"""
支付渠道工厂
根据配置返回对应的支付 Provider
默认使用 zpay 替代 xorpay
"""
from ..config import (
    PAYMENT_PROVIDER,
    XORPAY_AID,
    XORPAY_SECRET,
    XORPAY_CASHIER_URL,
    ZPAY_PID,
    ZPAY_KEY,
)
from .base import PaymentProvider
from .xorpay import XorPayProvider
from .zpay import ZPayProvider

_provider_instance: PaymentProvider | None = None


def get_payment_provider() -> PaymentProvider:
    """获取当前配置的支付渠道实例（单例）"""
    global _provider_instance
    if _provider_instance is not None:
        return _provider_instance
    if PAYMENT_PROVIDER == "zpay":
        _provider_instance = ZPayProvider(pid=ZPAY_PID, key=ZPAY_KEY)
    else:
        _provider_instance = XorPayProvider(
            aid=XORPAY_AID,
            secret=XORPAY_SECRET,
            cashier_url=XORPAY_CASHIER_URL,
        )
    return _provider_instance


def get_payment_provider_by_name(name: str) -> PaymentProvider:
    """按名称获取 Provider（用于 per-request 覆盖）"""
    if name == "xorpay":
        return XorPayProvider(
            aid=XORPAY_AID,
            secret=XORPAY_SECRET,
            cashier_url=XORPAY_CASHIER_URL,
        )
    return ZPayProvider(pid=ZPAY_PID, key=ZPAY_KEY)


def reset_provider():
    """重置 Provider（用于测试或切换渠道）"""
    global _provider_instance
    _provider_instance = None


def resolve_provider(
    device: str | None = None,
    req_provider: str | None = None,
    user_agent: str | None = None,
) -> PaymentProvider:
    """
    根据设备解析支付渠道：
    - 微信内(device=wechat 或 UA 含 MicroMessenger) → xorpay
    - PC/手机浏览器 → zpay
    显式传入的 provider 优先。
    """
    req = (req_provider or "").strip().lower()
    if req in ("xorpay", "zpay"):
        return get_payment_provider_by_name(req)
    dev = (device or "pc").lower()
    if dev == "wechat":
        return get_payment_provider_by_name("xorpay")
    ua = (user_agent or "").lower()
    if "micromessenger" in ua:
        return get_payment_provider_by_name("xorpay")
    return get_payment_provider_by_name("zpay")


def resolve_channel(item_channel: str | None) -> str:
    """支付方式固定为微信支付，支付宝暂不提供"""
    return "wxpay"