classroomio/prd/exercise-sections [DONE]

Exercise Question Sections PRD

Status

• Done (shipped)

Date

• April 30, 2026

Implementation Plan

• See implementation-plan.md for ticket breakdown and delivery sequencing.

Purpose

Allow instructors to group questions inside a single exercise into named sections, so one assignment, quiz, or exam can be structured into logical parts (e.g., "Section A: Multiple Choice", "Section B: Written Responses") with per-section instructions, navigation, and review.

Terminology

• Exercise question section: A grouping inside one exercise. This PRD is about this concept.
• Course section: The existing course content grouping that contains lessons and exercises. This PRD does not change course sections.
• The existing exercise.sectionId field points to a course section. New question-level grouping must use question.exerciseSectionId / DB question.exercise_section_id so the two concepts are not overloaded.

Problem Statement

Today, every exercise is a flat list of questions. Instructors cannot:

1. Organize questions by topic or format — a 30-question exam has no visual grouping, making it harder for students to navigate and for teachers to author.
2. Provide per-section instructions — if Section A requires different rules than Section B, the instructor must embed instructions into individual question prompts.
3. Control post-section flow — there is no way to submit answers after a subset of questions or to route students to a specific next section.
4. Grade or review by section — submissions are a single flat list, so teachers cannot quickly assess performance on distinct parts of an exercise.

Current-State Audit

Area	Current State	Gap
exercise table	Has title, description, and section_id for the parent course section; questions link via question.exercise_id	No internal question-section concept
question table	Has exercise_id, order, title, points, question_type_id	No exercise_section_id or section ordering
Exercise store	questionnaire.questions is a flat Question[]	No section grouping or section metadata
Edit mode UI	Renders all questions in a single vertical list	No section headers, section CRUD, or drag-between-sections
Take mode (view-mode)	Shows one question at a time via currentQuestionIndex on flat array	No section-at-a-time mode, no section overview screen
Question navigation	QuestionNavigation component has onPrevious/onNext with isLast flag	No section awareness
Preview mode	Renders all questions via QuestionList	No section grouping
Submissions/Grading UI	individual.svelte and summary.svelte iterate flat question list	No section-level subtotals
Exercise templates	exercise_template.questionnaire is { questions: [...] } JSON	No sections in template schema
Clone service	cloneExercises copies exercises → questions → options	No section cloning
Progress bar	Computes currentQuestionIndex / questions.length	No section-aware progress

Data Sources Checked

• packages/db/src/schema.ts — exercise, question, questionAnswer, submission, exerciseTemplate tables
• apps/dashboard/src/lib/features/course/components/exercise/store.ts
• apps/dashboard/src/lib/features/course/components/exercise/edit-mode.svelte
• apps/dashboard/src/lib/features/course/components/exercise/view-mode.svelte
• apps/dashboard/src/lib/features/course/components/exercise/preview.svelte
• apps/dashboard/src/lib/features/course/components/exercise/submissions/individual.svelte
• apps/dashboard/src/lib/features/course/components/exercise/submissions/summary.svelte
• apps/dashboard/src/lib/features/course/pages/exercise.svelte
• apps/api/src/services/course/clone.ts
• packages/ui/src/custom/exercise-question/question-navigation.svelte
• packages/ui/src/custom/exercise-question/question-list.svelte
• packages/question-types/src/exercise-types.ts
• prd/exercise-question-types [DONE]/README.md

Primary Users

• Instructors creating structured exams and assignments with logical groupings.
• Students taking exercises and navigating between sections.
• Admins/Tutors grading and reviewing submissions by section.

Goals

1. Allow instructors to create, edit, reorder, and delete sections within an exercise.
2. Allow students to navigate exercises section-by-section with configurable question display (one-at-a-time or all-at-once within a section).
3. Show section-level subtotals alongside overall totals in grading.
4. Support configurable post-section behavior (continue, go to specific section, submit).
5. Let instructors assign lightweight visual color themes to sections for easier scanning while authoring.
6. Maintain full backward compatibility — existing sectionless exercises work unchanged.
7. Support sections in exercise templates and cloning.

Non-Goals (v1)

• Per-section time limits (exercise-level timing does not exist yet; out of scope).
• Per-section scoring weights (section score is the sum of its question points).
• Conditional/branching logic beyond post-section routing (no "if student scored < 50% on Section A, skip to Section C").
• Section-level randomization separate from exercise-level randomization.
• Nested sections (sections within sections).
• Custom arbitrary color pickers. V1 uses a fixed set of color theme swatches.

Proposed Decisions / MVP Assumptions

1. An exercise is either flat questions (no sections) or sections with questions — not a mix of both. If an exercise has sections, every question must belong to a section.
2. A question belongs to exactly one exercise question section. No multi-section membership.
3. Section scoring is the sum of question points within that section — no separate section-level weight multiplier.
4. Student display mode is configurable per exercise: either "one question at a time" (current behavior, but section-aware) or "one section at a time" (all questions in the current section shown together).
5. Students see a section overview screen before beginning each section (section title + description + question count + total points).
6. Students navigate sections linearly by default, but the post-section behavior can route them elsewhere.
7. Post-section behavior options: "Continue to next section" (default), "Go to section [X]" (select from list), "Submit exercise".
8. Progress bar tracks questions completed (not sections). The question navigation sidebar shows questions grouped by section (e.g., "Section 1: Q1, Q2, Q3 | Section 2: Q1, Q2").
9. Grading UI shows submissions grouped by section with per-section subtotals and an overall total.
10. Existing exercises without sections continue to work exactly as they do today. Sections are fully optional.
11. Exercise templates support sections. Exercise cloning preserves sections.
12. Instructors can drag questions between sections, reorder sections, and select which section when adding a new question.
13. Section color themes are cosmetic only. They help authoring and review scanability and do not affect grading, routing, or student eligibility.

---

Functional Requirements

FR-1: Section CRUD (Instructor — Edit Mode)

FR-1.1: Create Section

• Instructor can add a section to an exercise via an "Add Section" button (similar to Google Forms section add).
• When the first section is added to a previously sectionless exercise, all existing questions are automatically moved into "Section 1".
• A new section is created with default title "Untitled Section" and empty description.
• The new section is appended after the last section (or after the current section if contextually clear).

FR-1.2: Edit Section

• Instructor can edit the section title (required, min 1 character).
• Instructor can edit the section description (optional, supports plain text).
• Instructor can choose a section color theme from a fixed set of swatches. The selected theme appears as a dot in the section header and is persisted with the section.
• Instructor can configure the after-section behavior via a compact settings row near the section card when routing is in scope:
  • "Continue to next section" (default)
  • "Go to section [X]" (dropdown listing all other sections by title)
  • "Submit exercise"
• The last section's default after-section behavior is "Submit exercise".

FR-1.3: Delete Section

• Instructor can delete a section.
• When a section is deleted, the instructor is prompted: "Move questions to [other section] or delete them?"
• If the exercise has only one section and it's deleted, the exercise becomes sectionless and all questions remain as a flat list.

FR-1.4: Reorder Sections

• Instructor can reorder sections via drag-and-drop or an order modal (consistent with the existing question reorder pattern).
• When sections are reordered, the order field on each section is updated accordingly.

FR-1.5: Move Questions Between Sections

• Instructor can drag a question from one section to another.
• Instructor can move a question via a context menu: "Move to Section → [list of sections]".
• When adding a new question, the instructor selects which section it belongs to (defaults to the currently focused or last section).

FR-2: Student Experience (Take Mode)

FR-2.1: Section Overview Screen

• Before the first question of each section, the student sees a section overview:
  • Section title
  • Section description (if any)
  • Number of questions in this section
  • Total points available in this section
  • "Begin Section" button
• This mirrors the existing exercise start screen pattern but at the section level.

FR-2.2: Question Display Mode (Configurable)

The exercise has a setting sectionDisplayMode with two options:

• one_question (default): Questions are shown one at a time. The student navigates with Previous/Next buttons. A section header/indicator is visible showing which section the student is in (e.g., "Section 1 of 3 — Multiple Choice"). When the last question of a section is completed, the post-section behavior fires.
• all_questions: All questions in the current section are displayed together in a scrollable list. The student answers all questions and clicks a "Complete Section" button. Post-section behavior then fires.

FR-2.3: Post-Section Behavior

After completing a section:

• "Continue to next section": Show the next section's overview screen.
• "Go to section [X]": Show section X's overview screen.
• "Submit exercise": Submit all answers collected so far and show the completion/grading screen.

If the student finishes the last section and its after-behavior is "Continue to next section" (or not explicitly set), the exercise auto-submits.

FR-2.4: Section-Aware Navigation

• The question navigation UI groups questions by section:

  Section 1: Multiple Choice
    Q1  Q2  Q3  Q4
  
  Section 2: Written Responses
    Q1  Q2
  

• Answered questions are visually distinguished (filled dot, checkmark, etc.).
• The current section and question are highlighted.
• Students can only navigate within the current section (no jumping between sections) unless the exercise allows free navigation (future enhancement, not v1).

FR-2.5: Progress Tracking

• The progress bar reflects total questions answered / total questions across all sections.
• A secondary indicator shows the current section (e.g., "Section 2 of 3").

FR-2.6: Autosave

• Existing autosave behavior extends to section-aware exercises.
• The autosaved state includes which section the student is currently in and which question within that section.
• On resume, the student returns to their last position (correct section and question).

FR-3: Preview Mode (Instructor)

• Preview mode shows questions grouped under section headers.
• Each section header displays the section title and description.
• Questions are numbered within their section (Section 1: Q1, Q2; Section 2: Q1, Q2).

FR-4: Grading & Submissions

FR-4.1: Section-Grouped Grading View

• In the individual student submission view (individual.svelte), questions are grouped under section headers.
• Each section shows a subtotal: "Section 1: 15/20 points".
• An overall total is shown at the top/bottom: "Total: 35/50 points".

FR-4.2: Summary Analytics

• In the summary view (summary.svelte), chart data is grouped by section.
• Each section has its own aggregate view before the overall aggregate.

FR-5: Exercise Templates

• Exercise templates (exercise_template table) support sections in the questionnaire JSONB field.
• Template schema extends to:

  {
    "sections": [
      {
        "title": "Section Title",
        "description": "Optional description",
        "order": 0,
        "colorTheme": "blue",
        "afterBehavior": { "action": "continue" },
        "questions": [{ "title": "...", ... }]
      }
    ],
    "questions": [...]
  }
  

• If sections is present, questions at the root level is empty/ignored.
• If sections is absent, questions is used (backward compatible).

FR-6: Cloning

• The clone service (apps/api/src/services/course/clone.ts) clones exercise sections alongside questions and options.
• Section ordering, titles, descriptions, color themes, and after-behavior settings are preserved.
• Question-to-section mappings are preserved via the section ID map.

---

Technical Design

1. Data Model Changes

1.1: New exercise_section Table

CREATE TABLE exercise_section (
  id          UUID PRIMARY KEY DEFAULT gen_random_uuid(),
  exercise_id UUID NOT NULL REFERENCES exercise(id) ON DELETE CASCADE,
  title       VARCHAR NOT NULL DEFAULT 'Untitled Section',
  description TEXT,
  "order"     BIGINT NOT NULL DEFAULT 0,
  color_theme VARCHAR NOT NULL DEFAULT 'blue',
  after_behavior JSONB NOT NULL DEFAULT '{"action": "continue"}',
  created_at  TIMESTAMPTZ DEFAULT NOW(),
  updated_at  TIMESTAMPTZ DEFAULT NOW()
);

CREATE INDEX idx_exercise_section_exercise_id ON exercise_section(exercise_id);

The after_behavior JSONB stores one of:

// Continue to the next section in order
{ action: 'continue' }

// Jump to a specific section
{ action: 'go_to_section', exerciseSectionId: '<uuid>' }

// Submit the exercise immediately
{ action: 'submit' }

1.2: question Table — Add exercise_section_id

ALTER TABLE question ADD COLUMN exercise_section_id UUID REFERENCES exercise_section(id) ON DELETE SET NULL;
CREATE INDEX idx_question_exercise_section_id ON question(exercise_section_id);

• exercise_section_id is nullable. When NULL, the question belongs to a sectionless exercise (backward compatible).
• When a question is part of a sectioned exercise, exercise_section_id is required (enforced at the application level, not DB constraint, to keep migration safe).

1.3: exercise Table — Add section_display_mode

ALTER TABLE exercise ADD COLUMN section_display_mode VARCHAR DEFAULT 'one_question';

Values: 'one_question' | 'all_questions'

This column is only meaningful when the exercise has sections. For sectionless exercises it is ignored.

1.4: Drizzle Schema Updates

File: packages/db/src/schema.ts

export const exerciseSection = pgTable(
  'exercise_section',
  {
    id: uuid()
      .default(sql`gen_random_uuid()`)
      .primaryKey()
      .notNull(),
    exerciseId: uuid('exercise_id').notNull(),
    title: varchar().notNull().default('Untitled Section'),
    description: text(),
    order: bigint({ mode: 'number' }).notNull().default(0),
    colorTheme: varchar('color_theme').notNull().default('blue'),
    afterBehavior: jsonb('after_behavior')
      .notNull()
      .default({ action: 'continue' })
      .$type<ExerciseSectionAfterBehavior>(),
    createdAt: timestamp('created_at', { withTimezone: true, mode: 'string' }).defaultNow(),
    updatedAt: timestamp('updated_at', { withTimezone: true, mode: 'string' }).defaultNow()
  },
  (table) => [
    foreignKey({
      columns: [table.exerciseId],
      foreignColumns: [exercise.id],
      name: 'exercise_section_exercise_id_fkey'
    }).onDelete('cascade'),
    index('idx_exercise_section_exercise_id').on(table.exerciseId)
  ]
);

Add to question table:

exerciseSectionId: uuid('exercise_section_id'),

Add foreign key in question table constraints:

foreignKey({
  columns: [table.exerciseSectionId],
  foreignColumns: [exerciseSection.id],
  name: 'question_exercise_section_id_fkey'
}).onDelete('set null')

Add to exercise table:

sectionDisplayMode: varchar('section_display_mode').default('one_question'),

1.5: TypeScript Types

File: packages/db/src/types.ts (inferred from schema)

export type TExerciseSection = typeof exerciseSection.$inferSelect;
export type TExerciseSectionInsert = typeof exerciseSection.$inferInsert;

File: packages/question-types/src/exercise-section-types.ts (new)

export type ExerciseSectionAfterAction = 'continue' | 'go_to_section' | 'submit';

export interface ExerciseSectionAfterBehavior {
  action: ExerciseSectionAfterAction;
  exerciseSectionId?: string; // only when action === 'go_to_section'
}

export type ExerciseSectionDisplayMode = 'one_question' | 'all_questions';
export type ExerciseSectionColorTheme = 'blue' | 'green' | 'amber' | 'rose' | 'violet' | 'slate';

export interface ExerciseSectionModel {
  id?: string;
  title: string;
  description?: string | null;
  order: number;
  colorTheme: ExerciseSectionColorTheme;
  afterBehavior: ExerciseSectionAfterBehavior;
  questions: ExerciseQuestionModel[];
}

2. Validation Layer

File: packages/utils/src/validation/exercise/exercise-section.ts (new)

import { z } from 'zod';

export const ZExerciseSectionAfterBehavior = z.discriminatedUnion('action', [
  z.object({ action: z.literal('continue') }),
  z.object({ action: z.literal('go_to_section'), exerciseSectionId: z.string().uuid() }),
  z.object({ action: z.literal('submit') })
]);

export const ZExerciseSection = z.object({
  id: z.string().uuid().optional(),
  title: z.string().min(1, 'Section title is required'),
  description: z.string().optional().nullable(),
  order: z.number().int().min(0),
  colorTheme: z.enum(['blue', 'green', 'amber', 'rose', 'violet', 'slate']).default('blue'),
  afterBehavior: ZExerciseSectionAfterBehavior.default({ action: 'continue' })
});

export const ZExerciseSectionCreate = ZExerciseSection.omit({ id: true });
export const ZExerciseSectionUpdate = ZExerciseSection.partial().required({ id: true });

export type TExerciseSection = z.infer<typeof ZExerciseSection>;
export type TExerciseSectionCreate = z.infer<typeof ZExerciseSectionCreate>;
export type TExerciseSectionUpdate = z.infer<typeof ZExerciseSectionUpdate>;

Extend existing ZExerciseUpdate to accept optional sections array:

export const ZExerciseUpdate = z.object({
  title: z.string().optional(),
  description: z.string().optional(),
  dueBy: z.string().optional(),
  questions: z.array(ZQuestion).optional(),
  sections: z.array(ZExerciseSection).optional(),
  sectionDisplayMode: z.enum(['one_question', 'all_questions']).optional()
});

3. Database Queries

File: packages/db/src/queries/exercise/exercise-section.ts (new)

Required query functions:

Function	Description
getExerciseSectionsByExerciseId(exerciseId)	Fetch all sections for an exercise, ordered by order
createExerciseSections(sections[])	Bulk insert sections, return created rows
updateExerciseSection(exerciseSectionId, data)	Update a single section's title, description, colorTheme, order, or afterBehavior
deleteExerciseSection(exerciseSectionId)	Delete a section (questions cascade to exercise_section_id = NULL)
reorderExerciseSections(exerciseId, orderedIds[])	Batch update order field for all sections
moveQuestionToSection(questionId, exerciseSectionId)	Update a question's exercise_section_id
bulkMoveQuestionsToSection(questionIds[], exerciseSectionId)	Move multiple questions to a section

4. API Layer Changes

4.1: Exercise Fetch — Include Sections

When fetching an exercise (GET /course/:courseId/exercise/:exerciseId), the response includes sections:

{
  id: string;
  title: string;
  description: string;
  sectionDisplayMode: 'one_question' | 'all_questions';
  sections: Array<{
    id: string;
    title: string;
    description: string | null;
    order: number;
    colorTheme: 'blue' | 'green' | 'amber' | 'rose' | 'violet' | 'slate';
    afterBehavior: { action: string; exerciseSectionId?: string };
    questions: Array<{ /* existing question shape */ }>;
  }>;
  questions: Array<{ /* questions without sections (backward compat) */ }>;
}

• If the exercise has sections, sections is populated and questions only contains ungrouped questions (should be empty for a properly formed sectioned exercise).
• If the exercise has no sections, sections is an empty array and questions contains all questions (current behavior preserved).

4.2: Exercise Update — Accept Sections

The PUT /course/:courseId/exercise/:exerciseId endpoint accepts an optional sections array:

{
  title?: string;
  description?: string;
  dueBy?: string;
  sectionDisplayMode?: 'one_question' | 'all_questions';
  sections?: Array<{
    id?: string;       // present for existing sections, absent for new
    title: string;
    description?: string;
    order: number;
    colorTheme?: 'blue' | 'green' | 'amber' | 'rose' | 'violet' | 'slate';
    afterBehavior: { action: string; exerciseSectionId?: string };
    questionIds: string[];  // ordered list of question IDs in this section
  }>;
  questions?: Array<{ /* existing question update shape */ }>;
}

Service logic:

1. Upsert sections (create new, update existing, delete removed).
2. Update question.exercise_section_id for each question based on questionIds in each section.
3. Update question.order within each section.
4. Validate that all go_to_section references point to valid section IDs within the same exercise.
5. Validate that if sections exist, every non-deleted question has a section assignment.

4.3: Exercise Submission — Section-Aware

No changes to the submission API shape. Students still submit a flat array of { questionId, optionId?, answer? }. The server groups answers by section for grading display, not at submission time.

4.4: Submission Fetch — Section-Grouped Response

When fetching submissions for grading, the API returns section groupings:

{
  sections: Array<{
    exerciseSectionId: string;
    sectionTitle: string;
    subtotal: number;
    maxPoints: number;
    answers: Array<{ /* per-question answer + grade */ }>;
  }>;
  totalScore: number;
  maxScore: number;
}

For sectionless exercises, sections is a single entry with no section metadata (backward compatible).

5. Clone Service Changes

File: apps/api/src/services/course/clone.ts

Update cloneExercises to:

1. After creating new exercises, fetch sections for all old exercises.
2. Create a section ID map (old → new).
3. Bulk insert new sections with the new exercise IDs.
4. When cloning questions, include the mapped exerciseSectionId.

// Pseudocode addition to cloneExercises():
const oldExerciseIds = oldExercises.map((ex) => ex.id);
const oldSections = await getExerciseSectionsByExerciseIds(oldExerciseIds);

if (oldSections.length > 0) {
  const newSections = await createExerciseSections(
    oldSections.map((section) => ({
      title: section.title,
      description: section.description,
      order: section.order,
      colorTheme: section.colorTheme,
      afterBehavior: section.afterBehavior,
      exerciseId: exerciseIdMap.get(section.exerciseId)!
    }))
  );

  const exerciseSectionIdMap = new Map<string, string>();
  oldSections.forEach((oldSection, index) => {
    exerciseSectionIdMap.set(oldSection.id, newSections[index].id);
  });

  // When cloning questions, include mapped exerciseSectionId:
  // exerciseSectionId: question.exerciseSectionId ? exerciseSectionIdMap.get(question.exerciseSectionId) : null
}

Update afterBehavior references: if a section's afterBehavior.action === 'go_to_section', remap the exerciseSectionId using the section ID map.

6. Exercise Template Changes

File: packages/db/src/schema.ts — exerciseTemplate

Extend the questionnaire JSONB type:

questionnaire: jsonb().default({}).$type<{
  sections?: Array<{
    title: string;
    description?: string;
    order: number;
    colorTheme?: string;
    afterBehavior: { action: string; exerciseSectionId?: string };
    questions: Array<{
      title: string;
      name: string;
      points: number;
      order: number;
      question_type: { id: number; label: string };
      options: Array<{ label: string; is_correct: boolean }>;
    }>;
  }>;
  questions: Array<{ /* existing shape */ }>;
}>()

7. Dashboard Store Changes

File: apps/dashboard/src/lib/features/course/components/exercise/store.ts

7.1: Extend Questionnaire Store

export interface ExerciseSectionState {
  id: string;
  title: string;
  description: string | null;
  order: number;
  colorTheme: ExerciseSectionColorTheme;
  afterBehavior: ExerciseSectionAfterBehavior;
  isDirty?: boolean;
  deletedAt?: string;
}

export const questionnaire: Writable<{
  title?: string | null;
  dueBy?: string | null;
  isDueByDirty?: boolean;
  isTitleDirty?: boolean;
  description?: string | null;
  isDescriptionDirty?: boolean;
  questions: Question[];
  sections: ExerciseSectionState[];
  sectionDisplayMode: ExerciseSectionDisplayMode;
  totalSubmissions: number;
}> = writable({
  title: '',
  dueBy: '',
  isDueByDirty: false,
  isTitleDirty: false,
  description: '',
  isDescriptionDirty: false,
  questions: [],
  sections: [],
  sectionDisplayMode: 'one_question',
  totalSubmissions: 0
});

7.2: Extend Question Type

Add exerciseSectionId to the Question type:

export type Question = Omit<ApiQuestion, 'options'> & {
  isDirty?: boolean;
  deletedAt?: string;
  exerciseSectionId?: string | null;
  options: QuestionOption[];
};

7.3: Extend Metadata Store

const initAnswerState = {
  answers: {},
  scores: {},
  grades: {},
  totalPossibleGrade: 0,
  finalTotalGrade: 0,
  currentQuestionIndex: 0,
  currentSectionIndex: 0,        // NEW
  sectionPhase: 'overview',      // NEW: 'overview' | 'questions' | 'completed'
  isFinished: false,
  progressValue: 0,
  status: STATUS.PENDING,
  comment: '',
  exerciseId: null as string | null
};

7.4: New Store Helper Functions

export function handleAddSection() {
  questionnaire.update((q) => {
    const newSection: ExerciseSectionState = {
      id: `${Date.now()}-section-form`,
      title: 'Untitled Section',
      description: null,
      order: q.sections.length,
      colorTheme: 'blue',
      afterBehavior: { action: 'continue' },
      isDirty: true
    };
    return { ...q, sections: [...q.sections, newSection] };
  });
}

export function handleRemoveSection(exerciseSectionId: string, moveQuestionsToExerciseSectionId?: string) {
  questionnaire.update((q) => {
    const section = q.sections.find((s) => s.id === exerciseSectionId);
    if (!section) return q;

    let updatedQuestions = q.questions;
    if (moveQuestionsToExerciseSectionId) {
      updatedQuestions = q.questions.map((question) =>
        question.exerciseSectionId === exerciseSectionId
          ? { ...question, exerciseSectionId: moveQuestionsToExerciseSectionId, isDirty: true }
          : question
      );
    } else {
      updatedQuestions = q.questions.map((question) =>
        question.exerciseSectionId === exerciseSectionId
          ? { ...question, deletedAt: new Date().toString() }
          : question
      );
    }

    return {
      ...q,
      sections: q.sections.map((s) =>
        s.id === exerciseSectionId ? { ...s, deletedAt: new Date().toString() } : s
      ),
      questions: updatedQuestions
    };
  });
}

export function handleMoveQuestionToSection(questionId: string, exerciseSectionId: string) {
  questionnaire.update((q) => ({
    ...q,
    questions: q.questions.map((question) =>
      question.id === questionId
        ? { ...question, exerciseSectionId, isDirty: true }
        : question
    )
  }));
}

export function handleUpdateSectionAfterBehavior(
  exerciseSectionId: string,
  afterBehavior: ExerciseSectionAfterBehavior
) {
  questionnaire.update((q) => ({
    ...q,
    sections: q.sections.map((section) =>
      section.id === exerciseSectionId
        ? { ...section, afterBehavior, isDirty: true }
        : section
    )
  }));
}

export function getQuestionsForSection(
  questions: Question[],
  exerciseSectionId: string
): Question[] {
  return questions
    .filter((q) => q.exerciseSectionId === exerciseSectionId && !q.deletedAt)
    .sort((a, b) => (a.order ?? 0) - (b.order ?? 0));
}

export function hasSections(sections: ExerciseSectionState[]): boolean {
  return sections.filter((s) => !s.deletedAt).length > 0;
}

8. Dashboard UI Changes

8.1: Edit Mode — Section Cards

File: apps/dashboard/src/lib/features/course/components/exercise/edit-mode.svelte

When sections exist, render questions inside section cards with three distinct zones:

┌────────────────────────────────────────────────────────┐
│ ⋮⋮  ● [Section title input              ] [3 questions] × │  Header
│     ● ● ● ● ●                                                │  Color swatches
├────────────────────────────────────────────────────────┤
│  ┌─ Question sub-card ──────────────────────────────┐  │
│  │ Q1: What is...                         [Radio ▼] │  │
│  └──────────────────────────────────────────────────┘  │
│  ┌─ Question sub-card ──────────────────────────────┐  │  Content
│  │ Q2: Explain...                       [Textarea ▼]│  │
│  └──────────────────────────────────────────────────┘  │
│                         [ + Add question ]             │
├────────────────────────────────────────────────────────┤
│  3 required questions                         [↑] [↓]  │  Footer
└────────────────────────────────────────────────────────┘

[ + Add Section ]

Header:

• Sits on a secondary background to visually separate it from the white content area.
• Contains, from left to right: drag handle, color theme dot, editable title input, color swatches, question count badge, and remove button.
• The title input should visually blend into the header background until focused.
• Color swatches update the section's colorTheme; the dot reflects the selected theme.

Content:

• Sits on the primary white background with comfortable padding.
• Renders question items stacked vertically.
• Each question item is its own bordered sub-card.
• A centered "Add question" button appears below the question list and appends a new question to that section.

Footer:

• Separated from content by a top border.
• Shows a small muted required-question count on the left. Until optional questions ship, this count equals the active question count.
• Shows small up/down arrow icon buttons on the right for moving the section within the exercise.

If post-section routing remains in v1, render the "After section N" control as a compact settings row above the footer or in section settings. Do not overload the footer, which is reserved for required count and section reorder controls. If section descriptions remain in v1, expose description editing in an expandable section settings area rather than in the compact header. Questions can be dragged between sections, with context-menu movement as a fallback.

8.2: New Dashboard Component — SectionEditor

File: apps/dashboard/src/lib/features/course/components/exercise/section-editor.svelte (new)

interface Props {
  exerciseSectionId: string;
  title: string;
  sectionNumber: number;
  totalSections: number;
  colorTheme: ExerciseSectionColorTheme;
  questionCount: number;
  requiredQuestionCount: number;
  onTitleChange: (title: string) => void;
  onColorThemeChange: (theme: ExerciseSectionColorTheme) => void;
  onAddQuestion: () => void;
  onDelete: () => void;
  onMoveUp: () => void;
  onMoveDown: () => void;
  canMoveUp: boolean;
  canMoveDown: boolean;
}

• Renders the three-zone edit-mode section card described above.
• Reuses existing question editor markup in the content zone.
• Uses existing UI primitives for buttons, inputs, badges, and icon buttons.
• Keep take/preview/read-only section headers separate from this editor component so student-facing screens do not inherit authoring controls.

8.3: New Shared UI Component — SectionAfterBehavior

File: packages/ui/src/custom/exercise-question/section-after-behavior.svelte (new)

A dropdown component that renders the "After section N" routing control. It should be visually adjacent to the section editor, but not inside the section editor footer.

interface Props {
  exerciseSectionId: string;
  allSections: Array<{ id: string; title: string }>;
  afterBehavior: ExerciseSectionAfterBehavior;
  onChange: (behavior: ExerciseSectionAfterBehavior) => void;
  labels: {
    afterSectionPrefix: string;  // "After section"
    continue: string;            // "Continue to next section"
    goToSection: string;         // "Go to section"
    submit: string;              // "Submit exercise"
  };
}

8.4: View Mode — Section-Aware Navigation

File: apps/dashboard/src/lib/features/course/components/exercise/view-mode.svelte

State machine for sectioned exercise student flow:

START → Section Overview (section 0) → Questions (section 0)
     → [after-behavior] → Section Overview (section 1) → Questions (section 1)
     → [after-behavior] → ... → Submit → Finished

Key state variables:

currentSectionIndex: number;    // which section the student is on
sectionPhase: 'overview' | 'questions' | 'completed';
currentQuestionIndex: number;   // within the current section

When sectionPhase === 'overview': render the SectionHeader in take mode with a "Begin Section" button. When sectionPhase === 'questions': render questions using existing QuestionRenderer / QuestionNavigation. When the last question in a section is answered: evaluate afterBehavior and transition.

8.5: Updated QuestionNavigation Component

File: packages/ui/src/custom/exercise-question/question-navigation.svelte

Add section-awareness:

interface Props {
  // ... existing props ...
  sectionLabel?: string;           // e.g., "Section 1 of 3"
  completeSectionLabel?: string;   // e.g., "Complete Section" (for all_questions mode)
  onCompleteSection?: () => void;
}

8.6: New Shared UI Component — SectionNavigationSidebar

File: packages/ui/src/custom/exercise-question/section-navigation-sidebar.svelte (new)

A sidebar/panel that shows the section-grouped question map:

interface Props {
  sections: Array<{
    id: string;
    title: string;
    questions: Array<{
      key: string;
      label: string;      // "Q1", "Q2"
      isAnswered: boolean;
      isCurrent: boolean;
    }>;
    isCurrent: boolean;
  }>;
}

Rendered as:

Section 1: Multiple Choice
  [●] Q1  [●] Q2  [○] Q3  [○] Q4

Section 2: Written Responses
  [○] Q1  [○] Q2

Where ● = answered, ○ = unanswered, and the current question is highlighted.

8.7: Preview Mode — Section-Grouped

File: apps/dashboard/src/lib/features/course/components/exercise/preview.svelte

When sections exist, group questions under section headers:

{#each activeSections as section, sectionIndex}
  <SectionHeader
    title={section.title}
    description={section.description}
    sectionNumber={sectionIndex + 1}
    totalSections={activeSections.length}
    colorTheme={section.colorTheme}
    questionCount={getQuestionsForSection(questions, section.id).length}
    totalPoints={getSectionPoints(questions, section.id)}
    mode="preview"
  />
  {#each getQuestionsForSection(questions, section.id) as question, qIndex}
    <QuestionRenderer ... />
  {/each}
{/each}

8.8: Grading Views — Section-Grouped

File: apps/dashboard/src/lib/features/course/components/exercise/submissions/individual.svelte

When sections exist, wrap question rendering in section groups:

{#each activeSections as section}
  <div class="section-group">
    <h3>{section.title}</h3>
    {#each getQuestionsForSection(questions, section.id) as q, i}
      <QuestionRenderer ... />
    {/each}
    <div class="section-subtotal">
      Section: {sectionScore}/{sectionMaxPoints} points
    </div>
  </div>
{/each}
<div class="overall-total">
  Total: {totalScore}/{totalMaxPoints} points
</div>

File: apps/dashboard/src/lib/features/course/components/exercise/submissions/summary.svelte

Group chart data by section, rendering a section header before each section's question charts.

9. Translation Keys

File: apps/dashboard/src/lib/utils/translations/en.json

Add under course.navItem.lessons.exercises.all_exercises:

{
  "section.add": "Add Section",
  "section.untitled": "Untitled Section",
  "section.description_placeholder": "Description (optional)",
  "section.delete": "Delete Section",
  "section.delete_confirm": "What should happen to the questions in this section?",
  "section.delete_move": "Move to another section",
  "section.delete_remove": "Delete questions",
  "section.move_up": "Move section up",
  "section.move_down": "Move section down",
  "section.drag": "Drag section",
  "section.reorder": "Reorder Sections",
  "section.question_count": "{count} questions",
  "section.required_count": "{count} required questions",
  "section.color_theme": "Section color",
  "section.after_behavior_prefix": "After section",
  "section.after_continue": "Continue to next section",
  "section.after_go_to": "Go to section",
  "section.after_submit": "Submit exercise",
  "section.overview_begin": "Begin Section",
  "section.overview_questions": "questions",
  "section.overview_points": "points",
  "section.of": "of",
  "section.complete": "Complete Section",
  "section.display_mode_label": "Question display within sections",
  "section.display_mode_one": "One question at a time",
  "section.display_mode_all": "All questions at once",
  "section.subtotal": "Section subtotal",
  "section.move_question_to": "Move to section",
  "section.add_question_to": "Add question to section",
  "section.nav_label": "Section {number} of {total}"
}

10. Backward Compatibility

Scenario	Behavior
Existing exercise, no sections	sections array is empty. All code paths fall through to existing flat-question logic. No migration needed.
Existing exercise, first section added	All questions auto-assigned to "Section 1". exerciseSectionId set on all questions.
Sectioned exercise, last section deleted	All questions become sectionless. exerciseSectionId set to NULL. Exercise reverts to flat mode.
Old API clients that don't send sections	sections field is optional in update payload. Omitting it means "don't change sections."
Exercise templates without sections	sections field is absent in JSONB. Template import uses questions array (current behavior).

---

Migration Plan

Database Migration

1. Create exercise_section table.
2. Add exercise_section_id column to question table (nullable, FK to exercise_section).
3. Add section_display_mode column to exercise table (default 'one_question').
4. Add color_theme to exercise_section with default 'blue'.
5. Add index on question.exercise_section_id.
6. No data migration needed — existing exercises remain sectionless.

Rollout Strategy

1. Feature flag: exercise_sections_enabled (off by default).
2. Deploy database migration first (additive, no breaking changes).
3. Deploy API changes (backward compatible — sections are optional in all endpoints).
4. Deploy dashboard changes behind feature flag.
5. Enable flag for internal testing.
6. Gradual rollout to all users.

---

File Change Manifest

New Files

File	Description
packages/db/src/queries/exercise/exercise-section.ts	CRUD queries for exercise sections
packages/utils/src/validation/exercise/exercise-section.ts	Zod schemas for section validation
packages/question-types/src/exercise-section-types.ts	TypeScript types for sections
packages/ui/src/custom/exercise-question/section-header.svelte	Read-only section header for take/preview/view modes
packages/ui/src/custom/exercise-question/section-after-behavior.svelte	After-section behavior dropdown
packages/ui/src/custom/exercise-question/section-navigation-sidebar.svelte	Section-grouped question nav
apps/dashboard/src/lib/features/course/components/exercise/section-editor.svelte	Section editing card (edit mode)
apps/dashboard/src/lib/features/course/components/exercise/section-overview.svelte	Section overview screen (take mode)
apps/dashboard/src/lib/features/course/components/exercise/section-delete-modal.svelte	Section deletion confirmation

Modified Files

File	Changes
packages/db/src/schema.ts	Add exerciseSection table with colorTheme, exerciseSectionId to question, sectionDisplayMode to exercise
packages/db/src/queries/exercise/index.ts	Export new section queries
packages/question-types/src/index.ts	Export exercise-section-types
packages/ui/src/custom/exercise-question/index.ts	Export new section components
packages/ui/src/custom/exercise-question/question-navigation.svelte	Add section-aware props
packages/ui/src/custom/exercise-question/question-list.svelte	Support section-grouped rendering
apps/api/src/routes/course/exercise.ts	Accept/return sections in exercise endpoints
apps/api/src/services/exercise/exercise.ts	Section upsert logic in exercise update
apps/api/src/services/course/clone.ts	Clone sections, remap IDs and afterBehavior references
apps/dashboard/src/lib/features/course/components/exercise/store.ts	Add sections, sectionDisplayMode, colorTheme, section helpers
apps/dashboard/src/lib/features/course/components/exercise/edit-mode.svelte	Render section-grouped editor
apps/dashboard/src/lib/features/course/components/exercise/view-mode.svelte	Section-aware take flow
apps/dashboard/src/lib/features/course/components/exercise/preview.svelte	Section-grouped preview
apps/dashboard/src/lib/features/course/components/exercise/submissions/individual.svelte	Section-grouped grading
apps/dashboard/src/lib/features/course/components/exercise/submissions/summary.svelte	Section-grouped analytics
apps/dashboard/src/lib/features/course/pages/exercise.svelte	"Add Section" button, section display mode setting
apps/dashboard/src/lib/features/course/types.ts	Extend Question with exerciseSectionId
apps/dashboard/src/lib/utils/translations/en.json	Section-related translation keys

---

Testing Requirements

API

• Section CRUD operations (create, read, update, delete).
• Exercise update with sections — questions correctly assigned to sections.
• Exercise fetch returns sections with nested questions in correct order.
• After-behavior validation — go_to_section must reference a valid section.
• Clone service preserves sections, question mappings, and remaps afterBehavior exerciseSectionIds.
• Backward compat: exercise without sections works identically to before.
• Submission fetch returns section-grouped data when sections exist.

Dashboard

• Edit mode: add/edit/delete/reorder sections.
• Edit mode: drag question between sections.
• Edit mode: add question to specific section.
• Edit mode: after-behavior dropdown shows correct options and persists selection.
• Edit mode: deleting a section with "move questions" moves them correctly.
• Take mode (one_question): section overview → questions one at a time → post-section behavior.
• Take mode (all_questions): section overview → all questions shown → complete section → post-section behavior.
• Take mode: progress bar reflects total questions across all sections.
• Take mode: section navigation sidebar shows correct grouping and answered state.
• Take mode: autosave preserves section + question position on resume.
• Preview mode: questions grouped under section headers.
• Grading: individual view shows section subtotals.
• Grading: summary view shows section-grouped charts.

Regression

• Existing sectionless exercises: all CRUD, take, preview, grading flows unchanged.
• Exercise cloning without sections works as before.
• Exercise templates without sections work as before.

---

Build and Verification Commands

pnpm --filter @cio/db build
pnpm --filter @cio/utils build
pnpm --filter @cio/question-types build
pnpm --filter @cio/ui build
pnpm --filter @cio/api build
pnpm --filter @cio/dashboard build

---

Success Metrics (90 Days Post-Launch)

1. 30% of newly created exercises with 10+ questions use at least one section.
2. Students report improved navigation experience in sectioned exercises (qualitative feedback).
3. Grading time for sectioned exercises is comparable to flat exercises (no regression).
4. Zero backward-compatibility incidents for existing exercises.

---

Risks and Mitigations

Risk	Mitigation
Section-aware state machine in take mode adds complexity and potential navigation bugs	Comprehensive state machine tests; keep flat-exercise code path untouched
After-behavior "go to section" can create loops (A→B→A)	Validate at save time: warn if cycles detected, but allow (instructor may want loops intentionally for review)
Drag-and-drop between sections may be unreliable on mobile	Provide "Move to section" context menu as a fallback; drag-drop is enhancement only
Large exercises with many sections may slow down the editor	Lazy-render collapsed sections; only expand the active section
Clone service must remap afterBehavior.exerciseSectionId references	Explicit remap step in clone logic with validation

---

Open Questions

1. Should v1 include Google Forms-style post-section routing, or should v1 only support linear sections with submit at the end?
2. Should we support a "section shuffle" mode (randomize section order) independently of question shuffle?
3. Should the section navigation sidebar be collapsible or always visible during take mode?
4. Should after-behavior "Go to section X" carry over answered data, or should the target section reset?