lazy generic http web linking / published by https://github.com/dacr/code-examples-manager #1b2530a6-4ce3-4689-88a0-2dfba7ce4960/53c03d7f33044e691bd46501b800294bbbf81e58

http-web-linking.sc

// summary : lazy generic http web linking
// keywords : weblinking, http, lazy
// publish : gist
// authors : David Crosson
// license : Apache License Version 2.0 (https://www.apache.org/licenses/LICENSE-2.0.txt)
// id : 1b2530a6-4ce3-4689-88a0-2dfba7ce4960
// created-on : 2020-08-04T20:57:04Z
// managed-by : https://github.com/dacr/code-examples-manager
// execution : scala ammonite script (http://ammonite.io/) - run as follow 'amm scriptname.sc'


/* Using Web Linking to get large amount of results : https://tools.ietf.org/html/rfc8288 */

// TODO Make the following code "generic"

/*

  def userGists(user: GistUser): LazyList[GistInfo] = {
    val nextLinkRE = """.*<([^>]+)>; rel="next".*""".r

    def worker(nextQuery: Option[Uri], currentRemaining: Iterable[GistInfo]): LazyList[GistInfo] = {
      (nextQuery, currentRemaining) match {
        case (None, Nil) => LazyList.empty
        case (_, head :: tail) => head #:: worker(nextQuery, tail)
        case (Some(query), Nil) =>
          val response = {
            basicRequest
              .get(query)
              .header("Authorization", s"token $token")
              .response(asJson[Array[GistInfo]])
              .send()
          }
          response.body match {
            case Left(responseException) =>
              logger.error(s"List gists - Something wrong has happened", responseException)
              throw responseException
            case Right(gistsArray) =>
              val next = response.header("Link") // it provides the link for the next & last page :)
              val newNextQuery = next.collect { case nextLinkRE(uri) => uri"$uri" }
              worker(newNextQuery, gistsArray.toList)
          }
        case other =>
          logger.warn("Not understandable response : " + other.toString())
          LazyList.empty
      }
    }

    val count = 10
    val userLogin = user.login
    val startQuery = uri"$apiUrl/users/$userLogin/gists?page=1&per_page=$count"
    worker(Some(startQuery), Nil)
  }

 */