ArgHintProvider.scala

package decline_derive

import quoted.*

private[decline_derive] case class ArgHintProvider(e: Expr[Seq[ArgHint]]):
  inline def getHint[T: Type](
      inline f: PartialFunction[ArgHint, T]
  )(using Quotes): Expr[Option[T]] =
    '{ $e.collectFirst(f) }

  inline def getHintOption[T: Type](
      inline f: PartialFunction[ArgHint, Option[T]]
  )(using Quotes): Expr[Option[T]] =
    '{ $e.collectFirst(f).flatten }

  def name(using Quotes) =
    getHint:
      case ArgHint.Name(value) => value

  def flag(using Quotes) =
    getHint:
      case ArgHint.FlagDefault(value) => value

  def short(using Quotes) =
    getHint:
      case ArgHint.Short(value) => value

  def help(using Quotes) =
    getHint:
      case ArgHint.Help(value) => value

  def envName(using Quotes) =
    getHint:
      case ArgHint.Env(name, _) => name

  def envHelp(using Quotes) =
    getHintOption:
      case ArgHint.Env(_, help: String)         => Some(help)
      case ArgHint.Env(_, help: Option[String]) => help

  def isArgument(using Quotes) =
    getHint:
      case ArgHint.Positional(metavar: String) => Some(metavar)
      case ArgHint.Positional(None)            => None
      case ArgHint.Positional(Some(metavar))   => Some(metavar)

end ArgHintProvider