package sbt
import Keys._
import complete.{DefaultParsers, Parser}
import DefaultParsers._
import Project.{ScopedKey, Setting}
import Scope.GlobalScope
object Cross
{
final val Switch = "++"
final val Cross = "+"
def switchParser(state: State): Parser[(String, String)] =
{
val knownVersions = crossVersions(state)
lazy val switchArgs = token(NotSpace.examples(knownVersions : _*)) ~ (token(Space ~> matched(state.combinedParser)) ?? "")
lazy val nextSpaced = spacedFirst(Switch)
token(Switch ~ OptSpace) flatMap { _ => switchArgs & nextSpaced }
}
def spacedFirst(name: String) = opOrIDSpaced(name) ~ any.+
lazy val switchVersion = Command.arb(requireSession(switchParser)) { case (state, (version, command)) =>
val x = Project.extract(state)
import x._
println("Setting version to " + version)
val add = (scalaVersion in GlobalScope :== version) :: (scalaHome in GlobalScope :== None) :: Nil
val cleared = session.mergeSettings.filterNot( crossExclude )
val newStructure = Load.reapply(add ++ cleared, structure)
Project.setProject(session, newStructure, command :: state)
}
def crossExclude(s: Setting[_]): Boolean =
s.key match {
case ScopedKey( Scope(_, Global, Global, _), scalaHome.key | scalaVersion.key) => true
case _ => false
}
def crossParser(state: State): Parser[String] =
token(Cross <~ OptSpace) flatMap { _ => token(matched( state.combinedParser & spacedFirst(Cross) )) }
lazy val crossBuild = Command.arb(requireSession(crossParser)) { (state, command) =>
val x = Project.extract(state)
import x._
val versions = crossVersions(state)
val current = scalaVersion in currentRef get structure.data map(Switch + " " + _) toList;
if(versions.isEmpty) command :: state else versions.map(Switch + " " + _ + " " + command) ::: current ::: state
}
def crossVersions(state: State): Seq[String] =
{
val x = Project.extract(state)
import x._
crossScalaVersions in currentRef get structure.data getOrElse Nil
}
def requireSession[T](p: State => Parser[T]): State => Parser[T] = s =>
if(s get sessionSettings isEmpty) failure("No project loaded") else p(s)
}