import { signature } from "./common/signature3"
import { Task }      from "./task"
import { create }    from "./create"

/**
 * creates a element task that allows a external value to be passed into a task stack.
 * @param {any} element the element.
 * @param {(any) => Task} element mapping function.
 * @returns {Task}
 */
export function element(element: any, func: (element: any) => Task): Task

/**
 * creates a task that runs its inner tasks in parallel.
 * @param {any[]} arguments
 * @returns {Task}
 */
export function element(...args: any[]): Task {
  return create("core/element", context => signature(args)
    .map   (["any", "function"])
    .err   ((err) => context.fail(err))
    .run   ((element: any, func: (element: any) => Task) => {

      let task = func(element)
      task.run  (data  => context.log(data))
          .then (()    => context.ok())
          .catch(error => context.fail(error))

      context.abort(() => {
        task.cancel()
        context.log("aborted")
        context.fail("aborted")
      })
    })
  )
}