"""Oracle 11.2 thick 连接。环境变量与 rpa_oms 相同。"""
from __future__ import annotations

import os

DEAL_USER_NAME = "rpa-select"

_client_ready = False


class RepoUnavailable(Exception):
    def __init__(self, message: str = "数据库不可用"):
        self.message = message
        super().__init__(message)


def oracle_dsn() -> tuple[str, str, str]:
    user = os.getenv("RPA_ORACLE_USER", "")
    password = os.getenv("RPA_ORACLE_PASSWORD", "")
    host = os.getenv("RPA_ORACLE_HOST", "")
    if not user or not password or not host:
        raise RepoUnavailable("未配置 RPA_ORACLE_HOST / RPA_ORACLE_USER / RPA_ORACLE_PASSWORD")
    port = os.getenv("RPA_ORACLE_PORT", "1521")
    service = os.getenv("RPA_ORACLE_SERVICE", "rpa")
    return user, password, f"{host}:{port}/{service}"


def connect_from_env():
    user, password, dsn = oracle_dsn()
    _ensure_client()
    import oracledb

    return oracledb.connect(user=user, password=password, dsn=dsn)


def _ensure_client() -> None:
    global _client_ready
    if _client_ready:
        return
    import oracledb

    if os.getenv("RPA_ORACLE_THICK", "1") == "1":
        lib_dir = os.getenv("RPA_ORACLE_CLIENT_LIB", "")
        kwargs = {"lib_dir": lib_dir} if lib_dir else {}
        oracledb.init_oracle_client(**kwargs)
    _client_ready = True