import sbt._
import Keys._
import StringUtilities.normalize

object Util {
  val ExclusiveTest = Tags.Tag("exclusive-test")
  lazy val componentID = SettingKey[Option[String]]("component-id")
  lazy val scalaKeywords = TaskKey[Set[String]]("scala-keywords")
  lazy val generateKeywords = TaskKey[File]("generateKeywords")

  def noPublishSettings: Seq[Setting[_]] = Seq(publish := {})

  def crossBuild: Seq[Setting[_]] =
    Seq(
      crossPaths := (scalaBinaryVersion.value match {
        case "2.11" => true
        case _      => false
      })
    )

  lazy val javaOnlySettings = Seq[Setting[_]]( /*crossPaths := false, */ compileOrder := CompileOrder.JavaThenScala, unmanagedSourceDirectories in Compile <<= Seq(javaSource in Compile).join)
  lazy val baseScalacOptions = Seq(
    scalacOptions ++= Seq("-Xelide-below", "0"),
    scalacOptions <++= scalaVersion map CrossVersion.partialVersion map {
      case Some((2, 9)) | Some((2, 8)) => Nil // support 2.9 for some subprojects for the Scala Eclipse IDE
      case _                           => Seq("-feature", "-language:implicitConversions", "-language:postfixOps", "-language:higherKinds", "-language:existentials")
    },
    scalacOptions <++= scalaVersion map CrossVersion.partialVersion map {
      case Some((2, 10)) => Seq("-deprecation", "-Xlint")
      case _             => Seq()
    }
  )

  def projectComponent = projectID <<= (projectID, componentID) { (pid, cid) =>
    cid match { case Some(id) => pid extra ("e:component" -> id); case None => pid }
  }

  lazy val apiDefinitions = TaskKey[Seq[File]]("api-definitions")

  def generateAPICached(cache: File, defs: Seq[File], cp: Classpath, out: File, main: Option[String], run: ScalaRun, s: TaskStreams): Seq[File] =
    {
      def gen() = generateAPI(defs, cp, out, main, run, s)
      val f = FileFunction.cached(cache / "gen-api", FilesInfo.hash) { _ => gen().toSet } // TODO: check if output directory changed
      f(defs.toSet).toSeq
    }
  def generateAPI(defs: Seq[File], cp: Classpath, out: File, main: Option[String], run: ScalaRun, s: TaskStreams): Seq[File] =
    {
      IO.delete(out)
      IO.createDirectory(out)
      val args = "xsbti.api" :: out.getAbsolutePath :: defs.map(_.getAbsolutePath).toList
      val mainClass = main getOrElse "No main class defined for datatype generator"
      toError(run.run(mainClass, cp.files, args, s.log))
      (out ** "*.java").get
    }
  def lastCompilationTime(analysis: sbt.inc.Analysis): Long =
    {
      val lastCompilation = analysis.compilations.allCompilations.lastOption
      lastCompilation.map(_.startTime) getOrElse 0L
    }
  def generateVersionFile(version: String, dir: File, s: TaskStreams, analysis: sbt.inc.Analysis): Seq[File] =
    {
      import java.util.{ Date, TimeZone }
      val formatter = new java.text.SimpleDateFormat("yyyyMMdd'T'HHmmss")
      formatter.setTimeZone(TimeZone.getTimeZone("GMT"))
      val timestamp = formatter.format(new Date)
      val content = versionLine(version) + "\ntimestamp=" + timestamp
      val f = dir / "xsbt.version.properties"
      if (!f.exists || f.lastModified < lastCompilationTime(analysis) || !containsVersion(f, version)) {
        s.log.info("Writing version information to " + f + " :\n" + content)
        IO.write(f, content)
      }
      f :: Nil
    }
  def versionLine(version: String): String = "version=" + version
  def containsVersion(propFile: File, version: String): Boolean = IO.read(propFile).contains(versionLine(version))

  def binID = "compiler-interface-bin"
  def srcID = "compiler-interface-src"

  def publishPomSettings: Seq[Setting[_]] = Seq(
    publishArtifact in makePom := false,
    pomPostProcess := cleanPom _
  )

  def cleanPom(pomNode: scala.xml.Node) =
    {
      import scala.xml._
      def cleanNodes(nodes: Seq[Node]): Seq[Node] = nodes flatMap {
        case elem @ Elem(prefix, "dependency", attributes, scope, children @ _*) if excludePomDependency(elem) =>
          NodeSeq.Empty
        case Elem(prefix, "classifier", attributes, scope, children @ _*) =>
          NodeSeq.Empty
        case Elem(prefix, label, attributes, scope, children @ _*) =>
          Elem(prefix, label, attributes, scope, cleanNodes(children): _*).theSeq
        case other => other
      }
      cleanNodes(pomNode.theSeq)(0)
    }

  def excludePomDependency(node: scala.xml.Node) = node \ "artifactId" exists { n => excludePomArtifact(n.text) }

  def excludePomArtifact(artifactId: String) = (artifactId == "compiler-interface") || (artifactId startsWith "precompiled")

  val testExclusive = tags in test += ((ExclusiveTest, 1))

  // TODO: replace with Tags.exclusive after 0.12.0
  val testExclusiveRestriction = Tags.customLimit { (tags: Map[Tags.Tag, Int]) =>
    val exclusive = tags.getOrElse(ExclusiveTest, 0)
    val all = tags.getOrElse(Tags.All, 0)
    exclusive == 0 || all == 1
  }

  def getScalaKeywords: Set[String] =
    {
      val g = new scala.tools.nsc.Global(new scala.tools.nsc.Settings)
      g.nme.keywords.map(_.toString)
    }
  def writeScalaKeywords(base: File, keywords: Set[String]): File =
    {
      val init = keywords.map(tn => '"' + tn + '"').mkString("Set(", ", ", ")")
      val ObjectName = "ScalaKeywords"
      val PackageName = "sbt"
      val keywordsSrc =
        """package %s
object %s {
	val values = %s
}""".format(PackageName, ObjectName, init)
      val out = base / PackageName.replace('.', '/') / (ObjectName + ".scala")
      IO.write(out, keywordsSrc)
      out
    }
  def keywordsSettings: Seq[Setting[_]] = inConfig(Compile)(Seq(
    scalaKeywords := getScalaKeywords,
    generateKeywords <<= (sourceManaged, scalaKeywords) map writeScalaKeywords,
    sourceGenerators <+= generateKeywords map (x => Seq(x))
  ))
}

object Licensed {
  lazy val notice = SettingKey[File]("notice")
  lazy val extractLicenses = TaskKey[Seq[File]]("extract-licenses")

  lazy val seeRegex = """\(see (.*?)\)""".r
  def licensePath(base: File, str: String): File = { val path = base / str; if (path.exists) path else sys.error("Referenced license '" + str + "' not found at " + path) }
  def seePaths(base: File, noticeString: String): Seq[File] = seeRegex.findAllIn(noticeString).matchData.map(d => licensePath(base, d.group(1))).toList

  def settings: Seq[Setting[_]] = Seq(
    notice <<= baseDirectory(_ / "NOTICE"),
    unmanagedResources in Compile <++= (notice, extractLicenses) map { _ +: _ },
    extractLicenses <<= (baseDirectory in ThisBuild, notice, streams) map extractLicenses0
  )
  def extractLicenses0(base: File, note: File, s: TaskStreams): Seq[File] =
    if (!note.exists) Nil else
      try { seePaths(base, IO.read(note)) }
      catch { case e: Exception => s.log.warn("Could not read NOTICE"); Nil }
}