WITH slice AS (
    SELECT e.user_id
    FROM core.enrollment e
    WHERE e.curriculum_id = CAST(:curriculumId AS uuid)
      AND e.status = 'ACTIVE'
      AND (CAST(:afterUserId AS uuid) IS NULL OR e.user_id > CAST(:afterUserId AS uuid))
      AND (CAST(:untilUserId AS uuid) IS NULL OR e.user_id <= CAST(:untilUserId AS uuid))
    ORDER BY e.user_id
    LIMIT :sliceLimit
), content AS (
    INSERT INTO core.notification_content (
        id, type, severity, title, message, targets, group_key,
        previous_starts_at, next_starts_at)
    SELECT CAST(:contentId AS uuid), :type, :severity, :title, :message,
           CAST(:targets AS jsonb), :groupKey,
           CAST(:previousStartsAt AS timestamptz), CAST(:nextStartsAt AS timestamptz)
    WHERE EXISTS (SELECT 1 FROM slice)
    ON CONFLICT (id) DO NOTHING
), inserted AS (
    INSERT INTO core.notification
            (id, recipient_id, content_id, dedupe_hash, read_status, action_status)
    SELECT gen_random_uuid(), s.user_id, CAST(:contentId AS uuid),
           md5(:dedupePrefix || s.user_id)::uuid, 'UNREAD', :actionStatus
    FROM slice s
    ON CONFLICT (dedupe_hash) WHERE dedupe_hash IS NOT NULL DO NOTHING
    RETURNING recipient_id
)
SELECT (SELECT count(*) FROM slice)    AS scanned,
       (SELECT count(*) FROM inserted) AS inserted,
       (SELECT array_agg(recipient_id) FROM inserted) AS inserted_recipients,
       (SELECT s.user_id FROM slice s ORDER BY s.user_id DESC LIMIT 1) AS last_user_id