/**
 * CSV Row Utilities
 *
 * Helper functions for working with different row formats:
 * - RowHashArray: Array of [key, value] tuples, e.g., [["name", "John"], ["age", "30"]]
 * - RowMap: Record<string, any> object format
 * - RowArray: Simple string[] array format
 *
 * Key functions:
 * - isRowHashArray(): Type guard for RowHashArray detection
 * - extractRowValues(): Extract values from any row format
 * - detectRowKeys(): Detect header keys from a row
 * - deduplicateHeaders(): Handle duplicate column names
 * - processColumns(): Process column configuration
 */
import type { ColumnConfig, HeaderArray, RowHashArray } from "../types.js";
export type { HeaderArray, RowHashArray } from "../types.js";
/**
 * Check if a row is a RowHashArray (array of [key, value] tuples)
 */
export declare function isRowHashArray(row: unknown): row is RowHashArray;
/**
 * Convert RowHashArray to RowMap
 * Note: Manual loop is ~4x faster than Object.fromEntries
 */
export declare function rowHashArrayToMap<V = any>(row: RowHashArray<V>): Record<string, V>;
/**
 * Convert RowHashArray to values array (preserving order)
 */
export declare function rowHashArrayToValues<V = any>(row: RowHashArray<V>): V[];
/**
 * Get headers from RowHashArray
 */
export declare function rowHashArrayToHeaders(row: RowHashArray): string[];
/**
 * Get value by key from RowHashArray (returns undefined if not found)
 * More efficient than creating a full map when you need only specific values
 */
export declare function rowHashArrayGet<V = any>(row: RowHashArray<V>, key: string): V | undefined;
/**
 * Map RowHashArray values according to header order
 * Optimized: builds values array in single pass without intermediate object
 */
export declare function rowHashArrayMapByHeaders<V = any>(row: RowHashArray<V>, headers: string[]): (V | undefined)[];
/**
 * Extract values from a row (array, object, or RowHashArray) in consistent order.
 * This is the unified function for row value extraction used by both
 * batch (formatCsv) and streaming (CsvFormatterStream) code paths.
 *
 * @param row - The row data (array, object, or RowHashArray)
 * @param keys - Optional key order for object/RowHashArray rows
 * @returns Array of values in the specified key order (or natural order if no keys)
 */
export declare function extractRowValues(row: unknown, keys: string[] | null | undefined): unknown[];
/**
 * Auto-detect keys (headers) from a row based on its type.
 * Returns empty array for arrays or primitive values.
 *
 * @param row - The row data to detect keys from
 * @returns Array of string keys, or empty array if not applicable
 */
export declare function detectRowKeys(row: unknown): string[];
/**
 * Deduplicate headers by appending suffix to duplicates.
 * Example: ["A", "B", "A", "A"] → ["A", "B", "A_1", "A_2"]
 *
 * @param headers - Original header array
 * @returns New array with unique header names
 */
export declare function deduplicateHeaders(headers: HeaderArray): HeaderArray;
export declare function deduplicateHeadersWithRenames(headers: HeaderArray): {
    headers: HeaderArray;
    renamedHeaders: Record<string, string> | null;
};
/**
 * Process columns configuration to extract keys and headers.
 * Returns null if columns is empty or undefined.
 *
 * This function is used by both formatCsv (batch) and CsvFormatterStream (streaming)
 * to normalize column configuration into separate key/header arrays.
 *
 * @param columns - Column configuration array (string names or ColumnConfig objects)
 * @returns Object with keys (data access) and headers (output names), or null if empty
 *
 * @example
 * ```ts
 * processColumns(['name', { key: 'age', header: 'Age (years)' }])
 * // { keys: ['name', 'age'], headers: ['name', 'Age (years)'] }
 * ```
 */
export declare function processColumns(columns: (string | ColumnConfig)[] | undefined): {
    keys: string[];
    headers: string[];
} | null;
/**
 * Check if a row should be skipped as empty.
 * When `shouldSkipEmpty` is "greedy", whitespace-only rows also count as empty.
 *
 * @param row - The row to check
 * @param shouldSkipEmpty - true, false, or "greedy"
 * @returns true if the row should be skipped
 */
export declare function isEmptyRow(row: string[], shouldSkipEmpty: boolean | "greedy"): boolean;
/**
 * Check if all values in a row are empty strings.
 * Used by skipRecordsWithEmptyValues option.
 *
 * @param row - The row to check
 * @returns true if all fields are empty strings
 */
export declare function hasAllEmptyValues(row: string[]): boolean;