Adding Dokka source to AOSP

This is taken from commit 4ff3d4153ca344398bffcdaaa28f1a1f6e76f6ad from
https://github.com/google/dokka, which is Google's customized fork of
Dokka (https://github.com/Kotlin/dokka).

Bug: 135767980
Test: ./gradlew :core:cleanTest :core:test
Test: ./gradlew :runners:gradle-integration-tests:clean :runners:gradle-integration-tests:test

Change-Id: I332d0b522706e353c3837f6308aac1a8340d71d3
diff --git a/core/src/main/kotlin/Formats/DacOutlineService.kt b/core/src/main/kotlin/Formats/DacOutlineService.kt
new file mode 100644
index 0000000..e249c39
--- /dev/null
+++ b/core/src/main/kotlin/Formats/DacOutlineService.kt
@@ -0,0 +1,395 @@
+package org.jetbrains.dokka.Formats
+
+import com.google.inject.Inject
+import org.jetbrains.dokka.*
+import java.net.URI
+import com.google.inject.name.Named
+import org.jetbrains.kotlin.cfg.pseudocode.AllTypes
+
+
+interface DacOutlineFormatService {
+    fun computeOutlineURI(node: DocumentationNode): URI
+    fun format(to: Appendable, node: DocumentationNode)
+}
+
+class DacOutlineFormatter @Inject constructor(
+        uriProvider: JavaLayoutHtmlUriProvider,
+        languageService: LanguageService,
+        @Named("dacRoot") dacRoot: String,
+        @Named("generateClassIndex") generateClassIndex: Boolean,
+        @Named("generatePackageIndex") generatePackageIndex: Boolean
+) : JavaLayoutHtmlFormatOutlineFactoryService {
+    val tocOutline = TocOutlineService(uriProvider, languageService, dacRoot, generateClassIndex, generatePackageIndex)
+    val outlines = listOf(tocOutline)
+
+    override fun generateOutlines(outputProvider: (URI) -> Appendable, nodes: Iterable<DocumentationNode>) {
+        for (node in nodes) {
+            for (outline in outlines) {
+                val uri = outline.computeOutlineURI(node)
+                val output = outputProvider(uri)
+                outline.format(output, node)
+            }
+        }
+    }
+}
+
+/**
+ * Outline service for generating a _toc.yaml file, responsible for pointing to the paths of each
+ * index.html file in the doc tree.
+ */
+class BookOutlineService(
+        val uriProvider: JavaLayoutHtmlUriProvider,
+        val languageService: LanguageService,
+        val dacRoot: String,
+        val generateClassIndex: Boolean,
+        val generatePackageIndex: Boolean
+) : DacOutlineFormatService {
+    override fun computeOutlineURI(node: DocumentationNode): URI = uriProvider.outlineRootUri(node).resolve("_book.yaml")
+
+    override fun format(to: Appendable, node: DocumentationNode) {
+        appendOutline(to, listOf(node))
+    }
+
+    var outlineLevel = 0
+
+    /** Appends formatted outline to [StringBuilder](to) using specified [location] */
+    fun appendOutline(to: Appendable, nodes: Iterable<DocumentationNode>) {
+        if (outlineLevel == 0) to.appendln("reference:")
+        for (node in nodes) {
+            appendOutlineHeader(node, to)
+            val subPackages = node.members.filter {
+                it.kind == NodeKind.Package
+            }
+            if (subPackages.any()) {
+                val sortedMembers = subPackages.sortedBy { it.name.toLowerCase() }
+                appendOutlineLevel(to) {
+                    appendOutline(to, sortedMembers)
+                }
+            }
+
+        }
+    }
+
+    fun appendOutlineHeader(node: DocumentationNode, to: Appendable) {
+        if (node is DocumentationModule) {
+            to.appendln("- title: Package Index")
+            to.appendln("  path: $dacRoot${uriProvider.outlineRootUri(node).resolve("packages.html")}")
+            to.appendln("  status_text: no-toggle")
+        } else {
+            to.appendln("- title: ${languageService.renderName(node)}")
+            to.appendln("  path: $dacRoot${uriProvider.mainUriOrWarn(node)}")
+            to.appendln("  status_text: no-toggle")
+        }
+    }
+
+    fun appendOutlineLevel(to: Appendable, body: () -> Unit) {
+        outlineLevel++
+        body()
+        outlineLevel--
+    }
+}
+
+/**
+ * Outline service for generating a _toc.yaml file, responsible for pointing to the paths of each
+ * index.html file in the doc tree.
+ */
+class TocOutlineService(
+        val uriProvider: JavaLayoutHtmlUriProvider,
+        val languageService: LanguageService,
+        val dacRoot: String,
+        val generateClassIndex: Boolean,
+        val generatePackageIndex: Boolean
+) : DacOutlineFormatService {
+    override fun computeOutlineURI(node: DocumentationNode): URI = uriProvider.outlineRootUri(node).resolve("_toc.yaml")
+
+    override fun format(to: Appendable, node: DocumentationNode) {
+        appendOutline(to, listOf(node))
+    }
+
+    var outlineLevel = 0
+
+    /** Appends formatted outline to [StringBuilder](to) using specified [location] */
+    fun appendOutline(to: Appendable, nodes: Iterable<DocumentationNode>) {
+        if (outlineLevel == 0) to.appendln("toc:")
+        for (node in nodes) {
+            appendOutlineHeader(node, to)
+            val subPackages = node.members.filter {
+                it.kind == NodeKind.Package
+            }
+            if (subPackages.any()) {
+                val sortedMembers = subPackages.sortedBy { it.nameWithOuterClass() }
+                appendOutlineLevel {
+                    appendOutline(to, sortedMembers)
+                }
+            }
+        }
+    }
+
+    fun appendOutlineHeader(node: DocumentationNode, to: Appendable) {
+        if (node is DocumentationModule) {
+            if (generateClassIndex) {
+                node.members.filter { it.kind == NodeKind.AllTypes }.firstOrNull()?.let {
+                    to.appendln("- title: Class Index")
+                    to.appendln("  path: $dacRoot${uriProvider.outlineRootUri(it).resolve("classes.html")}")
+                    to.appendln()
+                }
+            }
+            if (generatePackageIndex) {
+                to.appendln("- title: Package Index")
+                to.appendln("  path: $dacRoot${uriProvider.outlineRootUri(node).resolve("packages.html")}")
+                to.appendln()
+            }
+        } else if (node.kind != NodeKind.AllTypes && !(node is DocumentationModule)) {
+            to.appendln("- title: ${languageService.renderName(node)}")
+            to.appendln("  path: $dacRoot${uriProvider.mainUriOrWarn(node)}")
+            to.appendln()
+            var addedSectionHeader = false
+            for (kind in NodeKind.classLike) {
+                val members = node.getMembersOfKinds(kind)
+                if (members.isNotEmpty()) {
+                    if (!addedSectionHeader) {
+                        to.appendln("  section:")
+                        addedSectionHeader = true
+                    }
+                    to.appendln("  - title: ${kind.pluralizedName()}")
+                    to.appendln()
+                    to.appendln("    section:")
+                    members.sortedBy { it.nameWithOuterClass().toLowerCase() }.forEach { member ->
+                        to.appendln("    - title: ${languageService.renderNameWithOuterClass(member)}")
+                        to.appendln("      path: $dacRoot${uriProvider.mainUriOrWarn(member)}".trimEnd('#'))
+                        to.appendln()
+                    }
+                }
+            }
+            to.appendln().appendln()
+        }
+    }
+
+    fun appendOutlineLevel(body: () -> Unit) {
+        outlineLevel++
+        body()
+        outlineLevel--
+    }
+}
+
+class DacNavOutlineService constructor(
+        val uriProvider: JavaLayoutHtmlUriProvider,
+        val languageService: LanguageService,
+        val dacRoot: String
+) : DacOutlineFormatService {
+    override fun computeOutlineURI(node: DocumentationNode): URI =
+            uriProvider.outlineRootUri(node).resolve("navtree_data.js")
+
+    override fun format(to: Appendable, node: DocumentationNode) {
+        to.append("var NAVTREE_DATA = ").appendNavTree(node.members).append(";")
+    }
+
+    private fun Appendable.appendNavTree(nodes: Iterable<DocumentationNode>): Appendable {
+        append("[ ")
+        var first = true
+        for (node in nodes) {
+            if (!first) append(", ")
+            first = false
+            val interfaces = node.getMembersOfKinds(NodeKind.Interface)
+            val classes = node.getMembersOfKinds(NodeKind.Class)
+            val objects = node.getMembersOfKinds(NodeKind.Object)
+            val annotations = node.getMembersOfKinds(NodeKind.AnnotationClass)
+            val enums = node.getMembersOfKinds(NodeKind.Enum)
+            val exceptions = node.getMembersOfKinds(NodeKind.Exception)
+
+            append("[ \"${node.name}\", \"$dacRoot${uriProvider.tryGetMainUri(node)}\", [ ")
+            var needComma = false
+            if (interfaces.firstOrNull() != null) {
+                appendNavTreePagesOfKind("Interfaces", interfaces)
+                needComma = true
+            }
+            if (classes.firstOrNull() != null) {
+                if (needComma) append(", ")
+                appendNavTreePagesOfKind("Classes", classes)
+                needComma = true
+            }
+            if (objects.firstOrNull() != null) {
+                if (needComma) append(", ")
+                appendNavTreePagesOfKind("Objects", objects)
+            }
+            if (annotations.firstOrNull() != null) {
+                if (needComma) append(", ")
+                appendNavTreePagesOfKind("Annotations", annotations)
+                needComma = true
+            }
+            if (enums.firstOrNull() != null) {
+                if (needComma) append(", ")
+                appendNavTreePagesOfKind("Enums", enums)
+                needComma = true
+            }
+            if (exceptions.firstOrNull() != null) {
+                if (needComma) append(", ")
+                appendNavTreePagesOfKind("Exceptions", exceptions)
+            }
+            append(" ] ]")
+        }
+        append(" ]")
+        return this
+    }
+
+    private fun Appendable.appendNavTreePagesOfKind(kindTitle: String,
+                                                    nodesOfKind: Iterable<DocumentationNode>): Appendable {
+        append("[ \"$kindTitle\", null, [ ")
+        var started = false
+        for (node in nodesOfKind) {
+            if (started) append(", ")
+            started = true
+            appendNavTreeChild(node)
+        }
+        append(" ], null, null ]")
+        return this
+    }
+
+    private fun Appendable.appendNavTreeChild(node: DocumentationNode): Appendable {
+        append("[ \"${node.nameWithOuterClass()}\", \"${dacRoot}${uriProvider.tryGetMainUri(node)}\"")
+        append(", null, null, null ]")
+        return this
+    }
+}
+
+class DacSearchOutlineService(
+        val uriProvider: JavaLayoutHtmlUriProvider,
+        val languageService: LanguageService,
+        val dacRoot: String
+) : DacOutlineFormatService {
+
+    override fun computeOutlineURI(node: DocumentationNode): URI =
+            uriProvider.outlineRootUri(node).resolve("lists.js")
+
+    override fun format(to: Appendable, node: DocumentationNode) {
+        val pageNodes = node.getAllPageNodes()
+        var id = 0
+        to.append("var KTX_CORE_DATA = [\n")
+        var first = true
+        for (pageNode in pageNodes) {
+            if (pageNode.kind == NodeKind.Module) continue
+            if (!first) to.append(", \n")
+            first = false
+            to.append(" { " +
+                    "id:$id, " +
+                    "label:\"${pageNode.qualifiedName()}\", " +
+                    "link:\"${dacRoot}${uriProvider.tryGetMainUri(pageNode)}\", " +
+                    "type:\"${pageNode.getClassOrPackage()}\", " +
+                    "deprecated:\"false\" }")
+            id++
+        }
+        to.append("\n];")
+    }
+
+    private fun DocumentationNode.getClassOrPackage(): String =
+            if (hasOwnPage())
+                "class"
+            else if (isPackage()) {
+                "package"
+            } else {
+                ""
+            }
+
+    private fun DocumentationNode.getAllPageNodes(): Iterable<DocumentationNode> {
+        val allPageNodes = mutableListOf<DocumentationNode>()
+        recursiveSetAllPageNodes(allPageNodes)
+        return allPageNodes
+    }
+
+    private fun DocumentationNode.recursiveSetAllPageNodes(
+            allPageNodes: MutableList<DocumentationNode>) {
+        for (child in members) {
+            if (child.hasOwnPage() || child.isPackage()) {
+                allPageNodes.add(child)
+                child.qualifiedName()
+                child.recursiveSetAllPageNodes(allPageNodes)
+            }
+        }
+    }
+
+}
+
+/**
+ * Return all children of the node who are one of the selected `NodeKind`s. It recursively fetches
+ * all offspring, not just immediate children.
+ */
+fun DocumentationNode.getMembersOfKinds(vararg kinds: NodeKind): MutableList<DocumentationNode> {
+    val membersOfKind = mutableListOf<DocumentationNode>()
+    recursiveSetMembersOfKinds(kinds, membersOfKind)
+    return membersOfKind
+}
+
+private fun DocumentationNode.recursiveSetMembersOfKinds(kinds: Array<out NodeKind>,
+                                                         membersOfKind: MutableList<DocumentationNode>) {
+    for (member in members) {
+        if (member.kind in kinds) {
+            membersOfKind.add(member)
+        }
+        member.recursiveSetMembersOfKinds(kinds, membersOfKind)
+    }
+}
+
+/**
+ * Returns whether or not this node owns a page. The criteria for whether a node owns a page is
+ * similar to the way javadoc is structured. Classes, Interfaces, Enums, AnnotationClasses,
+ * Exceptions, and Objects (Kotlin-specific) meet the criteria.
+ */
+fun DocumentationNode.hasOwnPage() =
+        kind == NodeKind.Class || kind == NodeKind.Interface || kind == NodeKind.Enum ||
+                kind == NodeKind.AnnotationClass || kind == NodeKind.Exception ||
+                kind == NodeKind.Object
+
+/**
+ * In most cases, this returns the short name of the `Type`. When the Type is an inner Type, it
+ * prepends the name with the containing Type name(s).
+ *
+ * For example, if you have a class named OuterClass and an inner class named InnerClass, this would
+ * return OuterClass.InnerClass.
+ *
+ */
+fun DocumentationNode.nameWithOuterClass(): String {
+    val nameBuilder = StringBuilder(name)
+    var parent = owner
+    if (hasOwnPage()) {
+        while (parent != null && parent.hasOwnPage()) {
+            nameBuilder.insert(0, "${parent.name}.")
+            parent = parent.owner
+        }
+    }
+    return nameBuilder.toString()
+}
+
+/**
+ * Return whether the node is a package.
+ */
+fun DocumentationNode.isPackage(): Boolean {
+    return kind == NodeKind.Package
+}
+
+/**
+ * Return the 'page owner' of this node. `DocumentationNode.hasOwnPage()` defines the criteria for
+ * a page owner. If this node is not a page owner, then it iterates up through its ancestors to
+ * find the first page owner.
+ */
+fun DocumentationNode.pageOwner(): DocumentationNode {
+    if (hasOwnPage() || owner == null) {
+        return this
+    } else {
+        var parent: DocumentationNode = owner!!
+        while (!parent.hasOwnPage() && !parent.isPackage()) {
+            parent = parent.owner!!
+        }
+        return parent
+    }
+}
+
+fun NodeKind.pluralizedName() = when(this) {
+    NodeKind.Class -> "Classes"
+    NodeKind.Interface -> "Interfaces"
+    NodeKind.AnnotationClass -> "Annotations"
+    NodeKind.Enum -> "Enums"
+    NodeKind.Exception -> "Exceptions"
+    NodeKind.Object -> "Objects"
+    NodeKind.TypeAlias -> "TypeAliases"
+    else -> "${name}s"
+}
\ No newline at end of file