Boost Azure Demo

2026-05-25 17:05:06 +01:00
parent 675285e99d
commit 4f79137d89
230 changed files with 43275 additions and 2644 deletions
--- a/Backend/db/migrations/001_init.sql
+++ b/Backend/db/migrations/001_init.sql
@@ -0,0 +1,160 @@
+-- +goose Up
+CREATE TYPE user_role AS ENUM ('student', 'teacher');
+CREATE TYPE question_status AS ENUM ('draft', 'published', 'archived');
+CREATE TYPE assignment_status AS ENUM ('draft', 'assigned', 'closed');
+CREATE TYPE answer_status AS ENUM ('not_started', 'in_progress', 'submitted', 'reviewed');
+
+CREATE TABLE users (
+    id BIGSERIAL PRIMARY KEY,
+    email VARCHAR(255) NOT NULL UNIQUE,
+    password_hash TEXT,
+    role user_role NOT NULL,
+    full_name VARCHAR(255) NOT NULL,
+    is_active BOOLEAN NOT NULL DEFAULT TRUE,
+    created_at TIMESTAMPTZ NOT NULL DEFAULT NOW(),
+    updated_at TIMESTAMPTZ NOT NULL DEFAULT NOW()
+);
+
+CREATE TABLE classrooms (
+    id BIGSERIAL PRIMARY KEY,
+    teacher_id BIGINT NOT NULL REFERENCES users(id) ON DELETE CASCADE,
+    name VARCHAR(255) NOT NULL,
+    code VARCHAR(50) UNIQUE,
+    description TEXT,
+    created_at TIMESTAMPTZ NOT NULL DEFAULT NOW(),
+    updated_at TIMESTAMPTZ NOT NULL DEFAULT NOW()
+);
+
+CREATE TABLE classroom_students (
+    classroom_id BIGINT NOT NULL REFERENCES classrooms(id) ON DELETE CASCADE,
+    student_id BIGINT NOT NULL REFERENCES users(id) ON DELETE CASCADE,
+    joined_at TIMESTAMPTZ NOT NULL DEFAULT NOW(),
+    PRIMARY KEY (classroom_id, student_id)
+);
+
+CREATE TABLE questions (
+    id BIGSERIAL PRIMARY KEY,
+    author_teacher_id BIGINT NOT NULL REFERENCES users(id) ON DELETE RESTRICT,
+    title VARCHAR(255) NOT NULL,
+    prompt TEXT NOT NULL,
+    subject VARCHAR(100),
+    source TEXT,
+    status question_status NOT NULL DEFAULT 'draft',
+    created_at TIMESTAMPTZ NOT NULL DEFAULT NOW(),
+    updated_at TIMESTAMPTZ NOT NULL DEFAULT NOW()
+);
+
+CREATE TABLE tags (
+    id BIGSERIAL PRIMARY KEY,
+    name VARCHAR(100) NOT NULL UNIQUE,
+    created_at TIMESTAMPTZ NOT NULL DEFAULT NOW()
+);
+
+CREATE TABLE question_tags (
+    question_id BIGINT NOT NULL REFERENCES questions(id) ON DELETE CASCADE,
+    tag_id BIGINT NOT NULL REFERENCES tags(id) ON DELETE CASCADE,
+    PRIMARY KEY (question_id, tag_id)
+);
+
+CREATE TABLE assignments (
+    id BIGSERIAL PRIMARY KEY,
+    classroom_id BIGINT NOT NULL REFERENCES classrooms(id) ON DELETE CASCADE,
+    teacher_id BIGINT NOT NULL REFERENCES users(id) ON DELETE RESTRICT,
+    title VARCHAR(255) NOT NULL,
+    instructions TEXT,
+    status assignment_status NOT NULL DEFAULT 'draft',
+    due_at TIMESTAMPTZ,
+    published_at TIMESTAMPTZ,
+    created_at TIMESTAMPTZ NOT NULL DEFAULT NOW(),
+    updated_at TIMESTAMPTZ NOT NULL DEFAULT NOW()
+);
+
+CREATE TABLE assignment_assignees (
+    assignment_id BIGINT NOT NULL REFERENCES assignments(id) ON DELETE CASCADE,
+    student_id BIGINT NOT NULL REFERENCES users(id) ON DELETE CASCADE,
+    assigned_at TIMESTAMPTZ NOT NULL DEFAULT NOW(),
+    PRIMARY KEY (assignment_id, student_id)
+);
+
+CREATE TABLE assignment_questions (
+    assignment_id BIGINT NOT NULL REFERENCES assignments(id) ON DELETE CASCADE,
+    question_id BIGINT NOT NULL REFERENCES questions(id) ON DELETE RESTRICT,
+    position INTEGER NOT NULL,
+    PRIMARY KEY (assignment_id, question_id),
+    CONSTRAINT assignment_questions_assignment_position_key UNIQUE (assignment_id, position)
+);
+
+CREATE TABLE student_answers (
+    id BIGSERIAL PRIMARY KEY,
+    assignment_id BIGINT NOT NULL REFERENCES assignments(id) ON DELETE CASCADE,
+    question_id BIGINT NOT NULL REFERENCES questions(id) ON DELETE RESTRICT,
+    student_id BIGINT NOT NULL REFERENCES users(id) ON DELETE CASCADE,
+    answer_text TEXT,
+    ai_feedback TEXT,
+    teacher_feedback TEXT,
+    status answer_status NOT NULL DEFAULT 'not_started',
+    submitted_at TIMESTAMPTZ,
+    reviewed_at TIMESTAMPTZ,
+    created_at TIMESTAMPTZ NOT NULL DEFAULT NOW(),
+    updated_at TIMESTAMPTZ NOT NULL DEFAULT NOW(),
+    CONSTRAINT student_answers_assignment_question_student_key UNIQUE (assignment_id, question_id, student_id)
+);
+
+CREATE INDEX idx_users_role ON users(role);
+CREATE INDEX idx_classrooms_teacher_id ON classrooms(teacher_id);
+CREATE INDEX idx_questions_author_teacher_id ON questions(author_teacher_id);
+CREATE INDEX idx_questions_status ON questions(status);
+CREATE INDEX idx_assignments_classroom_id ON assignments(classroom_id);
+CREATE INDEX idx_assignments_teacher_id ON assignments(teacher_id);
+CREATE INDEX idx_assignment_assignees_student_id ON assignment_assignees(student_id);
+CREATE INDEX idx_student_answers_student_id ON student_answers(student_id);
+CREATE INDEX idx_student_answers_assignment_id ON student_answers(assignment_id);
+
+-- +goose StatementBegin
+CREATE OR REPLACE FUNCTION update_updated_at()
+RETURNS TRIGGER AS $$
+BEGIN
+    NEW.updated_at = NOW();
+    RETURN NEW;
+END;
+$$ LANGUAGE plpgsql;
+-- +goose StatementEnd
+
+CREATE TRIGGER users_updated_at BEFORE UPDATE ON users
+    FOR EACH ROW EXECUTE FUNCTION update_updated_at();
+
+CREATE TRIGGER classrooms_updated_at BEFORE UPDATE ON classrooms
+    FOR EACH ROW EXECUTE FUNCTION update_updated_at();
+
+CREATE TRIGGER questions_updated_at BEFORE UPDATE ON questions
+    FOR EACH ROW EXECUTE FUNCTION update_updated_at();
+
+CREATE TRIGGER assignments_updated_at BEFORE UPDATE ON assignments
+    FOR EACH ROW EXECUTE FUNCTION update_updated_at();
+
+CREATE TRIGGER student_answers_updated_at BEFORE UPDATE ON student_answers
+    FOR EACH ROW EXECUTE FUNCTION update_updated_at();
+
+-- +goose Down
+DROP TRIGGER IF EXISTS student_answers_updated_at ON student_answers;
+DROP TRIGGER IF EXISTS assignments_updated_at ON assignments;
+DROP TRIGGER IF EXISTS questions_updated_at ON questions;
+DROP TRIGGER IF EXISTS classrooms_updated_at ON classrooms;
+DROP TRIGGER IF EXISTS users_updated_at ON users;
+DROP FUNCTION IF EXISTS update_updated_at();
+
+DROP TABLE IF EXISTS student_answers;
+DROP TABLE IF EXISTS assignment_questions;
+DROP TABLE IF EXISTS assignment_assignees;
+DROP TABLE IF EXISTS assignments;
+DROP TABLE IF EXISTS question_tags;
+DROP TABLE IF EXISTS tags;
+DROP TABLE IF EXISTS questions;
+DROP TABLE IF EXISTS classroom_students;
+DROP TABLE IF EXISTS classrooms;
+DROP TABLE IF EXISTS users;
+
+DROP TYPE IF EXISTS answer_status;
+DROP TYPE IF EXISTS assignment_status;
+DROP TYPE IF EXISTS question_status;
+DROP TYPE IF EXISTS user_role;
--- a/Backend/db/migrations/002_profiles.sql
+++ b/Backend/db/migrations/002_profiles.sql
@@ -0,0 +1,44 @@
+-- +goose Up
+CREATE TABLE profiles (
+    user_id BIGINT PRIMARY KEY REFERENCES users(id) ON DELETE CASCADE,
+    preferred_name VARCHAR(100),
+    profile_icon_url TEXT,
+    headline VARCHAR(255),
+    bio TEXT,
+    timezone VARCHAR(100),
+    locale VARCHAR(20),
+    grade_level VARCHAR(100),
+    learning_goal TEXT,
+    created_at TIMESTAMPTZ NOT NULL DEFAULT NOW(),
+    updated_at TIMESTAMPTZ NOT NULL DEFAULT NOW()
+);
+
+INSERT INTO profiles (user_id)
+SELECT id
+FROM users
+ON CONFLICT (user_id) DO NOTHING;
+
+-- +goose StatementBegin
+CREATE OR REPLACE FUNCTION ensure_profile_for_user()
+RETURNS TRIGGER AS $$
+BEGIN
+    INSERT INTO profiles (user_id)
+    VALUES (NEW.id)
+    ON CONFLICT (user_id) DO NOTHING;
+
+    RETURN NEW;
+END;
+$$ LANGUAGE plpgsql;
+-- +goose StatementEnd
+
+CREATE TRIGGER profiles_updated_at BEFORE UPDATE ON profiles
+    FOR EACH ROW EXECUTE FUNCTION update_updated_at();
+
+CREATE TRIGGER users_ensure_profile_after_insert AFTER INSERT ON users
+    FOR EACH ROW EXECUTE FUNCTION ensure_profile_for_user();
+
+-- +goose Down
+DROP TRIGGER IF EXISTS users_ensure_profile_after_insert ON users;
+DROP TRIGGER IF EXISTS profiles_updated_at ON profiles;
+DROP FUNCTION IF EXISTS ensure_profile_for_user();
+DROP TABLE IF EXISTS profiles;
--- a/Backend/db/migrations/003_messages.sql
+++ b/Backend/db/migrations/003_messages.sql
@@ -0,0 +1,48 @@
+-- +goose Up
+CREATE TABLE message_threads (
+    id BIGSERIAL PRIMARY KEY,
+    created_by_user_id BIGINT NOT NULL REFERENCES users(id) ON DELETE CASCADE,
+    subject VARCHAR(255) NOT NULL,
+    created_at TIMESTAMPTZ NOT NULL DEFAULT NOW(),
+    updated_at TIMESTAMPTZ NOT NULL DEFAULT NOW(),
+    CONSTRAINT message_threads_subject_not_blank CHECK (length(btrim(subject)) > 0)
+);
+
+CREATE TABLE message_thread_participants (
+    thread_id BIGINT NOT NULL REFERENCES message_threads(id) ON DELETE CASCADE,
+    user_id BIGINT NOT NULL REFERENCES users(id) ON DELETE CASCADE,
+    joined_at TIMESTAMPTZ NOT NULL DEFAULT NOW(),
+    last_read_at TIMESTAMPTZ,
+    archived_at TIMESTAMPTZ,
+    PRIMARY KEY (thread_id, user_id)
+);
+
+CREATE TABLE messages (
+    id BIGSERIAL PRIMARY KEY,
+    thread_id BIGINT NOT NULL REFERENCES message_threads(id) ON DELETE CASCADE,
+    sender_user_id BIGINT NOT NULL REFERENCES users(id) ON DELETE CASCADE,
+    body TEXT NOT NULL,
+    created_at TIMESTAMPTZ NOT NULL DEFAULT NOW(),
+    updated_at TIMESTAMPTZ NOT NULL DEFAULT NOW(),
+    CONSTRAINT messages_body_not_blank CHECK (length(btrim(body)) > 0)
+);
+
+CREATE INDEX idx_message_threads_created_by_user_id ON message_threads(created_by_user_id);
+CREATE INDEX idx_message_threads_updated_at ON message_threads(updated_at DESC);
+CREATE INDEX idx_message_thread_participants_user_id ON message_thread_participants(user_id);
+CREATE INDEX idx_messages_thread_id_created_at ON messages(thread_id, created_at DESC);
+CREATE INDEX idx_messages_sender_user_id ON messages(sender_user_id);
+
+CREATE TRIGGER message_threads_updated_at BEFORE UPDATE ON message_threads
+    FOR EACH ROW EXECUTE FUNCTION update_updated_at();
+
+CREATE TRIGGER messages_updated_at BEFORE UPDATE ON messages
+    FOR EACH ROW EXECUTE FUNCTION update_updated_at();
+
+-- +goose Down
+DROP TRIGGER IF EXISTS messages_updated_at ON messages;
+DROP TRIGGER IF EXISTS message_threads_updated_at ON message_threads;
+
+DROP TABLE IF EXISTS messages;
+DROP TABLE IF EXISTS message_thread_participants;
+DROP TABLE IF EXISTS message_threads;
--- a/Backend/db/migrations/004_student_answer_workspace.sql
+++ b/Backend/db/migrations/004_student_answer_workspace.sql
@@ -0,0 +1,12 @@
+-- +goose Up
+ALTER TABLE student_answers
+    ADD COLUMN solve_mode TEXT NOT NULL DEFAULT 'just_answer',
+    ADD COLUMN working_steps TEXT,
+    ADD CONSTRAINT student_answers_solve_mode_check
+        CHECK (solve_mode IN ('just_answer', 'step_by_step', 'solve_together', 'handwritten'));
+
+-- +goose Down
+ALTER TABLE student_answers
+    DROP CONSTRAINT IF EXISTS student_answers_solve_mode_check,
+    DROP COLUMN IF EXISTS working_steps,
+    DROP COLUMN IF EXISTS solve_mode;
--- a/Backend/db/migrations/005_question_answers_and_correctness.sql
+++ b/Backend/db/migrations/005_question_answers_and_correctness.sql
@@ -0,0 +1,13 @@
+-- +goose Up
+ALTER TABLE questions
+ADD COLUMN correct_answer TEXT;
+
+ALTER TABLE student_answers
+ADD COLUMN is_correct BOOLEAN;
+
+-- +goose Down
+ALTER TABLE student_answers
+DROP COLUMN IF EXISTS is_correct;
+
+ALTER TABLE questions
+DROP COLUMN IF EXISTS correct_answer;
--- a/Backend/db/migrations/006_assignment_level_feedback.sql
+++ b/Backend/db/migrations/006_assignment_level_feedback.sql
@@ -0,0 +1,53 @@
+-- +goose Up
+
+ALTER TABLE assignment_assignees
+    ADD COLUMN ai_feedback TEXT,
+    ADD COLUMN teacher_feedback TEXT;
+
+UPDATE assignment_assignees aa
+SET ai_feedback = aggregated.ai_feedback
+FROM (
+    SELECT
+        sa.assignment_id,
+        sa.student_id,
+        string_agg(
+            format('Question %s: %s', aq.position, btrim(sa.ai_feedback)),
+            E'\n\n'
+            ORDER BY aq.position ASC
+        ) AS ai_feedback
+    FROM student_answers sa
+    JOIN assignment_questions aq
+        ON aq.assignment_id = sa.assignment_id
+       AND aq.question_id = sa.question_id
+    WHERE NULLIF(btrim(sa.ai_feedback), '') IS NOT NULL
+    GROUP BY sa.assignment_id, sa.student_id
+) AS aggregated
+WHERE aa.assignment_id = aggregated.assignment_id
+  AND aa.student_id = aggregated.student_id;
+
+UPDATE assignment_assignees aa
+SET teacher_feedback = aggregated.teacher_feedback
+FROM (
+    SELECT
+        sa.assignment_id,
+        sa.student_id,
+        string_agg(
+            format('Question %s: %s', aq.position, btrim(sa.teacher_feedback)),
+            E'\n\n'
+            ORDER BY aq.position ASC
+        ) AS teacher_feedback
+    FROM student_answers sa
+    JOIN assignment_questions aq
+        ON aq.assignment_id = sa.assignment_id
+       AND aq.question_id = sa.question_id
+    WHERE NULLIF(btrim(sa.teacher_feedback), '') IS NOT NULL
+    GROUP BY sa.assignment_id, sa.student_id
+) AS aggregated
+WHERE aa.assignment_id = aggregated.assignment_id
+  AND aa.student_id = aggregated.student_id;
+
+-- +goose Down
+
+ALTER TABLE assignment_assignees
+    DROP COLUMN IF EXISTS teacher_feedback,
+    DROP COLUMN IF EXISTS ai_feedback;
--- a/Backend/db/migrations/007_review_contract.sql
+++ b/Backend/db/migrations/007_review_contract.sql
@@ -0,0 +1,66 @@
+-- +goose Up
+
+CREATE TYPE assignment_pass_status AS ENUM ('pending', 'pass', 'no_pass');
+
+ALTER TABLE student_answers
+    ADD COLUMN review_needs_attention BOOLEAN NOT NULL DEFAULT FALSE,
+    ADD COLUMN review_issue_reason TEXT,
+    ADD COLUMN review_correctness_score NUMERIC(4,3),
+    ADD COLUMN review_understanding_score NUMERIC(4,3),
+    ADD COLUMN review_question_score NUMERIC(4,3),
+    ADD COLUMN review_confidence NUMERIC(4,3),
+    ADD COLUMN review_tags TEXT[] NOT NULL DEFAULT ARRAY[]::TEXT[],
+    ADD CONSTRAINT student_answers_review_correctness_score_range_check
+        CHECK (review_correctness_score IS NULL OR (review_correctness_score >= 0 AND review_correctness_score <= 1)),
+    ADD CONSTRAINT student_answers_review_understanding_score_range_check
+        CHECK (review_understanding_score IS NULL OR (review_understanding_score >= 0 AND review_understanding_score <= 1)),
+    ADD CONSTRAINT student_answers_review_question_score_range_check
+        CHECK (review_question_score IS NULL OR (review_question_score >= 0 AND review_question_score <= 1)),
+    ADD CONSTRAINT student_answers_review_confidence_range_check
+        CHECK (review_confidence IS NULL OR (review_confidence >= 0 AND review_confidence <= 1));
+
+UPDATE student_answers
+SET review_correctness_score = CASE
+        WHEN is_correct IS TRUE THEN 1.000
+        WHEN is_correct IS FALSE THEN 0.000
+        ELSE NULL
+    END,
+    review_question_score = CASE
+        WHEN is_correct IS TRUE THEN 1.000
+        WHEN is_correct IS FALSE THEN 0.000
+        ELSE NULL
+    END
+WHERE is_correct IS NOT NULL;
+
+ALTER TABLE assignment_assignees
+    ADD COLUMN overall_score NUMERIC(5,2),
+    ADD COLUMN pass_threshold NUMERIC(5,2) NOT NULL DEFAULT 8.00,
+    ADD COLUMN pass_status assignment_pass_status NOT NULL DEFAULT 'pending',
+    ADD CONSTRAINT assignment_assignees_overall_score_range_check
+        CHECK (overall_score IS NULL OR (overall_score >= 0 AND overall_score <= 10)),
+    ADD CONSTRAINT assignment_assignees_pass_threshold_range_check
+        CHECK (pass_threshold >= 0 AND pass_threshold <= 10);
+
+-- +goose Down
+
+ALTER TABLE assignment_assignees
+    DROP CONSTRAINT IF EXISTS assignment_assignees_pass_threshold_range_check,
+    DROP CONSTRAINT IF EXISTS assignment_assignees_overall_score_range_check,
+    DROP COLUMN IF EXISTS pass_status,
+    DROP COLUMN IF EXISTS pass_threshold,
+    DROP COLUMN IF EXISTS overall_score;
+
+ALTER TABLE student_answers
+    DROP CONSTRAINT IF EXISTS student_answers_review_confidence_range_check,
+    DROP CONSTRAINT IF EXISTS student_answers_review_question_score_range_check,
+    DROP CONSTRAINT IF EXISTS student_answers_review_understanding_score_range_check,
+    DROP CONSTRAINT IF EXISTS student_answers_review_correctness_score_range_check,
+    DROP COLUMN IF EXISTS review_tags,
+    DROP COLUMN IF EXISTS review_confidence,
+    DROP COLUMN IF EXISTS review_question_score,
+    DROP COLUMN IF EXISTS review_understanding_score,
+    DROP COLUMN IF EXISTS review_correctness_score,
+    DROP COLUMN IF EXISTS review_issue_reason,
+    DROP COLUMN IF EXISTS review_needs_attention;
+
+DROP TYPE IF EXISTS assignment_pass_status;
--- a/Backend/db/migrations/008_assignment_pass_threshold.sql
+++ b/Backend/db/migrations/008_assignment_pass_threshold.sql
@@ -0,0 +1,22 @@
+-- +goose Up
+
+ALTER TABLE assignments
+    ADD COLUMN pass_threshold NUMERIC(5,2) NOT NULL DEFAULT 8.00,
+    ADD CONSTRAINT assignments_pass_threshold_range_check
+        CHECK (pass_threshold >= 0 AND pass_threshold <= 10);
+
+UPDATE assignments a
+SET pass_threshold = COALESCE(
+    (
+        SELECT MAX(aa.pass_threshold)
+        FROM assignment_assignees aa
+        WHERE aa.assignment_id = a.id
+    ),
+    8.00
+);
+
+-- +goose Down
+
+ALTER TABLE assignments
+    DROP CONSTRAINT IF EXISTS assignments_pass_threshold_range_check,
+    DROP COLUMN IF EXISTS pass_threshold;
--- a/Backend/db/migrations/009_assignment_pass_status_override.sql
+++ b/Backend/db/migrations/009_assignment_pass_status_override.sql
@@ -0,0 +1,9 @@
+-- +goose Up
+
+ALTER TABLE assignment_assignees
+    ADD COLUMN pass_status_override assignment_pass_status;
+
+-- +goose Down
+
+ALTER TABLE assignment_assignees
+    DROP COLUMN IF EXISTS pass_status_override;
--- a/Backend/db/migrations/010_assignment_next_step_outcome.sql
+++ b/Backend/db/migrations/010_assignment_next_step_outcome.sql
@@ -0,0 +1,13 @@
+-- +goose Up
+
+CREATE TYPE assignment_next_step_outcome AS ENUM ('redo', 'accept', 'support');
+
+ALTER TABLE assignment_assignees
+    ADD COLUMN next_step_outcome assignment_next_step_outcome;
+
+-- +goose Down
+
+ALTER TABLE assignment_assignees
+    DROP COLUMN IF EXISTS next_step_outcome;
+
+DROP TYPE IF EXISTS assignment_next_step_outcome;
--- a/Backend/db/migrations/011_backfill_seeded_question_correct_answers.sql
+++ b/Backend/db/migrations/011_backfill_seeded_question_correct_answers.sql
@@ -0,0 +1,80 @@
+-- +goose Up
+
+UPDATE questions AS q
+SET correct_answer = seeded.correct_answer
+FROM (
+    VALUES
+        (1001, '700'),
+        (1002, '25000'),
+        (1003, '7/100'),
+        (1004, '0.37'),
+        (1101, '383'),
+        (1102, '456'),
+        (1103, '2627'),
+        (1104, '196'),
+        (1105, '24'),
+        (1106, '3744'),
+        (1201, '3'),
+        (1202, '-5'),
+        (1203, '-4'),
+        (1301, '11'),
+        (1302, '22'),
+        (1303, '19'),
+        (1401, '1/2'),
+        (1402, '2/3'),
+        (1403, '5/8'),
+        (1411, '5/6'),
+        (1412, '3/4'),
+        (1413, '11/15'),
+        (1414, '11/12'),
+        (1415, '1/2'),
+        (1416, '29/24'),
+        (1421, '1/6'),
+        (1422, '1/2'),
+        (1423, '28'),
+        (1501, '5'),
+        (1502, '7'),
+        (1503, '6'),
+        (1511, '14'),
+        (1512, '31'),
+        (1513, '3n+2'),
+        (1601, '28'),
+        (1602, '40'),
+        (1603, '27'),
+        (1611, '70'),
+        (1612, '75'),
+        (1613, '720'),
+        (1701, '8'),
+        (1702, '5'),
+        (1703, '7'),
+        (1711, '3/8'),
+        (1712, '1/3'),
+        (1801, '15'),
+        (1802, '3/8'),
+        (1803, '51'),
+        (1804, '23'),
+        (1805, '96')
+) AS seeded(id, correct_answer)
+WHERE q.id = seeded.id
+  AND (q.correct_answer IS NULL OR BTRIM(q.correct_answer) = '');
+
+-- +goose Down
+
+UPDATE questions
+SET correct_answer = NULL
+WHERE id IN (
+    1001, 1002, 1003, 1004,
+    1101, 1102, 1103, 1104, 1105, 1106,
+    1201, 1202, 1203,
+    1301, 1302, 1303,
+    1401, 1402, 1403,
+    1411, 1412, 1413, 1414, 1415, 1416,
+    1421, 1422, 1423,
+    1501, 1502, 1503,
+    1511, 1512, 1513,
+    1601, 1602, 1603,
+    1611, 1612, 1613,
+    1701, 1702, 1703,
+    1711, 1712,
+    1801, 1802, 1803, 1804, 1805
+);
--- a/Backend/db/migrations/012_phase_a_topics_difficulty_and_threshold.sql
+++ b/Backend/db/migrations/012_phase_a_topics_difficulty_and_threshold.sql
@@ -0,0 +1,123 @@
+-- +goose Up
+
+CREATE TYPE question_topic AS ENUM (
+    'place_value',
+    'arithmetic',
+    'negative_numbers',
+    'bidmas',
+    'fractions',
+    'algebra',
+    'geometry',
+    'data'
+);
+
+CREATE TYPE question_difficulty AS ENUM ('easy', 'medium', 'hard');
+
+ALTER TABLE questions
+    ADD COLUMN topic question_topic,
+    ADD COLUMN difficulty question_difficulty;
+
+UPDATE questions
+SET topic = CASE BTRIM(COALESCE(subject, ''))
+    WHEN 'Place Value' THEN 'place_value'::question_topic
+    WHEN 'Arithmetic' THEN 'arithmetic'::question_topic
+    WHEN 'Negative Numbers' THEN 'negative_numbers'::question_topic
+    WHEN 'BIDMAS' THEN 'bidmas'::question_topic
+    WHEN 'Fractions' THEN 'fractions'::question_topic
+    WHEN 'Algebra' THEN 'algebra'::question_topic
+    WHEN 'Geometry' THEN 'geometry'::question_topic
+    WHEN 'Data' THEN 'data'::question_topic
+    ELSE NULL
+END
+WHERE topic IS NULL;
+
+UPDATE questions AS q
+SET difficulty = seeded.difficulty::question_difficulty
+FROM (
+    VALUES
+        (1001, 'easy'),
+        (1002, 'medium'),
+        (1003, 'medium'),
+        (1004, 'hard'),
+        (1101, 'easy'),
+        (1102, 'medium'),
+        (1103, 'hard'),
+        (1104, 'medium'),
+        (1105, 'medium'),
+        (1106, 'hard'),
+        (1201, 'easy'),
+        (1202, 'medium'),
+        (1203, 'hard'),
+        (1301, 'easy'),
+        (1302, 'medium'),
+        (1303, 'hard'),
+        (1401, 'easy'),
+        (1402, 'medium'),
+        (1403, 'hard'),
+        (1411, 'easy'),
+        (1412, 'easy'),
+        (1413, 'medium'),
+        (1414, 'medium'),
+        (1415, 'medium'),
+        (1416, 'hard'),
+        (1421, 'easy'),
+        (1422, 'medium'),
+        (1423, 'hard'),
+        (1501, 'easy'),
+        (1502, 'medium'),
+        (1503, 'hard'),
+        (1511, 'easy'),
+        (1512, 'medium'),
+        (1513, 'hard'),
+        (1601, 'easy'),
+        (1602, 'medium'),
+        (1603, 'hard'),
+        (1611, 'easy'),
+        (1612, 'medium'),
+        (1613, 'hard'),
+        (1701, 'easy'),
+        (1702, 'medium'),
+        (1703, 'easy'),
+        (1711, 'medium'),
+        (1712, 'hard'),
+        (1801, 'easy'),
+        (1802, 'medium'),
+        (1803, 'medium'),
+        (1804, 'hard'),
+        (1805, 'hard')
+) AS seeded(id, difficulty)
+WHERE q.id = seeded.id
+  AND q.difficulty IS NULL;
+
+ALTER TABLE assignments
+    ALTER COLUMN pass_threshold SET DEFAULT 6.00;
+
+UPDATE assignments
+SET pass_threshold = 6.00;
+
+ALTER TABLE assignment_assignees
+    ALTER COLUMN pass_threshold SET DEFAULT 6.00;
+
+UPDATE assignment_assignees
+SET pass_threshold = 6.00;
+
+-- +goose Down
+
+UPDATE assignment_assignees
+SET pass_threshold = 8.00;
+
+ALTER TABLE assignment_assignees
+    ALTER COLUMN pass_threshold SET DEFAULT 8.00;
+
+UPDATE assignments
+SET pass_threshold = 8.00;
+
+ALTER TABLE assignments
+    ALTER COLUMN pass_threshold SET DEFAULT 8.00;
+
+ALTER TABLE questions
+    DROP COLUMN IF EXISTS difficulty,
+    DROP COLUMN IF EXISTS topic;
+
+DROP TYPE IF EXISTS question_difficulty;
+DROP TYPE IF EXISTS question_topic;
--- a/Backend/db/migrations/013_redo_assignment_plan.sql
+++ b/Backend/db/migrations/013_redo_assignment_plan.sql
@@ -0,0 +1,11 @@
+-- +goose Up
+
+ALTER TABLE assignment_assignees
+    ADD COLUMN redo_plan TEXT,
+    ADD COLUMN redo_plan_generated_at TIMESTAMPTZ;
+
+-- +goose Down
+
+ALTER TABLE assignment_assignees
+    DROP COLUMN IF EXISTS redo_plan_generated_at,
+    DROP COLUMN IF EXISTS redo_plan;
--- a/Backend/db/migrations/014_assignment_student_questions.sql
+++ b/Backend/db/migrations/014_assignment_student_questions.sql
@@ -0,0 +1,30 @@
+-- +goose Up
+
+CREATE TABLE assignment_student_questions (
+    id BIGSERIAL PRIMARY KEY,
+    assignment_id BIGINT NOT NULL,
+    student_id BIGINT NOT NULL,
+    question_id BIGINT NOT NULL REFERENCES questions(id) ON DELETE CASCADE,
+    position INTEGER NOT NULL CHECK (position > 0),
+    source_bucket TEXT NOT NULL CHECK (btrim(source_bucket) <> ''),
+    source_topic question_topic,
+    source_difficulty question_difficulty,
+    generator_seed BIGINT,
+    created_at TIMESTAMPTZ NOT NULL DEFAULT NOW(),
+    CONSTRAINT assignment_student_questions_assignment_student_fkey
+        FOREIGN KEY (assignment_id, student_id)
+        REFERENCES assignment_assignees(assignment_id, student_id)
+        ON DELETE CASCADE,
+    CONSTRAINT assignment_student_questions_assignment_student_question_key
+        UNIQUE (assignment_id, student_id, question_id),
+    CONSTRAINT assignment_student_questions_assignment_student_position_key
+        UNIQUE (assignment_id, student_id, position)
+);
+
+CREATE INDEX idx_assignment_student_questions_assignment_student
+    ON assignment_student_questions (assignment_id, student_id);
+
+-- +goose Down
+
+DROP INDEX IF EXISTS idx_assignment_student_questions_assignment_student;
+DROP TABLE IF EXISTS assignment_student_questions;