feat(CORE-001B): migrate overview and hedge math to unit types

app/pages/common.py

@@ -6,6 +6,7 @@ from typing import Any
 
 from nicegui import ui
 
+from app.domain.portfolio_math import portfolio_snapshot_from_config, strategy_metrics_from_snapshot
 from app.models.portfolio import PortfolioConfig
 from app.services.strategy_templates import StrategyTemplateService
 
@@ -37,33 +38,7 @@ def demo_spot_price() -> float:
 
 
 def portfolio_snapshot(config: PortfolioConfig | None = None) -> dict[str, float]:
-    if config is None:
-        gold_units = 1_000.0
-        spot = demo_spot_price()
-        gold_value = gold_units * spot
-        loan_amount = 145_000.0
-        margin_call_ltv = 0.75
-        hedge_budget = 8_000.0
-    else:
-        gold_units = float(config.gold_ounces or 0.0)
-        spot = float(config.entry_price or 0.0)
-        gold_value = float(config.gold_value or gold_units * spot)
-        loan_amount = float(config.loan_amount)
-        margin_call_ltv = float(config.margin_threshold)
-        hedge_budget = float(config.monthly_budget)
-
-    return {
-        "gold_value": gold_value,
-        "loan_amount": loan_amount,
-        "ltv_ratio": loan_amount / gold_value,
-        "net_equity": gold_value - loan_amount,
-        "spot_price": spot,
-        "gold_units": gold_units,
-        "margin_call_ltv": margin_call_ltv,
-        "margin_call_price": loan_amount / (margin_call_ltv * gold_units),
-        "cash_buffer": 18_500.0,
-        "hedge_budget": hedge_budget,
-    }
+    return portfolio_snapshot_from_config(config)
 
 
 def strategy_catalog() -> list[dict[str, Any]]:
@@ -145,54 +120,7 @@ def strategy_metrics(
         strategy_catalog()[0],
     )
     portfolio = portfolio or portfolio_snapshot()
-    spot = float(portfolio["spot_price"])
-    underlying_units = portfolio["gold_value"] / spot
-    loan_amount = float(portfolio["loan_amount"])
-    base_equity = float(portfolio["net_equity"])
-    floor = float(strategy.get("max_drawdown_floor", spot * 0.95))
-    cap = strategy.get("upside_cap")
-    cost = float(strategy["estimated_cost"])
-
-    scenario_prices = [round(spot * (1 + pct / 100), 2) for pct in range(-25, 30, 5)]
-    benefits: list[float] = []
-    for price in scenario_prices:
-        payoff = max(floor - price, 0.0)
-        if isinstance(cap, (int, float)) and price > float(cap):
-            payoff -= price - float(cap)
-        benefits.append(round(payoff - cost, 2))
-
-    scenario_price = round(spot * (1 + scenario_pct / 100), 2)
-    unhedged_equity = scenario_price * underlying_units - loan_amount
-    scenario_payoff_per_unit = max(floor - scenario_price, 0.0)
-    capped_upside_per_unit = 0.0
-    if isinstance(cap, (int, float)) and scenario_price > float(cap):
-        capped_upside_per_unit = -(scenario_price - float(cap))
-
-    option_payoff_cash = scenario_payoff_per_unit * underlying_units
-    capped_upside_cash = capped_upside_per_unit * underlying_units
-    hedge_cost_cash = cost * underlying_units
-    hedged_equity = unhedged_equity + option_payoff_cash + capped_upside_cash - hedge_cost_cash
-
-    waterfall_steps = [
-        ("Base equity", round(base_equity, 2)),
-        ("Spot move", round((scenario_price - spot) * underlying_units, 2)),
-        ("Option payoff", round(option_payoff_cash, 2)),
-        ("Call cap", round(capped_upside_cash, 2)),
-        ("Hedge cost", round(-hedge_cost_cash, 2)),
-        ("Net equity", round(hedged_equity, 2)),
-    ]
-
-    return {
-        "strategy": strategy,
-        "scenario_pct": scenario_pct,
-        "scenario_price": scenario_price,
-        "scenario_series": [
-            {"price": price, "benefit": benefit} for price, benefit in zip(scenario_prices, benefits, strict=True)
-        ],
-        "waterfall_steps": waterfall_steps,
-        "unhedged_equity": round(unhedged_equity, 2),
-        "hedged_equity": round(hedged_equity, 2),
-    }
+    return strategy_metrics_from_snapshot(strategy, scenario_pct, portfolio)
 
 
 @contextmanager