Scala-Play-Slick-Demo/app/controllers/HomeController.scala

package controllers

import javax.inject.{Inject, Singleton}

import com.example.user.UserDAO
import play.api.mvc._

import scala.concurrent.ExecutionContext
import com.example.user.CarDAO
import com.example.services.LibraryService
import play.api.libs.json.Json

@Singleton
class HomeController @Inject() (
    userDAO: UserDAO,
    carDAO: CarDAO,
    libraryService: LibraryService,
    cc: ControllerComponents
)(implicit ec: ExecutionContext)
    extends AbstractController(cc) {

  def index = Action.async { implicit request =>
    userDAO.all.map { users => Ok(views.html.index(users)) }
  }

  def cars = Action.async { implicit request =>
    carDAO.all.map { cars => Ok(views.html.cars(cars)) }
  }

  def book = Action.async {
    // libraryService.findBookById(1).map(e => Ok(Json.toJson(e)))
    // libraryService.insertBookAndAuthor(Book("new book"), Author(2, "Some retard"))

    for {
      maybeBook <- libraryService.findBookById(1)
    } yield (Ok(Json.toJson(maybeBook)))
  }

  def authors(bookId: Long) = Action.async { implicit request =>
    libraryService.getAuthorsForBook(bookId).map( t => {
      Ok(Json.toJson(t))
    })
  }

}