import type { Uint8ArrayBuffer } from './utils/byteUtils'
import { concatBuffers } from './utils/byteUtils'
import { noop } from './utils/functionUtils'

interface Options {
  // TODO(next-major): always collect stream body when `trackEarlyRequests` is removed, as we don't
  // need to use this function to just wait for the end of the stream without collecting it
  collectStreamBody?: boolean
}

/**
 * Read bytes from a ReadableStream until the end of the stream.
 * Returns the bytes if collectStreamBody is true, otherwise returns undefined.
 */
export async function readBytesFromStream(stream: ReadableStream<Uint8ArrayBuffer>, options: Options) {
  const reader = stream.getReader()
  const chunks: Uint8ArrayBuffer[] = []

  while (true) {
    const result = await reader.read()
    if (result.done) {
      break
    }

    if (options.collectStreamBody) {
      chunks.push(result.value)
    }
  }

  reader.cancel().catch(
    // we don't care if cancel fails, but we still need to catch the error to avoid reporting it
    // as an unhandled rejection
    noop
  )

  return options.collectStreamBody ? concatBuffers(chunks) : undefined
}