package xsbt.api

	import java.io.File
	import java.net.URLClassLoader
	import org.specs.Specification
	import sbt.WithFiles
	import sbt.compiler.{CallbackTest,TestCompile}

/** Verifies that the analyzer plugin properly detects main methods.  The main method must be
* public with the right signature and be defined on a public, top-level module.*/
object ApplicationsTest extends Specification
{
	val sourceContent =
		"""
		object Main { def main(args: Array[String]) {} }
		""" :: """
		class Main2 { def main(args: Array[String]) {} }
		""" :: """
		object Main3 { private def main(args: Array[String]) {} }
		private object Main3b extends Main2
		object Main3c  { private def main(args: Array[String]) {} }
		protected object Main3d  { def main(args: Array[String]) {} }
		object Main3e {
			protected def main(args: Array[String]) {}
		}
		package a {
			object Main3f { private[a] def main(args: Array[String]) {} }
			object Main3g { protected[a] def main(args: Array[String]) {} }
		}
		""" ::"""
		object Main4 extends Main2
		""" :: """
		trait Main5 { def main(args: Array[String]) {} }; trait Main5b extends Main5; trait Main5c extends Main2; abstract class Main5d { def main(args: Array[String]) {} };
		trait Main5e[T] { def main(args: Array[T]) {} }
		trait Main5f[T <: String] { def main(args: Array[T]) {} }
		""" :: """
		object Main6a { var main = () }
		object Main6b { var main = (args: Array[String]) => () }
		""" :: """
		object Main7 { object Main7b extends Main2 }
		""" :: """
		object Main8 extends Main2 { object Main7b extends Main2 }
		""" :: """
		object Main9 {
			def main() {}
			def main(i: Int) {}
			def main(args: Array[String]) {}
		}
		""" :: """
		object MainA {
			def main() {}
			def main(i: Int) {}
			def main(args: Array[String], other: String) {}
			def main(i: Array[Int]) {}
		}
		object MainA2 {
			def main[T](args: Array[T]) {}
		}
		""" :: """
		object MainB extends Main2 {
			def main() {}
			def main(i: Int) {}
		}
		""" :: """
		object MainC1 {
			def main(args: Array[String]) = 3
		}
		object MainC2 {
			def main1(args: Array[String]) {}
		}
		""" :: """
		object MainD1 {
			val main = ()
		}
		object MainD2 {
			val main = (args: Array[String]) => ()
		}
		""" :: """
		object MainE1 {
			type T = String
			def main(args: Array[T]) {}
		}
		object MainE2 {
			type AT = Array[String]
			def main(args: AT) {}
		}
		object MainE3 {
			type U = Unit
			type T = String
			def main(args: Array[T]): U = ()
		}
		object MainE4 {
			def main[T](args: Array[String]) {}
		}
		object MainE5 {
			type A[T] = Array[String]
			def main[T](args: A[T]) {}
		}
		object MainE6 extends Main5e[String]
		object MainE7 extends Main5e[Int]
		object MainE8 extends Main5f[String]
		""" :: """
		object MainF1  extends Application { var x = 3; x = 5 }
		object MainF2  { def main(args: Array[java.lang.String]) {} }
		trait MainF3 { def main(args: Array[String]) {} }
		object MainF4 extends MainF3 { }
		""" ::
		Nil
	val sources = for((source, index) <- sourceContent.zipWithIndex) yield  new File("Main" + (index+1) + ".scala") -> source

	"Analysis plugin should detect applications" in {
		WithFiles(sources : _*) { case files @ Seq(main, main2, main3, main4, main5, main6, main7, main8, main9, mainA, mainB, mainC, mainD, mainE, mainF) =>
			for(scalaVersion <- TestCompile.allVersions)
				CallbackTest.full(scalaVersion, files) { (callback, file, scalaInstance, log) =>
					val expected = Set( main -> "Main", main4 -> "Main4", main8 -> "Main8", main9 -> "Main9", mainB -> "MainB",
						mainE -> "MainE1", mainE -> "MainE2", mainE -> "MainE3", mainE -> "MainE4", mainE -> "MainE5", mainE -> "MainE6", mainE -> "MainE8",
						mainF -> "MainF1", mainF -> "MainF2", mainF -> "MainF4")
						// the source signature is valid for the following, but the binary signature is not, so they can't actually be run.
						//   these are then known discrepancies between detected and actual entry points
					val erased = Set( mainE -> "MainE6", mainE -> "MainE8" )
					val actual = applications(callback).toSet
					(actual -- expected) must beEmpty
					(expected -- actual) must beEmpty
					val loader = new URLClassLoader(Array(file.toURI.toURL), scalaInstance.loader)
					for( (_, className) <- expected filterNot erased) testRun(loader, className)
				}
		}
	}
	def applications(callback: xsbti.TestCallback): Seq[(File, String)] =
		for( (file, api) <- CallbackTest.apis(callback);
	x = println("\n" + file + ":\n" + (api.definitions.flatMap { case c: xsbti.api.ClassLike => c.structure.inherited.filter(_.name == "main"); case _ => Nil }).map(xsbt.api.DefaultShowAPI.apply).mkString("\n"));
 application <- applications(api))
			yield	(file, application)
	def applications(src: xsbti.api.SourceAPI): Seq[String] =
		Discovery.applications(src.definitions) collect { case (definition, Discovered(_, _, true, _)) => definition.name }

	private def testRun(loader: ClassLoader, className: String)
	{
		val obj = Class.forName(className, true, loader)
		obj.getMethod("main", classOf[Array[String]]).invoke(null, new Array[String](0))
	}
}