import zio._

trait Dependency1
trait Dependency2

trait Module1 {
  // It's quite common for dependencies to depend on some resources,
  // so I put them in managed even for illustrating purposes
  def dependency1: Managed[Nothing, Dependency1]
}

trait Module2 {
  def dependency2: Managed[Nothing, Dependency2]
}

// The service interface doesn't know anything about Module1 or Module2
trait Service {
  def foo: Task[Int]
}

// Only the service module references the modules it depends on
trait ServiceModule {
  def service: ZManaged[Module1 with Module2, Nothing, Service]
}

// The actual implementation contains its dependencies as normal parameters
class LiveService private (dependency1: Dependency1, dependency2: Dependency2) extends Service {
  def foo = ???
}

// The companion object contains a factory method that uses the ZIO environment
// to extract dependencies needed for our LiveService
object LiveService {
  def make: ZManaged[Module1 with Module2, Nothing, Service] =
    for {
      deps <- ZIO.access[Module1 with Module2](identity).toManaged_
      dep1 <- deps.dependency1
      dep2 <- deps.dependency2
    } yield new LiveService(dep1, dep2)
}

object ServiceModule {
  // A live environment can now be trivially implemented on top of what we have so far
  trait Live extends ServiceModule {
    def service = LiveService.make
  }