import sbt.contraband.ast.*
import sbt.contraband.CodecCodeGen

object DatatypeConfig:

  /** Extract the only type parameter from a TpeRef */
  def oneArg(tpe: Type): Type =
    val pat = s"""${tpe.removeTypeParameters.name}[<\\[](.+?)[>\\]]""".r
    val pat(arg0) = tpe.name.runtimeChecked
    NamedType(arg0.split('.').toList)

  /** Extract the two type parameters from a TpeRef */
  def twoArgs(tpe: Type): List[Type] =
    val pat = s"""${tpe.removeTypeParameters.name}[<\\[](.+?), (.+?)[>\\]]""".r
    val pat(arg0, arg1) = tpe.name.runtimeChecked
    NamedType(arg0.split('.').toList) :: NamedType(arg1.split('.').toList) :: Nil

  /** Codecs that were manually written. */
  val myCodecs: PartialFunction[String, Type => List[String]] = {
    case "scala.xml.NodeSeq" => _ => "sbt.internal.librarymanagement.formats.NodeSeqFormat" :: Nil

    case "xsbti.GlobalLock" => _ => "sbt.internal.librarymanagement.formats.GlobalLockFormat" :: Nil
    case "xsbti.Logger"     => _ => "sbt.internal.librarymanagement.formats.LoggerFormat" :: Nil

    case "sbt.librarymanagement.IvyPaths" => _ => "sbt.librarymanagement.IvyPathsFormats" :: Nil

    case "sbt.librarymanagement.LogicalClock" =>
      _ => "sbt.internal.librarymanagement.formats.LogicalClockFormats" :: Nil

    case "sbt.librarymanagement.CrossVersion" =>
      _ =>
        "sbt.librarymanagement.CrossVersionFormats" ::
          "sbt.librarymanagement.DisabledFormats" ::
          "sbt.librarymanagement.BinaryFormats" ::
          "sbt.librarymanagement.ConstantFormats" ::
          "sbt.librarymanagement.PatchFormats" ::
          "sbt.librarymanagement.FullFormats" ::
          "sbt.librarymanagement.For3Use2_13Formats" ::
          "sbt.librarymanagement.For2_13Use3Formats" ::
          Nil

    case "sbt.librarymanagement.ConfigRef" => _ => "sbt.librarymanagement.ConfigRefFormats" :: Nil

    case "sbt.testing.Status" => _ => "sbt.internal.testing.StatusFormats" :: Nil

    case "scalajson.ast.unsafe.JValue" | "sjsonnew.shaded.scalajson.ast.unsafe.JValue" =>
      _ => "sbt.internal.util.codec.JValueFormats" :: Nil

    case "xsbti.HashedVirtualFileRef" =>
      _ => "sbt.internal.util.codec.HashedVirtualFileRefFormats" :: Nil

    case "java.nio.ByteBuffer" => _ => "sbt.internal.util.codec.ByteBufferFormats" :: Nil

    // TODO: These are handled by BasicJsonProtocol, and sbt-datatype should handle them by default, imo
    case "Option" | "Set" | "scala.Vector"  => tpe => getFormats(oneArg(tpe))
    case "Map" | "Tuple2" | "scala.Tuple2"  => tpe => twoArgs(tpe).flatMap(getFormats)
    case "Int" | "Long" | "sbt.util.Digest" => _ => Nil
  }

  /** Types for which we don't include the format -- they're just aliases to InclExclRule */
  val excluded = Set("sbt.librarymanagement.InclusionRule", "sbt.librarymanagement.ExclusionRule")

  /** Returns the list of formats required to encode the given `TpeRef`. */
  val getFormats: Type => List[String] =
    CodecCodeGen.extensibleFormatsForType {
      case NamedType(List("sbt", "internal", "librarymanagement", "RetrieveConfiguration"), _) =>
        "sbt.librarymanagement.RetrieveConfigurationFormats" :: Nil
      case tpe: Type if myCodecs isDefinedAt tpe.removeTypeParameters.name =>
        myCodecs(tpe.removeTypeParameters.name)(tpe)
      case tpe: Type if excluded contains tpe.removeTypeParameters.name =>
        Nil
      case other =>
        CodecCodeGen.formatsForType(other)
    }
end DatatypeConfig