/* sbt -- Simple Build Tool
 * Copyright 2011 Mark Harrah
 */
package sbt

	import java.io.File
	import java.net.URI
	import Project._
	import Keys.{appConfiguration, stateBuildStructure, commands, configuration, historyPath, projectCommand, sessionSettings, sessionVars, shellPrompt, thisProject, thisProjectRef, watch}
	import Scope.{GlobalScope,ThisScope}
	import Load.BuildStructure
	import Types.{idFun, Id}
	import complete.DefaultParsers

sealed trait ProjectDefinition[PR <: ProjectReference]
{
	def id: String
	def base: File
	def configurations: Seq[Configuration]
	def settings: Seq[Project.Setting[_]]
	def aggregate: Seq[PR]
	def delegates: Seq[PR]
	def dependencies: Seq[ClasspathDep[PR]]
	def uses: Seq[PR] = aggregate ++ dependencies.map(_.project)
	def referenced: Seq[PR] = delegates ++ uses

	override final def hashCode: Int = id.hashCode ^ base.hashCode ^ getClass.hashCode
	override final def equals(o: Any) = o match {
		case p: ProjectDefinition[_] => p.getClass == this.getClass && p.id == id && p.base == base
		case _ => false
	}
	override def toString = "Project(id: " + id + ", base: " + base + ", aggregate: " + aggregate + ", dependencies: " + dependencies + ", delegates: " + delegates + ", configurations: " + configurations + ")"
}
sealed trait Project extends ProjectDefinition[ProjectReference]
{
	def copy(id: String = id, base: File = base, aggregate: => Seq[ProjectReference] = aggregate, dependencies: => Seq[ClasspathDep[ProjectReference]] = dependencies, delegates: => Seq[ProjectReference] = delegates,
		settings: => Seq[Project.Setting[_]] = settings, configurations: Seq[Configuration] = configurations): Project =
			Project(id, base, aggregate = aggregate, dependencies = dependencies, delegates = delegates, settings, configurations)

	def resolve(resolveRef: ProjectReference => ProjectRef): ResolvedProject =
	{
		def resolveRefs(prs: Seq[ProjectReference]) = prs map resolveRef
		def resolveDeps(ds: Seq[ClasspathDep[ProjectReference]]) = ds map resolveDep
		def resolveDep(d: ClasspathDep[ProjectReference]) = ResolvedClasspathDependency(resolveRef(d.project), d.configuration)
		resolved(id, base, aggregate = resolveRefs(aggregate), dependencies = resolveDeps(dependencies), delegates = resolveRefs(delegates), settings, configurations)
	}
	def resolveBuild(resolveRef: ProjectReference => ProjectReference): Project =
	{
		def resolveRefs(prs: Seq[ProjectReference]) = prs map resolveRef
		def resolveDeps(ds: Seq[ClasspathDep[ProjectReference]]) = ds map resolveDep
		def resolveDep(d: ClasspathDep[ProjectReference]) = ClasspathDependency(resolveRef(d.project), d.configuration)
		apply(id, base, aggregate = resolveRefs(aggregate), dependencies = resolveDeps(dependencies), delegates = resolveRefs(delegates), settings, configurations)
	}

	def overrideConfigs(cs: Configuration*): Project = copy(configurations = Defaults.overrideConfigs(cs : _*)(configurations))
	def dependsOn(deps: ClasspathDep[ProjectReference]*): Project = copy(dependencies = dependencies ++ deps)
	def delegateTo(from: ProjectReference*): Project = copy(delegates = delegates ++ from)
	def aggregate(refs: ProjectReference*): Project = copy(aggregate = (aggregate: Seq[ProjectReference]) ++ refs)
	def configs(cs: Configuration*): Project = copy(configurations = configurations ++ cs)
	def settings(ss: Project.Setting[_]*): Project = copy(settings = (settings: Seq[Project.Setting[_]]) ++ ss)
}
sealed trait ResolvedProject extends ProjectDefinition[ProjectRef]

final case class Extracted(structure: BuildStructure, session: SessionSettings, currentRef: ProjectRef)(implicit val showKey: Show[ScopedKey[_]])
{
	def rootProject = structure.rootProject
	lazy val currentUnit = structure units currentRef.build
	lazy val currentProject = currentUnit defined currentRef.project
	lazy val currentLoader: ClassLoader = currentUnit.loader
	def get[T](key: TaskKey[T]): Task[T] = get(key.task)
	def get[T](key: SettingKey[T]) = getOrError(inCurrent(key), key.key)
	def getOpt[T](key: SettingKey[T]): Option[T] = structure.data.get(inCurrent(key), key.key)
	private[this] def inCurrent[T](key: SettingKey[T]): Scope  =  if(key.scope.project == This) key.scope.copy(project = Select(currentRef)) else key.scope
	@deprecated("This method does not apply state changes requested during task execution.  Use 'runTask' instead, which does.", "0.11.1")
	def evalTask[T](key: TaskKey[T], state: State): T = runTask(key, state)._2
	def runTask[T](key: TaskKey[T], state: State): (State, T) =
	{
			import EvaluateTask._
		val rkey = resolve(key.scopedKey)
		val config = extractedConfig(this, structure)
		val value: Option[(State, Result[T])] = apply(structure, key.task.scopedKey, state, currentRef, config)
		val (newS, result) = getOrError(rkey.scope, rkey.key, value)
		(newS, processResult(result, newS.log))
	}
	def runAggregated[T](key: TaskKey[T], state: State): State =
	{
		val rkey = resolve(key.scopedKey)
		val keys = Aggregation.aggregate(rkey, ScopeMask(), structure.extra)
		val tasks = Act.keyValues(structure)(keys)
		Aggregation.runTasks(state, structure, tasks, Aggregation.Dummies(KNil, HNil), show = false )(showKey)
	}
	private[this] def resolve[T](key: ScopedKey[T]): ScopedKey[T] =
		Project.mapScope(Scope.resolveScope(GlobalScope, currentRef.build, rootProject) )( key.scopedKey )
	private def getOrError[T](scope: Scope, key: AttributeKey[_], value: Option[T])(implicit display: Show[ScopedKey[_]]): T =
		value getOrElse error(display(ScopedKey(scope, key)) + " is undefined.")
	private def getOrError[T](scope: Scope, key: AttributeKey[T])(implicit display: Show[ScopedKey[_]]): T =
		structure.data.get(scope, key) getOrElse error(display(ScopedKey(scope, key)) + " is undefined.")

	def append(settings: Seq[Setting[_]], state: State): State =
	{
		val appendSettings = Load.transformSettings(Load.projectScope(currentRef), currentRef.build, rootProject, settings)
		val newStructure = Load.reapply(session.original ++ appendSettings, structure)
		Project.setProject(session, newStructure, state)
	}
}

sealed trait ClasspathDep[PR <: ProjectReference] { def project: PR; def configuration: Option[String] }
final case class ResolvedClasspathDependency(project: ProjectRef, configuration: Option[String]) extends ClasspathDep[ProjectRef]
final case class ClasspathDependency(project: ProjectReference, configuration: Option[String]) extends ClasspathDep[ProjectReference]

object Project extends Init[Scope] with ProjectExtra
{
	lazy val showFullKey: Show[ScopedKey[_]] = showFullKey(None)
	def showFullKey(keyNameColor: Option[String]): Show[ScopedKey[_]] =
		new Show[ScopedKey[_]] { def apply(key: ScopedKey[_]) = displayFull(key, keyNameColor) }
	def showContextKey(state: State): Show[ScopedKey[_]] =
		showContextKey(state, None)

	def showContextKey(state: State, keyNameColor: Option[String]): Show[ScopedKey[_]] =
		if(isProjectLoaded(state)) showContextKey( session(state), structure(state), keyNameColor ) else showFullKey

	def showContextKey(session: SessionSettings, structure: BuildStructure, keyNameColor: Option[String] = None): Show[ScopedKey[_]] =
		showRelativeKey(session.current, structure.allProjects.size > 1, keyNameColor)

	def showLoadingKey(loaded: Load.LoadedBuild, keyNameColor: Option[String] = None): Show[ScopedKey[_]] =
		showRelativeKey( ProjectRef(loaded.root, loaded.units(loaded.root).rootProjects.head), loaded.allProjectRefs.size > 1, keyNameColor)

	def showRelativeKey(current: ProjectRef, multi: Boolean, keyNameColor: Option[String] = None): Show[ScopedKey[_]] = new Show[ScopedKey[_]] {
		def apply(key: ScopedKey[_]) =
			Scope.display(key.scope, colored(key.key.label, keyNameColor), ref => displayRelative(current, multi, ref))
	}
	def displayRelative(current: ProjectRef, multi: Boolean, project: Reference): String = project match {
		case BuildRef(current.build) => "{.}/"
		case `current` => if(multi) current.project + "/" else ""
		case ProjectRef(current.build, x) => x + "/"
		case _ => display(project) + "/"
	}

	private abstract class ProjectDef[PR <: ProjectReference](val id: String, val base: File, aggregate0: => Seq[PR], dependencies0: => Seq[ClasspathDep[PR]], delegates0: => Seq[PR],
		settings0: => Seq[Setting[_]], val configurations: Seq[Configuration]) extends ProjectDefinition[PR]
	{
		lazy val aggregate = aggregate0
		lazy val dependencies = dependencies0
		lazy val delegates = delegates0
		lazy val settings = settings0
	
		Dag.topologicalSort(configurations)(_.extendsConfigs) // checks for cyclic references here instead of having to do it in Scope.delegates
	}

	def apply(id: String, base: File, aggregate: => Seq[ProjectReference] = Nil, dependencies: => Seq[ClasspathDep[ProjectReference]] = Nil, delegates: => Seq[ProjectReference] = Nil,
		settings: => Seq[Setting[_]] = defaultSettings, configurations: Seq[Configuration] = Configurations.default): Project =
	{
		DefaultParsers.parse(id, DefaultParsers.ID).left.foreach(errMsg => error("Invalid project ID: " + errMsg))
		new ProjectDef[ProjectReference](id, base, aggregate, dependencies, delegates, settings, configurations) with Project
	}

	def resolved(id: String, base: File, aggregate: => Seq[ProjectRef], dependencies: => Seq[ResolvedClasspathDependency], delegates: => Seq[ProjectRef],
		settings: Seq[Setting[_]], configurations: Seq[Configuration]): ResolvedProject =
			new ProjectDef[ProjectRef](id, base, aggregate, dependencies, delegates, settings, configurations) with ResolvedProject

	def defaultSettings: Seq[Setting[_]] = Defaults.defaultSettings

	final class Constructor(p: ProjectReference) {
		def %(conf: Configuration): ClasspathDependency = %(conf.name)

		def %(conf: String): ClasspathDependency = new ClasspathDependency(p, Some(conf))
	}

	def getOrError[T](state: State, key: AttributeKey[T], msg: String): T = state get key getOrElse error(msg)
	def structure(state: State): BuildStructure = getOrError(state, stateBuildStructure, "No build loaded.")
	def session(state: State): SessionSettings = getOrError(state, sessionSettings, "Session not initialized.")
	def isProjectLoaded(state: State): Boolean = (state has sessionSettings) && (state has stateBuildStructure)

	def extract(state: State): Extracted  =  extract( session(state), structure(state) )
	def extract(se: SessionSettings, st: BuildStructure): Extracted  =  Extracted(st, se, se.current)( showContextKey(se, st) )

	def getProjectForReference(ref: Reference, structure: BuildStructure): Option[ResolvedProject] =
		ref match { case pr: ProjectRef => getProject(pr, structure); case _ => None }
	def getProject(ref: ProjectRef, structure: BuildStructure): Option[ResolvedProject] = getProject(ref, structure.units)
	def getProject(ref: ProjectRef, structure: Load.LoadedBuild): Option[ResolvedProject] = getProject(ref, structure.units)
	def getProject(ref: ProjectRef, units: Map[URI, Load.LoadedBuildUnit]): Option[ResolvedProject] =
		(units get ref.build).flatMap(_.defined get ref.project)

	def runUnloadHooks(s: State): State =
	{
		val previousOnUnload = orIdentity(s get Keys.onUnload.key)
		previousOnUnload(s.runExitHooks())
	}
	def setProject(session: SessionSettings, structure: BuildStructure, s: State): State =
	{
		val unloaded = runUnloadHooks(s)
		val (onLoad, onUnload) = getHooks(structure.data)
		val newAttrs = unloaded.attributes.put(stateBuildStructure, structure).put(sessionSettings, session).put(Keys.onUnload.key, onUnload)
		val newState = unloaded.copy(attributes = newAttrs)
		onLoad(updateCurrent( newState ))
	}
	def orIdentity[T](opt: Option[T => T]): T => T = opt getOrElse idFun
	def getHook[T](key: SettingKey[T => T], data: Settings[Scope]): T => T  =  orIdentity(key in GlobalScope get data)
	def getHooks(data: Settings[Scope]): (State => State, State => State)  =  (getHook(Keys.onLoad, data), getHook(Keys.onUnload, data))

	def current(state: State): ProjectRef = session(state).current
	def updateCurrent(s: State): State =
	{
		val structure = Project.structure(s)
		val ref = Project.current(s)
		val project = Load.getProject(structure.units, ref.build, ref.project)
		val msg = Keys.onLoadMessage in ref get structure.data getOrElse ""
		if(!msg.isEmpty) s.log.info(msg)
		def get[T](k: SettingKey[T]): Option[T] = k in ref get structure.data
		def commandsIn(axis: ResolvedReference) = commands in axis get structure.data toList ;

		val allCommands = commandsIn(ref) ++ commandsIn(BuildRef(ref.build)) ++ (commands in Global get structure.data toList )
		val history = get(historyPath) flatMap idFun
		val prompt = get(shellPrompt)
		val watched = get(watch)
		val commandDefs = allCommands.distinct.flatten[Command].map(_ tag (projectCommand, true))
		val newDefinedCommands = commandDefs ++ BasicCommands.removeTagged(s.definedCommands, projectCommand)
		val newAttrs = setCond(Watched.Configuration, watched, s.attributes).put(historyPath.key, history)
		s.copy(attributes = setCond(shellPrompt.key, prompt, newAttrs), definedCommands = newDefinedCommands)
	}
	def setCond[T](key: AttributeKey[T], vopt: Option[T], attributes: AttributeMap): AttributeMap =
		vopt match { case Some(v) => attributes.put(key, v); case None => attributes.remove(key) }
	def makeSettings(settings: Seq[Setting[_]], delegates: Scope => Seq[Scope], scopeLocal: ScopedKey[_] => Seq[Setting[_]])(implicit display: Show[ScopedKey[_]]) =
		make(settings)(delegates, scopeLocal, display)

	def equal(a: ScopedKey[_], b: ScopedKey[_], mask: ScopeMask): Boolean =
		a.key == b.key && Scope.equal(a.scope, b.scope, mask)

	def colored(s: String, color: Option[String]): String = color match {
		case Some(c) => c + s + scala.Console.RESET
		case None => s
	}
	def displayFull(scoped: ScopedKey[_]): String = displayFull(scoped, None)
	def displayFull(scoped: ScopedKey[_], keyNameColor: Option[String]): String = Scope.display(scoped.scope, colored(scoped.key.label, keyNameColor))
	def displayMasked(scoped: ScopedKey[_], mask: ScopeMask): String = Scope.displayMasked(scoped.scope, scoped.key.label, mask)
	def display(ref: Reference): String =
		ref match
		{
			case pr: ProjectReference => display(pr)
			case br: BuildReference => display(br)
		}
	def display(ref: BuildReference) =
		ref match
		{
			case ThisBuild => "{<this>}"
			case BuildRef(uri) => "{" + uri + "}"
		}
	def display(ref: ProjectReference) =
		ref match
		{
			case ThisProject => "{<this>}<this>"
			case LocalRootProject => "{<this>}<root>"
			case LocalProject(id) => "{<this>}" + id
			case RootProject(uri) => "{" + uri + " }<root>"
			case ProjectRef(uri, id) => "{" + uri + "}" + id
		}

	def fillTaskAxis(scoped: ScopedKey[_]): ScopedKey[_] =
		ScopedKey(Scope.fillTaskAxis(scoped.scope, scoped.key), scoped.key)

	def mapScope(f: Scope => Scope) = new  (ScopedKey ~> ScopedKey) { def apply[T](key: ScopedKey[T]) =
		ScopedKey( f(key.scope), key.key)
	}

	def transform(g: Scope => Scope, ss: Seq[Setting[_]]): Seq[Setting[_]] = {
		val f = mapScope(g)
		ss.map(_ mapKey f mapReferenced f)
	}
	def transformRef(g: Scope => Scope, ss: Seq[Setting[_]]): Seq[Setting[_]] = {
		val f = mapScope(g)
		ss.map(_ mapReferenced f)
	}

	def delegates(structure: BuildStructure, scope: Scope, key: AttributeKey[_]): Seq[ScopedKey[_]] =
		structure.delegates(scope).map(d => ScopedKey(d, key))

	def scopedKeyData(structure: BuildStructure, scope: Scope, key: AttributeKey[_]): Option[ScopedKeyData[_]] =
		structure.data.get(scope, key) map { v => ScopedKeyData(ScopedKey(scope, key), v) }

	def details(structure: BuildStructure, actual: Boolean, scope: Scope, key: AttributeKey[_])(implicit display: Show[ScopedKey[_]]): String =
	{
		val scoped = ScopedKey(scope,key)
		
		val data = scopedKeyData(structure, scope, key) map {_.description} getOrElse {"No entry for key."}
		val description = key.description match { case Some(desc) => "Description:\n\t" + desc + "\n"; case None => "" }

		val providedBy = structure.data.definingScope(scope, key) match {
			case Some(sc) => "Provided by:\n\t" + Scope.display(sc, key.label) + "\n"
			case None => ""
		}
		val comp = compiled(structure.settings, actual)(structure.delegates, structure.scopeLocal, display)
		val definedAt = comp get scoped map { c =>
			def fmt(s: Setting[_]) = s.pos match {
				case pos: FilePosition => Some(pos.path + ":" + pos.startLine)
				case NoPosition => None
			}
			val posDefined = c.settings.map(fmt).flatten
			if (posDefined.size > 0) {
				val header = if (posDefined.size == c.settings.size) "Defined at:" else
					"Some of the defining occurrences:"
				header + (posDefined mkString ("\n\t", "\n\t", "\n"))
			} else ""
    } getOrElse ""


		val cMap = flattenLocals(comp)
		val related = cMap.keys.filter(k => k.key == key && k.scope != scope)
		val depends = cMap.get(scoped) match { case Some(c) => c.dependencies.toSet; case None => Set.empty }

		val reverse = reverseDependencies(cMap, scoped)
		def printScopes(label: String, scopes: Iterable[ScopedKey[_]]) =
			if(scopes.isEmpty) "" else scopes.map(display.apply).mkString(label + ":\n\t", "\n\t", "\n")

		data + "\n" +
			description +
			providedBy +
			definedAt +
			printScopes("Dependencies", depends) +
			printScopes("Reverse dependencies", reverse) +
			printScopes("Delegates", delegates(structure, scope, key)) +
			printScopes("Related", related)
	}
	def settingGraph(structure: BuildStructure, basedir: File, scoped: ScopedKey[_])(implicit display: Show[ScopedKey[_]]): SettingGraph =
		SettingGraph(structure, basedir, scoped, 0)
	def graphSettings(structure: BuildStructure, basedir: File)(implicit display: Show[ScopedKey[_]])
	{
		def graph(actual: Boolean, name: String) = graphSettings(structure, actual, name, new File(basedir, name + ".dot"))
		graph(true, "actual_dependencies")
		graph(false, "declared_dependencies")
	}
	def graphSettings(structure: BuildStructure, actual: Boolean, graphName: String, file: File)(implicit display: Show[ScopedKey[_]])
	{
		val rel = relation(structure, actual)
		val keyToString = display.apply _
		DotGraph.generateGraph(file, graphName, rel, keyToString, keyToString)
	}
	def relation(structure: BuildStructure, actual: Boolean)(implicit display: Show[ScopedKey[_]]) =
	{
		type Rel = Relation[ScopedKey[_], ScopedKey[_]]
		val cMap = flattenLocals(compiled(structure.settings, actual)(structure.delegates, structure.scopeLocal, display))
		((Relation.empty: Rel) /: cMap) { case (r, (key, value)) =>
			r + (key, value.dependencies)
		}
	}

	def showDefinitions(key: AttributeKey[_], defs: Seq[Scope])(implicit display: Show[ScopedKey[_]]): String =
		defs.map(scope => display(ScopedKey(scope, key))).sorted.mkString("\n\t", "\n\t", "\n\n")
	def showUses(defs: Seq[ScopedKey[_]])(implicit display: Show[ScopedKey[_]]): String =
		defs.map(display.apply).sorted.mkString("\n\t", "\n\t", "\n\n")

	def definitions(structure: BuildStructure, actual: Boolean, key: AttributeKey[_])(implicit display: Show[ScopedKey[_]]): Seq[Scope] =
		relation(structure, actual)(display)._1s.toSeq flatMap { sk => if(sk.key == key) sk.scope :: Nil else Nil }
	def usedBy(structure: BuildStructure, actual: Boolean, key: AttributeKey[_])(implicit display: Show[ScopedKey[_]]): Seq[ScopedKey[_]] =
		relation(structure, actual)(display).all.toSeq flatMap { case (a,b) => if(b.key == key) List[ScopedKey[_]](a) else Nil }

	def reverseDependencies(cMap: Map[ScopedKey[_],Flattened], scoped: ScopedKey[_]): Iterable[ScopedKey[_]] =
		for( (key,compiled) <- cMap; dep <- compiled.dependencies if dep == scoped)  yield  key

	//@deprecated("Use SettingCompletions.setAll when available.", "0.13.0")
	def setAll(extracted: Extracted, settings: Seq[Setting[_]]): SessionSettings =
		SettingCompletions.setAll(extracted, settings).session

	val ExtraBuilds = AttributeKey[List[URI]]("extra-builds", "Extra build URIs to load in addition to the ones defined by the project.")
	def extraBuilds(s: State): List[URI] = getOrNil(s, ExtraBuilds)
	def getOrNil[T](s: State, key: AttributeKey[List[T]]): List[T] = s get key getOrElse Nil
	def setExtraBuilds(s: State, extra: List[URI]): State = s.put(ExtraBuilds, extra)
	def addExtraBuilds(s: State, extra: List[URI]): State = setExtraBuilds(s, extra ::: extraBuilds(s))
	def removeExtraBuilds(s: State, remove: List[URI]): State = updateExtraBuilds(s, _.filterNot(remove.toSet))
	def updateExtraBuilds(s: State, f: List[URI] => List[URI]): State = setExtraBuilds(s, f(extraBuilds(s)))

	object LoadAction extends Enumeration {
		val Return, Current, Plugins = Value
	}
	import LoadAction._
	import DefaultParsers._

	val loadActionParser = token(Space ~> ("plugins" ^^^ Plugins | "return" ^^^ Return)) ?? Current
	
	val ProjectReturn = AttributeKey[List[File]]("project-return", "Maintains a stack of builds visited using reload.")
	def projectReturn(s: State): List[File] = getOrNil(s, ProjectReturn)
	def inPluginProject(s: State): Boolean = projectReturn(s).toList.length > 1
	def setProjectReturn(s: State, pr: List[File]): State = s.copy(attributes = s.attributes.put( ProjectReturn, pr) )
	def loadAction(s: State, action: LoadAction.Value) = action match {
		case Return =>
			projectReturn(s) match
			{
				case current :: returnTo :: rest => (setProjectReturn(s, returnTo :: rest), returnTo)
				case _ => error("Not currently in a plugin definition")
			}
		case Current =>
			val base = s.configuration.baseDirectory
			projectReturn(s) match { case Nil => (setProjectReturn(s, base :: Nil), base); case x :: xs => (s, x) }
		case Plugins =>
			val extracted = Project.extract(s)
			val newBase = extracted.currentUnit.unit.plugins.base
			val newS = setProjectReturn(s, newBase :: projectReturn(s))
			(newS, newBase)
	}
	@deprecated("This method does not apply state changes requested during task execution.  Use 'runTask' instead, which does.", "0.11.1")
	def evaluateTask[T](taskKey: ScopedKey[Task[T]], state: State, checkCycles: Boolean = false, maxWorkers: Int = EvaluateTask.SystemProcessors): Option[Result[T]] =
		runTask(taskKey, state, EvaluateConfig(true, EvaluateTask.defaultRestrictions(maxWorkers), checkCycles)).map(_._2)
	def runTask[T](taskKey: ScopedKey[Task[T]], state: State, checkCycles: Boolean = false): Option[(State, Result[T])] =
		runTask(taskKey, state, EvaluateConfig(true, EvaluateTask.restrictions(state), checkCycles))
	def runTask[T](taskKey: ScopedKey[Task[T]], state: State, config: EvaluateConfig): Option[(State, Result[T])] =
	{
		val extracted = Project.extract(state)
		EvaluateTask(extracted.structure, taskKey, state, extracted.currentRef, config)
	}
	// this is here instead of Scoped so that it is considered without need for import (because of Project.Initialize)
	implicit def richInitializeTask[T](init: Initialize[Task[T]]): Scoped.RichInitializeTask[T] = new Scoped.RichInitializeTask(init)
	implicit def richInitializeInputTask[T](init: Initialize[InputTask[T]]): Scoped.RichInitializeInputTask[T] = new Scoped.RichInitializeInputTask(init)
	implicit def richInitialize[T](i: Initialize[T]): Scoped.RichInitialize[T] = new Scoped.RichInitialize[T](i)
}

final case class ScopedKeyData[A](scoped: ScopedKey[A], value: Any)
{
	import Types.const
	val key = scoped.key
	val scope = scoped.scope
	def typeName: String = fold(fmtMf("Task[%s]"), fmtMf("InputTask[%s]"), key.manifest.toString)
	def settingValue: Option[Any] = fold(const(None), const(None), Some(value))
	def description: String = fold(fmtMf("Task: %s"), fmtMf("Input task: %s"),
		"Setting: %s = %s" format (key.manifest.toString, value.toString))
	def fold[A](targ: OptManifest[_] => A, itarg: OptManifest[_] => A, s: => A): A =
		if (key.manifest.erasure == classOf[Task[_]]) targ(key.manifest.typeArguments.head)
		else if (key.manifest.erasure == classOf[InputTask[_]]) itarg(key.manifest.typeArguments.head)
		else s
	def fmtMf(s: String): OptManifest[_] => String = s format _
}

trait ProjectExtra
{
	implicit def configDependencyConstructor[T <% ProjectReference](p: T): Constructor = new Constructor(p)
	implicit def classpathDependency[T <% ProjectReference](p: T): ClasspathDependency = new ClasspathDependency(p, None)

	def inConfig(conf: Configuration)(ss: Seq[Setting[_]]): Seq[Setting[_]] =
		inScope(ThisScope.copy(config = Select(conf)) )( (configuration :== conf) +: ss)
	def inTask(t: Scoped)(ss: Seq[Setting[_]]): Seq[Setting[_]] =
		inScope(ThisScope.copy(task = Select(t.key)) )( ss )
	def inScope(scope: Scope)(ss: Seq[Setting[_]]): Seq[Setting[_]] =
		Project.transform(Scope.replaceThis(scope), ss)
}

	import sbinary.{Format, Operations}
object SessionVar
{
	val DefaultDataID = "data"

	// these are required because of inference+manifest limitations
	final case class Key[T](key: ScopedKey[Task[T]])
	final case class Map(map: IMap[Key, Id]) {
		def get[T](k: ScopedKey[Task[T]]): Option[T] = map get Key(k)
		def put[T](k: ScopedKey[Task[T]], v: T): Map = Map(map put (Key(k), v))
	}
	def emptyMap = Map(IMap.empty)

	def persistAndSet[T](key: ScopedKey[Task[T]], state: State, value: T)(implicit f: sbinary.Format[T]): State =
	{
		persist(key, state, value)(f)
		set(key, state, value)
	}

	def persist[T](key: ScopedKey[Task[T]], state: State, value: T)(implicit f: sbinary.Format[T]): Unit =
		Project.structure(state).streams(state).use(key)( s =>
			Operations.write(s.binary(DefaultDataID), value)(f)
		)

	def clear(s: State): State  =  s.put(sessionVars, SessionVar.emptyMap)

	def get[T](key: ScopedKey[Task[T]], state: State): Option[T] = orEmpty(state get sessionVars) get key

	def set[T](key: ScopedKey[Task[T]], state: State, value: T): State = state.update(sessionVars)(om => orEmpty(om) put (key, value))

	def orEmpty(opt: Option[Map]) = opt getOrElse emptyMap

	def transform[S](task: Task[S], f: (State, S) => State): Task[S] =
	{
		val g = (s: S, map: AttributeMap) => map.put(Keys.transformState, (state: State) => f(state, s))
		task.copy(info = task.info.postTransform(g))
	}

	def resolveContext[T](key: ScopedKey[Task[T]], context: Scope, state: State): ScopedKey[Task[T]] =
	{
		val subScope = Scope.replaceThis(context)(key.scope)
		val scope = Project.structure(state).data.definingScope(subScope, key.key) getOrElse subScope
		ScopedKey(scope, key.key)
	}

	def read[T](key: ScopedKey[Task[T]], state: State)(implicit f: Format[T]): Option[T] =
		Project.structure(state).streams(state).use(key) { s =>
			try { Some(Operations.read(s.readBinary(key, DefaultDataID))) }
			catch { case e: Exception => None }
		}

	def load[T](key: ScopedKey[Task[T]], state: State)(implicit f: Format[T]): Option[T] =
		get(key, state) orElse read(key, state)(f)

	def loadAndSet[T](key: ScopedKey[Task[T]], state: State, setIfUnset: Boolean = true)(implicit f: Format[T]): (State, Option[T]) =
		get(key, state) match {
			case s: Some[T] => (state, s)
			case None => read(key, state)(f) match {
				case s @ Some(t) =>
					val newState = if(setIfUnset && get(key, state).isDefined) state else set(key, state, t)
					(newState, s)
				case None => (state, None)
			}
		}
}