import { Sure, InferBad, InferGood, sure, bad, good, MetaNever, MetaObj } from './core.js'

export function array<
  //
  TPropFail,
  TPropGood,
  TSchema extends Sure<TPropFail, TPropGood, unknown, MetaObj | MetaNever>,
>(
  schema: TSchema
): Sure<
  //
  Array<InferBad<TSchema> | undefined>,
  Array<InferGood<TSchema>>,
  unknown,
  MetaObj<{
    type: 'array'

    schema: TSchema
  }>
> {
  const struct = sure(
    value => {
      if (!Array.isArray(value)) {
        return bad([])
      }

      let atLeastOneBad = false
      let bads = []
      let goods = []

      for (const elem of value) {
        const [good, unsure] = schema(elem)

        if (good) {
          goods.push(unsure)
          // This is necessary in order to maintain the same length
          bads.push(undefined)
        } else {
          bads.push(unsure)

          // Since the `bads` array can containe `undefined` values, it's more clear to
          // have an imperative boolean to make the check
          atLeastOneBad = true
        }
      }

      if (atLeastOneBad) {
        return bad(bads)
      }

      return good(goods)
    },
    {
      type: 'array',

      schema,
    }
  )

  // @ts-expect-error Expected error
  return struct
}