"""
支付专用商户配置（与提现收款 WechatPayMchConfig / wechat_mch_service 完全分离）。

读取优先级：
  1) XcxSysPeizhi.pay_* 
  2) 过渡回退：旧 weixin_* / settings.WEIXIN_*
历史订单退款：若订单 pay_mch_id 与当前支付商户不一致，但等于旧 weixin_mchid，则用旧 weixin_* 退款。
"""
import logging
import os

from django.conf import settings

from utils.xcx_sys_config import wx_cfg, _val

logger = logging.getLogger(__name__)


def pay_cert_base_dir():
    base = getattr(settings, 'WECHAT_PAY_CERT_BASE_DIR', '') or ''
    if base:
        return base
    return os.path.join(str(settings.BASE_DIR), 'zhifuzhengshu')


def _pay_val(pay_attr, legacy_db_attr, settings_attr, default=''):
    """pay_* 优先；空则回退旧 weixin_* / settings。"""
    v = _val(pay_attr, None, None)
    if v is not None and v != '':
        return v
    return _val(legacy_db_attr, settings_attr, default) or default


class PayWxConfig:
    """支付商户配置代理（属性名兼容旧 WEIXIN_*，便于替换调用点）。"""

    @property
    def WEIXIN_MCHID(self):
        return _pay_val('pay_mch_id', 'weixin_mchid', 'WEIXIN_MCHID', '')

    @property
    def WEIXIN_SHANGHUMIYAO(self):
        return _pay_val('pay_api_v2_key', 'weixin_shanghu_miyao', 'WEIXIN_SHANGHUMIYAO', '')

    @property
    def WEIXIN_NOTIFY_URL(self):
        return _pay_val('pay_notify_url', 'weixin_notify_url', 'WEIXIN_NOTIFY_URL', '')

    @property
    def WEIXIN_CERT_PATH(self):
        return _pay_val('pay_cert_path', 'weixin_cert_path', 'WEIXIN_CERT_PATH', '')

    @property
    def WEIXIN_KEY_PATH(self):
        return _pay_val('pay_key_path', 'weixin_key_path', 'WEIXIN_KEY_PATH', '')

    @property
    def PAY_API_V3_KEY(self):
        return _val('pay_api_v3_key', None, '') or ''

    @property
    def PAY_CERT_SERIAL_NO(self):
        return _val('pay_cert_serial_no', None, '') or ''

    # 别名，语义更清晰
    @property
    def PAY_MCH_ID(self):
        return self.WEIXIN_MCHID

    @property
    def PAY_API_V2_KEY(self):
        return self.WEIXIN_SHANGHUMIYAO


pay_cfg = PayWxConfig()


def get_current_pay_mch_id():
    return (pay_cfg.PAY_MCH_ID or '').strip()


def pay_cfg_as_dict():
    return {
        'MCHID': pay_cfg.WEIXIN_MCHID,
        'KEY': pay_cfg.WEIXIN_SHANGHUMIYAO,
        'NOTIFY_URL': pay_cfg.WEIXIN_NOTIFY_URL,
        'CERT_PATH': pay_cfg.WEIXIN_CERT_PATH,
        'KEY_PATH': pay_cfg.WEIXIN_KEY_PATH,
        'API_V3_KEY': pay_cfg.PAY_API_V3_KEY,
        'CERT_SERIAL_NO': pay_cfg.PAY_CERT_SERIAL_NO,
    }


def get_pay_wx_cfg(mch_id=None):
    """
    按商户号取支付配置（用于退款反查）。
    - mch_id 空 / 等于当前支付商户 → 当前 pay_cfg
    - mch_id 等于旧 weixin_mchid 且与当前不同 → 用旧 weixin_*（换号后历史单退款）
    - 否则若 zhifuzhengshu/{mch_id}/ 下有证书，拼路径但仍需密钥；密钥仅当前/旧库有，故仍回退当前并打日志
    """
    current = pay_cfg_as_dict()
    want = (mch_id or '').strip()
    current_mch = (current.get('MCHID') or '').strip()
    if not want or want == current_mch:
        return current

    legacy_mch = (wx_cfg.WEIXIN_MCHID or '').strip()
    if want == legacy_mch and want != current_mch:
        return {
            'MCHID': wx_cfg.WEIXIN_MCHID,
            'KEY': wx_cfg.WEIXIN_SHANGHUMIYAO,
            'NOTIFY_URL': wx_cfg.WEIXIN_NOTIFY_URL,
            'CERT_PATH': wx_cfg.WEIXIN_CERT_PATH,
            'KEY_PATH': wx_cfg.WEIXIN_KEY_PATH,
            'API_V3_KEY': '',
            'CERT_SERIAL_NO': '',
        }

    cert_path = os.path.join(pay_cert_base_dir(), want, 'apiclient_cert.pem')
    key_path = os.path.join(pay_cert_base_dir(), want, 'apiclient_key.pem')
    if os.path.isfile(cert_path) and os.path.isfile(key_path):
        logger.warning(
            '支付商户 %s 与当前配置 %s 不一致，仅找到证书文件，密钥仍用当前配置，退款可能失败',
            want, current_mch,
        )
        out = dict(current)
        out['MCHID'] = want
        out['CERT_PATH'] = cert_path
        out['KEY_PATH'] = key_path
        return out

    logger.warning(
        '订单支付商户 %s 无可用历史配置，回退当前支付商户 %s',
        want, current_mch,
    )
    return current


def apply_pay_cfg_to_proxy(cfg_dict):
    """把 get_pay_wx_cfg 结果转成带 WEIXIN_* 属性的简单对象，兼容旧代码写法。"""
    class _Cfg:
        pass

    o = _Cfg()
    o.WEIXIN_MCHID = cfg_dict.get('MCHID') or ''
    o.WEIXIN_SHANGHUMIYAO = cfg_dict.get('KEY') or ''
    o.WEIXIN_NOTIFY_URL = cfg_dict.get('NOTIFY_URL') or ''
    o.WEIXIN_CERT_PATH = cfg_dict.get('CERT_PATH') or ''
    o.WEIXIN_KEY_PATH = cfg_dict.get('KEY_PATH') or ''
    return o