modules/analysis.py

def calculate_retirement_needs(current_age: int, retirement_age: int, monthly_expenses: float, inflation_rate: float = 0.03, annual_return: float = 0.07) -> dict:
    """
    Calculates the required savings for retirement.
    """
    years_to_retire = retirement_age - current_age
    if years_to_retire <= 0: return {"error": "Already retired or invalid age."}
    
    # Future monthly expenses at retirement (adjusted for inflation)
    future_monthly_expenses = monthly_expenses * (1 + inflation_rate)**years_to_retire
    annual_retirement_spend = future_monthly_expenses * 12
    
    # Using the 4% rule (safe withdrawal rate)
    target_nest_egg = annual_retirement_spend / 0.04
    
    return {
        "years_to_retirement": years_to_retire,
        "monthly_expenses_at_retirement": future_monthly_expenses,
        "annual_retirement_spend": annual_retirement_spend,
        "target_nest_egg": target_nest_egg,
        "analysis": f"Adjusted for {inflation_rate*100}% inflation, you will need ${target_nest_egg:,.2f} to sustain a ${monthly_expenses:,.2f} (today's value) lifestyle."
    }

def calculate_financial_ratios(current_assets: float, current_liabilities: float, net_income: float, total_revenue: float) -> dict:
    """
    Calculates basic financial ratios.
    """
    current_ratio = current_assets / current_liabilities if current_liabilities != 0 else 0
    profit_margin = (net_income / total_revenue) * 100 if total_revenue != 0 else 0
    
    return {
        "current_ratio": current_ratio,
        "profit_margin_pct": profit_margin,
        "liquidity_status": "Healthy" if current_ratio > 1.5 else "Tight" if current_ratio >= 1 else "Risky"
    }

def compound_interest_breakdown(principal: float, annual_rate: float, years: int, monthly_contribution: float = 0) -> list:
    """
    Provides a year-by-year breakdown of compound growth.
    """
    history = []
    current = principal
    for y in range(1, years + 1):
        # Monthly compounding approximation
        for _ in range(12):
            current = (current * (1 + annual_rate/12)) + monthly_contribution
        history.append({"year": y, "balance": current})
    return history