-- exam_sessions — historical import of the old SQLite `sessions` table (exam mode records).
-- Scope note (see docs/PHASE2B_ADMIN_AND_PLATFORM_DATA.md "Known limitations"): exam mode's
-- LIVE session bookkeeping (start/submit/shuffle/abandon) remains Lab-image-local for Phase
-- 2B — it's tightly coupled to a single Lab's live cluster state the same way scenario
-- validation is, and productionizing it would need the same relay pattern progress got in
-- Phase 2A, which is scoped out here (not in the Phase 2B acceptance test). This table exists
-- so historical exam records survive the SQLite migration and are visible to instructors, not
-- because new exam sessions get written here yet.

CREATE TABLE IF NOT EXISTS exam_sessions (
  session_id     TEXT PRIMARY KEY,
  student_id     TEXT REFERENCES students(student_id),
  bundle_id      TEXT NOT NULL,
  started_at     TIMESTAMPTZ NOT NULL,
  submitted_at   TIMESTAMPTZ,
  status         TEXT NOT NULL DEFAULT 'active',
  exam_minutes   INTEGER NOT NULL DEFAULT 120,
  duration_secs  INTEGER,
  snapshot       JSONB,
  scenario_ids   JSONB,
  created_at     TIMESTAMPTZ NOT NULL DEFAULT now()
);

CREATE INDEX IF NOT EXISTS idx_exam_sessions_student ON exam_sessions(student_id);