473 lines
13 KiB
Markdown
473 lines
13 KiB
Markdown
# 业务解决方案（P0问题修复）
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> 版本：v1.0
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> 日期：2026-03-18
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> 目的：系统性解决评审发现的业务P0问题
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---
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## 1. 资金合规解决方案
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### 1.1 当前问题
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- 资金池可能需要支付牌照
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- 资金沉淀处理不明确
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- 税务合规未确认
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### 1.2 解决方案
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#### 1.2.1 资金托管模式
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```
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传统模式（有问题）：
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用户 ──▶ 平台账户 ──▶ 供应方结算
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↑
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资金沉淀
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托管模式（推荐）：
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用户 ──▶ 第三方支付 ──▶ 平台运营账户 ──▶ 供应方结算
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(Stripe) (无沉淀) (T+N结算)
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```
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```python
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class PaymentService:
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"""支付服务 - 修复B-D-01：支持多支付渠道"""
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# 支持的支付渠道
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CHANNELS = {
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'stripe': {'name': 'Stripe', 'regions': ['US', 'EU', 'APAC']},
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'alipay': {'name': '支付宝', 'regions': ['CN']},
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'wechat': {'name': '微信支付', 'regions': ['CN']},
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'bank': {'name': '银行转账', 'regions': ['CN', 'US']}
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}
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def __init__(self):
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# 初始化各渠道
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self.providers = {
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'stripe': StripePaymentProvider(),
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'alipay': AlipayProvider(),
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'wechat': WechatPayProvider(),
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'bank': BankTransferProvider()
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}
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async def create_payment(
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self,
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user_id: int,
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amount: float,
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currency: str,
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channel: str = None
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) -> PaymentResult:
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"""创建支付 - 自动选择渠道"""
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# 1. 自动选择最优渠道
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if not channel:
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channel = self.select_optimal_channel(user_id, currency)
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# 2. 获取渠道提供商
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provider = self.providers.get(channel)
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if not provider:
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raise PaymentChannelError(f"不支持的支付渠道: {channel}")
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# 3. 创建支付
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payment = await provider.create_checkout(
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amount=int(amount * 100),
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currency=currency,
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metadata={'user_id': user_id, 'type': 'top_up'}
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)
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return PaymentResult(
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channel=channel,
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payment_url=payment.url,
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payment_id=payment.id,
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expires_at=payment.expires_at
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)
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def select_optimal_channel(self, user_id: int, currency: str) -> str:
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"""自动选择最优渠道"""
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# 根据用户位置和币种选择
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user = self.get_user(user_id)
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region = user.region
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# 优先使用用户地区支持的渠道
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for channel, config in self.CHANNELS.items():
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if region in config['regions']:
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return channel
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# 默认使用Stripe
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return 'stripe'
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```
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#### 1.2.2 结算T+N模式
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```python
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class SettlementService:
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"""结算服务：T+N 结算"""
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# 根据供应方等级确定结算周期
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SETTLEMENT_CONFIG = {
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'new': {'days': 30, 'min_amount': 100}, # 新供应方
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'stable': {'days': 14, 'min_amount': 50}, # 稳定供应方
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'excellent': {'days': 7, 'min_amount': 0}, # 优质供应方
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}
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async def process_settlement(self, provider_id, period):
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"""处理结算"""
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# 1. 获取结算周期配置
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provider = await self.get_provider(provider_id)
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config = self.SETTLEMENT_CONFIG[provider.tier]
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# 2. 计算结算金额
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pending_amount = await self.get_pending_amount(provider_id, period)
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# 3. 检查最低金额
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if pending_amount < config['min_amount']:
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return {'status': 'pending', 'reason': 'Below minimum'}
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# 4. 对账验证
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if not await self.verify_settlement(provider_id, period):
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raise SettlementError('Verification failed')
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# 5. 风控检查
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if await self.is_flagged(provider_id):
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await self.flag_for_manual_review(provider_id, pending_amount)
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return {'status': 'pending', 'reason': 'Manual review'}
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# 6. 执行结算
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settlement = await self.execute_settlement(
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provider_id=provider_id,
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amount=pending_amount,
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settlement_days=config['days']
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)
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return {'status': 'completed', 'settlement_id': settlement.id}
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```
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#### 1.2.3 税务合规
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```python
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class TaxService:
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"""税务服务"""
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# 代扣代缴个人所得税率（示例）
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PERSONAL_INCOME_TAX_RATES = {
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0: 0.00, # 0-3000
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3000: 0.03, # 3001-12000
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12000: 0.10, # 12001-25000
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25000: 0.20, # 25001-35000
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35000: 0.25, # 35001-55000
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55000: 0.30, # 55001-80000
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80000: 0.35, # 80001+
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}
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def calculate_tax(self, income):
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"""计算个人所得税"""
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tax = 0
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remaining = income
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for threshold, rate in self.PERSONAL_INCOME_TAX_RATES.items():
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if remaining <= 0:
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break
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taxable = min(remaining, threshold + 3000 if threshold > 0 else threshold)
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tax += taxable * rate
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remaining -= taxable
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return tax
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def process_settlement_with_tax(self, provider_id, gross_amount):
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"""结算并代扣税"""
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# 1. 计算税额
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tax = self.calculate_tax(gross_amount)
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# 2. 净收入
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net_amount = gross_amount - tax
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# 3. 生成税务凭证
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tax_record = {
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'provider_id': provider_id,
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'gross_amount': gross_amount,
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'tax': tax,
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'net_amount': net_amount,
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'tax_period': self.get_current_period(),
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'generated_at': datetime.now()
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}
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# 4. 存储并生成报表
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await self.save_tax_record(tax_record)
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return {
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'gross_amount': gross_amount,
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'tax': tax,
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'net_amount': net_amount,
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'tax_certificate_url': f'/api/v1/tax/{tax_record.id}'
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}
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```
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---
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## 2. 计费精度解决方案
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### 2.1 当前问题
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- 浮点数精度问题
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- 并发计费问题
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- 退款处理问题
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### 2.2 解决方案
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#### 2.2.1 Decimal 精确计算
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```python
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from decimal import Decimal, ROUND_HALF_UP
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from dataclasses import dataclass
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@dataclass
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class Money:
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amount: Decimal
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currency: str = 'USD'
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@classmethod
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def from_float(cls, amount: float, currency: str = 'USD') -> 'Money':
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# 从浮点数创建，避免精度问题
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return cls(amount=Decimal(str(amount)), currency=currency)
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def __add__(self, other: 'Money') -> 'Money':
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if self.currency != other.currency:
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raise CurrencyMismatchError()
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return Money(amount=self.amount + other.amount, currency=self.currency)
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def __mul__(self, multiplier: Decimal) -> 'Money':
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return Money(amount=self.amount * multiplier, currency=self.currency)
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def round(self, places: int = 2) -> 'Money':
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quantizer = Decimal(10) ** -places
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return Money(
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amount=self.amount.quantize(quantizer, rounding=ROUND_HALF_UP),
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currency=self.currency
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)
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```
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#### 2.2.2 高精度计费引擎
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```python
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class PrecisionBillingEngine:
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"""高精度计费引擎"""
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def calculate_cost(
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self,
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model: str,
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usage: Usage,
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price: Price
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) -> Money:
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# 1. 使用 Decimal 计算
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input_cost = Decimal(str(usage.prompt_tokens)) * Decimal(str(price.input_per_1k)) / 1000
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output_cost = Decimal(str(usage.completion_tokens)) * Decimal(str(price.output_per_1k)) / 1000
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# 2. 计算总价
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total = (input_cost + output_cost).quantize(
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Decimal('0.01'),
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rounding=ROUND_HALF_UP
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)
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# 3. 返回 Money 对象
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return Money(amount=total, currency=price.currency)
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def charge(
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self,
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user_id: int,
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cost: Money,
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transaction_id: str
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) -> BillingResult:
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# 1. 分布式锁防止并发
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with self.distributed_lock(f'billing:{user_id}', timeout=5):
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# 2. 获取当前余额
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balance = self.get_balance(user_id)
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# 3. 扣款
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if balance < cost.amount:
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raise InsufficientBalanceError()
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new_balance = balance - cost.amount
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self.set_balance(user_id, new_balance)
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# 4. 记录流水
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self.record_transaction(
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user_id=user_id,
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amount=-cost.amount,
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transaction_id=transaction_id,
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balance_after=new_balance
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)
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return BillingResult(
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success=True,
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transaction_id=transaction_id,
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amount=cost.amount,
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balance_after=new_balance
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)
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```
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---
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## 3. 结算风控解决方案
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### 3.1 当前问题
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- 虚假挂载风险
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- 额度作弊风险
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- 恶意退款风险
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### 3.2 解决方案
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#### 3.2.1 多维度风控
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```python
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class ProviderSettlementRiskController:
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"""供应方结算风控"""
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RISK_INDICATORS = {
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'abnormal_usage_pattern': {
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'weight': 30,
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'check': lambda p: self.check_usage_pattern(p)
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},
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'low_verification_rate': {
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'weight': 20,
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'check': lambda p: self.check_verification_rate(p)
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},
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'high_refund_rate': {
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'weight': 25,
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'check': lambda p: self.check_refund_rate(p)
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},
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'new_account': {
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'weight': 15,
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'check': lambda p: self.check_account_age(p)
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},
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'inconsistent_income': {
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'weight': 10,
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'check': lambda p: self.check_income_consistency(p)
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}
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}
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async def evaluate_settlement_risk(self, provider_id, amount) -> RiskResult:
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"""评估结算风险"""
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provider = await self.get_provider(provider_id)
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# 1. 计算风险分数
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risk_score = 0
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risk_details = []
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for indicator_name, config in self.RISK_INDICATORS.items():
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is_risky, detail = config['check'](provider)
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if is_risky:
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risk_score += config['weight']
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risk_details.append({
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'indicator': indicator_name,
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'detail': detail
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})
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# 2. 风险分级
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if risk_score >= 70:
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# 高风险：拒绝结算
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return RiskResult(
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level='HIGH',
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action='BLOCK',
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score=risk_score,
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details=risk_details,
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message='Settlement blocked due to high risk'
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)
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elif risk_score >= 40:
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# 中风险：人工审核
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await self.queue_for_review(provider_id, amount)
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return RiskResult(
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level='MEDIUM',
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action='REVIEW',
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score=risk_score,
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details=risk_details,
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message='Settlement queued for manual review'
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)
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else:
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# 低风险：正常结算
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return RiskResult(
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level='LOW',
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action='APPROVE',
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score=risk_score,
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details=risk_details,
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message='Settlement approved'
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)
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```
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#### 3.2.2 阶梯结算策略
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```python
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class TieredSettlement:
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"""阶梯结算策略"""
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TIERS = {
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'new': {
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'settlement_days': 30,
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'max_daily_settlement': 1000,
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'require_verification': True,
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'保证金': 500
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},
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'stable': {
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'settlement_days': 14,
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'max_daily_settlement': 5000,
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'require_verification': False,
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'保证金': 0
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},
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'excellent': {
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'settlement_days': 7,
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'max_daily_settlement': None, # 无限制
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'require_verification': False,
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'保证金': 0
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}
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}
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def calculate_settlement_limit(self, provider) -> dict:
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"""计算结算限额"""
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tier = self.get_provider_tier(provider)
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# 基于历史结算金额动态调整
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history_avg = self.get_avg_daily_settlement(provider.id, 30)
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max_limit = self.TIERS[tier]['max_daily_settlement']
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# 限制为历史平均的2倍，防止突然大额
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if max_limit:
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effective_limit = min(max_limit, history_avg * 2)
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else:
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effective_limit = history_avg * 2
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return {
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'tier': tier,
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'settlement_days': self.TIERS[tier]['settlement_days'],
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'daily_limit': effective_limit,
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'require_verification': self.TIERS[tier]['require_verification']
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}
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```
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---
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## 4. 实施计划
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### 4.1 任务分解
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| 任务 | 负责人 | 截止 | 依赖 |
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|------|--------|------|------|
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| 法务合规确认 | 产品 | 立即 | - |
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| 支付SDK集成 | 后端 | S0-M2 | 法务确认 |
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| 税务计算模块 | 后端 | S0-M2 | - |
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| Decimal计费引擎 | 后端 | S1前 | - |
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| 结算风控模块 | 风控 | S0-M1 | - |
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| 阶梯结算策略 | 后端 | S0-M1 | - |
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### 4.2 验证标准
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- 资金由第三方托管
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- 计费精度 100%
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- 结算风控拦截率 >95%
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---
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**文档状态**：业务解决方案
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**关联文档**：
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- `business_model_profitability_design_v1_2026-03-18.md`
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- `supply_side_product_design_v1_2026-03-18.md`
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