import type { BestKind } from "../conversions/types.js";
import type { BestUnits, BestUnitsForUnit, Unit } from "./units.js";
import type { LiteralToPrimitive } from "./utils.js";
/**
 * The return value from converting a unit to `'best'`.
 * @public
 */
export type BestConversion<Q extends number | bigint, U extends BestUnits> = {
    /**
     * The quantity of the unit.
     */
    quantity: LiteralToPrimitive<Q>;
    /** The unit. */
    unit: U;
    /**
     * Join the quantity and the unit together in a string.
     * This method is automatically called when casting this object to a string, meaning you can safely do things like concatenate the object with a string.
     *
     * @param toFixed - The number of decimal places to include in the string.
     * The result will be padded with zeros if necessary.
     * Providing `undefined` will use the original number of decimal places.
     * Providing `0` will round the number to the nearest integer.
     * This option is ignored when converting `bigint`s.
     */
    toString(toFixed?: number): `${LiteralToPrimitive<Q>} ${U}`;
};
/**
 * The return value from calling a conversion function.
 * @public
 */
export type Converter<Q extends number | bigint, U extends Unit> = {
    /**
     * Convert a quantity of one unit into a new unit
     *
     * @param to - The unit you want to convert to
     *
     * @returns The converted value
     */
    to(to: U): LiteralToPrimitive<Q>;
    /**
     * Convert a measurement to the best unit for display.
     *
     * @param to - The string `best`
     * @param kind - The set of units to use (defaults to `'metric'`)
     *
     * @returns An object with a `quantity` property of the `unit` unit, which can be casted to a string using the `toString()` method
     */
    to<K extends BestKind = BestKind>(to: 'best', kind?: K | undefined): BestConversion<Q, BestUnitsForUnit<U, K>>;
};