- All domain monetary fields now use Decimal: - Account.balance, Asset.value, Asset.growth_rate - Liability.balance, Liability.interest, Liability.payment - Transaction.amount, RecurringCashflow.amount - ExchangeRate.rate - ForecastScenario.income_multiplier, expense_multiplier, growth_multiplier - CurrencyConverter: all arithmetic in Decimal, quantize to 0.01 with ROUND_HALF_UP - ForecastService: Decimal arithmetic throughout (income, expenses, balance, growth, liability cost) - ScenarioService: Decimal multipliers, deepcopy safe with Decimal fields - assistant.py: _DecimalEncoder for json.dumps (Decimal -> str in JSON) Pydantic v2 + Decimal: - model_dump(mode='json') converts Decimal to str (JSON-safe) - model_validate() parses str back to Decimal - Round-trip preserves precision (100.50 stays 100.50) Tests: 63/63 pass.
92 lines
3.0 KiB
Python
92 lines
3.0 KiB
Python
from copy import deepcopy
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from decimal import Decimal
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from domain import FinancialModel, ForecastScenario
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from application.forecast import ForecastService
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class ScenarioError(Exception):
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pass
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DEFAULT_SCENARIOS = {
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"baseline": ForecastScenario(
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name="baseline",
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income_multiplier=Decimal("1.0"),
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expense_multiplier=Decimal("1.0"),
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growth_multiplier=Decimal("1.0"),
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description="Базовый сценарий без изменений",
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),
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"optimistic": ForecastScenario(
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name="optimistic",
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income_multiplier=Decimal("1.15"),
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expense_multiplier=Decimal("0.95"),
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growth_multiplier=Decimal("1.2"),
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description="Оптимистичный: доход +15%, расход -5%, рост активов +20%",
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),
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"pessimistic": ForecastScenario(
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name="pessimistic",
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income_multiplier=Decimal("0.85"),
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expense_multiplier=Decimal("1.1"),
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growth_multiplier=Decimal("0.8"),
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description="Пессимистичный: доход -15%, расход +10%, рост активов -20%",
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),
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}
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class ScenarioService:
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def __init__(self, model: FinancialModel):
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self.model = deepcopy(model)
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def apply(self, scenario: ForecastScenario, months: int = 12) -> dict:
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model = deepcopy(self.model)
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for t in model.transactions:
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if t.amount > 0:
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t.amount = t.amount * scenario.income_multiplier
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else:
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t.amount = t.amount * scenario.expense_multiplier
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for r in model.recurring:
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if r.category == "income":
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r.amount = r.amount * scenario.income_multiplier
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else:
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r.amount = r.amount * scenario.expense_multiplier
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for a in model.assets:
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a.growth_rate = a.growth_rate * scenario.growth_multiplier
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service = ForecastService(model)
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result = service.summary(months)
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result["scenario"] = scenario.name
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result["scenario_description"] = scenario.description
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return result
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def compare(self, months: int = 12) -> dict:
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results = {}
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for name, scenario in DEFAULT_SCENARIOS.items():
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results[name] = self.apply(scenario, months)
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return results
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def what_if(
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self,
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income_mult: Decimal | float = Decimal("1.0"),
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expense_mult: Decimal | float = Decimal("1.0"),
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growth_mult: Decimal | float = Decimal("1.0"),
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months: int = 12,
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) -> dict:
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def to_d(v: Decimal | float) -> Decimal:
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return v if isinstance(v, Decimal) else Decimal(str(v))
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scenario = ForecastScenario(
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name="what-if",
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income_multiplier=to_d(income_mult),
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expense_multiplier=to_d(expense_mult),
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growth_multiplier=to_d(growth_mult),
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description=(
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f"What-if: income x{income_mult}, "
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f"expense x{expense_mult}, growth x{growth_mult}"
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),
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)
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return self.apply(scenario, months)
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