E2606 Final Project Backend PR

app/controllers/export_controller.rb

@@ -0,0 +1,151 @@
+# This controller handles exporting data from the application to various formats.
+class ExportController < ApplicationController
+  SUPPORTED_EXPORT_CLASSES = {
+    "User" => User,
+    "Team" => Team,
+    "CourseParticipant" => CourseParticipant,
+    "AssignmentParticipant" => AssignmentParticipant,
+    "ProjectTopic" => ProjectTopic,
+    "Questionnaire" => Questionnaire,
+    "Item" => Item,
+    "QuestionAdvice" => QuestionAdvice
+  }.freeze
+
+  before_action :export_params
+
+  def resolve_export_class(name)
+    SUPPORTED_EXPORT_CLASSES[name.to_s]
+  end
+
+  def index
+    klass = resolve_export_class(params[:class])
+    raise ArgumentError, "Unsupported export class: #{params[:class]}" if klass.nil?
+
+    render json: export_metadata_for(klass), status: :ok
+  rescue StandardError => e
+    render json: { error: e.message }, status: :unprocessable_entity
+  end
+
+  def export
+    # Parse ordered fields from JSON, if provided
+    ordered_fields =
+      begin
+        JSON.parse(params[:ordered_fields]) if params[:ordered_fields]
+      rescue JSON::ParserError
+        render json: { error: "Invalid JSON for ordered_fields" }, status: :unprocessable_entity
+        return
+      end
+
+    klass = resolve_export_class(params[:class])
+    raise ArgumentError, "Unsupported export class: #{params[:class]}" if klass.nil?
+
+    csv_file = if klass == Team
+                 Team.with_assignment_context(params[:assignment_id]) do
+                   Export.perform(klass, ordered_fields)
+                 end
+               elsif klass == AssignmentParticipant
+                 # AssignmentParticipant export should include only the
+                 # participants for the selected assignment.
+                 AssignmentParticipant.with_assignment_context(params[:assignment_id], current_user) do
+                   named_export_files(Export.perform(klass, ordered_fields), assignment_participant_export_name(params[:assignment_id]))
+                 end
+               elsif klass == CourseParticipant
+                 # CourseParticipant export should include only the
+                 # participants for the selected course.
+                 CourseParticipant.with_course_context(params[:course_id], current_user) do
+                   named_export_files(Export.perform(klass, ordered_fields), course_participant_export_name(params[:course_id]))
+                 end
+               elsif klass == ProjectTopic
+                 ProjectTopic.with_assignment_context(params[:assignment_id]) do
+                   Export.perform(klass, ordered_fields)
+                 end
+               else
+                 Export.perform(klass, ordered_fields)
+               end
+
+    render json: {
+      message: "#{params[:class]} has been exported!",
+      file: csv_file
+    }, status: :ok
+
+  rescue StandardError => e
+    render json: { error: e.message }, status: :unprocessable_entity
+  end
+
+  private
+
+  def export_params
+    params.permit(:class, :ordered_fields, :assignment_id, :course_id)
+  end
+
+  def export_metadata_for(klass)
+    # The participant CSV intentionally exposes username only. Other user
+    # details are previewed from the users table but not exported as input.
+    if klass == AssignmentParticipant
+      AssignmentParticipant.with_assignment_context(params[:assignment_id], current_user) do
+        return {
+          mandatory_fields: klass.mandatory_fields,
+          optional_fields: klass.optional_fields,
+          external_fields: klass.external_fields
+        }
+      end
+    end
+
+    if klass == CourseParticipant
+      CourseParticipant.with_course_context(params[:course_id], current_user) do
+        return {
+          mandatory_fields: klass.mandatory_fields,
+          optional_fields: klass.optional_fields,
+          external_fields: klass.external_fields
+        }
+      end
+    end
+
+    if klass == Team
+      Team.with_assignment_context(params[:assignment_id]) do
+        return {
+          mandatory_fields: klass.mandatory_fields,
+          optional_fields: klass.optional_fields,
+          external_fields: klass.external_fields
+        }
+      end
+    end
+
+    if klass == ProjectTopic
+      ProjectTopic.with_assignment_context(params[:assignment_id]) do
+        return {
+          mandatory_fields: klass.mandatory_fields,
+          optional_fields: klass.optional_fields,
+          external_fields: klass.external_fields
+        }
+      end
+    end
+
+    {
+      mandatory_fields: klass.mandatory_fields,
+      optional_fields: klass.optional_fields,
+      external_fields: klass.external_fields
+    }
+  end
+
+  # Scoped participant exports use readable filenames while keeping the CSV
+  # body limited to import-friendly fields such as username.
+  def named_export_files(files, name)
+    Array(files).map { |file| file.merge(name: name) }
+  end
+
+  def assignment_participant_export_name(assignment_id)
+    assignment = Assignment.find_by(id: assignment_id)
+    scoped_export_name('AssignmentParticipant', assignment&.name, assignment_id)
+  end
+
+  def course_participant_export_name(course_id)
+    course = Course.find_by(id: course_id)
+    scoped_export_name('CourseParticipant', course&.name, course_id)
+  end
+
+  def scoped_export_name(base_name, scope_name, scope_id)
+    parts = [base_name, scope_name.presence || 'scope', scope_id.presence].compact
+    parts.join('_').parameterize(separator: '_')
+  end
+end

app/controllers/grades_controller.rb

@@ -1,12 +1,17 @@
+require 'csv'
+
 class GradesController < ApplicationController
     include GradesHelper
 
+    GRADES_EXPORT_HEADERS = %w[username grade comment].freeze
+    GRADES_EXPORT_OPTIONAL_HEADERS = %w[email].freeze
+
     def action_allowed?
         case params[:action]
         when 'view_our_scores','view_my_scores'
             set_participant_and_team_via_assignment
             current_user_is_assignment_participant?(params[:assignment_id])
-        when 'view_all_scores', 'get_review_tableau_data'
+        when 'view_all_scores', 'get_review_tableau_data', 'export'
             current_user_teaching_staff_of_assignment?(params[:assignment_id])
         when 'edit', 'assign_grade', 'instructor_review'
             set_team_and_assignment_via_participant
@@ -37,6 +42,20 @@ def view_all_scores
         }
     end
 
+    # export (GET /grades/:assignment_id/export)
+    # Exports fixed, gradebook-friendly CSV columns for an assignment.
+    def export
+        assignment = Assignment.find(params[:assignment_id])
+        filename = "#{assignment.name.parameterize.presence || 'assignment'}-grades.csv"
+
+        send_data(
+            grades_csv_for(assignment, include_email: include_email_in_grades_export?),
+            type: 'text/csv; charset=utf-8',
+            disposition: 'attachment',
+            filename: filename
+        )
+    end
+
 
     # view_our_scores (GET /grades/:assignment_id/view_our_scores)
     # similar to view but scoped to the requesting student’s own team.
@@ -245,6 +264,32 @@ def set_participant_and_team_via_assignment
         @assignment = @participant.assignment
     end
 
+    # Export one row per assignment participant. A participant-specific grade
+    # overrides the team submission grade; submission comments remain team-level.
+    def grades_csv_for(assignment, include_email: false)
+        headers = GRADES_EXPORT_HEADERS + (include_email ? GRADES_EXPORT_OPTIONAL_HEADERS : [])
+
+        CSV.generate(headers: true) do |csv|
+            csv << headers
+
+            assignment.participants.includes(:user).find_each do |participant|
+                team = participant.team
+                row = [
+                    participant.user_name,
+                    participant.grade || team&.grade_for_submission,
+                    team&.comment_for_submission
+                ]
+                row << participant.user&.email if include_email
+
+                csv << row
+            end
+        end
+    end
+
+    def include_email_in_grades_export?
+        ActiveModel::Type::Boolean.new.cast(params[:include_email])
+    end
+
 
     # returns the heatgrid data required for a team to view their scores and average score of their work for an assignment
     def get_our_scores_data(team)
@@ -374,4 +419,4 @@ def get_answer(score, index)
             reviewee_name: reviewee_name
         }
     end 
-end
+end