1 files changed, 120 insertions, 0 deletions
diff --git a/backend/app/services/wacc_service.py b/backend/app/services/wacc_service.py
new file mode 100644
index 0000000..2b4ee3e
--- /dev/null
+++ b/backend/app/services/wacc_service.py
@@ -0,0 +1,120 @@
+from __future__ import annotations
+
+from typing import Final
+
+from app.services import data_service
+
+DEFAULT_RISK_FREE_RATE: Final = 0.044
+DEFAULT_BETA: Final = 1.0
+DEFAULT_EQUITY_RISK_PREMIUM: Final = 0.055
+DEFAULT_COST_OF_DEBT: Final = 0.05
+DEFAULT_TAX_RATE: Final = 0.21
+
+
+def _unavailable(sym: str) -> dict[str, str | bool | float | None]:
+    info = data_service.get_company_info(sym)
+    fast_info = data_service.get_fast_info(sym)
+    currency_metadata = data_service._currency_metadata(info, fast_info, prefer_reporting=True)
+
+    return {
+        "symbol": sym,
+        "available": False,
+        "wacc": None,
+        "cost_of_equity": None,
+        "after_tax_cost_of_debt": None,
+        "risk_free_rate": DEFAULT_RISK_FREE_RATE,
+        "beta": DEFAULT_BETA,
+        "equity_risk_premium": DEFAULT_EQUITY_RISK_PREMIUM,
+        "cost_of_debt": DEFAULT_COST_OF_DEBT,
+        "tax_rate": DEFAULT_TAX_RATE,
+        "market_cap": None,
+        "total_debt": None,
+        "cash": None,
+        "net_debt": None,
+        "equity_weight": None,
+        "debt_weight": None,
+        **currency_metadata,
+    }
+
+
+def compute_wacc_value(symbol: str) -> dict[str, str | bool | float | None]:
+    sym = data_service.normalize_symbol(symbol)
+    info = data_service.get_company_info(sym)
+    fast_info = data_service.get_fast_info(sym)
+    balance = data_service.get_balance_sheet(sym, quarterly=True)
+    income = data_service.get_income_statement(sym, quarterly=True)
+
+    market_cap = data_service._safe_float(info.get("marketCap")) or data_service._safe_float(
+        fast_info.get("marketCap")
+    )
+    if market_cap is None or market_cap <= 0:
+        return _unavailable(sym)
+
+    beta = data_service._safe_float(info.get("beta"))
+    if beta is None:
+        beta = DEFAULT_BETA
+
+    total_debt = data_service._balance_value(
+        balance,
+        "Total Debt",
+        "Long Term Debt And Capital Lease Obligation",
+    )
+    if total_debt is None:
+        total_debt = data_service._safe_float(info.get("totalDebt")) or 0.0
+
+    cash = data_service._balance_value(
+        balance,
+        "Cash And Cash Equivalents",
+        "Cash Cash Equivalents And Short Term Investments",
+    )
+    if cash is None:
+        cash = data_service._safe_float(info.get("totalCash")) or 0.0
+
+    interest_expense = data_service._statement_ttm(income, "Interest Expense")
+    cost_of_debt = DEFAULT_COST_OF_DEBT
+    if interest_expense is not None and total_debt > 0:
+        computed_cost_of_debt = abs(interest_expense) / total_debt
+        if 0 < computed_cost_of_debt < 1:
+            cost_of_debt = computed_cost_of_debt
+
+    tax_rate = DEFAULT_TAX_RATE
+    tax_provision = data_service._statement_ttm(income, "Tax Provision")
+    pretax_income = data_service._statement_ttm(income, "Pretax Income")
+    if tax_provision is not None and pretax_income is not None and pretax_income > 0:
+        computed_tax_rate = tax_provision / pretax_income
+        if 0 <= computed_tax_rate <= 1:
+            tax_rate = computed_tax_rate
+
+    risk_free_rate = DEFAULT_RISK_FREE_RATE
+    equity_risk_premium = DEFAULT_EQUITY_RISK_PREMIUM
+    cost_of_equity = risk_free_rate + (beta * equity_risk_premium)
+    after_tax_cost_of_debt = cost_of_debt * (1 - tax_rate)
+    net_debt = max(total_debt - cash, 0.0)
+    total_capital = market_cap + net_debt
+    if total_capital <= 0:
+        return _unavailable(sym)
+
+    equity_weight = market_cap / total_capital
+    debt_weight = net_debt / total_capital
+    wacc = (cost_of_equity * equity_weight) + (after_tax_cost_of_debt * debt_weight)
+    currency_metadata = data_service._currency_metadata(info, fast_info, prefer_reporting=True)
+
+    return {
+        "symbol": sym,
+        "available": True,
+        "wacc": wacc,
+        "cost_of_equity": cost_of_equity,
+        "after_tax_cost_of_debt": after_tax_cost_of_debt,
+        "risk_free_rate": risk_free_rate,
+        "beta": beta,
+        "equity_risk_premium": equity_risk_premium,
+        "cost_of_debt": cost_of_debt,
+        "tax_rate": tax_rate,
+        "market_cap": market_cap,
+        "total_debt": total_debt,
+        "cash": cash,
+        "net_debt": net_debt,
+        "equity_weight": equity_weight,
+        "debt_weight": debt_weight,
+        **currency_metadata,
+    }