types.ts

/**
 * Scribe is an innovative context-aware workflow orchestrator.
 * Copyright (C) 2023 We Can Do Better
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program. If not, see <https://www.gnu.org/licenses/>.
 */

import type Graph from "./lib/Graph.ts";
import type Pipeline from "./lib/Pipeline.ts";

/**
 * An object with string keys, can contain any value.
 */
export type AnyRecord = Record<string, any>;

/**
 * Executes the next task in the workflow.
 */
export type Next = () => Promise<void>;

/**
 * A task is a function that takes a context and a next function.
 * @template Ctx The context type.
 * @param ctx The context.
 * @param next The next function.
 * @returns A promise that resolves when the task is done.
 */
export type Task<Ctx> = (ctx: Ctx, next: Next) => Promise<void>;

/**
 * A workflow is a task, a pipeline or a graph.
 * @template Ctx The context type.
 */
export type Workflow<Ctx = any> = Task<Ctx> | Pipeline<Ctx> | Graph<Ctx>;

/**
 * A tail is a function that is called when the workflow is done.
 * @returns A promise that resolves when the tail is done.
 */
export type Tail<Ctx> = (ctx: Ctx) => Promise<void>;

/**
 * The metadata of a workflow. This is an object with string keys, can contain any value.
 */
export type Metadata = AnyRecord;

/**
 * A partial type that makes some properties optional.
 * @template T The type to make partial.
 * @template K The keys of the type to make partial.
 */
export type PartialBy<T, K extends keyof T> = Omit<T, K> & Partial<Pick<T, K>>;

/**
 * A reaadonly version of WeakSet.
 * @template T The type of the values in the set.
 */
export type ReadonlyWeakSet<T> = {
  /** Checks whether the set has a value. */
  has(value: T): boolean;
};

/**
 * Extracts the context type from a workflow.
 * @template W The workflow type.
 */
export type WorkflowCtx<W extends Workflow<any>> = W extends Workflow<infer Ctx> ? Ctx : never;

/**
 * Makes the `ops` property of the type optional.
 * @template T The type to make partial.
 */
export type PartialOps<T extends { ops: Record<string, Workflow<any>> }> = Omit<T, "ops"> & Partial<Pick<T, "ops">>;