import scala.deriving.Mirror
import scala.compiletime.*

trait Test[A] {
  def test: String
}

object Test {

  inline def findA[T <: Tuple]: Unit =
    inline erasedValue[T] match {
      case _: EmptyTuple  => error("Field 'a' not found")
      case _: ("a" *: tl) => ()
      case _: (_ *: tl)   => findA[tl]
    }

  inline given [A <: Product](using mm: Mirror.ProductOf[A]): Test[A] = new {
    override def test: String = {
      findA[mm.MirroredElemLabels]
      "test"
    }
  }
}

final case class Test1(a: String, b: Int)
final case class Test2(q: String, w: Int)

object Main {
  inline def fff1[P <: Product](using ggg: Test[P]): String = {
    ggg.test
  }

  inline def fff2[P <: Product]: String = {
    summonInline[Test[P]].test
  }

  fff1[Test1]
  fff1[Test2]

  summonInline[Test[Test1]].test
  summonInline[Test[Test2]].test

  fff2[Test1]
  fff2[Test2]
}

-- Error: xxx.scala:38:13 ------------------------------------------------------
38 |  fff1[Test2]
   |             ^
   |             Field 'a' not found
-- Error: xxx.scala:41:15 ------------------------------------------------------
41 |  summonInline[Test[Test2]].test
   |               ^
   |               Field 'a' not found
-- Error: xxx.scala:44:6 -------------------------------------------------------
44 |  fff2[Test2]
   |  ^^^^^^^^^^^
   |no given instance of type Test[Test2] was found.
   |I found:
   |
   |    Test.given_Test_A[Test2](
   |      Test2.$asInstanceOf[
   |
   |          (
   |            deriving.Mirror.Product{
   |              MirroredType = Test2; MirroredMonoType = Test2;
   |                MirroredElemTypes <: Tuple
   |            }
   |           &
   |            scala.deriving.Mirror.Product{
   |              MirroredMonoType = Test2; MirroredType = Test2;
   |                MirroredLabel = ("Test2" : String)
   |            }
   |          ){
   |            MirroredElemTypes = (String, Int);
   |              MirroredElemLabels = (("q" : String), ("w" : String))
   |          }
   |
   |      ]
   |    )
   |
   |But given instance given_Test_A in object Test does not match type Test[Test2].
   |----------------------------------------------------------------------------
   |Inline stack trace
   |- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
   |This location contains code that was inlined from xxx.scala:34
34 |    summonInline[Test[P]].test
   |    ^^^^^^^^^^^^^^^^^^^^^
    ----------------------------------------------------------------------------