/**
 * Transaction Aggregator
 *
 * Aggregates multiple transactions from a single charge into a unified representation
 * for matching purposes. Handles fee exclusion, currency validation, business ID
 * validation, amount summation, date selection, and description concatenation.
 */
import type { currency } from '../../transactions/types.js';
import type { AggregatedTransaction } from '../types.js';
/**
 * Minimal transaction interface for aggregation
 * Based on database schema from accounter_schema.transactions
 */
export interface Transaction {
    id: string;
    charge_id: string;
    amount: string;
    currency: currency;
    business_id: string | null;
    event_date: Date;
    debit_date: Date | null;
    debit_timestamp: Date | null;
    source_description: string | null;
    is_fee: boolean | null;
}
/**
 * Aggregate multiple transactions into a single representation
 *
 * Per specification (section 4.2):
 * 1. Exclude transactions where is_fee = true
 * 2. If multiple currencies exist: throw error
 * 3. If multiple non-null business IDs exist: throw error
 * 4. Amount: sum of all amounts
 * 5. Currency: the common currency
 * 6. Business ID: the single non-null business ID (or null if all null)
 * 7. Date: earliest event_date
 * 8. Description: concatenate all source_description values with line breaks
 *
 * @param transactions - Array of transactions from a charge
 * @returns Aggregated transaction data
 *
 * @throws {Error} If transactions array is empty
 * @throws {Error} If no non-fee transactions exist after filtering
 * @throws {Error} If multiple different currencies exist
 * @throws {Error} If multiple different non-null business IDs exist
 *
 * @example
 * const aggregated = aggregateTransactions([
 *   { amount: 100, currency: 'USD', business_id: 'b1', event_date: new Date('2024-01-15'), ... },
 *   { amount: 50, currency: 'USD', business_id: 'b1', event_date: new Date('2024-01-20'), ... }
 * ]);
 * // Returns: { amount: 150, currency: 'USD', businessId: 'b1', date: Date('2024-01-15'), ... }
 */
export declare function aggregateTransactions(transactions: Transaction[]): AggregatedTransaction;