-- =============================================================================
-- Vignette · 17_improvement_workbook_contracts.sql
-- 개선관리 워크북의 기존 DB forward 계약.
-- 신규 볼륨의 02/03/05 foundation과 중복 적용되어도 안전해야 한다.
-- =============================================================================

BEGIN;

ALTER TABLE app.app_user
  ADD COLUMN IF NOT EXISTS learner_feedback_enabled BOOLEAN NOT NULL DEFAULT TRUE;

ALTER TABLE app.sessions
  ADD COLUMN IF NOT EXISTS learner_feedback_enabled BOOLEAN NOT NULL DEFAULT TRUE;

CREATE SCHEMA IF NOT EXISTS kb;

-- 과거 행도 외부 LLM 경계를 위반하지 않도록 먼저 fail-closed로 정규화한다.
UPDATE kb.source
SET external_llm_ok = FALSE
WHERE license_class IN ('C', 'D')
  AND external_llm_ok IS TRUE;

DO $$
BEGIN
  IF NOT EXISTS (
    SELECT 1
    FROM pg_constraint c
    JOIN pg_class t ON t.oid = c.conrelid
    JOIN pg_namespace n ON n.oid = t.relnamespace
    WHERE n.nspname = 'kb'
      AND t.relname = 'source'
      AND c.conname = 'ck_kb_source_external_license'
  ) THEN
    ALTER TABLE kb.source
      ADD CONSTRAINT ck_kb_source_external_license
      CHECK (license_class IN ('A', 'B') OR external_llm_ok = FALSE)
      NOT VALID;
  END IF;
END $$;

ALTER TABLE kb.source
  VALIDATE CONSTRAINT ck_kb_source_external_license;

CREATE TABLE IF NOT EXISTS kb.protocol_registration (
  protocol_id     UUID PRIMARY KEY,
  source_id       TEXT NOT NULL UNIQUE,
  title           TEXT NOT NULL CHECK (btrim(title) <> ''),
  source_ref      TEXT NOT NULL CHECK (btrim(source_ref) <> ''),
  version         INT NOT NULL CHECK (version > 0),
  license_class   CHAR(1) NOT NULL CHECK (license_class IN ('A', 'B', 'C', 'D')),
  external_llm_ok BOOLEAN NOT NULL DEFAULT FALSE,
  content         TEXT NOT NULL CHECK (btrim(content) <> ''),
  content_hash    CHAR(64) NOT NULL CHECK (content_hash ~ '^[0-9a-f]{64}$'),
  status          TEXT NOT NULL DEFAULT 'draft'
                    CHECK (status IN ('draft', 'active', 'retired')),
  registered_by   UUID NOT NULL REFERENCES app.app_user(user_id) ON DELETE RESTRICT,
  registered_at   TIMESTAMPTZ NOT NULL DEFAULT now(),
  activated_at    TIMESTAMPTZ,
  retired_at      TIMESTAMPTZ
);

-- 테이블이 이전 런타임 DDL로 만들어졌어도 정책 제약을 같은 이름으로 보강한다.
UPDATE kb.protocol_registration
SET external_llm_ok = FALSE
WHERE license_class IN ('C', 'D')
  AND external_llm_ok IS TRUE;

DO $$
BEGIN
  IF NOT EXISTS (
    SELECT 1
    FROM pg_constraint c
    JOIN pg_class t ON t.oid = c.conrelid
    JOIN pg_namespace n ON n.oid = t.relnamespace
    WHERE n.nspname = 'kb'
      AND t.relname = 'protocol_registration'
      AND c.conname = 'ck_protocol_external_license'
  ) THEN
    ALTER TABLE kb.protocol_registration
      ADD CONSTRAINT ck_protocol_external_license
      CHECK (license_class IN ('A', 'B') OR external_llm_ok = FALSE)
      NOT VALID;
  END IF;

  IF NOT EXISTS (
    SELECT 1
    FROM pg_constraint c
    JOIN pg_class t ON t.oid = c.conrelid
    JOIN pg_namespace n ON n.oid = t.relnamespace
    WHERE n.nspname = 'kb'
      AND t.relname = 'protocol_registration'
      AND c.conname = 'ck_protocol_lifecycle_timestamps'
  ) THEN
    ALTER TABLE kb.protocol_registration
      ADD CONSTRAINT ck_protocol_lifecycle_timestamps CHECK (
        (status = 'draft' AND activated_at IS NULL AND retired_at IS NULL)
        OR (status = 'active' AND activated_at IS NOT NULL AND retired_at IS NULL)
        OR (status = 'retired' AND activated_at IS NOT NULL AND retired_at IS NOT NULL)
      ) NOT VALID;
  END IF;
END $$;

ALTER TABLE kb.protocol_registration
  VALIDATE CONSTRAINT ck_protocol_external_license;
ALTER TABLE kb.protocol_registration
  VALIDATE CONSTRAINT ck_protocol_lifecycle_timestamps;

CREATE INDEX IF NOT EXISTS idx_protocol_registration_status
  ON kb.protocol_registration(status, registered_at DESC);

-- 활성화/퇴역은 admin 역할로 kb.chunk를 같은 트랜잭션에서 갱신한다.
-- 기존 볼륨에도 신규 볼륨과 동일한 admin-only write RLS 계약을 보강한다.
ALTER TABLE kb.chunk ENABLE ROW LEVEL SECURITY;
DROP POLICY IF EXISTS p_kb_chunk_admin_write ON kb.chunk;
CREATE POLICY p_kb_chunk_admin_write ON kb.chunk
  FOR ALL
  USING (app.current_role_name() = 'admin')
  WITH CHECK (app.current_role_name() = 'admin');

COMMIT;