import { ConvertFunction } from './Binding.js';

/**
 * Transforms a value into another value.
 */
type Transformer = ConvertFunction;
/**
 * A transformer that also supports an `else` function that can be used
 * when the transformer would otherwise skip a value (e.g. if `isDefined` is being used).
 */
interface TransformerWithElse extends Transformer {
    /**
     * Transformer that either invokes the given value (if its a function)
     * or simply returns it.
     *
     * @param value function or plain value in the
     */
    else(value: any): Transformer;
}
/**
 * Builds function which executes a given callback only if value is not undefined or null.
 * The created function will have a "else" method, which can be used to bind default values.
 * @param callback to execute if value is defined.
 * @returns transformer function.
 * @example
 * ```
 * let a = new Clazz();
 * let b = new Clazz();
 * Binding.for(a, b)
 *     .syncToRight("prop",
 *         ifDefined((v) => v.toUpperCase()).else("missing value")
 *      ).enable().syncToRightNow();
 * //-> b.prop === "missing value";
 * a.prop = "test"; // -> b.prop === "TEST"
 * ```
 */
declare function ifDefined(callback?: Transformer): TransformerWithElse;
/**
 * Builds function which executes a given callback only if value is not 'almost' equal to the target value.
 * The created function will have a "else" method, which can be used to bind default values.
 * @param eps epsilon number which defines the allowed difference to the target value.
 * @param callback to execute if value is not almost equal.
 * @returns transformer function.
 * @example
 * ```
 * let a = new Clazz({prop: 2});
 * let b = new Clazz();
 * Binding.for(a, b)
 *     .syncToRight("prop",
 *         ifTargetNotEqualsAlmost(0.001)
 *      ).enable().syncToRightNow();
 * a.prop = 2.0002; // -> b.prop === 2, detects no change
 * ```
 */
declare function ifTargetNotEqualsAlmost(eps: number, callback?: Transformer): TransformerWithElse;
/**
 * Builds function which delays the synchronization for given msec.
 * @param delay time in msec to wait before synchronizing.
 * @param callback callback which transforms the value.
 * @returns transformer function.
 * @example
 * ```
 * let a = new Clazz({prop: 2});
 * let b = new Clazz();
 * Binding.for(a, b)
 *     .syncToRight("prop",
 *         debounce(100)
 *      ).enable().syncToRightNow();
 * b.prop // is undefined but will be set after 100msec to 2
 * ```
 */
declare function debounce(delay: number, callback?: Transformer): Transformer;
/**
 * Builds function which delays the synchronization for given msec and cancels the execution if transformer is triggered
 * again.
 * @param delay time in msec to wait before synchronizing.
 * @param callback callback which transforms the value.
 * @returns transformer function.
 * @example
 * ```
 * let a = new Clazz({prop: 2});
 * let b = new Clazz();
 * Binding.for(a, b)
 *     .syncToRight("prop",
 *         debounceOrCancel(100)
 *      ).enable().syncToRightNow();
 * b.prop // is undefined but will be set after 100msec to 2
 * ```
 */
declare function debounceOrCancel(delay: number, callback?: Transformer): Transformer;
/**
 * Builds function which delays the synchronization for given msec and cancels the execution if transformer is triggered
 * again.
 * In contrast to debounceOrCancel this method ensures that after the given delay at least one update is performed.
 *
 * @param delay time in msec to wait before synchronizing.
 * @param callback callback which transforms the value.
 * @returns transformer function.
 * @example
 * ```
 * let a = new Clazz({prop: 2});
 * let b = new Clazz();
 * Binding.for(a, b)
 *    .syncToRight("prop",
 *        deferOrCancel(100)
 *     ).enable().syncToRightNow();
 * b.prop // is undefined but will be set after 100msec to 2
 * ```
 */
declare function deferOrCancel(delay: number, callback?: Transformer): Transformer;
/**
 * Builds a function which returns the sub property "instance" of an object.
 * @param callback delegation function to which the value is passed to.
 * @returns property accessor function.
 */
declare function instance(callback?: Transformer): Transformer;
/**
 * Builds a function which accesses a sub property of an object.
 * @param name property name
 * @param callback delegation function to which the value is passed to.
 * @returns property accessor function.
 */
declare function prop(name: string, callback?: Transformer): Transformer;

export { debounce, debounceOrCancel, deferOrCancel, ifDefined, ifTargetNotEqualsAlmost, instance, prop };
export type { Transformer, TransformerWithElse };