import type { RemixNode } from '../jsx.ts'

export type EmptyChild = boolean | null | undefined
export type PrimitiveChild = string | number | bigint

export function isEmptyChild(value: RemixNode): value is EmptyChild {
  return value == null || typeof value === 'boolean'
}

export function isPrimitiveChild(value: RemixNode): value is PrimitiveChild {
  let type = typeof value
  return type === 'string' || type === 'number' || type === 'bigint'
}

export function normalizeChildren(children: readonly RemixNode[]): RemixNode[] {
  for (let child of children) {
    if (Array.isArray(child)) {
      return (children as unknown[]).flat(Infinity) as RemixNode[]
    }
  }

  return children as RemixNode[]
}

export function packChildren(children: readonly RemixNode[]): RemixNode | undefined {
  if (children.length === 0) {
    return undefined
  }

  if (children.length === 1) {
    let child = children[0]

    if (child === undefined || isEmptyChild(child)) {
      return undefined
    }

    return Array.isArray(child) ? normalizeChildren(child) : child
  }

  let normalized = normalizeChildren(children)
  return normalized.length === 0 ? undefined : normalized
}