-- hyungi_Document_Server 초기 스키마
-- PostgreSQL 16 + pgvector + pg_trgm

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

-- ENUM 타입
CREATE TYPE doc_type AS ENUM ('immutable', 'editable', 'note');
CREATE TYPE source_channel AS ENUM (
    'law_monitor', 'devonagent', 'email', 'web_clip',
    'tksafety', 'inbox_route', 'manual', 'drive_sync'
);
CREATE TYPE data_origin AS ENUM ('work', 'external');
CREATE TYPE process_stage AS ENUM ('extract', 'classify', 'embed');
CREATE TYPE process_status AS ENUM ('pending', 'processing', 'completed', 'failed');

-- documents 테이블
CREATE TABLE documents (
    id              BIGSERIAL PRIMARY KEY,

    -- 1계층: 원본 파일 참조
    file_path       TEXT NOT NULL UNIQUE,
    file_hash       CHAR(64) NOT NULL,
    file_format     VARCHAR(20) NOT NULL,
    file_size       BIGINT,
    file_type       doc_type NOT NULL DEFAULT 'immutable',
    import_source   TEXT,

    -- 2계층: 텍스트 추출
    extracted_text      TEXT,
    extracted_at        TIMESTAMPTZ,
    extractor_version   VARCHAR(50),

    -- 2계층: AI 가공
    ai_summary          TEXT,
    ai_tags             JSONB DEFAULT '[]',
    ai_domain           VARCHAR(100),
    ai_sub_group        VARCHAR(100),
    ai_model_version    VARCHAR(50),
    ai_processed_at     TIMESTAMPTZ,

    -- 3계층: 벡터 임베딩
    embedding           vector(768),
    embed_model_version VARCHAR(50),
    embedded_at         TIMESTAMPTZ,

    -- 메타데이터
    source_channel  source_channel,
    data_origin     data_origin,
    title           TEXT,

    -- 타임스탬프
    created_at      TIMESTAMPTZ DEFAULT NOW(),
    updated_at      TIMESTAMPTZ DEFAULT NOW()
);

-- 전문검색 인덱스
CREATE INDEX idx_documents_fts ON documents
    USING GIN (to_tsvector('simple', coalesce(title, '') || ' ' || coalesce(extracted_text, '')));

-- 트리그램 인덱스 (한국어 부분 매칭)
CREATE INDEX idx_documents_trgm ON documents
    USING GIN ((coalesce(title, '') || ' ' || coalesce(extracted_text, '')) gin_trgm_ops);

-- 해시 기반 중복 검색
CREATE INDEX idx_documents_hash ON documents (file_hash);

-- 재가공 대상 필터링
CREATE INDEX idx_documents_ai_version ON documents (ai_model_version);
CREATE INDEX idx_documents_extractor_version ON documents (extractor_version);
CREATE INDEX idx_documents_embed_version ON documents (embed_model_version);

-- tasks 테이블 (CalDAV 캐시)
CREATE TABLE tasks (
    id              BIGSERIAL PRIMARY KEY,
    caldav_uid      TEXT UNIQUE,
    title           TEXT NOT NULL,
    description     TEXT,
    due_date        TIMESTAMPTZ,
    priority        SMALLINT DEFAULT 0,
    completed       BOOLEAN DEFAULT FALSE,
    completed_at    TIMESTAMPTZ,
    document_id     BIGINT REFERENCES documents(id),
    source          VARCHAR(50),
    created_at      TIMESTAMPTZ DEFAULT NOW(),
    updated_at      TIMESTAMPTZ DEFAULT NOW()
);

-- processing_queue 테이블 (비동기 가공 큐)
CREATE TABLE processing_queue (
    id              BIGSERIAL PRIMARY KEY,
    document_id     BIGINT REFERENCES documents(id) NOT NULL,
    stage           process_stage NOT NULL,
    status          process_status DEFAULT 'pending',
    attempts        SMALLINT DEFAULT 0,
    max_attempts    SMALLINT DEFAULT 3,
    error_message   TEXT,
    created_at      TIMESTAMPTZ DEFAULT NOW(),
    started_at      TIMESTAMPTZ,
    completed_at    TIMESTAMPTZ,

    UNIQUE (document_id, stage, status)
);

CREATE INDEX idx_queue_pending ON processing_queue (stage, status)
    WHERE status = 'pending';