import { AsyncOperation, SyncOperation } from "../operations/operation";
import { MinusOne, LastIndex } from "./util-types";
export interface InputFunction<T = unknown, O = unknown> {
    (input: T): O;
}
type InputOperation<T = unknown, O = unknown> = AsyncOperation<T, O> | SyncOperation<T, O> | InputFunction<T, O>;
export type InputOperationsArray<T = unknown, O = unknown> = [InputOperation<T, O>, ...InputOperation<T, O>[]];
type OperationReturnType<V> = V extends Iterable<infer Z> ? Z extends Promise<infer K> ? K : Z : V extends AsyncIterable<infer Z> ? Z : never;
export type DirectOperationsArray<O extends unknown[], OT = unknown, OO = unknown> = O extends InputOperationsArray<OT, OO> ? O : never;
export type TypedOperationsArray<O extends InputOperationsArray> = O & ({
    [P in keyof O]: P extends 0 ? O[P] : P extends number ? SyncOperation<OperationReturnType<O[MinusOne<P>]>, OperationReturnType<O[P]>> | AsyncOperation<OperationReturnType<O[MinusOne<P>]>, OperationReturnType<O[P]>> : O[P];
}[keyof O]);
export type OperationsInputType<Operations extends unknown[]> = [
    Operations[0]
] extends DirectOperationsArray<[Operations[0]], infer T> ? T : (AsyncIterable<unknown> | Iterable<unknown>);
export interface IterablePromise<T> extends Iterable<T>, AsyncIterable<T> {
    then: PromiseLike<Iterable<T>>["then"];
}
export interface IterableEngineAbortSignal {
    aborted: boolean;
}
export interface IterableEngineContext<Operations extends unknown[], OIndex extends number | never> {
    operation?: OIndex extends number ? DirectOperationsArray<Operations>[OIndex] : never;
    index?: OIndex;
    signal?: IterableEngineAbortSignal;
    operations: Operations;
    concat(...operations: unknown[]): IterableEngineContext<unknown[], number | never>;
    asyncIterable(input: OperationsInputType<Operations>): AsyncIterable<OperationReturnType<Operations[LastIndex<Operations>]>>;
    iterable(input: OperationsInputType<Operations>): Iterable<OperationReturnType<Operations[LastIndex<Operations>]>>;
    contexts(): Iterable<IterableEngineContext<Operations, number>>;
    instance(input: OperationsInputType<Operations>): IterablePromise<Operations[LastIndex<Operations>]>;
}
export declare function createIterableEngineContext<OT, OO, O extends InputOperationsArray<OT, OO>, Operations extends InputOperationsArray<OT, OO>>(...operations: Operations): IterableEngineContext<Operations, never>;
export declare function getNextIterableEngineContext<O extends unknown[], C extends IterableEngineContext<O, number | never>>(context: C): IterableEngineContext<O, number>;
declare class IterableError extends Error {
}
export declare class UnknownReturnedIterableError extends IterableError {
    value?: unknown;
    constructor(value?: unknown);
}
export declare function iterateAsync<O extends unknown[], C extends IterableEngineContext<O, number | never>>(context: IterableEngineContext<unknown[], never | number> | CallableIterableEngineContext, input: AsyncIterable<unknown> | Iterable<unknown>): AsyncIterable<OperationReturnType<C["operations"][LastIndex<C["operations"]>]>>;
export declare function iterate<O extends (unknown[] | InputOperationsArray), C extends IterableEngineContext<O, number | never>>(context: IterableEngineContext<unknown[], never | number>, input: AsyncIterable<unknown> | Iterable<unknown>): Iterable<OperationReturnType<O[LastIndex<C["operations"]>]>>;
type CallableIterableEngineContext = IterableEngineContext<[InputFunction<AsyncIterable<unknown> | Iterable<unknown>>, ...InputFunction<AsyncIterable<unknown> | Iterable<unknown>>[]], number>;
export declare function isIterableEngineContext<O extends unknown[], I extends number | never>(context: unknown): context is IterableEngineContext<O, I>;
export {};