transferred Code Ocean from original repository to GitHub

app/models/exercise.rb

@@ -0,0 +1,60 @@
+class Exercise < ActiveRecord::Base
+  include Context
+  include Creation
+
+  after_initialize :generate_token
+  after_initialize :set_default_values
+
+  belongs_to :execution_environment
+  has_many :submissions
+  has_many :users, source_type: ExternalUser, through: :submissions
+
+  scope :with_submissions, -> { where('id IN (SELECT exercise_id FROM submissions)') }
+
+  validate :valid_main_file?
+  validates :description, presence: true
+  validates :execution_environment_id, presence: true
+  validates :public, inclusion: {in: [true, false]}
+  validates :title, presence: true
+  validates :token, presence: true, uniqueness: true
+
+  def average_percentage
+    (average_score / maximum_score * 100).round if average_score
+  end
+
+  def average_score
+    ActiveRecord::Base.connection.execute("SELECT AVG(score) AS average_score FROM (SELECT MAX(score) AS score FROM submissions WHERE cause = 'submit' AND exercise_id = '#{id}' GROUP BY user_id) AS maximum_scores")[0]['average_score'].to_f.round(2)
+  end
+
+  def duplicate(attributes)
+    exercise = dup
+    exercise.attributes = attributes
+    files.each { |file| exercise.files << file.dup }
+    exercise
+  end
+
+  def generate_token
+    self.token ||= SecureRandom.hex(4)
+  end
+  private :generate_token
+
+  def maximum_score
+    files.where(role: 'teacher_defined_test').sum(:weight)
+  end
+
+  def set_default_values
+    self.public ||= false
+  end
+  private :set_default_values
+
+  def to_s
+    title
+  end
+
+  def valid_main_file?
+    if files.where(role: 'main_file').count > 1
+      errors.add(:files, I18n.t('activerecord.errors.models.exercise.at_most_one_main_file'))
+    end
+  end
+  private :valid_main_file?
+end