"""LPS 동기화 CRUD — negosium(main) 쪽 조회/반영 + lps_db(읽기전용) 결과 조회.

경계 규칙
- lps_db 는 LPS 서비스 소유라 ORM 모델을 만들지 않는다 — anchoring reader 선례대로
  raw table() 로 **price_history 만** 읽는다(그 외 테이블은 LPS 내부 구현으로 간주).
- 워터마크는 별도 상태 테이블 없이 partner.item_internet_lowest_prices 의
  max(crawl_end_time) 을 쓴다(crawl_end_time = price_history.created_at 을 그대로 보존).
  반영이 중간에 실패해도 다음 tick 이 같은 지점부터 다시 읽는다(자기 치유).
"""
from abc import ABC, abstractmethod
from typing import Tuple

from sqlalchemy import column, func, select, table, update
from sqlalchemy.ext.asyncio import AsyncSession

from common.database.db_session_manager import DB_SESSION_MNG
from common.database.model.models import item_internet_lowest_prices, items
from common.enums import ErrorType
from common.logger import LOG

# lps_db.price_history — LPS 가 검색 1건마다 남기는 append-only 스냅샷(읽기 계약).
_price_history = table(
    "price_history",
    column("product_code"),   # = negosium items.item_id (요청 시 그대로 넣는다)
    column("outcome"),        # found | not_found
    column("final_lowest"),   # 전체 최저가(원)
    column("final_source"),   # naver | coupang | (폴백몰)
    column("created_at"),
)


class ILpsSyncCRUD(ABC):
    @abstractmethod
    async def watermark(self, cdb: AsyncSession) -> Tuple[ErrorType, object]:
        pass

    @abstractmethod
    async def existing_item_ids(self, cdb: AsyncSession, item_ids: list) -> Tuple[ErrorType, set]:
        pass

    @abstractmethod
    async def fetch_results_since(self, ldb: AsyncSession, since) -> Tuple[ErrorType, list]:
        pass

    @abstractmethod
    async def recent_history(self, cdb: AsyncSession, item_id, limit) -> Tuple[ErrorType, list]:
        pass

    @abstractmethod
    async def add_history_rows(self, cdb: AsyncSession, rows: list) -> ErrorType:
        pass

    @abstractmethod
    async def update_item_lowest(self, cdb: AsyncSession, item_id, price) -> ErrorType:
        pass


class LpsSyncCRUD(ILpsSyncCRUD):
    # ---- negosium(main) 조회 -------------------------------------------
    async def watermark(self, cdb: AsyncSession):
        """수집 이력의 최신 crawl_end_time — 증분 동기화 기준점. 이력이 없으면 None(전체 수집)."""
        try:
            q = select(func.max(item_internet_lowest_prices.crawl_end_time)).where(
                item_internet_lowest_prices.deleted == False  # noqa: E712
            )
            return ErrorType.SUCCESS, (await cdb.execute(q)).scalar()
        except Exception as ex:
            LOG.e_no_callstack(f"[lps-sync] watermark 조회 실패: {ex}")
            return ErrorType.DB_RUN_FAILED, None

    async def existing_item_ids(self, cdb: AsyncSession, item_ids: list):
        """전달된 id 중 실재하는 활성 상품 id 집합 — 결과 반영 전 매핑 검증용."""
        if not item_ids:
            return ErrorType.SUCCESS, set()
        try:
            q = select(items.item_id).where(
                items.item_id.in_(item_ids),
                items.deleted == False,  # noqa: E712
            )
            return ErrorType.SUCCESS, {r[0] for r in (await cdb.execute(q)).all()}
        except Exception as ex:
            LOG.e_no_callstack(f"[lps-sync] existing_item_ids 조회 실패: {ex}")
            return ErrorType.DB_RUN_FAILED, set()

    async def recent_history(self, cdb: AsyncSession, item_id, limit: int):
        """상품의 최근 수집 이력(최신순) — lowest-price 조회 API 용. idx_iilp_item_crawl_time 사용."""
        try:
            q = (
                select(item_internet_lowest_prices)
                .where(
                    item_internet_lowest_prices.item_id == item_id,
                    item_internet_lowest_prices.deleted == False,  # noqa: E712
                )
                .order_by(item_internet_lowest_prices.crawl_end_time.desc())
                .limit(limit)
            )
            return ErrorType.SUCCESS, (await cdb.execute(q)).scalars().all()
        except Exception as ex:
            LOG.e_no_callstack(f"[lps-sync] recent_history 조회 실패: {ex}")
            return ErrorType.DB_RUN_FAILED, []

    # ---- lps_db(읽기전용) 조회 -----------------------------------------
    async def fetch_results_since(self, ldb: AsyncSession, since):
        """워터마크 이후의 price_history 증분. since 가 None 이면 전체(첫 동기화)."""
        try:
            q = select(
                _price_history.c.product_code,
                _price_history.c.outcome,
                _price_history.c.final_lowest,
                _price_history.c.final_source,
                _price_history.c.created_at,
            ).order_by(_price_history.c.created_at.asc())
            if since is not None:
                q = q.where(_price_history.c.created_at > since)
            return ErrorType.SUCCESS, (await ldb.execute(q)).all()
        except Exception as ex:
            LOG.e_no_callstack(f"[lps-sync] price_history 조회 실패: {ex}")
            return ErrorType.DB_RUN_FAILED, []

    # ---- negosium(main) 반영 (execute_lambda_run 안에서 호출) -----------
    async def add_history_rows(self, cdb: AsyncSession, rows: list) -> ErrorType:
        """수집 이력 일괄 insert. rows = item_internet_lowest_prices ORM 객체 리스트."""
        if not rows:
            return ErrorType.SUCCESS
        return await DB_SESSION_MNG.insert(cdb, rows, err_msg="lps-sync history insert 실패")

    async def update_item_lowest(self, cdb: AsyncSession, item_id, price) -> ErrorType:
        """상품 대표 최저가 박제 — items.internet_lowest_price + yn 플래그."""
        q = (
            update(items)
            .where(items.item_id == item_id, items.deleted == False)  # noqa: E712
            .values(internet_lowest_price=price, internet_lowest_price_yn=True)
        )
        return await DB_SESSION_MNG.add(cdb, q, err_msg=f"lps-sync 최저가 반영 실패 item={item_id}")