"""极简 MySQL 访问层(pymysql)。够第1步用,后面要换 SQLAlchemy 也行。"""
import pymysql
from pymysql.cursors import DictCursor

from .config import settings


def _parse_dsn(dsn: str) -> dict:
    # mysql+pymysql://user:pass@host:port/db?charset=utf8mb4
    body = dsn.split("://", 1)[1]
    creds, rest = body.split("@", 1)
    user, password = creds.split(":", 1)
    hostport, dbq = rest.split("/", 1)
    host, port = (hostport.split(":", 1) + ["3306"])[:2]
    db = dbq.split("?", 1)[0]
    return dict(host=host, port=int(port), user=user, password=password, database=db)


def get_conn():
    cfg = _parse_dsn(settings.MYSQL_DSN)
    return pymysql.connect(charset="utf8mb4", cursorclass=DictCursor, autocommit=True, **cfg)