1 files changed, 55 insertions, 17 deletions
diff --git a/stage2/BuildBuild.scala b/stage2/BuildBuild.scala
index c52c3c6..bab8d88 100644
--- a/stage2/BuildBuild.scala
+++ b/stage2/BuildBuild.scala
@@ -1,25 +1,63 @@
 package cbt
 import java.io.File
+import java.nio.file._
 import scala.collection.immutable.Seq
 
-class BuildBuild(context: Context) extends Build(context){
-  override def dependencies = Seq( CbtDependency()(context.logger) ) ++ super.dependencies
+class BuildBuild(context: Context) extends BasicBuild(context){
+  override def dependencies =
+    super.dependencies :+ context.cbtDependency
   def managedBuildDirectory: File = lib.realpath( projectDirectory.parent )
-  val managedBuild = try{
-    val managedContext = context.copy( projectDirectory = managedBuildDirectory )
-    val cl = classLoader(context.classLoaderCache)
-    logger.composition("Loading build at "+managedContext.projectDirectory)
-      cl
-        .loadClass(lib.buildClassName)
-        .getConstructor(classOf[Context])
-        .newInstance(managedContext)
-        .asInstanceOf[Build]
-  } catch {
-    case e: ClassNotFoundException if e.getMessage == lib.buildClassName => 
-      throw new Exception("You need to remove the directory or define a class Build in: "+context.projectDirectory)
-    case e: Exception =>
-      throw new Exception("during build: "+context.projectDirectory, e)
+  private object managedBuildCache extends Cache[BuildInterface]
+  def managedBuild = managedBuildCache{
+    try{
+      val managedContext = context.copy(
+        projectDirectory = managedBuildDirectory,
+        parentBuild=Some(this)
+      )
+      val managedBuildFile = projectDirectory++"/build.scala"
+      logger.composition("Loading build at "++managedContext.projectDirectory.toString)
+      (
+        if(managedBuildFile.exists){
+          val contents = new String(Files.readAllBytes(managedBuildFile.toPath))
+          val cbtUrl = ("cbt:"++GitDependency.GitUrl.regex++"#[a-z0-9A-Z]+").r
+          cbtUrl
+            .findFirstIn(contents)
+            .flatMap{
+              url =>
+              val Array(base,hash) = url.drop(4).split("#")
+              if(context.cbtHome.string.contains(hash))
+                None
+              else Some{
+                val checkoutDirectory = new GitDependency(base, hash).checkout
+                val build = new BasicBuild( context.copy( projectDirectory = checkoutDirectory ++ "/nailgun_launcher" ) )
+                val cl = build
+                  .classLoader(classLoaderCache)
+                // Note: cbt can't use an old version of itself for building,
+                // otherwise we'd have to recursively build all versions since
+                // the beginning. Instead CBT always needs to build the pure Java
+                // Launcher in the checkout with itself and then run it via reflection.
+                cl
+                  .loadClass( "cbt.NailgunLauncher" )
+                  .getMethod( "getBuild", classOf[AnyRef] )
+                  .invoke( null, managedContext.copy(cbtHome=checkoutDirectory) )
+              }
+            }.getOrElse{
+              classLoader(context.classLoaderCache)
+                .loadClass(lib.buildClassName)
+                .getConstructors.head
+                .newInstance(managedContext)
+            }
+        } else {
+          new BasicBuild(managedContext)
+        }
+      ).asInstanceOf[BuildInterface]
+    } catch {
+      case e: ClassNotFoundException if e.getMessage == lib.buildClassName => 
+        throw new Exception("You need to remove the directory or define a class Build in: "+context.projectDirectory)
+      case e: Exception =>
+        throw new Exception("during build: "+context.projectDirectory, e)
+    }
   }
   override def triggerLoopFiles = super.triggerLoopFiles ++ managedBuild.triggerLoopFiles
-  override def finalBuild = if( context.projectDirectory == context.cwd ) this else managedBuild.finalBuild
+  override def finalBuild: BuildInterface = if( context.projectDirectory == context.cwd ) this else managedBuild.finalBuild
 }