-- ============================================================================
-- 20260929020000_unify_llm_quota_inflight.sql
--
-- One LLM quota ledger and one lock for every path that spends LLM allowance.
--
-- Bug
--   Meeting-document generation held its in-flight unit in a different ledger
--   and under a different lock than llm-proxy / consume_quota:
--     * claim_meeting_document_generation_v1 (20260928000037) locked
--       hashtextextended(user:feature, 0) and counted daily_usage PLUS
--       meeting_document_generation_requests rows in status 'processing';
--       it wrote nothing to daily_usage;
--     * reserve_llm_quota / finalize_llm_quota (20260928020800) and
--       consume_quota (20260928000131) locked hashtextextended(user:feature,
--       20260928) and counted daily_usage only.
--   So an in-flight document unit was invisible to llm-proxy. With one Opus
--   unit left, a document claim passed (49 < 50), a Talk/command request then
--   reserved the same unit through llm-proxy (daily_usage 49 -> 50), and
--   commit_meeting_document_generation_v1 re-checked the allowance, saw
--   50 >= 50 and raised generation_quota_exceeded: the paid Opus generation
--   was thrown away (or, with overage credits, a credit the claim promised
--   was covered by the base allowance was spent silently). The two paths also
--   never serialised against each other because the lock keys differed.
--
-- Fix (single source of truth for LLM quota state)
--   1. public.daily_usage_lock_v1(user, feature) is the only place that knows
--      the per-user/per-feature advisory-lock key for the daily_usage ledger.
--      reserve_llm_quota, finalize_llm_quota, consume_quota and the three
--      meeting-document RPCs all take the lock through it.
--   2. A meeting-document claim now reserves its unit with reserve_llm_quota
--      (a fresh server-generated reservation id, stored on the request row in
--      llm_reservation_id). The unit is in daily_usage from the moment of the
--      claim, so llm-proxy and consume_quota see it.
--        commit -> finalize_llm_quota(id, true)   (the unit stays spent;
--                  consumedFrom comes from the reservation)
--        fail   -> finalize_llm_quota(id, false)  (daily_usage -1, overage
--                  credit refunded when the unit came from overage)
--      The separate 'processing'-row in-flight count and commit's allowance
--      re-check / daily_usage insert are gone, so usage is counted once.
--   3. Crashed workers: the reservation lease (10 minutes) is reclaimed by the
--      next reserve for that user/feature, exactly like llm-proxy. That
--      replaces the old "processing rows older than 10 minutes stop counting"
--      rule.
--
-- Single-path behaviour is unchanged: "allowed" is still
-- usage + in-flight < base limit + overage, because daily_usage now includes
-- in-flight units. What moves: document usage is recorded at claim instead of
-- commit, and an overage credit is taken at claim and refunded on failure
-- (the llm-proxy model).
--
-- Compatibility
--   * RPC signatures and return shapes are unchanged.
--   * Request rows that were already 'processing' when this migration ran have
--     llm_reservation_id NULL. commit charges them through the same ledger at
--     commit time (the previous behaviour), and fail has nothing to release.
--     The same path covers a reservation whose lease expired and was
--     reclaimed before commit arrived.
--   * The reservation id is generated server-side (gen_random_uuid), never the
--     client's idempotency key: idempotency keys are unique only per user,
--     llm_quota_reservations.id is a global primary key.
--
-- Only service_role may call the quota functions. Local verification:
-- tests/meeting-document-generation-quota.integration.sql.
-- ============================================================================

-- ----------------------------------------------------------------------------
-- 1. The single lock for the daily_usage quota ledger.
-- ----------------------------------------------------------------------------
CREATE OR REPLACE FUNCTION public.daily_usage_lock_v1(
  p_user_id uuid,
  p_feature text
) RETURNS void
LANGUAGE plpgsql
SET search_path = pg_catalog, public
AS $$
BEGIN
  IF p_user_id IS NULL OR p_feature IS NULL THEN
    RAISE EXCEPTION 'invalid_daily_usage_lock' USING ERRCODE = '22023';
  END IF;
  -- Seed 20260928 is the key consume_quota and reserve_llm_quota already used,
  -- so existing sessions of those functions keep serialising with new ones.
  PERFORM pg_advisory_xact_lock(hashtextextended(p_user_id::text || ':' || p_feature, 20260928));
END;
$$;

REVOKE ALL ON FUNCTION public.daily_usage_lock_v1(uuid, text) FROM PUBLIC, anon, authenticated;
GRANT EXECUTE ON FUNCTION public.daily_usage_lock_v1(uuid, text) TO service_role;

COMMENT ON FUNCTION public.daily_usage_lock_v1(uuid, text) IS
  'Transaction advisory lock guarding the daily_usage quota ledger for one user/feature. Every quota path (consume_quota, reserve/finalize_llm_quota, meeting-document claim/commit/fail) must take it through this function.';

-- ----------------------------------------------------------------------------
-- 2. Request rows point at the reservation that holds their unit.
-- ----------------------------------------------------------------------------
ALTER TABLE public.meeting_document_generation_requests
  ADD COLUMN IF NOT EXISTS llm_reservation_id uuid
    REFERENCES public.llm_quota_reservations(id) ON DELETE SET NULL;

CREATE INDEX IF NOT EXISTS meeting_document_generation_llm_reservation_idx
  ON public.meeting_document_generation_requests(llm_reservation_id)
  WHERE llm_reservation_id IS NOT NULL;

-- The 'processing'-row in-flight count is replaced by the reservation ledger.
DROP INDEX IF EXISTS public.meeting_document_generation_in_flight_idx;

-- ----------------------------------------------------------------------------
-- 3. reserve_llm_quota / finalize_llm_quota / consume_quota: same bodies as
--    20260928020800 and 20260928000131, lock taken through the helper.
-- ----------------------------------------------------------------------------
CREATE OR REPLACE FUNCTION public.reserve_llm_quota(
  p_user_id uuid,
  p_reservation_id uuid,
  p_feature text,
  p_base_limit integer,
  p_period text
) RETURNS jsonb
LANGUAGE plpgsql
SECURITY DEFINER
SET search_path = public, pg_temp
AS $$
DECLARE
  existing public.llm_quota_reservations%ROWTYPE;
  expired public.llm_quota_reservations%ROWTYPE;
  subscription_tier text := 'free';
  overage integer := 0;
  new_overage integer;
  current_count integer := 0;
  consumed_from text;
BEGIN
  IF p_user_id IS NULL
     OR p_reservation_id IS NULL
     OR p_feature IS NULL
     OR p_feature NOT IN ('llm_haiku', 'llm_sonnet', 'llm_opus')
     OR p_base_limit IS NULL
     OR p_base_limit < -1
     OR p_period IS NULL
     OR p_period NOT IN ('daily', 'weekly') THEN
    RAISE EXCEPTION 'invalid_llm_quota_reservation' USING ERRCODE = '22023';
  END IF;

  PERFORM public.daily_usage_lock_v1(p_user_id, p_feature);

  SELECT * INTO existing
  FROM public.llm_quota_reservations
  WHERE id = p_reservation_id
  FOR UPDATE;

  IF FOUND THEN
    IF existing.user_id <> p_user_id OR existing.feature <> p_feature THEN
      RAISE EXCEPTION 'llm_quota_reservation_conflict' USING ERRCODE = 'PT409';
    END IF;
    RETURN jsonb_build_object(
      'allowed', existing.status IN ('reserved', 'completed'),
      'reservation_id', existing.id,
      'status', existing.status,
      'current', existing.current_count,
      'limit', existing.quota_limit,
      'period', existing.quota_period,
      'tier', existing.tier,
      'overage_credits', existing.overage_after,
      'consumed_from', existing.consumed_from
    );
  END IF;

  -- Reclaim crashed requests before calculating the next allowance.
  FOR expired IN
    SELECT *
    FROM public.llm_quota_reservations
    WHERE user_id = p_user_id
      AND feature = p_feature
      AND status = 'reserved'
      AND lease_expires_at <= now()
    FOR UPDATE
  LOOP
    UPDATE public.daily_usage
    SET count = greatest(count - 1, 0)
    WHERE user_id = expired.user_id
      AND date = expired.usage_date
      AND feature = expired.feature;

    IF expired.consumed_from = 'overage' THEN
      UPDATE public.subscriptions
      SET overage_credits = overage_credits + 1,
          updated_at = now()
      WHERE user_id = expired.user_id;
    END IF;

    UPDATE public.llm_quota_reservations
    SET status = 'released', finalized_at = now(), release_reason = 'lease_expired'
    WHERE id = expired.id;
  END LOOP;

  SELECT coalesce(tier, 'free'), coalesce(overage_credits, 0)
  INTO subscription_tier, overage
  FROM public.subscriptions
  WHERE user_id = p_user_id
  FOR UPDATE;

  IF NOT FOUND THEN
    subscription_tier := 'free';
    overage := 0;
  END IF;

  -- Not available: never spend credits on a model the tier does not include.
  IF p_base_limit = 0 THEN
    RETURN jsonb_build_object(
      'allowed', false,
      'reservation_id', NULL,
      'status', 'denied',
      'current', 0,
      'limit', 0,
      'period', p_period,
      'tier', subscription_tier,
      'overage_credits', overage,
      'consumed_from', 'none'
    );
  END IF;

  -- daily_usage already includes units held by in-flight reservations
  -- (llm-proxy requests and meeting-document claims alike).
  SELECT coalesce(sum(count), 0)::integer INTO current_count
  FROM public.daily_usage
  WHERE user_id = p_user_id
    AND feature = p_feature
    AND date >= CASE WHEN p_period = 'weekly' THEN CURRENT_DATE - 6 ELSE CURRENT_DATE END
    AND date <= CURRENT_DATE;

  IF p_base_limit = -1 THEN
    consumed_from := 'unlimited';
  ELSIF current_count < p_base_limit THEN
    consumed_from := 'base';
  ELSE
    UPDATE public.subscriptions
    SET overage_credits = overage_credits - 1,
        updated_at = now()
    WHERE user_id = p_user_id
      AND overage_credits > 0
    RETURNING overage_credits INTO new_overage;

    IF NOT FOUND THEN
      RETURN jsonb_build_object(
        'allowed', false,
        'reservation_id', NULL,
        'status', 'denied',
        'current', current_count,
        'limit', p_base_limit,
        'period', p_period,
        'tier', subscription_tier,
        'overage_credits', 0,
        'consumed_from', 'none'
      );
    END IF;

    overage := new_overage;
    consumed_from := 'overage';
  END IF;

  INSERT INTO public.daily_usage(user_id, date, feature, count)
  VALUES (p_user_id, CURRENT_DATE, p_feature, 1)
  ON CONFLICT (user_id, date, feature)
  DO UPDATE SET count = public.daily_usage.count + 1;

  current_count := current_count + 1;
  INSERT INTO public.llm_quota_reservations(
    id, user_id, feature, consumed_from, tier, quota_period, quota_limit,
    current_count, overage_after, lease_expires_at
  ) VALUES (
    p_reservation_id, p_user_id, p_feature, consumed_from, subscription_tier, p_period, p_base_limit,
    current_count, overage, now() + interval '10 minutes'
  );

  RETURN jsonb_build_object(
    'allowed', true,
    'reservation_id', p_reservation_id,
    'status', 'reserved',
    'current', current_count,
    'limit', p_base_limit,
    'period', p_period,
    'tier', subscription_tier,
    'overage_credits', overage,
    'consumed_from', consumed_from
  );
END;
$$;

CREATE OR REPLACE FUNCTION public.finalize_llm_quota(
  p_reservation_id uuid,
  p_succeeded boolean
) RETURNS jsonb
LANGUAGE plpgsql
SECURITY DEFINER
SET search_path = public, pg_temp
AS $$
DECLARE
  reservation public.llm_quota_reservations%ROWTYPE;
  final_status text;
BEGIN
  IF p_reservation_id IS NULL OR p_succeeded IS NULL THEN
    RAISE EXCEPTION 'invalid_llm_quota_finalize' USING ERRCODE = '22023';
  END IF;

  SELECT * INTO reservation
  FROM public.llm_quota_reservations
  WHERE id = p_reservation_id;
  IF NOT FOUND THEN
    RAISE EXCEPTION 'llm_quota_reservation_not_found' USING ERRCODE = 'P0002';
  END IF;

  PERFORM public.daily_usage_lock_v1(reservation.user_id, reservation.feature);
  SELECT * INTO reservation
  FROM public.llm_quota_reservations
  WHERE id = p_reservation_id
  FOR UPDATE;

  IF reservation.status <> 'reserved' THEN
    RETURN jsonb_build_object('reservation_id', reservation.id, 'status', reservation.status);
  END IF;

  IF p_succeeded THEN
    final_status := 'completed';
  ELSE
    UPDATE public.daily_usage
    SET count = greatest(count - 1, 0)
    WHERE user_id = reservation.user_id
      AND date = reservation.usage_date
      AND feature = reservation.feature;

    IF reservation.consumed_from = 'overage' THEN
      UPDATE public.subscriptions
      SET overage_credits = overage_credits + 1,
          updated_at = now()
      WHERE user_id = reservation.user_id;
    END IF;
    final_status := 'released';
  END IF;

  UPDATE public.llm_quota_reservations
  SET status = final_status,
      finalized_at = now(),
      release_reason = CASE WHEN p_succeeded THEN NULL ELSE 'provider_failed' END
  WHERE id = reservation.id;

  RETURN jsonb_build_object('reservation_id', reservation.id, 'status', final_status);
END;
$$;

REVOKE ALL ON FUNCTION public.reserve_llm_quota(uuid, uuid, text, integer, text) FROM PUBLIC, anon, authenticated;
REVOKE ALL ON FUNCTION public.finalize_llm_quota(uuid, boolean) FROM PUBLIC, anon, authenticated;
GRANT EXECUTE ON FUNCTION public.reserve_llm_quota(uuid, uuid, text, integer, text) TO service_role;
GRANT EXECUTE ON FUNCTION public.finalize_llm_quota(uuid, boolean) TO service_role;

CREATE OR REPLACE FUNCTION public.consume_quota(
  p_user_id uuid,
  p_feature text,
  p_base_limit integer,
  p_period text DEFAULT 'daily'
) RETURNS jsonb
LANGUAGE plpgsql
SECURITY DEFINER
SET search_path = public, pg_temp
AS $$
DECLARE
  v_window_start date;
  v_current integer := 0;
  v_overage integer := 0;
  v_new_overage integer;
  v_consumed_from text;
BEGIN
  IF p_user_id IS NULL
     OR p_feature IS NULL
     OR p_base_limit IS NULL
     OR p_base_limit < -1
     OR p_period IS NULL
     OR p_period NOT IN ('daily', 'weekly') THEN
    RAISE EXCEPTION 'invalid_quota_consumption' USING ERRCODE = '22023';
  END IF;

  -- Serialise read-then-increment for this user/feature.
  PERFORM public.daily_usage_lock_v1(p_user_id, p_feature);

  SELECT coalesce(overage_credits, 0) INTO v_overage
    FROM public.subscriptions
   WHERE user_id = p_user_id
   FOR UPDATE;
  v_overage := coalesce(v_overage, 0);

  -- Not available: never spend credits on a feature the tier does not include.
  IF p_base_limit = 0 THEN
    RETURN jsonb_build_object(
      'allowed', false,
      'current', 0,
      'limit', 0,
      'overage_credits', v_overage,
      'consumed_from', 'none'
    );
  END IF;

  v_window_start := CASE WHEN p_period = 'weekly' THEN CURRENT_DATE - 6 ELSE CURRENT_DATE END;

  SELECT coalesce(sum(count), 0)::integer INTO v_current
    FROM public.daily_usage
   WHERE user_id = p_user_id
     AND feature = p_feature
     AND date >= v_window_start
     AND date <= CURRENT_DATE;

  IF p_base_limit = -1 THEN
    v_consumed_from := 'unlimited';
  ELSIF v_current < p_base_limit THEN
    v_consumed_from := 'base';
  ELSE
    UPDATE public.subscriptions
       SET overage_credits = overage_credits - 1,
           updated_at = now()
     WHERE user_id = p_user_id
       AND overage_credits > 0
    RETURNING overage_credits INTO v_new_overage;

    IF NOT FOUND THEN
      RETURN jsonb_build_object(
        'allowed', false,
        'current', v_current,
        'limit', p_base_limit,
        'overage_credits', 0,
        'consumed_from', 'none'
      );
    END IF;

    v_overage := v_new_overage;
    v_consumed_from := 'overage';
  END IF;

  INSERT INTO public.daily_usage (user_id, date, feature, count)
  VALUES (p_user_id, CURRENT_DATE, p_feature, 1)
  ON CONFLICT (user_id, date, feature) DO UPDATE
    SET count = public.daily_usage.count + 1;

  RETURN jsonb_build_object(
    'allowed', true,
    'current', v_current + 1,
    'limit', p_base_limit,
    'overage_credits', v_overage,
    'consumed_from', v_consumed_from
  );
END;
$$;

REVOKE ALL ON FUNCTION public.consume_quota(uuid, text, integer, text) FROM PUBLIC, anon, authenticated;
GRANT EXECUTE ON FUNCTION public.consume_quota(uuid, text, integer, text) TO service_role;

-- ----------------------------------------------------------------------------
-- 4. Meeting-document claim: reserve the unit in the shared ledger.
-- ----------------------------------------------------------------------------
CREATE OR REPLACE FUNCTION public.claim_meeting_document_generation_v1(
  p_actor_id uuid,
  p_idempotency_key uuid,
  p_meeting_id uuid,
  p_template_id uuid,
  p_title text,
  p_model text
)
RETURNS jsonb
LANGUAGE plpgsql
SECURITY DEFINER
SET search_path = pg_catalog, public, auth, extensions
AS $$
DECLARE
  meeting_row public.meetings;
  template_row public.user_templates;
  transcript_value text;
  transcript_digest text;
  request_digest text;
  request_row public.meeting_document_generation_requests;
  inserted boolean := false;
  tier_value text := 'free';
  quota_feature_value text;
  quota_limit_value integer;
  quota_period_value text;
  reservation_id_value uuid;
  reservation jsonb;
  is_replay boolean := false;
  safe_title text := trim(p_title);
BEGIN
  IF p_actor_id IS NULL OR p_idempotency_key IS NULL OR p_meeting_id IS NULL OR p_template_id IS NULL THEN
    RAISE EXCEPTION 'generation_identifiers_required' USING ERRCODE = '22023';
  END IF;
  IF char_length(safe_title) NOT BETWEEN 1 AND 160 THEN
    RAISE EXCEPTION 'invalid_document_title' USING ERRCODE = '22023';
  END IF;
  IF p_model NOT IN ('claude-haiku-4-5-20251001', 'claude-sonnet-4-6', 'claude-opus-4-6') THEN
    RAISE EXCEPTION 'invalid_generation_model' USING ERRCODE = '22023';
  END IF;

  SELECT * INTO meeting_row FROM public.meetings WHERE id = p_meeting_id;
  IF meeting_row.id IS NULL THEN
    RAISE EXCEPTION 'meeting_not_found' USING ERRCODE = 'P0002';
  END IF;
  IF meeting_row.user_id <> p_actor_id AND NOT (
    meeting_row.team_id IS NOT NULL
    AND (
      EXISTS (
        SELECT 1 FROM public.teams
        WHERE id = meeting_row.team_id AND owner_id = p_actor_id
      )
      OR EXISTS (
        SELECT 1 FROM public.team_members
        WHERE team_id = meeting_row.team_id
          AND user_id = p_actor_id
          AND role IN ('owner', 'admin')
      )
    )
  ) THEN
    RAISE EXCEPTION 'meeting_generation_forbidden' USING ERRCODE = '42501';
  END IF;

  SELECT * INTO template_row
  FROM public.user_templates
  WHERE id = p_template_id
    AND user_id = p_actor_id
    AND template_kind = 'meeting_document';
  IF template_row.id IS NULL THEN
    RAISE EXCEPTION 'meeting_template_not_found' USING ERRCODE = 'P0002';
  END IF;

  SELECT nullif(string_agg(
           CASE WHEN nullif(trim(transcript.speaker), '') IS NULL
                THEN transcript.text
                ELSE trim(transcript.speaker) || ': ' || transcript.text
           END,
           E'\n' ORDER BY transcript.segment_index
         ), '')
  INTO transcript_value
  FROM public.transcripts AS transcript
  WHERE transcript.meeting_id = meeting_row.id;

  transcript_value := coalesce(
    transcript_value,
    nullif(trim(meeting_row.edited_transcript), ''),
    nullif(trim(meeting_row.raw_transcript), '')
  );
  IF transcript_value IS NULL THEN
    RAISE EXCEPTION 'meeting_transcript_required' USING ERRCODE = '22023';
  END IF;
  IF char_length(transcript_value) > 48000 THEN
    RAISE EXCEPTION 'meeting_transcript_too_large' USING ERRCODE = '22023';
  END IF;

  SELECT coalesce(subscription.tier, 'free')
  INTO tier_value
  FROM public.subscriptions AS subscription
  WHERE subscription.user_id = p_actor_id;
  tier_value := coalesce(tier_value, 'free');

  IF tier_value = 'free' AND p_model <> 'claude-haiku-4-5-20251001' THEN
    RAISE EXCEPTION 'generation_model_not_allowed' USING ERRCODE = '42501';
  END IF;

  quota_feature_value := CASE
    WHEN p_model LIKE '%sonnet%' THEN 'llm_sonnet'
    WHEN p_model LIKE '%opus%' THEN 'llm_opus'
    ELSE 'llm_haiku'
  END;
  quota_limit_value := CASE
    WHEN tier_value = 'free' AND quota_feature_value = 'llm_haiku' THEN 250
    WHEN tier_value = 'free' THEN 0
    WHEN tier_value = 'pro' AND quota_feature_value = 'llm_haiku' THEN 1500
    WHEN tier_value = 'pro' AND quota_feature_value = 'llm_sonnet' THEN 300
    WHEN tier_value = 'pro' AND quota_feature_value = 'llm_opus' THEN 50
    WHEN tier_value = 'pro_plus' AND quota_feature_value = 'llm_haiku' THEN -1
    WHEN tier_value = 'pro_plus' AND quota_feature_value = 'llm_sonnet' THEN 1500
    WHEN tier_value = 'pro_plus' AND quota_feature_value = 'llm_opus' THEN 300
    WHEN tier_value = 'team' AND quota_feature_value = 'llm_haiku' THEN -1
    WHEN tier_value = 'team' AND quota_feature_value = 'llm_sonnet' THEN 3000
    WHEN tier_value = 'team' AND quota_feature_value = 'llm_opus' THEN 600
    WHEN tier_value = 'enterprise' THEN -1
    ELSE 0
  END;
  quota_period_value := CASE WHEN tier_value = 'free' THEN 'weekly' ELSE 'daily' END;
  IF quota_limit_value = 0 THEN
    RAISE EXCEPTION 'generation_quota_exceeded' USING ERRCODE = 'P0001';
  END IF;

  -- The shared ledger lock: claims, commits, fails, llm-proxy reservations and
  -- consume_quota for one user/feature all serialise here.
  PERFORM public.daily_usage_lock_v1(p_actor_id, quota_feature_value);

  SELECT EXISTS (
    SELECT 1 FROM public.meeting_document_generation_requests
    WHERE user_id = p_actor_id AND idempotency_key = p_idempotency_key
  ) INTO is_replay;

  -- A replay never starts provider work, so it takes no unit.
  IF NOT is_replay THEN
    reservation_id_value := gen_random_uuid();
    reservation := public.reserve_llm_quota(
      p_actor_id, reservation_id_value, quota_feature_value, quota_limit_value, quota_period_value
    );
    IF (reservation->>'allowed')::boolean IS NOT TRUE THEN
      RAISE EXCEPTION 'generation_quota_exceeded' USING ERRCODE = 'P0001';
    END IF;
  END IF;

  transcript_digest := encode(extensions.digest(transcript_value, 'sha256'), 'hex');
  request_digest := encode(extensions.digest(
    jsonb_build_object(
      'meeting_id', meeting_row.id,
      'template_id', template_row.id,
      'template_revision', template_row.revision,
      'transcript_hash', transcript_digest,
      'title', safe_title,
      'model', p_model
    )::text,
    'sha256'
  ), 'hex');

  INSERT INTO public.meeting_document_generation_requests(
    user_id, idempotency_key, meeting_id, template_id, request_hash,
    document_title, model, quota_feature, quota_limit, quota_period,
    template_revision, template_type, transcript_hash, status, llm_reservation_id
  )
  VALUES (
    p_actor_id, p_idempotency_key, meeting_row.id, template_row.id, request_digest,
    safe_title, p_model, quota_feature_value, quota_limit_value, quota_period_value,
    template_row.revision, template_row.template_type, transcript_digest, 'processing',
    reservation_id_value
  )
  ON CONFLICT DO NOTHING
  RETURNING true INTO inserted;

  SELECT * INTO request_row
  FROM public.meeting_document_generation_requests
  WHERE user_id = p_actor_id AND idempotency_key = p_idempotency_key;

  IF NOT coalesce(inserted, false) THEN
    IF request_row.request_hash <> request_digest THEN
      RAISE EXCEPTION 'generation_idempotency_conflict' USING ERRCODE = '22023';
    END IF;
    -- A concurrent claim for the same key won the insert; give our unit back.
    IF reservation_id_value IS NOT NULL THEN
      PERFORM public.finalize_llm_quota(reservation_id_value, false);
    END IF;
  END IF;

  RETURN jsonb_build_object(
    'claimed', coalesce(inserted, false),
    'status', request_row.status,
    'documentId', request_row.document_id,
    'meetingTitle', coalesce(meeting_row.title, 'Meeting'),
    'documentTitle', request_row.document_title,
    'templateType', request_row.template_type,
    'systemPrompt', CASE WHEN coalesce(inserted, false) THEN template_row.system_prompt ELSE NULL END,
    'transcript', CASE WHEN coalesce(inserted, false) THEN transcript_value ELSE NULL END,
    'model', request_row.model
  );
END;
$$;

REVOKE ALL ON FUNCTION public.claim_meeting_document_generation_v1(uuid, uuid, uuid, uuid, text, text)
  FROM PUBLIC, anon, authenticated;
GRANT EXECUTE ON FUNCTION public.claim_meeting_document_generation_v1(uuid, uuid, uuid, uuid, text, text)
  TO service_role;

-- ----------------------------------------------------------------------------
-- 5. Meeting-document fail: release the reserved unit.
-- ----------------------------------------------------------------------------
CREATE OR REPLACE FUNCTION public.fail_meeting_document_generation_v1(
  p_actor_id uuid,
  p_idempotency_key uuid,
  p_error_code text
)
RETURNS boolean
LANGUAGE plpgsql
SECURITY DEFINER
SET search_path = pg_catalog, public
AS $$
DECLARE
  changed integer;
  held_reservation uuid;
BEGIN
  IF p_error_code NOT IN (
    'provider_unavailable', 'provider_timeout', 'provider_request_failed',
    'provider_invalid_response', 'quota_exceeded', 'commit_failed'
  ) THEN
    RAISE EXCEPTION 'invalid_generation_error_code' USING ERRCODE = '22023';
  END IF;
  UPDATE public.meeting_document_generation_requests
  SET status = 'failed', error_code = p_error_code, completed_at = now()
  WHERE user_id = p_actor_id
    AND idempotency_key = p_idempotency_key
    AND status = 'processing'
  RETURNING llm_reservation_id INTO held_reservation;
  GET DIAGNOSTICS changed = ROW_COUNT;

  -- Rows claimed before 20260929020000 hold no reservation: nothing to release.
  -- finalize is a no-op for a reservation whose lease was already reclaimed.
  IF changed > 0 AND held_reservation IS NOT NULL THEN
    PERFORM public.finalize_llm_quota(held_reservation, false);
  END IF;
  RETURN changed > 0;
END;
$$;

REVOKE ALL ON FUNCTION public.fail_meeting_document_generation_v1(uuid, uuid, text)
  FROM PUBLIC, anon, authenticated;
GRANT EXECUTE ON FUNCTION public.fail_meeting_document_generation_v1(uuid, uuid, text)
  TO service_role;

-- ----------------------------------------------------------------------------
-- 6. Meeting-document commit: settle the reserved unit, never re-evaluate it.
-- ----------------------------------------------------------------------------
CREATE OR REPLACE FUNCTION public.commit_meeting_document_generation_v1(
  p_actor_id uuid,
  p_idempotency_key uuid,
  p_content text,
  p_latency_ms integer,
  p_input_tokens integer DEFAULT NULL,
  p_output_tokens integer DEFAULT NULL
)
RETURNS jsonb
LANGUAGE plpgsql
SECURITY DEFINER
SET search_path = pg_catalog, public
AS $$
DECLARE
  request_row public.meeting_document_generation_requests;
  document_row public.meeting_documents;
  settled jsonb;
  reservation jsonb;
  charged_reservation uuid;
  consumed_from text;
BEGIN
  IF char_length(trim(p_content)) NOT BETWEEN 1 AND 100000
     OR p_latency_ms NOT BETWEEN 0 AND 600000
     OR (p_input_tokens IS NOT NULL AND p_input_tokens < 0)
     OR (p_output_tokens IS NOT NULL AND p_output_tokens < 0) THEN
    RAISE EXCEPTION 'invalid_generation_result' USING ERRCODE = '22023';
  END IF;

  SELECT * INTO request_row
  FROM public.meeting_document_generation_requests
  WHERE user_id = p_actor_id AND idempotency_key = p_idempotency_key
  FOR UPDATE;
  IF request_row.user_id IS NULL THEN
    RAISE EXCEPTION 'generation_request_not_found' USING ERRCODE = 'P0002';
  END IF;
  IF request_row.status = 'succeeded' THEN
    SELECT * INTO document_row FROM public.meeting_documents WHERE id = request_row.document_id;
    RETURN jsonb_build_object('idempotent', true, 'document', to_jsonb(document_row));
  END IF;
  IF request_row.status <> 'processing' THEN
    RAISE EXCEPTION 'generation_request_not_committable' USING ERRCODE = '55000';
  END IF;

  PERFORM public.daily_usage_lock_v1(p_actor_id, request_row.quota_feature);

  charged_reservation := request_row.llm_reservation_id;
  IF charged_reservation IS NOT NULL THEN
    -- The claim already holds the unit: spend it (no allowance re-check).
    settled := public.finalize_llm_quota(charged_reservation, true);
  END IF;

  IF settled->>'status' = 'completed' THEN
    SELECT reservation_row.consumed_from
    INTO consumed_from
    FROM public.llm_quota_reservations AS reservation_row
    WHERE reservation_row.id = charged_reservation;
  ELSE
    -- No unit is held: a row claimed before 20260929020000, or a reservation
    -- whose lease expired and was reclaimed before commit arrived. Charge one
    -- unit now through the same ledger (the previous commit-time rule).
    charged_reservation := gen_random_uuid();
    reservation := public.reserve_llm_quota(
      p_actor_id, charged_reservation, request_row.quota_feature,
      request_row.quota_limit, request_row.quota_period
    );
    IF (reservation->>'allowed')::boolean IS NOT TRUE THEN
      RAISE EXCEPTION 'generation_quota_exceeded' USING ERRCODE = 'P0001';
    END IF;
    PERFORM public.finalize_llm_quota(charged_reservation, true);
    consumed_from := reservation->>'consumed_from';
  END IF;

  INSERT INTO public.meeting_documents(
    meeting_id, user_id, template_type, title, content, prompt_used,
    llm_model, llm_latency_ms, template_id, generation_idempotency_key
  )
  VALUES (
    request_row.meeting_id,
    p_actor_id,
    request_row.template_type,
    request_row.document_title,
    trim(p_content),
    'template:' || request_row.template_id::text || '@' || request_row.template_revision::text,
    request_row.model,
    p_latency_ms,
    request_row.template_id,
    p_idempotency_key
  )
  RETURNING * INTO document_row;

  INSERT INTO public.meeting_document_generation_audit(
    user_id, meeting_id, template_id, document_id, idempotency_key,
    model, template_revision, transcript_hash, input_tokens, output_tokens, latency_ms
  )
  VALUES (
    p_actor_id, request_row.meeting_id, request_row.template_id, document_row.id,
    p_idempotency_key, request_row.model, request_row.template_revision,
    request_row.transcript_hash, p_input_tokens, p_output_tokens, p_latency_ms
  );

  UPDATE public.meeting_document_generation_requests
  SET status = 'succeeded',
      document_id = document_row.id,
      llm_reservation_id = charged_reservation,
      error_code = NULL,
      completed_at = now()
  WHERE user_id = p_actor_id AND idempotency_key = p_idempotency_key;

  RETURN jsonb_build_object(
    'idempotent', false,
    'consumedFrom', consumed_from,
    'document', to_jsonb(document_row)
  );
END;
$$;

REVOKE ALL ON FUNCTION public.commit_meeting_document_generation_v1(uuid, uuid, text, integer, integer, integer)
  FROM PUBLIC, anon, authenticated;
GRANT EXECUTE ON FUNCTION public.commit_meeting_document_generation_v1(uuid, uuid, text, integer, integer, integer)
  TO service_role;