three15.scala

import tapir.server.akkahttp._
import tapir.model.StatusCodes
import Database._
import akka.http.scaladsl.server.Route
import scala.concurrent.Future

val getBooksRoute: Route = Endpoints.getBooks.toRoute { booksQuery =>
  if (booksQuery.limit.getOrElse(0) < 0) {
    Future.successful(Left((StatusCodes.BadRequest, ErrorInfo("Limit must be positive"))))
  } else {
    val filteredByYear = booksQuery.year
      .map(year => books.filter(_.year == year))
      .getOrElse(books)
    val limited = booksQuery.limit
      .map(limit => filteredByYear.take(limit))
      .getOrElse(filteredByYear)
    Future.successful(Right(limited))
  }
}