// ets_tracing: off

import { append_, empty } from "../core.js"
import type { Chunk } from "../definition.js"
import { concreteId } from "../definition.js"

/**
 * Zips with chunk with the specified chunk to produce a new chunk with
 * pairs of elements from each chunk combined using the specified function
 * `both`. If one chunk is shorter than the other uses the specified
 * function `left` or `right` to map the element that does exist to the
 * result type.
 */
export function zipAllWith_<A, B, C, D, E>(
  self: Chunk<A>,
  that: Chunk<B>,
  f: (a: A, b: B) => C,
  left: (a: A) => D,
  right: (b: B) => E
): Chunk<C | D | E> {
  const length = Math.max(concreteId(self).length, concreteId(that).length)

  if (length === 0) {
    return empty()
  }

  const leftIterator = concreteId(self).arrayLikeIterator()
  const rightIterator = concreteId(that).arrayLikeIterator()
  let i = 0
  let j = 0
  let k = 0
  let leftLength = 0
  let rightLength = 0
  let leftArray: ArrayLike<A> | undefined = undefined
  let rightArray: ArrayLike<B> | undefined = undefined
  let leftNext
  let rightNext
  let builder = empty<C | D | E>()

  while (i < length) {
    if (j < leftLength && k < rightLength) {
      builder = append_(builder, f(leftArray![j]!, rightArray![k]!))
      i++
      j++
      k++
    } else if (j === leftLength && (leftNext = leftIterator.next()) && !leftNext.done) {
      leftArray = leftNext.value
      leftLength = leftArray.length
      j = 0
    } else if (
      k === rightLength &&
      (rightNext = rightIterator.next()) &&
      !rightNext.done
    ) {
      rightArray = rightNext.value
      rightLength = rightArray.length
      k = 0
    } else if (j < leftLength) {
      builder = append_(builder, left(leftArray![j]!))
      i++
      j++
    } else if (k < rightLength) {
      builder = append_(builder, right(rightArray![k]!))
      i++
      k++
    }
  }

  return builder
}

/**
 * Zips with chunk with the specified chunk to produce a new chunk with
 * pairs of elements from each chunk combined using the specified function
 * `both`. If one chunk is shorter than the other uses the specified
 * function `left` or `right` to map the element that does exist to the
 * result type.
 *
 * @ets_data_first zipAllWith_
 */
export function zipAllWith<A, B, C, D, E>(
  that: Chunk<B>,
  f: (a: A, b: B) => C,
  left: (a: A) => D,
  right: (b: B) => E
): (self: Chunk<A>) => Chunk<C | D | E> {
  return (self) => zipAllWith_(self, that, f, left, right)
}