import type { Infer, Pred } from 'runtyp';
import type { DefineErrorsInput, RouteFailuresFor } from './defineErrors';
import { emptyObjectInput } from './routeDefaults';
/** Preds (+ optional errors) for a route — used by `route` and `HandlerFor`. */
export type RouteHandlerDef = {
    input?: Pred<any>;
    output?: Pred<any>;
    errors?: DefineErrorsInput;
};
type RoutePredsOf<Def extends RouteHandlerDef> = Pick<Def, 'input' | 'output' | 'errors'>;
type InferPred<T> = T extends Pred<infer U> ? U : never;
type HandlerInput<Def extends RouteHandlerDef> = [RoutePredsOf<Def>['input']] extends [undefined] ? Infer<typeof emptyObjectInput> : InferPred<RoutePredsOf<Def>['input']>;
type HandlerOutput<Def extends RouteHandlerDef> = [RoutePredsOf<Def>['output']] extends [undefined] ? void : InferPred<RoutePredsOf<Def>['output']>;
/** Handler fn type derived from route preds — use on a separate binding passed as `handler:`. */
export type HandlerFor<Def extends RouteHandlerDef, Ctx = unknown> = (input: HandlerInput<Def>, ctx: Ctx) => Promise<HandlerOutput<Def> | RouteFailuresFor<RoutePredsOf<Def>['errors']>>;
export {};