```ruby
class ProfilesController < ApplicationController
  before_filter :signed_in!

  def show
    @user = current_user
    send current_user.role
  end

  def update
    # this is called by the 'join classroom' page
    @user = current_user
    @user.update_attributes(user_params)
    @user.assign_classroom_activities
    redirect_to profile_path
  end

  def user
    student
  end

  def student
    if @classroom = current_user.classroom
      @units = @classroom.classroom_activities.map(&:unit).uniq

      @next_activity_session = ActivitySession.joins(:classroom_activity)
          .where("activity_sessions.completed_at IS NULL")
          .where("activity_sessions.user_id = ?", current_user.id)
          .order("classroom_activities.due_date DESC")
          .select("activity_sessions.*")
          .first

      @next_activity = @next_activity_session.activity if @next_activity_session.present?

      render 'student'
    else
      render 'join-classroom'
    end
  end

  def teacher
    if @user.classrooms.any?
      redirect_to scorebook_teachers_classrooms_path
    else
      redirect_to new_teachers_classroom_path
    end
  end

  def admin
    render :admin
  end

protected
  def user_params
    params.require(:user).permit(:classcode, :email, :name, :username, :password)
  end
end```

Fix one N+1 query found via bullet
user
```ruby
class ProfilesController < ApplicationController
  before_filter :signed_in!

  def show
    @user = current_user
    send current_user.role
  end

  def update
    # this is called by the 'join classroom' page
    @user = current_user
    @user.update_attributes(user_params)
    @user.assign_classroom_activities
    redirect_to profile_path
  end

  def user
    student
  end

  def student
    if @classroom = current_user.classroom
      @units = @classroom.classroom_activities.includes(:unit).map(&:unit).uniq

      @next_activity_session = ActivitySession.joins(:classroom_activity)
          .where("activity_sessions.completed_at IS NULL")
          .where("activity_sessions.user_id = ?", current_user.id)
          .order("classroom_activities.due_date DESC")
          .select("activity_sessions.*")
          .first

      @next_activity = @next_activity_session.activity if @next_activity_session.present?

      render 'student'
    else
      render 'join-classroom'
    end
  end

  def teacher
    if @user.classrooms.any?
      redirect_to scorebook_teachers_classrooms_path
    else
      redirect_to new_teachers_classroom_path
    end
  end

  def admin
    render :admin
  end

protected
  def user_params
    params.require(:user).permit(:classcode, :email, :name, :username, :password)
  end
end```
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