper.getBoardX(); i++) { // loop through all positions
          for (int j = 0; j < temporaryHelper.getBoardY(); j++) {
            int pairs2 = temporaryHelper.searchForPairs(friendlyCharacter, temporaryHelper.getBoardChars(), 2);
            int pairs3 = temporaryHelper.searchForPairs(friendlyCharacter, temporaryHelper.getBoardChars(), 3);
            thisMove = +pairs2 + pairs3 * 100;
          }
        }
        listOfMoves.add(thisMove);
      } else {
        listOfMoves.add(0);
      }
    }
    return listOfMoves;
  }

  @Override
  public void setEnemyCharacter(ArrayList<Character> enemyCharacters) {
    for(char enemyCharacter : enemyCharacters){
      this.enemyCharacterList.add(enemyCharacter);
    }
  }

  @Override
  public int makeMove(InputHandler input) {
    // look for win
    if (canMoveWin(this.playerCharacter, this.board) != 0) {
      this.myMove(canMoveWin(this.playerCharacter, this.board));
      ;
      return 1; // i won
    } else {
        for(char enemyCharacter : this.enemyCharacterList){
          if (canMoveWin(enemyCharacter, this.board) != 0) {
            this.myMove(canMoveWin(enemyCharacter, this.board));
            return 1; // i blocked enemy
          }
        }
    }
    ArrayList<Integer> moves = moveValue(this.playerCharacter, this.board);
    // since more than 1 spot can be "best-move", lets choose randomly one
    ArrayList<Integer> bestmoves = new ArrayList<Integer>();
    int maxVal = Collections.max(moves);
    for (int spot : moves) {
      if (spot == maxVal) {
        bestmoves.add(moves.indexOf(spot));
        moves.set(moves.indexOf(spot), spot - 1);
      }
    }
    int moveToPlay = bestmoves.get(new Random().nextInt(bestmoves.size()));
    moves.clear();
    myMove(moveToPlay + 1);
    return 0; // i moved
  }
}