package scala.tools.nsc.doc
package model
package diagram

import model._

// statistics
import  html.page.diagram.DiagramStats

import scala.collection.immutable.SortedMap

/**
 *  This trait takes care of generating the diagram for classes and packages
 *
 *  @author Damien Obrist
 *  @author Vlad Ureche
 */
trait DiagramFactory extends DiagramDirectiveParser {
  this: ModelFactory with ModelFactoryTypeSupport with DiagramFactory with CommentFactory with TreeFactory =>

  import this.global.definitions._
  import this.global._

  // the following can used for hardcoding different relations into the diagram, for bootstrapping purposes
  def aggregationNode(text: String) =
    NormalNode(new TypeEntity { val name = text; val refEntity = SortedMap[Int, (base.LinkTo, Int)]() }, None)()

  /** Create the inheritance diagram for this template */
  def makeInheritanceDiagram(tpl: DocTemplateImpl): Option[Diagram] = {

    tFilter = 0
    tModel = -System.currentTimeMillis

    // the diagram filter
    val diagramFilter = makeInheritanceDiagramFilter(tpl)

    def implicitTooltip(from: DocTemplateEntity, to: TemplateEntity, conv: ImplicitConversion) =
      Some(from.qualifiedName + " can be implicitly converted to " + conv.targetType + " by the implicit method "
        + conv.conversionShortName + " in " + conv.convertorOwner.kind + " " + conv.convertorOwner.qualifiedName)

    val result =
      if (diagramFilter == NoDiagramAtAll)
        None
      else {
        // the main node
        val thisNode = ThisNode(tpl.resultType, Some(tpl))(Some(tpl.qualifiedName + " (this " + tpl.kind + ")"))

        // superclasses
        val superclasses: List[Node] =
          tpl.parentTypes.collect {
            case p: (TemplateEntity, TypeEntity) if !classExcluded(p._1) => NormalNode(p._2, Some(p._1))()
          }.reverse

        // incoming implicit conversions
        lazy val incomingImplicitNodes = tpl.incomingImplicitlyConvertedClasses.map {
          case (incomingTpl, conv) =>
            ImplicitNode(makeType(incomingTpl.sym.tpe, tpl), Some(incomingTpl))(implicitTooltip(from=incomingTpl, to=tpl, conv=conv))
        }

        // subclasses
        var subclasses: List[Node] =
          tpl.directSubClasses.collect {
            case d: TemplateImpl if !classExcluded(d) => NormalNode(makeType(d.sym.tpe, tpl), Some(d))()
          }.sortBy(_.tpl.get.name)(implicitly[Ordering[String]].reverse)

        // outgoing implicit conversions
        lazy val outgoingImplicitNodes = tpl.outgoingImplicitlyConvertedClasses.map {
          case (outgoingTpl, outgoingType, conv) =>
            ImplicitNode(outgoingType, Some(outgoingTpl))(implicitTooltip(from=tpl, to=tpl, conv=conv))
        }

        // TODO: Everyone should be able to use the @{inherit,content}Diagram annotation to change the diagrams.
        // Currently, it's possible to leave nodes and edges out, but there's no way to create new nodes and edges
        // The implementation would need to add the annotations and the logic to select nodes (or create new ones)
        // and add edges to the diagram -- I bet it wouldn't take too long for someone to do it (one or two days
        // at most) and it would be a great add to the diagrams.
        if (tpl.sym == AnyRefClass)
          subclasses = List(aggregationNode("All user-defined classes and traits"))

        val filteredSuperclasses = if (diagramFilter.hideSuperclasses) Nil else superclasses
        val filteredIncomingImplicits = if (diagramFilter.hideIncomingImplicits) Nil else incomingImplicitNodes
        val filteredSubclasses = if (diagramFilter.hideSubclasses) Nil else subclasses
        val filteredImplicitOutgoingNodes = if (diagramFilter.hideOutgoingImplicits) Nil else outgoingImplicitNodes

        // final diagram filter
        filterDiagram(InheritanceDiagram(thisNode, filteredSuperclasses.reverse, filteredSubclasses.reverse, filteredIncomingImplicits, filteredImplicitOutgoingNodes), diagramFilter)
      }

    tModel += System.currentTimeMillis
    DiagramStats.addFilterTime(tFilter)
    DiagramStats.addModelTime(tModel-tFilter)

    result
  }

  /** Create the content diagram for this template */
  def makeContentDiagram(pack: DocTemplateImpl): Option[Diagram] = {

    tFilter = 0
    tModel = -System.currentTimeMillis

    // the diagram filter
    val diagramFilter = makeContentDiagramFilter(pack)

    val result =
      if (diagramFilter == NoDiagramAtAll)
        None
      else {
        var mapNodes = Map[TemplateEntity, Node]()
        var nodesShown = Set[TemplateEntity]()
        var edgesAll = List[(TemplateEntity, List[TemplateEntity])]()

        // classes is the entire set of classes and traits in the package, they are the superset of nodes in the diagram
        // we collect classes, traits and objects without a companion, which are usually used as values(e.g. scala.None)
        val nodesAll = pack.members collect {
          case d: TemplateEntity if ((!diagramFilter.hideInheritedNodes) || (d.inTemplate == pack)) => d
        }

        def listSuperClasses(member: MemberTemplateImpl) = {
          // TODO: Everyone should be able to use the @{inherit,content}Diagram annotation to add nodes to diagrams.
          (pack.sym, member.sym) match {
            case (ScalaPackage, NullClass) =>
              List(makeTemplate(AnyRefClass))
            case (ScalaPackage, NothingClass) =>
              (List(NullClass) ::: ScalaValueClasses) map { makeTemplate(_) }
            case _ =>
              member.parentTypes map {
                case (template, tpe) => template
              } filter {
                nodesAll.contains(_)
              }
          }
        }

        // for each node, add its subclasses
        for (node <- nodesAll if !classExcluded(node)) {
          node match {
            case dnode: MemberTemplateImpl =>
              val superClasses = listSuperClasses(dnode)

              if (superClasses.nonEmpty) {
                nodesShown += dnode
                nodesShown ++= superClasses
              }
              edgesAll ::= dnode -> superClasses
            case _ =>
          }

          mapNodes += node -> (
            if (node.inTemplate == pack && (node.isDocTemplate || node.isAbstractType || node.isAliasType))
              NormalNode(node.resultType, Some(node))()
            else
              OutsideNode(node.resultType, Some(node))()
          )
        }

        if (nodesShown.isEmpty)
          None
        else {
          val nodes = nodesAll.filter(nodesShown.contains(_)).flatMap(mapNodes.get(_))
          val edges = edgesAll.map {
            case (entity, superClasses) => {
              (mapNodes(entity), superClasses flatMap { mapNodes.get(_) })
            }
          } filterNot {
            case (node, superClassNodes) => superClassNodes.isEmpty
          }

          val diagram =
            // TODO: Everyone should be able to use the @{inherit,content}Diagram annotation to change the diagrams.
            if (pack.sym == ScalaPackage) {
              // Tried it, but it doesn't look good:
              // var anyRefSubtypes: List[Node] = List(mapNodes(makeTemplate(AnyRefClass)))
              // var dirty = true
              // do {
              //   val length = anyRefSubtypes.length
              //   anyRefSubtypes :::= edges.collect { case p: (Node, List[Node]) if p._2.exists(anyRefSubtypes.contains(_)) => p._1 }
              //   anyRefSubtypes = anyRefSubtypes.distinct
              //   dirty = (anyRefSubtypes.length != length)
              // } while (dirty)
              // println(anyRefSubtypes)
              val anyRefSubtypes = Nil
              val allAnyRefTypes = aggregationNode("All AnyRef subtypes")
              val nullTemplate = makeTemplate(NullClass)
              if (nullTemplate.isDocTemplate)
                ContentDiagram(allAnyRefTypes::nodes, (mapNodes(nullTemplate), allAnyRefTypes::anyRefSubtypes)::edges.filterNot(_._1.tpl == Some(nullTemplate)))
              else
                ContentDiagram(nodes, edges)
            } else
              ContentDiagram(nodes, edges)

          filterDiagram(diagram, diagramFilter)
        }
      }

    tModel += System.currentTimeMillis
    DiagramStats.addFilterTime(tFilter)
    DiagramStats.addModelTime(tModel-tFilter)

    result
  }

  /** Diagram filtering logic */
  private def filterDiagram(diagram: Diagram, diagramFilter: DiagramFilter): Option[Diagram] = {
    tFilter -= System.currentTimeMillis

    val result =
      if (diagramFilter == FullDiagram)
        Some(diagram)
      else if (diagramFilter == NoDiagramAtAll)
        None
      else {
        // Final diagram, with the filtered nodes and edges
        diagram match {
          case InheritanceDiagram(thisNode, _, _, _, _) if diagramFilter.hideNode(thisNode) =>
            None

          case InheritanceDiagram(thisNode, superClasses, subClasses, incomingImplicits, outgoingImplicits) =>

            def hideIncoming(node: Node): Boolean =
              diagramFilter.hideNode(node) || diagramFilter.hideEdge(node, thisNode)

            def hideOutgoing(node: Node): Boolean =
              diagramFilter.hideNode(node) || diagramFilter.hideEdge(thisNode, node)

            // println(thisNode)
            // println(superClasses.map(cl => "super: " + cl + "  " + hideOutgoing(cl)).mkString("\n"))
            // println(subClasses.map(cl => "sub: " + cl + "  " + hideIncoming(cl)).mkString("\n"))
            Some(InheritanceDiagram(thisNode,
                             superClasses.filterNot(hideOutgoing(_)),
                             subClasses.filterNot(hideIncoming(_)),
                             incomingImplicits.filterNot(hideIncoming(_)),
                             outgoingImplicits.filterNot(hideOutgoing(_))))

          case ContentDiagram(nodes0, edges0) =>
            // Filter out all edges that:
            // (1) are sources of hidden classes
            // (2) are manually hidden by the user
            // (3) are destinations of hidden classes
            val edges: List[(Node, List[Node])] =
              diagram.edges.flatMap({
                case (source, dests) if !diagramFilter.hideNode(source) =>
                  val dests2 = dests.collect({ case dest if (!(diagramFilter.hideEdge(source, dest) || diagramFilter.hideNode(dest))) => dest })
                  if (dests2 != Nil)
                    List((source, dests2))
                  else
                    Nil
                case _ => Nil
              })

            // Only show the non-isolated nodes
            // TODO: Decide if we really want to hide package members, I'm not sure that's a good idea (!!!)
            // TODO: Does .distinct cause any stability issues?
            val sourceNodes = edges.map(_._1)
            val sinkNodes = edges.map(_._2).flatten
            val nodes = (sourceNodes ::: sinkNodes).distinct
            Some(ContentDiagram(nodes, edges))
        }
      }

    tFilter += System.currentTimeMillis

    // eliminate all empty diagrams
    if (result.isDefined && result.get.edges.forall(_._2.isEmpty))
      None
    else
      result
  }

}
