/**
 * Local mortgage / PITI calculator — the canonical helper reconciling
 * five cohort implementations.
 *
 * Surveyed implementations:
 *
 *  - zillow-mcp `src/tools/mortgage.ts` `computeMortgage` — the most
 *    complete output shape (loan_amount, down_payment, monthly_*,
 *    monthly_total, total_interest_paid, total_paid_over_loan,
 *    loan_term_years, interest_rate, ltv_percent as 0..100).
 *  - redfin-mcp `src/tools/mortgage.ts` — line-for-line identical to
 *    zillow's.
 *  - compass-mcp `src/tools/mortgage.ts` — leaner inline shape:
 *    `monthly_total_piti`, `total_interest_over_term`, `ltv` as a
 *    0..1 ratio, no `interest_rate` echo. Same math.
 *  - homes-mcp `src/tools/mortgage.ts` — line-for-line copy of compass.
 *  - onehome-mcp `src/tools/mortgage.ts` — copy of compass minus one
 *    field, same math.
 *
 * Canonical policy (union over the cohort):
 *
 *  1. PMT formula: M = P * r * (1+r)^n / ((1+r)^n - 1). Guard the
 *     zero-interest case with straight-line amortization (M = P/n) so
 *     the formula stays finite at r = 0.
 *  2. Defaults: `loan_term_years = 30`, `down_payment_percent = 20`
 *     when neither `down_payment` nor `down_payment_percent` is given.
 *  3. `down_payment` overrides `down_payment_percent` when both are
 *     provided (the zillow precedence).
 *  4. `property_tax_annual` overrides `property_tax_rate` when both
 *     are provided; `property_tax_rate` decomposes via `home_price`.
 *  5. PMI applies strictly above 80% LTV (> 80, not >=) and only when
 *     `pmi_rate` is provided.
 *  6. LTV is reported as a percent (0..100), matching the zillow shape.
 *  7. Output shape carries the zillow union (most complete) plus
 *     `home_price` (echoed from input, matches the compass/homes/
 *     onehome variant) so each cohort wrapper can map cleanly.
 *  8. Validation: `home_price` must be positive, `interest_rate` must
 *     be non-negative, `loan_term_years` must be positive.
 */
/**
 * Inputs to `calculateMortgage`. Match the cohort's
 * `*_calculate_mortgage` tool input schema.
 */
export interface MortgageInput {
    /** Home purchase price in dollars. Must be positive. */
    home_price: number;
    /** Down payment in dollars. Overrides `down_payment_percent`. */
    down_payment?: number;
    /** Down payment as a percent of `home_price` (0..100). Default 20. */
    down_payment_percent?: number;
    /** Annual interest rate as a percent (e.g. 6.5 for 6.5%). */
    interest_rate: number;
    /** Loan term in years. Default 30. */
    loan_term_years?: number;
    /** Annual property tax in dollars. Overrides `property_tax_rate`. */
    property_tax_annual?: number;
    /** Property tax as a percent of `home_price` annually (0..100). */
    property_tax_rate?: number;
    /** Annual homeowner's insurance in dollars. */
    insurance_annual?: number;
    /** Monthly HOA dues in dollars. */
    hoa_monthly?: number;
    /** PMI as an annual percent of the loan balance (0..100). */
    pmi_rate?: number;
}
/**
 * Output of `calculateMortgage`. Carries the full PITI breakdown plus
 * loan-level totals.
 */
export interface MortgageBreakdown {
    /** Home purchase price (echoed from input). */
    home_price: number;
    /** Down payment in dollars. */
    down_payment: number;
    /** Loan principal (home_price - down_payment). */
    loan_amount: number;
    /** Monthly P&I (principal + interest). */
    monthly_principal_interest: number;
    /** Monthly property tax. */
    monthly_property_tax: number;
    /** Monthly insurance. */
    monthly_insurance: number;
    /** Monthly HOA dues. */
    monthly_hoa: number;
    /** Monthly PMI. Zero when LTV ≤ 80% or `pmi_rate` is not provided. */
    monthly_pmi: number;
    /** Sum of all monthly components — full PITI + HOA + PMI. */
    monthly_total: number;
    /** Total interest paid over the life of the loan. */
    total_interest_paid: number;
    /** Total dollars paid over the life of the loan (P&I only). */
    total_paid_over_loan: number;
    /** Loan term in years (echoed from input or default 30). */
    loan_term_years: number;
    /** Annual interest rate as a percent (echoed from input). */
    interest_rate: number;
    /** Loan-to-value as a percent (0..100). */
    ltv_percent: number;
}
/**
 * Compute a PITI breakdown from a mortgage scenario. Pure / deterministic
 * — no I/O, no dependencies. Hoisted from the realty cohort
 * (zillow/redfin/compass/homes/onehome).
 */
export declare function calculateMortgage(input: MortgageInput): MortgageBreakdown;