import os
import sys
import pandas as pd
import shutil
import threading
from queue import Queue
from sqlalchemy import Table, MetaData
from sqlalchemy.dialects.mysql import insert as mysql_insert
from sqlalchemy.exc import SQLAlchemyError

sys.path.append(os.path.abspath(os.path.join(os.path.dirname(__file__), '..')))

from lib.common import get_logger
from conf import db, db_schema  # get_engine, get_session 포함

logger = get_logger("POS_UPS")

DATA_DIR = os.path.abspath(os.path.join(os.path.dirname(__file__), "../data"))
FINISH_DIR = os.path.join(DATA_DIR, "finish")
os.makedirs(FINISH_DIR, exist_ok=True)


def nan_to_none(value):
    import pandas as pd
    if pd.isna(value):
        return None
    return value


def load_excel_data(filepath: str):
    df = pd.read_excel(filepath, header=1)  # 2행이 header, 3행부터 데이터
    df.columns = [col.strip() for col in df.columns]
    required_cols = ['영수증 번호', '품목명']
    for col in required_cols:
        if col not in df.columns:
            raise ValueError(f"필수 컬럼 누락: {col}")
    df = df.dropna(subset=required_cols)
    return df


def prepare_bulk_data(df):
    bulk_data = []
    for idx, row in df.iterrows():
        try:
            data = {
                "sale_date": pd.to_datetime(row["매출일시"]),
                "shop_name": str(row["매장명"]).strip(),
                "pos_no": str(row["포스"]).strip(),
                "bill_no": str(row["영수증 번호"]).strip(),
                "product_cd": str(row["품목"]).strip(),
                "product_name": str(row["품목명"]).strip(),
                "qty": int(row["수량"]),

                "ca01": nan_to_none(row.get("대분류", None)),
                "ca02": nan_to_none(row.get("중분류", None)),
                "ca03": nan_to_none(row.get("소분류", None)),
                "barcode": nan_to_none(row.get("바코드", None)),
                "amt": int(row.get("단가", 0)),
                "tot_sale_amt": int(row.get("주문 금액", 0)),
                "dc_amt": int(row.get("할인 금액", 0)),
                "dcm_sale_amt": int(row.get("공급가액", 0)),
                "vat_amt": int(row.get("세금", 0)),
                "net_amt": int(row.get("결제 금액", 0)),
                "cash_receipt": int(row.get("현금영수증", 0)),
                "card": int(row.get("카드", 0)),
            }
            bulk_data.append(data)
        except Exception as e:
            logger.warning(f"[ERROR:ROW] 데이터 생성 실패: {e} / 인덱스: {idx}")
    return bulk_data


def process_bulk_upsert(bulk_data, session, table):
    if not bulk_data:
        logger.info("[INFO] 삽입할 데이터가 없습니다.")
        return

    insert_stmt = mysql_insert(table).values(bulk_data)

    update_cols = {c.name: insert_stmt.inserted[c.name] for c in table.columns
                   if c.name not in ['sale_date', 'shop_name', 'pos_no', 'bill_no', 'product_cd']}

    upsert_stmt = insert_stmt.on_duplicate_key_update(update_cols)

    try:
        result = session.execute(upsert_stmt)
        session.commit()
        logger.info(f"[DONE] 총 {len(bulk_data)}건 처리 완료 (insert+update)")
    except SQLAlchemyError as e:
        session.rollback()
        logger.error(f"[FAIL] bulk upsert 실패: {e}")
        raise


def file_reader(queue, files):
    for filepath in files:
        try:
            logger.info(f"[READ] {os.path.basename(filepath)} 읽기 시작")
            df = load_excel_data(filepath)
            logger.info(f"[READ] {os.path.basename(filepath)} 읽기 완료 - {len(df)}건")
            bulk_data = prepare_bulk_data(df)
            queue.put((filepath, bulk_data))
        except Exception as e:
            logger.error(f"[FAIL] {os.path.basename(filepath)} 읽기 실패 - {e}")
    queue.put(None)  # 종료 신호


def db_writer(queue, session, table):
    while True:
        item = queue.get()
        if item is None:
            break
        filepath, bulk_data = item
        logger.info(f"[START] {os.path.basename(filepath)} DB 삽입 시작")
        try:
            process_bulk_upsert(bulk_data, session, table)
            dest = os.path.join(FINISH_DIR, os.path.basename(filepath))
            shutil.move(filepath, dest)
            logger.info(f"[MOVE] 완료: {dest}")
        except Exception as e:
            logger.error(f"[FAIL] {os.path.basename(filepath)} DB 삽입 실패 - {e}")


def main():
    engine = db.get_engine()
    session = db.get_session()

    metadata = MetaData()
    table = Table(
        db_schema.get_full_table_name("pos_ups_billdata"),
        metadata,
        autoload_with=engine
    )

    files = [os.path.join(DATA_DIR, f) for f in os.listdir(DATA_DIR)
             if f.endswith(".xlsx") and f.startswith("영수증별 상세매출")]

    logger.info(f"[INFO] 처리할 파일 {len(files)}개")

    queue = Queue(maxsize=2)  # 2개 정도 여유 있게

    reader_thread = threading.Thread(target=file_reader, args=(queue, files))
    writer_thread = threading.Thread(target=db_writer, args=(queue, session, table))

    reader_thread.start()
    writer_thread.start()

    reader_thread.join()
    writer_thread.join()


if __name__ == "__main__":
    main()