def in_check?(color)
    king = find_king(color)
    opponents = opponents_pieces(color)
    @enemies_causing_check = []
    opponents.each do |piece|
      @enemies_causing_check << piece if piece.valid_move?(king.x_position, king.y_position) == true
    end
    return true if @enemies_causing_check.any?
    false
  end

  def i_can_move_out_of_check?(color)
    king = find_king(color)
    x_start = king.x_position
    y_start = king.y_position
    state = false
    ((king.x_position - 1)..(king.x_position + 1)).each do |x|
      ((king.y_position - 1)..(king.y_position + 1)).each do |y|
        king.update(x_position: x, y_position: y) if king.valid_move?(x, y)
        state = true unless in_check?(color)
        king.update(x_position: x_start, y_position: y_start)
      end
    end
    state
  end

  def capture_opponent_causing_check?(color)
    friendlies = friendly_pieces(color)
    the_liberator = []
    friendlies.each do |friend|
      @enemies_causing_check.each do |enemy|
        the_liberator << friend if friend.valid_move?(enemy.x_position, enemy.y_position) == true
      end
    end
    return true if the_liberator.any?
    false
  end

  def stalemate?(color)
    your_pieces = friends_on_board(color)
    available_moves = []
    your_pieces.each do |piece|
      1.upto(8) do |x|
        1.upto(8) do |y|
          if piece.valid_move?(x, y) && !piece.move_causes_check?(x, y)
            available_moves << [x, y]
          end
        end
      end
    end
    return false if available_moves.any?
    true
  end

  def friendly_pieces(color)
    friendly_pieces = if color == 'BLACK'
                       'BLACK'
                     else
                       'WHITE'
                     end
    pieces.where(color: friendly_pieces).to_a
  end

  def opponents_pieces(color)
    opposing_color = if color == 'BLACK'
                       'WHITE'
                     else
                       'BLACK'
                     end
    pieces.where(color: opposing_color).to_a
  end

  def move_to!(x, y)
    if occupied_by_mycolor_piece?(x, y)
      false
    elsif valid_move?(x, y)
      if occupied_by_opposing_piece?(x, y)
        capture_piece_at!(x, y)
        update_attributes(x_position: x, y_position: y)
      elsif unoccupied?(x, y)
        update_attributes(x_position: x, y_position: y)
      end
    else
      false
    end
  end

  def move_causes_check?(next_x, next_y)
    state = false
    ActiveRecord::Base.transaction do
      move!(next_x, next_y)
      state = game.check?(color)
      raise ActiveRecord::Rollback
    end
    reload
    state
  end

  def available_moves
    Game.all_board_coordinates.select do |coordinate_pair|
      valid_move?(coordinate_pair[0], coordinate_pair[1]) &&
        !is_obstructed?(coordinate_pair[0], coordinate_pair[1]) &&
        !occupied_by_mycolor_piece?(coordinate_pair[0], coordinate_pair[1])
    end
  end