-- =============================================================================
-- Vignette · 03_kb.sql
-- kb 스키마: 정적 지식 KB (DSM/이론/technique/taxonomy) — app 과 물리 분리
--   ⑤ KNOWLEDGE 계층. 3-AI 가 같은 물리 테이블을 다른 정책(visible_to+sensitivity)으로 검색.
-- 근거: MEMORY_KNOWLEDGE_PERSONA_DESIGN.md §3.6, §4.3 / MASTERPLAN §3.6
-- 전제: 02_schema.sql (app.technique_label_def 존재). 적용 순서: 02 → 03(본 파일).
-- 원칙: app 으로의 FK 없음(read-only 독립). license_class C/D = 외부 LLM 차단.
-- =============================================================================

CREATE SCHEMA IF NOT EXISTS kb;
CREATE EXTENSION IF NOT EXISTS vector;
CREATE EXTENSION IF NOT EXISTS pg_trgm;

SET search_path TO kb, public;

-- =============================================================================
-- 1. 출처 + 라이선스 (DSM-5 저작권 1차 통제, 설계서 §3.6)
-- =============================================================================
CREATE TABLE IF NOT EXISTS kb.source (
  source_id       TEXT PRIMARY KEY,                     -- 'dsm5','theory','taxonomy_0615'
  title           TEXT NOT NULL,
  kb_kind         TEXT NOT NULL CHECK (kb_kind IN
                    ('diagnostic','theory','technique','taxonomy',
                     'supervisor_pattern','template','ko_context','microskill')),
  license_class   CHAR(1) NOT NULL CHECK (license_class IN ('A','B','C','D')),
                    -- C=저작권민감 D=미성년파생
  origin_path     TEXT,
  citation        TEXT,
  external_llm_ok BOOLEAN NOT NULL DEFAULT FALSE,        -- C/D면 false → 국내 라우팅
  created_at      TIMESTAMPTZ NOT NULL DEFAULT now()
);

-- =============================================================================
-- 2. 문서 + 버전 (graphify content_hash 증분 인덱싱 차용)
-- =============================================================================
CREATE TABLE IF NOT EXISTS kb.document (
  doc_id        BIGINT GENERATED ALWAYS AS IDENTITY PRIMARY KEY,
  source_id     TEXT NOT NULL REFERENCES kb.source(source_id),
  doc_uri       TEXT NOT NULL,
  version       INT  NOT NULL DEFAULT 1,
  content_hash  TEXT NOT NULL,                           -- SHA256 → 변경감지(증분)
  superseded_by BIGINT REFERENCES kb.document(doc_id),
  is_active     BOOLEAN NOT NULL DEFAULT TRUE,
  indexed_at    TIMESTAMPTZ,
  created_at    TIMESTAMPTZ NOT NULL DEFAULT now(),
  UNIQUE (source_id, doc_uri, version)
);
CREATE INDEX IF NOT EXISTS idx_kb_doc_active
  ON kb.document(source_id) WHERE is_active;

-- =============================================================================
-- 3. 청크 + 멀티벡터 (검색 본체, 설계서 §3.6)
--    visible_to + sensitivity 가 3-AI 정보비대칭을 DB WHERE 로 강제.
-- =============================================================================
CREATE TABLE IF NOT EXISTS kb.chunk (
  chunk_id       BIGINT GENERATED ALWAYS AS IDENTITY PRIMARY KEY,
  doc_id         BIGINT NOT NULL REFERENCES kb.document(doc_id) ON DELETE CASCADE,
  source_id      TEXT NOT NULL,                          -- 비정규화(필터 가속)
  kb_kind        TEXT NOT NULL,                          -- 비정규화
  seq            INT  NOT NULL,
  heading_path   TEXT,
  chunk_text     TEXT NOT NULL,                          -- 표시·LLM 주입(prefix 미포함)
  context_prefix TEXT,                                   -- Contextual Retrieval 주입문
  embedding      vector(1024),                           -- BGE-M3 dense
  sparse_vec     JSONB,                                  -- BGE-M3 sparse
  colbert_vecs   JSONB,                                  -- 멀티벡터(단일 호출 산출)
  visible_to     TEXT[] NOT NULL DEFAULT '{client,counselor,evaluator}',
  sensitivity    SMALLINT NOT NULL DEFAULT 0
                   CHECK (sensitivity BETWEEN 0 AND 3),  -- 0공개 1내부 2평가전용 3원천격리
  label_id       BIGINT REFERENCES app.technique_label_def(label_id),  -- taxonomy 정답라벨
  meta           JSONB DEFAULT '{}',                     -- {dsm_category,theory,bias_weight,...}
  token_count    INT,
  created_at     TIMESTAMPTZ NOT NULL DEFAULT now()
);
-- dense ANN
CREATE INDEX IF NOT EXISTS idx_chunk_hnsw ON kb.chunk
  USING hnsw (embedding vector_cosine_ops) WITH (m = 16, ef_construction = 64);
-- sparse/BM25 (한국어: simple + pg_trgm 병용, M10 완화)
CREATE INDEX IF NOT EXISTS idx_chunk_fts ON kb.chunk
  USING gin (to_tsvector('simple', chunk_text));
CREATE INDEX IF NOT EXISTS idx_chunk_trgm ON kb.chunk
  USING gin (chunk_text gin_trgm_ops);
-- 정보비대칭 사전필터
CREATE INDEX IF NOT EXISTS idx_chunk_visible ON kb.chunk USING gin (visible_to);
CREATE INDEX IF NOT EXISTS idx_chunk_route ON kb.chunk (kb_kind, sensitivity);
CREATE INDEX IF NOT EXISTS idx_chunk_source ON kb.chunk (source_id);

-- =============================================================================
-- 4. KB 검색 로그 (환각측정·캐시검증, 람다 cost.json 차용, 설계서 §3.7)
-- =============================================================================
CREATE TABLE IF NOT EXISTS kb.retrieval_log (
  id             BIGINT GENERATED ALWAYS AS IDENTITY PRIMARY KEY,
  session_id     UUID,
  turn_id        UUID,
  ai_role        TEXT NOT NULL,                          -- 'client'|'counselor'|'evaluator'
  query_text     TEXT,
  policy         TEXT NOT NULL,                          -- 4-튜플 정책명
  hit_chunk_ids  BIGINT[],
  rerank_scores  REAL[],
  top1_score     REAL,                                   -- CRAG 게이트
  used_in_answer BOOLEAN,
  latency_ms     INT,
  created_at     TIMESTAMPTZ NOT NULL DEFAULT now()
);
CREATE INDEX IF NOT EXISTS idx_kb_retr_session ON kb.retrieval_log(session_id);