1 files changed, 217 insertions, 0 deletions
diff --git a/plugins/base/src/main/kotlin/resolvers/local/DefaultLocationProvider.kt b/plugins/base/src/main/kotlin/resolvers/local/DefaultLocationProvider.kt
new file mode 100644
index 00000000..1df0a700
--- /dev/null
+++ b/plugins/base/src/main/kotlin/resolvers/local/DefaultLocationProvider.kt
@@ -0,0 +1,217 @@
+package org.jetbrains.dokka.base.resolvers.local
+
+import org.jetbrains.dokka.DokkaConfiguration
+import org.jetbrains.dokka.DokkaConfiguration.DokkaSourceSet
+import org.jetbrains.dokka.base.resolvers.anchors.SymbolAnchorHint
+import org.jetbrains.dokka.base.resolvers.external.ExternalLocationProvider
+import org.jetbrains.dokka.links.DRI
+import org.jetbrains.dokka.model.withDescendants
+import org.jetbrains.dokka.pages.*
+import org.jetbrains.dokka.plugability.DokkaContext
+import java.net.HttpURLConnection
+import java.net.URL
+import java.net.URLConnection
+import java.util.*
+
+private const val PAGE_WITH_CHILDREN_SUFFIX = "index"
+
+open class DefaultLocationProvider(
+    protected val pageGraphRoot: RootPageNode,
+    dokkaContext: DokkaContext
+) : BaseLocationProvider(dokkaContext) {
+    protected open val extension = ".html"
+
+    protected val pagesIndex: Map<DRI, ContentPage> = pageGraphRoot.withDescendants().filterIsInstance<ContentPage>()
+        .map { it.dri.map { dri -> dri to it } }.flatten()
+        .groupingBy { it.first }
+        .aggregate { dri, _, (_, page), first ->
+            if (first) page else throw AssertionError("Multiple pages associated with dri: $dri")
+        }
+
+    protected val anchorsIndex = pageGraphRoot.withDescendants().filterIsInstance<ContentPage>()
+        .flatMap { page ->
+            page.content.withDescendants()
+                .filter { it.extra[SymbolAnchorHint] != null }
+                .mapNotNull { it.dci.dri.singleOrNull() }
+                .distinct()
+                .map { it to page }
+        }.toMap()
+
+
+    protected val pathsIndex: Map<PageNode, List<String>> = IdentityHashMap<PageNode, List<String>>().apply {
+        fun registerPath(page: PageNode, prefix: List<String>) {
+            val newPrefix = prefix + page.pathName
+            put(page, newPrefix)
+            page.children.forEach { registerPath(it, newPrefix) }
+        }
+        put(pageGraphRoot, emptyList())
+        pageGraphRoot.children.forEach { registerPath(it, emptyList()) }
+    }
+
+    override fun resolve(node: PageNode, context: PageNode?, skipExtension: Boolean): String =
+        pathTo(node, context) + if (!skipExtension) extension else ""
+
+    override fun resolve(dri: DRI, sourceSets: Set<DokkaSourceSet>, context: PageNode?): String =
+        pagesIndex[dri]?.let { resolve(it, context) }
+            ?: anchorsIndex[dri]?.let { resolve(it, context) + "#$dri" }
+        // Not found in PageGraph, that means it's an external link
+            ?: getExternalLocation(dri, sourceSets)
+
+    override fun resolveRoot(node: PageNode): String =
+        pathTo(pageGraphRoot, node).removeSuffix(PAGE_WITH_CHILDREN_SUFFIX)
+
+    override fun ancestors(node: PageNode): List<PageNode> =
+        generateSequence(node) { it.parent() }.toList()
+
+    protected open fun pathTo(node: PageNode, context: PageNode?): String {
+        fun pathFor(page: PageNode) = pathsIndex[page] ?: throw AssertionError(
+            "${page::class.simpleName}(${page.name}) does not belong to current page graph so it is impossible to compute its path"
+        )
+
+        val contextNode =
+            if (context !is ClasslikePageNode && context?.children?.isEmpty() == true && context.parent() != null) context.parent() else context
+        val nodePath = pathFor(node)
+        val contextPath = contextNode?.let { pathFor(it) }.orEmpty()
+
+        val commonPathElements = nodePath.asSequence().zip(contextPath.asSequence())
+            .takeWhile { (a, b) -> a == b }.count()
+
+        return (List(contextPath.size - commonPathElements) { ".." } + nodePath.drop(commonPathElements) +
+                    if (node is ClasslikePageNode || node.children.isNotEmpty())
+                        listOf(PAGE_WITH_CHILDREN_SUFFIX)
+                    else
+                        emptyList()
+                ).joinToString("/")
+    }
+
+    private fun PageNode.parent() = pageGraphRoot.parentMap[this]
+
+    private val cache: MutableMap<URL, LocationInfo> = mutableMapOf()
+
+    private fun getLocation(
+        dri: DRI,
+        jdkToExternalDocumentationLinks: Map<Int, List<DokkaConfiguration.ExternalDocumentationLink>>
+    ): String {
+        val toResolve: MutableMap<Int, MutableList<DokkaConfiguration.ExternalDocumentationLink>> = mutableMapOf()
+        for ((jdk, links) in jdkToExternalDocumentationLinks) {
+            for (link in links) {
+                val info = cache[link.packageListUrl]
+                if (info == null) {
+                    toResolve.getOrPut(jdk) { mutableListOf() }.add(link)
+                } else if (info.packages.contains(dri.packageName)) {
+                    return link.url.toExternalForm() + getLink(dri, info)
+                }
+            }
+        }
+        // Not in cache, resolve packageLists
+        for ((jdk, links) in toResolve) {
+            for (link in links) {
+                if(dokkaContext.configuration.offlineMode && link.packageListUrl.protocol.toLowerCase() != "file")
+                    continue
+                val locationInfo =
+                    loadPackageList(jdk, link.packageListUrl)
+                if (locationInfo.packages.contains(dri.packageName)) {
+                    return link.url.toExternalForm() + getLink(dri, locationInfo)
+                }
+            }
+            toResolve.remove(jdk)
+        }
+        return ""
+    }
+
+    private fun getLink(dri: DRI, locationInfo: LocationInfo): String =
+        locationInfo.locations[dri.packageName + "." + dri.classNames]
+            ?: // Not sure if it can be here, previously it shadowed only kotlin/dokka related sources, here it shadows both dokka/javadoc, cause I cannot distinguish what LocationProvider has been hypothetically chosen
+            if (locationInfo.externalLocationProvider != null)
+                with(locationInfo.externalLocationProvider) {
+                    dri.toLocation()
+                }
+            else
+                throw IllegalStateException("Have not found any convenient ExternalLocationProvider for $dri DRI!")
+
+    private fun loadPackageList(jdk: Int, url: URL): LocationInfo {
+        val packageListStream = url.doOpenConnectionToReadContent().getInputStream()
+        val (params, packages) =
+            packageListStream
+                .bufferedReader()
+                .useLines { lines -> lines.partition { it.startsWith(DOKKA_PARAM_PREFIX) } }
+
+        val paramsMap = params.asSequence()
+            .map { it.removePrefix(DOKKA_PARAM_PREFIX).split(":", limit = 2) }
+            .groupBy({ (key, _) -> key }, { (_, value) -> value })
+
+        val format = paramsMap["format"]?.singleOrNull() ?: when {
+            jdk < 8 -> "javadoc1" // Covers JDK 1 - 7
+            jdk < 10 -> "javadoc8" // Covers JDK 8 - 9
+            else -> "javadoc10" // Covers JDK 10+
+        }
+
+        val locations = paramsMap["location"].orEmpty()
+            .map { it.split("\u001f", limit = 2) }
+            .map { (key, value) -> key to value }
+            .toMap()
+
+        val externalLocationProvider =
+            externalLocationProviderFactories.asSequence().map { it.getExternalLocationProvider(format) }
+                .filterNotNull().take(1).firstOrNull()
+
+        val info = LocationInfo(
+            externalLocationProvider,
+            packages.toSet(),
+            locations
+        )
+        cache[url] = info
+        return info
+    }
+
+    private fun URL.doOpenConnectionToReadContent(timeout: Int = 10000, redirectsAllowed: Int = 16): URLConnection {
+        val connection = this.openConnection().apply {
+            connectTimeout = timeout
+            readTimeout = timeout
+        }
+
+        when (connection) {
+            is HttpURLConnection -> {
+                return when (connection.responseCode) {
+                    in 200..299 -> {
+                        connection
+                    }
+                    HttpURLConnection.HTTP_MOVED_PERM,
+                    HttpURLConnection.HTTP_MOVED_TEMP,
+                    HttpURLConnection.HTTP_SEE_OTHER -> {
+                        if (redirectsAllowed > 0) {
+                            val newUrl = connection.getHeaderField("Location")
+                            URL(newUrl).doOpenConnectionToReadContent(timeout, redirectsAllowed - 1)
+                        } else {
+                            throw RuntimeException("Too many redirects")
+                        }
+                    }
+                    else -> {
+                        throw RuntimeException("Unhandled http code: ${connection.responseCode}")
+                    }
+                }
+            }
+            else -> return connection
+        }
+    }
+
+    data class LocationInfo(
+        val externalLocationProvider: ExternalLocationProvider?,
+        val packages: Set<String>,
+        val locations: Map<String, String>
+    )
+}
+
+private val reservedFilenames = setOf("index", "con", "aux", "lst", "prn", "nul", "eof", "inp", "out")
+
+internal fun identifierToFilename(name: String): String {
+    if (name.isEmpty()) return "--root--"
+    val escaped = name.replace("<|>".toRegex(), "-")
+    val lowercase = escaped.replace("[A-Z]".toRegex()) { matchResult -> "-" + matchResult.value.toLowerCase() }
+    return if (lowercase in reservedFilenames) "--$lowercase--" else lowercase
+}
+
+private val PageNode.pathName: String
+    get() = if (this is PackagePageNode) name else identifierToFilename(
+        name
+    )