import { concreteChunkId } from "@tsplus/stdlib/collections/Chunk/definition"

/**
 * Folds over the elements in this chunk from the left.
 * Stops the fold early when the condition is not fulfilled.
 *
 * @tsplus static Chunk.Aspects reduceWhile
 * @tsplus pipeable Chunk reduceWhile
 */
export function reduceWhile<A, S>(s: S, pred: Predicate<S>, f: (s: S, a: A) => S) {
  return (self: Chunk<A>): S => {
    const iterator = concreteChunkId(self)._arrayLikeIterator()
    let next
    let s1 = s
    let cont = true

    while (cont && (next = iterator.next()) && !next.done) {
      const array = next.value
      const len = array.length
      let i = 0
      while (cont && i < len) {
        const a = array[i]!
        s1 = f(s1, a)
        cont = pred(s1)
        i++
      }
      next = iterator.next()
    }

    return s1
  }
}