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

import requests
from datetime import datetime, timedelta
from sqlalchemy import select, func, and_
from sqlalchemy.exc import IntegrityError
from sqlalchemy.dialects.mysql import insert as mysql_insert

from conf import db, db_schema

def test_num_of_rows(api_key, station_name, date_str=None):
    if date_str is None:
        date_str = (datetime.now() - timedelta(days=1)).strftime('%Y%m%d')

    max_rows = 1000
    min_rows = 100

    while max_rows >= min_rows:
        try:
            url = "http://apis.data.go.kr/B552584/ArpltnStatsSvc/getMsrstnAcctoRDyrg"
            params = {
                'serviceKey': api_key,
                'returnType': 'json',
                'numOfRows': str(max_rows),
                'pageNo': '1',
                'inqBginDt': date_str,
                'inqEndDt': date_str,
                'msrstnName': station_name,
            }
            resp = requests.get(url, params=params, timeout=10)
            resp.raise_for_status()
            resp.json()
            print(f"[INFO] numOfRows 최대값 탐색 성공: {max_rows}")
            return max_rows
        except (requests.RequestException, ValueError) as e:
            print(f"[WARN] numOfRows={max_rows} 에러 발생: {e}, 100 감소 후 재시도")
            max_rows -= 100

    print("[WARN] 최소 numOfRows 값(100)도 실패했습니다. 기본값 100 사용")
    return 100

def fetch_air_quality_data_range(start_date_str, end_date_str, api_key, station_name, num_of_rows=100, page_no=1):
    url = "http://apis.data.go.kr/B552584/ArpltnStatsSvc/getMsrstnAcctoRDyrg"
    params = {
        'serviceKey': api_key,
        'returnType': 'json',
        'numOfRows': str(num_of_rows),
        'pageNo': str(page_no),
        'inqBginDt': start_date_str,
        'inqEndDt': end_date_str,
        'msrstnName': station_name,
    }

    try:
        resp = requests.get(url, params=params, timeout=10)
        resp.raise_for_status()
        data = resp.json()
        items = data.get('response', {}).get('body', {}).get('items', [])
        return items
    except requests.RequestException as e:
        print(f"[ERROR] 요청 실패: {e}")
        return []
    except ValueError as e:
        print(f"[ERROR] JSON 파싱 실패: {e}")
        return []

def save_data_to_db(items, conn, table, station, force_update=False, debug=False):
    for item in items:
        try:
            item_date = datetime.strptime(item['msurDt'], '%Y-%m-%d').date()
        except Exception as e:
            print(f"[ERROR] 날짜 파싱 오류: {item.get('msurDt')} → {e}")
            continue

        data = {
            'date': item_date,
            'station': station,
            'pm25': float(item.get('pm25Value')) if item.get('pm25Value') else None,
            'pm10': float(item.get('pm10Value')) if item.get('pm10Value') else None,
            'so2': float(item.get('so2Value')) if item.get('so2Value') else None,
            'co': float(item.get('coValue')) if item.get('coValue') else None,
            'no2': float(item.get('no2Value')) if item.get('no2Value') else None,
            'o3': float(item.get('o3Value')) if item.get('o3Value') else None,
        }

        try:
            if debug:
                print(f"[DEBUG] {item_date} [{station}] → DB 저장 시도: {data}")
                continue

            if force_update:
                stmt = mysql_insert(table).values(**data)
                on_duplicate_stmt = stmt.on_duplicate_key_update(**data)
                conn.execute(on_duplicate_stmt)
                print(f"[INFO] {item_date} [{station}] 저장/업데이트 완료 (강제업데이트)")
            else:
                sel = select(table.c.date).where(and_(table.c.date == item_date, table.c.station == station))
                exists = conn.execute(sel).fetchone()
                if exists:
                    print(f"[INFO] {item_date} [{station}] 이미 존재. 저장 생략")
                    continue
                ins = table.insert().values(**data)
                conn.execute(ins)
                print(f"[INFO] {item_date} [{station}] 저장 완료")
        except IntegrityError as e:
            print(f"[ERROR] DB 중복 오류: {e}")
        except Exception as e:
            print(f"[ERROR] DB 저장 실패: {e}")

def get_latest_date(conn, table, station):
    try:
        sel = select(func.max(table.c.date)).where(table.c.station == station)
        result = conn.execute(sel).scalar()
        if result is None:
            print(f"[INFO] {station}: 테이블에 데이터가 없습니다.")
        return result
    except Exception as e:
        print(f"[ERROR] 가장 최근 날짜 조회 실패: {e}")
        return None

def main():
    config = db.load_config()
    api_key = config['DATA_API']['serviceKey']
    station_list = config['DATA_API']['air']['station_name']
    debug = config.get('debug', False)
    force_update = config.get('force_update', False)
    config_start_date = datetime.strptime(config['DATA_API']['startDt'], '%Y%m%d').date()
    yesterday = (datetime.now() - timedelta(days=1)).date()

    engine = db.engine
    table = db_schema.air

    with engine.connect() as conn:
        for station_name in station_list:
            print(f"\n[INFO] 측정소: {station_name}")

            latest_date = get_latest_date(conn, table, station_name)
            if latest_date:
                start_date = max(config_start_date, latest_date + timedelta(days=1))
            else:
                start_date = config_start_date

            if start_date > yesterday:
                print(f"[INFO] {station_name}: 최신 데이터가 이미 존재합니다. ({latest_date})")
                continue

            optimal_num_rows = test_num_of_rows(api_key, station_name=station_name, date_str=start_date.strftime('%Y%m%d'))
            print(f"[INFO] 최적 numOfRows: {optimal_num_rows}")

            current_start = start_date
            while current_start <= yesterday:
                current_end = min(current_start + timedelta(days=optimal_num_rows - 1), yesterday)
                start_str = current_start.strftime('%Y%m%d')
                end_str = current_end.strftime('%Y%m%d')

                print(f"[INFO] {station_name}: {start_str} ~ {end_str} 데이터 요청 중...")
                items = fetch_air_quality_data_range(start_str, end_str, api_key, station_name, num_of_rows=optimal_num_rows)

                if items:
                    save_data_to_db(items, conn, table, station=station_name, force_update=force_update, debug=debug)
                else:
                    print(f"[INFO] {station_name}: {start_str} ~ {end_str} 데이터 없음")

                current_start = current_end + timedelta(days=1)

        print("[INFO] 모든 측정소 데이터 처리 완료")

if __name__ == '__main__':
    main()