/* sbt -- Simple Build Tool
 * Copyright 2008, 2009, 2010, 2011  Mark Harrah
 */
package xsbt.boot

import Pre._
import BootConfiguration.{ CompilerModuleName, JAnsiVersion, LibraryModuleName }
import java.io.File
import java.net.{ URL, URLClassLoader, URI }
import java.util.concurrent.Callable
import scala.collection.immutable.List
import scala.annotation.tailrec
import ConfigurationStorageState._

class LauncherArguments(val args: List[String], val isLocate: Boolean)

object Launch {
  def apply(arguments: LauncherArguments): Option[Int] = apply((new File("")).getAbsoluteFile, arguments)

  def apply(currentDirectory: File, arguments: LauncherArguments): Option[Int] = {
    val (configLocation, newArgs2, state) = Configuration.find(arguments.args, currentDirectory)
    val config = state match {
      case SerializedFile => LaunchConfiguration.restore(configLocation)
      case PropertiesFile => parseAndInitializeConfig(configLocation, currentDirectory)
    }
    if (arguments.isLocate) {
      if (!newArgs2.isEmpty) {
        // TODO - Print the arguments without exploding proguard size.
        System.err.println("Warning: --locate option ignores arguments.")
      }
      locate(currentDirectory, config)
    } else {
      // First check to see if there are java system properties we need to set. Then launch the application.
      updateProperties(config)
      launch(run(Launcher(config)))(makeRunConfig(currentDirectory, config, newArgs2))
    }
  }
  /** Locate a server, print where it is, and exit. */
  def locate(currentDirectory: File, config: LaunchConfiguration): Option[Int] = {
    config.serverConfig match {
      case Some(_) =>
        val uri = ServerLocator.locate(currentDirectory, config)
        System.out.println(uri.toASCIIString)
        Some(0)
      case None => sys.error(s"${config.app.groupID}-${config.app.main} is not configured as a server.")
    }
  }
  /**
   * Some hackery to allow sys.props to be configured via a file. If this launch config has
   * a valid file configured, we load the properties and and apply them to this jvm.
   */
  def updateProperties(config: LaunchConfiguration): Unit = {
    config.serverConfig match {
      case Some(config) =>
        config.jvmPropsFile match {
          case Some(file) if file.exists =>
            try setSystemProperties(readProperties(file))
            catch {
              case e: Exception => throw new RuntimeException(s"Unable to load server properties file: ${file}", e)
            }
          case _ =>
        }
      case None =>
    }
  }

  /** Parses the configuration *and* runs the initialization code that will remove variable references. */
  def parseAndInitializeConfig(configLocation: URL, currentDirectory: File): LaunchConfiguration =
    {
      val (parsed, bd) = parseConfiguration(configLocation, currentDirectory)
      resolveConfig(parsed)
    }
  /** Parse configuration and return it and the baseDirectory of the launch. */
  def parseConfiguration(configLocation: URL, currentDirectory: File): (LaunchConfiguration, File) =
    Find(Configuration.parse(configLocation, currentDirectory), currentDirectory)

  /** Setups the Initialize object so we can fill in system properties in the configuration */
  def resolveConfig(parsed: LaunchConfiguration): LaunchConfiguration =
    {
      // Set up initialize.
      val propertiesFile = parsed.boot.properties
      import parsed.boot.{ enableQuick, promptCreate, promptFill }
      if (isNonEmpty(promptCreate) && !propertiesFile.exists)
        Initialize.create(propertiesFile, promptCreate, enableQuick, parsed.appProperties)
      else if (promptFill)
        Initialize.fill(propertiesFile, parsed.appProperties)

      parsed.logging.debug("Parsed configuration: " + parsed)
      val resolved = ResolveValues(parsed)
      resolved.logging.debug("Resolved configuration: " + resolved)
      resolved
    }

  /** Create run configuration we'll use to launch the app. */
  def makeRunConfig(currentDirectory: File, config: LaunchConfiguration, arguments: List[String]): RunConfiguration =
    new RunConfiguration(config.getScalaVersion, config.app.toID, currentDirectory, arguments)

  /** The actual mechanism used to run a launched application. */
  def run(launcher: xsbti.Launcher)(config: RunConfiguration): xsbti.MainResult =
    {
      import config._
      val appProvider: xsbti.AppProvider = launcher.app(app, orNull(scalaVersion)) // takes ~40 ms when no update is required
      val appConfig: xsbti.AppConfiguration = new AppConfiguration(toArray(arguments), workingDirectory, appProvider)

      // TODO - Jansi probably should be configurable via some other mechanism...
      JAnsi.install(launcher.topLoader)
      try {
        val main = appProvider.newMain()
        try { withContextLoader(appProvider.loader)(main.run(appConfig)) }
        catch { case e: xsbti.FullReload => if (e.clean) delete(launcher.bootDirectory); throw e }
      } finally {
        JAnsi.uninstall(launcher.topLoader)
      }
    }
  final def launch(run: RunConfiguration => xsbti.MainResult)(config: RunConfiguration): Option[Int] =
    {
      run(config) match {
        case e: xsbti.Exit     => Some(e.code)
        case c: xsbti.Continue => None
        case r: xsbti.Reboot   => launch(run)(new RunConfiguration(Option(r.scalaVersion), r.app, r.baseDirectory, r.arguments.toList))
        case x                 => throw new BootException("Invalid main result: " + x + (if (x eq null) "" else " (class: " + x.getClass + ")"))
      }
    }
  private[this] def withContextLoader[T](loader: ClassLoader)(eval: => T): T =
    {
      val oldLoader = Thread.currentThread.getContextClassLoader
      Thread.currentThread.setContextClassLoader(loader)
      try { eval } finally { Thread.currentThread.setContextClassLoader(oldLoader) }
    }

  // Cache of classes for lookup later.
  val ServerMainClass = classOf[xsbti.ServerMain]
  val AppMainClass = classOf[xsbti.AppMain]
}
final class RunConfiguration(val scalaVersion: Option[String], val app: xsbti.ApplicationID, val workingDirectory: File, val arguments: List[String])

import BootConfiguration.{ appDirectoryName, baseDirectoryName, extractScalaVersion, ScalaDirectoryName, TestLoadScalaClasses, ScalaOrg }
class Launch private[xsbt] (val bootDirectory: File, val lockBoot: Boolean, val ivyOptions: IvyOptions) extends xsbti.Launcher {
  import ivyOptions.{ checksums => checksumsList, classifiers, repositories }
  bootDirectory.mkdirs
  private val scalaProviders = new Cache[(String, String), String, xsbti.ScalaProvider]((x, y) => getScalaProvider(x._1, x._2, y))
  def getScala(version: String): xsbti.ScalaProvider = getScala(version, "")
  def getScala(version: String, reason: String): xsbti.ScalaProvider = getScala(version, reason, ScalaOrg)
  def getScala(version: String, reason: String, scalaOrg: String) = scalaProviders((scalaOrg, version), reason)
  def app(id: xsbti.ApplicationID, version: String): xsbti.AppProvider = app(id, Option(version))
  def app(id: xsbti.ApplicationID, scalaVersion: Option[String]): xsbti.AppProvider =
    getAppProvider(id, scalaVersion, false)

  val bootLoader = new BootFilteredLoader(getClass.getClassLoader)
  val topLoader = if (isWindows && !isCygwin) jansiLoader(bootLoader) else bootLoader

  val updateLockFile = if (lockBoot) Some(new File(bootDirectory, "sbt.boot.lock")) else None

  def globalLock: xsbti.GlobalLock = Locks
  def ivyHome = orNull(ivyOptions.ivyHome)
  def ivyRepositories = (repositories: List[xsbti.Repository]).toArray
  def appRepositories = ((repositories filterNot (_.bootOnly)): List[xsbti.Repository]).toArray
  def isOverrideRepositories: Boolean = ivyOptions.isOverrideRepositories
  def checksums = checksumsList.toArray[String]

  // JAnsi needs to be shared between Scala and the application so there aren't two competing versions
  def jansiLoader(parent: ClassLoader): ClassLoader =
    {
      val id = AppID("org.fusesource.jansi", "jansi", JAnsiVersion, "", toArray(Nil), xsbti.CrossValue.Disabled, array())
      val configuration = makeConfiguration(ScalaOrg, None)
      val jansiHome = appDirectory(new File(bootDirectory, baseDirectoryName(ScalaOrg, None)), id)
      val module = appModule(id, None, false, "jansi")
      def makeLoader(): ClassLoader = {
        val urls = toURLs(wrapNull(jansiHome.listFiles(JarFilter)))
        val loader = new URLClassLoader(urls, bootLoader)
        checkLoader(loader, module, "org.fusesource.jansi.internal.WindowsSupport" :: Nil, loader)
      }
      val existingLoader =
        if (jansiHome.exists)
          try Some(makeLoader()) catch { case e: Exception => None }
        else
          None
      existingLoader getOrElse {
        update(module, "")
        makeLoader()
      }
    }
  def checkLoader[T](loader: ClassLoader, module: ModuleDefinition, testClasses: Seq[String], ifValid: T): T =
    {
      val missing = getMissing(loader, testClasses)
      if (missing.isEmpty)
        ifValid
      else
        module.retrieveCorrupt(missing)
    }

  private[this] def makeConfiguration(scalaOrg: String, version: Option[String]): UpdateConfiguration =
    new UpdateConfiguration(bootDirectory, ivyOptions.ivyHome, scalaOrg, version, repositories, checksumsList)

  final def getAppProvider(id: xsbti.ApplicationID, explicitScalaVersion: Option[String], forceAppUpdate: Boolean): xsbti.AppProvider =
    locked(new Callable[xsbti.AppProvider] { def call = getAppProvider0(id, explicitScalaVersion, forceAppUpdate) })

  @tailrec private[this] final def getAppProvider0(id: xsbti.ApplicationID, explicitScalaVersion: Option[String], forceAppUpdate: Boolean): xsbti.AppProvider =
    {
      val app = appModule(id, explicitScalaVersion, true, "app")
      /** Replace the version of an ApplicationID with the given one, if set. */
      def resolveId(appVersion: Option[String], id: xsbti.ApplicationID) = appVersion map { v =>
        import id._
        AppID(groupID(), name(), v, mainClass(), mainComponents(), crossVersionedValue(), classpathExtra())
      } getOrElse id
      val baseDirs = (resolvedVersion: Option[String]) => (base: File) => appBaseDirs(base, resolveId(resolvedVersion, id))
      def retrieve() = {
        val (appv, sv) = update(app, "")
        val scalaVersion = strictOr(explicitScalaVersion, sv)
        new RetrievedModule(true, app, sv, appv, baseDirs(appv)(scalaHome(ScalaOrg, scalaVersion)))
      }
      val retrievedApp =
        if (forceAppUpdate)
          retrieve()
        else
          existing(app, ScalaOrg, explicitScalaVersion, baseDirs(None)) getOrElse retrieve()

      val scalaVersion = getOrError(strictOr(explicitScalaVersion, retrievedApp.detectedScalaVersion), "No Scala version specified or detected")
      val scalaProvider = getScala(scalaVersion, "(for " + id.name + ")")
      val resolvedId = resolveId(retrievedApp.resolvedAppVersion, id)

      val (missing, appProvider) = checkedAppProvider(resolvedId, retrievedApp, scalaProvider)
      if (missing.isEmpty)
        appProvider
      else if (retrievedApp.fresh)
        app.retrieveCorrupt(missing)
      else
        getAppProvider0(resolvedId, explicitScalaVersion, true)
    }
  def scalaHome(scalaOrg: String, scalaVersion: Option[String]): File = new File(bootDirectory, baseDirectoryName(scalaOrg, scalaVersion))
  def appHome(id: xsbti.ApplicationID, scalaVersion: Option[String]): File = appDirectory(scalaHome(ScalaOrg, scalaVersion), id)
  def checkedAppProvider(id: xsbti.ApplicationID, module: RetrievedModule, scalaProvider: xsbti.ScalaProvider): (Iterable[String], xsbti.AppProvider) =
    {
      val p = appProvider(id, module, scalaProvider, appHome(id, Some(scalaProvider.version)))
      val missing = getMissing(p.loader, id.mainClass :: Nil)
      (missing, p)
    }
  private[this] def locked[T](c: Callable[T]): T = Locks(orNull(updateLockFile), c)
  def getScalaProvider(scalaOrg: String, scalaVersion: String, reason: String): xsbti.ScalaProvider =
    locked(new Callable[xsbti.ScalaProvider] { def call = getScalaProvider0(scalaOrg, scalaVersion, reason) })

  private[this] final def getScalaProvider0(scalaOrg: String, scalaVersion: String, reason: String) =
    {
      val scalaM = scalaModule(scalaOrg, scalaVersion)
      val (scalaHome, lib) = scalaDirs(scalaM, scalaOrg, scalaVersion)
      val baseDirs = lib :: Nil
      def provider(retrieved: RetrievedModule): xsbti.ScalaProvider = {
        val p = scalaProvider(scalaVersion, retrieved, topLoader, lib)
        checkLoader(p.loader, retrieved.definition, TestLoadScalaClasses, p)
      }
      existing(scalaM, scalaOrg, Some(scalaVersion), _ => baseDirs) flatMap { mod =>
        try Some(provider(mod))
        catch { case e: Exception => None }
      } getOrElse {
        val (_, scalaVersion) = update(scalaM, reason)
        provider(new RetrievedModule(true, scalaM, scalaVersion, baseDirs))
      }
    }

  def existing(module: ModuleDefinition, scalaOrg: String, explicitScalaVersion: Option[String], baseDirs: File => List[File]): Option[RetrievedModule] =
    {
      val filter = new java.io.FileFilter {
        val explicitName = explicitScalaVersion.map(sv => baseDirectoryName(scalaOrg, Some(sv)))
        def accept(file: File) = file.isDirectory && explicitName.forall(_ == file.getName)
      }
      val retrieved = wrapNull(bootDirectory.listFiles(filter)) flatMap { scalaDir =>
        val appDir = directory(scalaDir, module.target)
        if (appDir.exists)
          new RetrievedModule(false, module, extractScalaVersion(scalaDir), baseDirs(scalaDir)) :: Nil
        else
          Nil
      }
      retrieved.headOption
    }
  def directory(scalaDir: File, target: UpdateTarget): File = target match {
    case _: UpdateScala => scalaDir
    case ua: UpdateApp  => appDirectory(scalaDir, ua.id.toID)
  }
  def appBaseDirs(scalaHome: File, id: xsbti.ApplicationID): List[File] =
    {
      val appHome = appDirectory(scalaHome, id)
      val components = componentProvider(appHome)
      appHome :: id.mainComponents.map(components.componentLocation).toList
    }
  def appDirectory(base: File, id: xsbti.ApplicationID): File =
    new File(base, appDirectoryName(id, File.separator))

  def scalaDirs(module: ModuleDefinition, scalaOrg: String, scalaVersion: String): (File, File) =
    {
      val scalaHome = new File(bootDirectory, baseDirectoryName(scalaOrg, Some(scalaVersion)))
      val libDirectory = new File(scalaHome, ScalaDirectoryName)
      (scalaHome, libDirectory)
    }

  def appProvider(appID: xsbti.ApplicationID, app: RetrievedModule, scalaProvider0: xsbti.ScalaProvider, appHome: File): xsbti.AppProvider =
    new xsbti.AppProvider {
      import Launch.{ ServerMainClass, AppMainClass }
      val scalaProvider = scalaProvider0
      val id = appID
      def mainClasspath = app.fullClasspath
      lazy val loader = app.createLoader(scalaProvider.loader)
      // TODO - For some reason we can't call this from vanilla scala.  We get a 
      // no such method exception UNLESS we're in the same project.
      lazy val entryPoint: Class[T] forSome { type T } =
        {
          val c = Class.forName(id.mainClass, true, loader)
          if (classOf[xsbti.AppMain].isAssignableFrom(c)) c
          else if (PlainApplication.isPlainApplication(c)) c
          else if (ServerApplication.isServerApplication(c)) c
          else sys.error(s"${c} is not an instance of xsbti.AppMain, xsbti.ServerMain nor does it have one of these static methods:\n" +
            " * void main(String[] args)\n * int main(String[] args)\n * xsbti.Exit main(String[] args)\n")
        }
      // Deprecated API.  Remove when we can.
      def mainClass: Class[T] forSome { type T <: xsbti.AppMain } = entryPoint.asSubclass(AppMainClass)
      def newMain(): xsbti.AppMain = {
        if (ServerApplication.isServerApplication(entryPoint)) ServerApplication(this)
        else if (PlainApplication.isPlainApplication(entryPoint)) PlainApplication(entryPoint)
        else if (AppMainClass.isAssignableFrom(entryPoint)) mainClass.newInstance
        else throw new IncompatibleClassChangeError(s"Main class ${entryPoint.getName} is not an instance of xsbti.AppMain, xsbti.ServerMain nor does it have a valid `main` method.")
      }
      lazy val components = componentProvider(appHome)
    }
  def componentProvider(appHome: File) = new ComponentProvider(appHome, lockBoot)

  def scalaProvider(scalaVersion: String, module: RetrievedModule, parentLoader: ClassLoader, scalaLibDir: File): xsbti.ScalaProvider = new xsbti.ScalaProvider {
    def launcher = Launch.this
    def version = scalaVersion
    lazy val loader = module.createLoader(parentLoader)

    def compilerJar = new File(scalaLibDir, CompilerModuleName + ".jar")
    def libraryJar = new File(scalaLibDir, LibraryModuleName + ".jar")
    def jars = module.fullClasspath

    def app(id: xsbti.ApplicationID) = Launch.this.app(id, Some(scalaVersion))
  }

  def appModule(id: xsbti.ApplicationID, scalaVersion: Option[String], getClassifiers: Boolean, tpe: String): ModuleDefinition = new ModuleDefinition(
    configuration = makeConfiguration(ScalaOrg, scalaVersion),
    target = new UpdateApp(Application(id), if (getClassifiers) Value.get(classifiers.app) else Nil, tpe),
    failLabel = id.name + " " + id.version,
    extraClasspath = id.classpathExtra
  )
  def scalaModule(org: String, version: String): ModuleDefinition = new ModuleDefinition(
    configuration = makeConfiguration(org, Some(version)),
    target = new UpdateScala(Value.get(classifiers.forScala)),
    failLabel = "Scala " + version,
    extraClasspath = array()
  )
  /** Returns the resolved appVersion (if this was an App), as well as the scalaVersion. */
  def update(mm: ModuleDefinition, reason: String): (Option[String], Option[String]) =
    {
      val result = (new Update(mm.configuration))(mm.target, reason)
      if (result.success) result.appVersion -> result.scalaVersion else mm.retrieveFailed
    }
}
object Launcher {
  def apply(bootDirectory: File, repositories: List[Repository.Repository]): xsbti.Launcher =
    apply(bootDirectory, IvyOptions(None, Classifiers(Nil, Nil), repositories, BootConfiguration.DefaultChecksums, false))
  def apply(bootDirectory: File, ivyOptions: IvyOptions): xsbti.Launcher =
    apply(bootDirectory, ivyOptions, GetLocks.find)
  def apply(bootDirectory: File, ivyOptions: IvyOptions, locks: xsbti.GlobalLock): xsbti.Launcher =
    new Launch(bootDirectory, true, ivyOptions) {
      override def globalLock = locks
    }
  def apply(explicit: LaunchConfiguration): xsbti.Launcher =
    new Launch(explicit.boot.directory, explicit.boot.lock, explicit.ivyConfiguration)
  def defaultAppProvider(baseDirectory: File): xsbti.AppProvider = getAppProvider(baseDirectory, Configuration.configurationOnClasspath)
  def getAppProvider(baseDirectory: File, configLocation: URL): xsbti.AppProvider =
    {
      val parsed = ResolvePaths(Configuration.parse(configLocation, baseDirectory), baseDirectory)
      Initialize.process(parsed.boot.properties, parsed.appProperties, Initialize.selectQuick)
      val config = ResolveValues(parsed)
      val launcher = apply(config)
      launcher.app(config.app.toID, orNull(config.getScalaVersion))
    }
}
class ComponentProvider(baseDirectory: File, lockBoot: Boolean) extends xsbti.ComponentProvider {
  def componentLocation(id: String): File = new File(baseDirectory, id)
  def component(id: String) = wrapNull(componentLocation(id).listFiles).filter(_.isFile)
  def defineComponent(id: String, files: Array[File]) =
    {
      val location = componentLocation(id)
      if (location.exists)
        throw new BootException("Cannot redefine component.  ID: " + id + ", files: " + files.mkString(","))
      else
        Copy(files.toList, location)
    }
  def addToComponent(id: String, files: Array[File]): Boolean =
    Copy(files.toList, componentLocation(id))
  def lockFile = if (lockBoot) ComponentProvider.lockFile(baseDirectory) else null // null for the Java interface
}
object ComponentProvider {
  def lockFile(baseDirectory: File) =
    {
      baseDirectory.mkdirs()
      new File(baseDirectory, "sbt.components.lock")
    }
}
