export interface ExportColumn {
    key: string;
    header: string;
    width?: number;
}
export declare class ExcelExportService {
    /**
     * Export data to Excel file
     * @param data - Array of objects to export
     * @param columns - Column configuration (optional)
     * @param fileName - Name of the exported file
     * @param sheetName - Name of the Excel sheet
     */
    exportToExcel(data: any[], columns?: ExportColumn[], fileName?: string, sheetName?: string): void;
    /**
     * Export multiple sheets to one Excel file
     * @param sheets - Array of sheet data
     * @param fileName - Name of the exported file
     */
    exportMultipleSheets(sheets: Array<{
        data: any[];
        columns?: ExportColumn[];
        sheetName: string;
    }>, fileName?: string): void;
    /**
     * Export HTML table to Excel
     * @param tableId - ID of the HTML table element
     * @param fileName - Name of the exported file
     * @param sheetName - Name of the Excel sheet
     */
    exportTableToExcel(tableId: string, fileName?: string, sheetName?: string): void;
    /**
     * Get nested object value using dot notation
     * @param obj - Object to search in
     * @param path - Dot notation path (e.g., 'user.address.city')
     */
    private getNestedValue;
    private getFlatValue;
    /**
     * Format date for Excel export
     * @param date - Date to format
     * @param format - Format string (default: 'MM/DD/YYYY')
     */
    formatDateForExport(date: Date | string, format?: string): string;
}
