feat(gradebook): keep-highest N for equal-mode tabs + pin expanded rows

app/controllers/components/course/gradebook_component.rb

@@ -0,0 +1,42 @@
+# frozen_string_literal: true
+class Course::GradebookComponent < SimpleDelegator
+  include Course::ControllerComponentHost::Component
+
+  def self.display_name
+    'Gradebook'
+  end
+
+  def sidebar_items
+    main_sidebar_items + settings_sidebar_items
+  end
+
+  private
+
+  def main_sidebar_items
+    return [] unless can?(:read_gradebook, current_course)
+
+    [
+      {
+        key: self.class.key,
+        icon: :gradebook,
+        title: I18n.t('course.gradebook.component.sidebar_title'),
+        type: :normal,
+        weight: 9,
+        path: course_gradebook_path(current_course)
+      }
+    ]
+  end
+
+  def settings_sidebar_items
+    return [] unless can?(:manage_gradebook_settings, current_course)
+
+    [
+      {
+        key: self.class.key,
+        type: :settings,
+        weight: 14,
+        path: course_admin_gradebook_path(current_course)
+      }
+    ]
+  end
+end

app/controllers/course/admin/gradebook_settings_controller.rb

@@ -0,0 +1,28 @@
+# frozen_string_literal: true
+class Course::Admin::GradebookSettingsController < Course::Admin::Controller
+  def edit
+    respond_to(&:json)
+  end
+
+  def update
+    if @settings.update(gradebook_settings_params) && current_course.save
+      render 'edit'
+    else
+      render json: { errors: @settings.errors }, status: :bad_request
+    end
+  end
+
+  private
+
+  def gradebook_settings_params
+    params.require(:settings_gradebook_component).permit(:weighted_view_enabled)
+  end
+
+  def component
+    current_component_host[:course_gradebook_component]
+  end
+
+  def authorize_admin
+    authorize! :manage_gradebook_settings, current_course
+  end
+end

app/controllers/course/gradebook_controller.rb

@@ -0,0 +1,102 @@
+# frozen_string_literal: true
+class Course::GradebookController < Course::ComponentController
+  before_action :authorize_read_gradebook!
+
+  def index
+    respond_to do |format|
+      format.json do
+        @weighted_view_enabled = @settings.weighted_view_enabled
+        @published_assessments = fetch_published_assessments
+        @categories, @tabs = fetch_categories_and_tabs
+        @students = fetch_students
+        assessment_ids = @published_assessments.pluck(:id)
+        load_weighted_view_contributions(assessment_ids) if @weighted_view_enabled
+        @assessment_max_grades = Course::Assessment.max_grades(assessment_ids)
+        @submissions = Course::Assessment::Submission.grade_summary(
+          student_ids: @students.map(&:user_id),
+          assessment_ids: assessment_ids
+        )
+      end
+    end
+  end
+
+  def update_weights
+    authorize! :manage_gradebook_weights, current_course
+    updates = update_weights_params[:weights].map { |entry| parse_weight_entry(entry) }
+    Course::Gradebook::Contribution.bulk_update(course: current_course, updates: updates)
+    render json: { weights: serialize_weight_updates(updates) }
+  rescue ActiveRecord::RecordInvalid, ActiveRecord::RecordNotFound => e
+    render json: { errors: { base: e.message } }, status: :unprocessable_entity
+  end
+
+  private
+
+  def authorize_read_gradebook!
+    authorize! :read_gradebook, current_course
+  end
+
+  def load_weighted_view_contributions(assessment_ids)
+    @tab_contributions = Course::Gradebook::Contribution.
+                         where(tab_id: @tabs.map(&:id)).index_by(&:tab_id)
+    @assessment_contributions = Course::Gradebook::AssessmentContribution.
+                                where(assessment_id: assessment_ids).index_by(&:assessment_id)
+  end
+
+  def parse_weight_entry(entry)
+    {
+      tab_id: entry[:tabId].to_i,
+      weight: entry[:weight].to_f,
+      weight_mode: entry[:weightMode] || 'equal',
+      keep_highest: entry[:keepHighest].to_i,
+      excluded_assessment_ids: (entry[:excludedAssessmentIds] || []).map(&:to_i),
+      assessment_weights: (entry[:assessmentWeights] || []).map do |aw|
+        { assessment_id: aw[:assessmentId].to_i, weight: aw[:weight].to_f }
+      end
+    }
+  end
+
+  def update_weights_params
+    params.permit(
+      weights: [:tabId, :weight, :weightMode, :keepHighest,
+                excludedAssessmentIds: [], assessmentWeights: [:assessmentId, :weight]]
+    )
+  end
+
+  def serialize_weight_updates(updates)
+    updates.map do |u|
+      entry = { tabId: u[:tab_id], weight: u[:weight], weightMode: u[:weight_mode].to_s,
+                keepHighest: u[:keep_highest],
+                excludedAssessmentIds: u[:excluded_assessment_ids] }
+      if u[:weight_mode].to_s == 'custom'
+        entry[:assessmentWeights] = u[:assessment_weights].map do |aw|
+          { assessmentId: aw[:assessment_id], weight: aw[:weight] }
+        end
+      end
+      entry
+    end
+  end
+
+  def component
+    current_component_host[:course_gradebook_component]
+  end
+
+  def fetch_categories_and_tabs
+    tabs = @published_assessments.map(&:tab).uniq(&:id)
+    [tabs.map(&:category).uniq(&:id), tabs]
+  end
+
+  def fetch_students
+    current_course.levels.to_a
+    current_course.course_users.students.without_phantom_users.
+      calculated(:experience_points).includes(:user).to_a.
+      sort_by { |cu| cu.user.name }
+  end
+
+  def fetch_published_assessments
+    current_course.assessments.
+      published.
+      includes(tab: :category).
+      joins(tab: :category).
+      reorder('course_assessment_categories.weight, course_assessment_tabs.weight, course_assessments.id')
+  end
+end

app/controllers/course/statistics/aggregate_controller.rb

@@ -47,13 +47,6 @@ def activity_get_help
     @course_user_hash = current_course.course_users.index_by(&:user_id)
   end
 
-  def download_score_summary
-    job = Course::Statistics::AssessmentsScoreSummaryDownloadJob.
-          perform_later(current_course, params[:assessment_ids]).job
-
-    render partial: 'jobs/submitted', locals: { job: job }
-  end
-
   private
 
   def sanitize_date_range(start_at_param, end_at_param)

app/models/components/course/gradebook_ability_component.rb

@@ -0,0 +1,11 @@
+# frozen_string_literal: true
+module Course::GradebookAbilityComponent
+  include AbilityHost::Component
+
+  def define_permissions
+    can :read_gradebook, Course, id: course.id if course_user&.staff?
+    can :manage_gradebook_weights, Course, id: course.id if course_user&.manager_or_owner?
+    can :manage_gradebook_settings, Course, id: course.id if course_user&.manager_or_owner?
+    super
+  end
+end

app/models/course.rb

@@ -53,6 +53,8 @@ class Course < ApplicationRecord
                                    dependent: :destroy, inverse_of: :course
   has_many :assessment_tabs, source: :tabs, through: :assessment_categories
   has_many :assessments, through: :assessment_categories
+  has_many :gradebook_contributions, class_name: 'Course::Gradebook::Contribution',
+                                     dependent: :destroy, inverse_of: :course
   has_many :assessment_skills, class_name: 'Course::Assessment::Skill',
                                dependent: :destroy
   has_many :assessment_skill_branches, class_name: 'Course::Assessment::SkillBranch',
@@ -361,11 +363,22 @@ def nearest_forum_discussions(query_embedding, limit: 3)
 
   # Set default values
   def set_defaults
+    set_default_times
+    set_default_timeline
+    build_creator_course_user
+  end
+
+  def set_default_times
     self.start_at ||= Time.zone.now.beginning_of_hour
-    self.end_at ||= self.start_at + 1.month
+    self.end_at ||= start_at + 1.month
+  end
+
+  def set_default_timeline
     self.default_reference_timeline ||= reference_timelines.new(default: true)
     self.default_timeline_algorithm ||= 0 # 'fixed' algorithm
+  end
 
+  def build_creator_course_user
     return unless creator && course_users.empty?
 
     course_users.build(user: creator,

app/models/course/assessment.rb

@@ -79,6 +79,9 @@ class Course::Assessment < ApplicationRecord
                                   inverse_of: :assessment, dependent: :destroy
   has_one :plagiarism_check, class_name: 'Course::Assessment::PlagiarismCheck',
                              inverse_of: :assessment, dependent: :destroy, autosave: true
+  has_one :gradebook_assessment_contribution,
+          class_name: 'Course::Gradebook::AssessmentContribution',
+          dependent: :destroy, inverse_of: :assessment
   has_many :live_feedbacks, class_name: 'Course::Assessment::LiveFeedback',
                             inverse_of: :assessment, dependent: :destroy
   has_many :links, class_name: 'Course::Assessment::Link', inverse_of: :assessment, dependent: :destroy
@@ -160,6 +163,22 @@ def self.use_relative_model_naming?
     true
   end
 
+  # Returns a hash of assessment_id => max_grade (sum of question maximum_grades).
+  def self.max_grades(assessment_ids)
+    return {} if assessment_ids.empty?
+
+    rows = find_by_sql(
+      sanitize_sql_array([<<-SQL.squish, assessment_ids])
+        SELECT cqa.assessment_id, COALESCE(SUM(caq.maximum_grade), 0) AS max_grade
+        FROM course_question_assessments cqa
+        JOIN course_assessment_questions caq ON caq.id = cqa.question_id
+        WHERE cqa.assessment_id IN (?)
+        GROUP BY cqa.assessment_id
+      SQL
+    )
+    rows.to_h { |row| [row.assessment_id, row.max_grade.to_f] }
+  end
+
   def to_partial_path
     'course/assessment/assessments/assessment'
   end
@@ -195,7 +214,7 @@ def update_randomization(params)
   # - The assessment don't have any submissions.
   # - Switching from autograded mode to manually graded mode.
   def allow_mode_switching?
-    submissions.count == 0 || autograded?
+    submissions.none? || autograded?
   end
 
   # @override ConditionalInstanceMethods#permitted_for!

app/models/course/assessment/submission.rb

@@ -323,6 +323,27 @@ def self.on_dependent_status_change(answer)
     answer.submission.last_graded_time = Time.now
   end
 
+  # Returns an array of submission rows for the given students and assessments.
+  # Each row has: student_id (creator_id), assessment_id, grade (float).
+  # Only graded/published submissions are included.
+  def self.grade_summary(student_ids:, assessment_ids:)
+    return [] if student_ids.empty? || assessment_ids.empty?
+
+    find_by_sql(
+      sanitize_sql_array([<<-SQL.squish, student_ids, assessment_ids])
+        SELECT cas.creator_id AS student_id, cas.assessment_id,
+               cas.id AS submission_id, SUM(caa.grade) AS grade
+        FROM course_assessment_submissions cas
+        JOIN course_assessment_answers caa ON caa.submission_id = cas.id
+        WHERE cas.creator_id IN (?)
+          AND cas.assessment_id IN (?)
+          AND cas.workflow_state IN ('graded', 'published')
+          AND caa.current_answer = TRUE
+        GROUP BY cas.creator_id, cas.assessment_id, cas.id
+      SQL
+    )
+  end
+
   private
 
   # Queues the submission for auto grading, after the submission has changed to the submitted state.

app/models/course/assessment/tab.rb

@@ -8,6 +8,9 @@ class Course::Assessment::Tab < ApplicationRecord
 
   belongs_to :category, class_name: 'Course::Assessment::Category', inverse_of: :tabs
   has_many :assessments, class_name: 'Course::Assessment', dependent: :destroy, inverse_of: :tab
+  has_one :gradebook_contribution, class_name: 'Course::Gradebook::Contribution',
+                                   dependent: :destroy, inverse_of: :tab
+
   has_many :folders, class_name: 'Course::Material::Folder', through: :assessments,
                      inverse_of: nil
 
@@ -33,17 +36,25 @@ def other_tabs_remaining?
   end
 
   def initialize_duplicate(duplicator, other)
-    self.category = if duplicator.duplicated?(other.category)
-                      duplicator.duplicate(other.category)
-                    else
-                      duplicator.options[:destination_course].assessment_categories.first
-                    end
-    assessments <<
-      other.assessments.select { |assessment| duplicator.duplicated?(assessment) }.map do |assessment|
-        duplicator.duplicate(assessment).tap do |duplicate_assessment|
-          duplicate_assessment.folder.parent = category.folder
-        end
+    self.category = duplicated_category_for(duplicator, other)
+
+    assessments << duplicated_assessments_for(duplicator, other)
+  end
+
+  def duplicated_category_for(duplicator, other)
+    return duplicator.duplicate(other.category) if duplicator.duplicated?(other.category)
+
+    duplicator.options[:destination_course].assessment_categories.first
+  end
+
+  def duplicated_assessments_for(duplicator, other)
+    other.assessments.filter_map do |assessment|
+      next unless duplicator.duplicated?(assessment)
+
+      duplicator.duplicate(assessment).tap do |duplicate_assessment|
+        duplicate_assessment.folder.parent = category.folder
       end
+    end
   end
 
   private

app/models/course/gradebook.rb

@@ -0,0 +1,6 @@
+# frozen_string_literal: true
+module Course::Gradebook
+  def self.table_name_prefix
+    "#{Course.table_name.singularize}_gradebook_"
+  end
+end

app/models/course/gradebook/assessment_contribution.rb

@@ -0,0 +1,11 @@
+# frozen_string_literal: true
+class Course::Gradebook::AssessmentContribution < ApplicationRecord
+  belongs_to :assessment, class_name: 'Course::Assessment',
+                          inverse_of: :gradebook_assessment_contribution
+
+  validates :creator, presence: true
+  validates :updater, presence: true
+  validates :weight, numericality: { greater_than_or_equal_to: 0 }, allow_nil: true
+  validates :excluded, inclusion: { in: [true, false] }
+  validates :assessment_id, uniqueness: true
+end