动态账期标签引擎 — 基于现金流预测的供应商账期智能优化与动态调整

"""
动态账期标签引擎
功能：现金流状态评估 / 最优账期计算 / 早付折扣分析 / Tag动态更新
"""
from dataclasses import dataclass, field
from typing import Optional
import warnings
warnings.filterwarnings('ignore')


@dataclass
class CashFlowContext:
    current_cash_usd: float
    monthly_gmv_usd: float
    monthly_cogs_usd: float
    upcoming_large_payments_usd: float  # 未来30天大额支出
    financing_rate_annual: float = 0.08  # 融资年利率

    @property
    def cash_coverage_days(self) -> float:
        """现金能覆盖多少天的运营"""
        daily_burn = self.monthly_cogs_usd / 30
        return self.current_cash_usd / max(1, daily_burn)

    @property
    def cash_stress_level(self) -> str:
        days = self.cash_coverage_days
        if days < 15: return "CRITICAL"
        elif days < 30: return "TIGHT"
        elif days < 60: return "NORMAL"
        else: return "ABUNDANT"


@dataclass
class SupplierPaymentTerms:
    supplier_id: str
    current_terms_days: int
    min_terms_days: int = 0
    max_terms_days: int = 90
    early_pay_discount_pct: float = 0.0   # 提前付款折扣%
    early_pay_trigger_days: int = 10      # 提前多少天付款触发折扣
    monthly_purchase_usd: float = 10_000
    # Tags
    recommended_terms: int = 30
    terms_tag: dict = field(default_factory=dict)


def compute_optimal_payment_terms(context: CashFlowContext,
                                    supplier: SupplierPaymentTerms) -> dict:
    """计算最优账期和账期价值"""
    fin_rate = context.financing_rate_annual

    # 账期延长的资金价值（以融资利率计算）
    def term_value(days: int) -> float:
        return supplier.monthly_purchase_usd * fin_rate * (days / 365)

    # 早付折扣净收益
    def early_pay_benefit(trigger_days: int) -> float:
        discount_value = supplier.monthly_purchase_usd * supplier.early_pay_discount_pct / 100
        opp_cost = supplier.monthly_purchase_usd * fin_rate * (supplier.current_terms_days - trigger_days) / 365