Refactor selecting of inbound link resolvers

2 files changed, 47 insertions, 12 deletions

diff --git a/core/src/main/kotlin/Kotlin/ExternalDocumentationLinkResolver.kt b/core/src/main/kotlin/Kotlin/ExternalDocumentationLinkResolver.kt
index 400326d2..7be37177 100644
--- a/core/src/main/kotlin/Kotlin/ExternalDocumentationLinkResolver.kt
+++ b/core/src/main/kotlin/Kotlin/ExternalDocumentationLinkResolver.kt
@@ -4,6 +4,10 @@ import com.google.inject.Inject
 import com.google.inject.Singleton
 import com.intellij.psi.PsiMethod
 import com.intellij.util.io.*
+import org.jetbrains.dokka.Formats.FileGeneratorBasedFormatDescriptor
+import org.jetbrains.dokka.Formats.FormatDescriptor
+import org.jetbrains.dokka.Utilities.ServiceLocator
+import org.jetbrains.dokka.Utilities.lookup
 import org.jetbrains.kotlin.descriptors.*
 import org.jetbrains.kotlin.descriptors.impl.EnumEntrySyntheticClassDescriptor
 import org.jetbrains.kotlin.load.java.descriptors.JavaCallableMemberDescriptor
@@ -21,6 +25,7 @@ import java.net.URL
 import java.net.URLConnection
 import java.nio.file.Path
 import java.security.MessageDigest
+import kotlin.reflect.full.findAnnotation
 
 fun ByteArray.toHexString() = this.joinToString(separator = "") { "%02x".format(it) }
 
@@ -129,13 +134,22 @@ class ExternalDocumentationLinkResolver @Inject constructor(
                 .map { (key, value) -> key to value }
                 .toMap()
 
-        val resolver = if (format == "javadoc") {
-            InboundExternalLinkResolutionService.Javadoc()
-        } else {
-            val linkExtension = paramsMap["linkExtension"]?.singleOrNull() ?:
-                    throw RuntimeException("Failed to parse package list from $packageListUrl")
-            InboundExternalLinkResolutionService.Dokka(linkExtension)
-        }
+
+        val defaultResolverDesc = services["dokka-default"]!!
+        val resolverDesc = services[format]
+                ?: defaultResolverDesc.takeIf { format in formatsWithDefaultResolver }
+                ?: defaultResolverDesc.also {
+                    logger.warn("Couldn't find InboundExternalLinkResolutionService(format = `$format`) for $link, using Dokka default")
+                }
+
+
+        val resolverClass = javaClass.classLoader.loadClass(resolverDesc.className).kotlin
+
+        val constructors = resolverClass.constructors
+
+        val constructor = constructors.singleOrNull()
+                ?: constructors.first { it.findAnnotation<Inject>() != null }
+        val resolver = constructor.call(paramsMap) as InboundExternalLinkResolutionService
 
         val rootInfo = ExternalDocumentationRoot(link.url, resolver, locations)
 
@@ -170,6 +184,15 @@ class ExternalDocumentationLinkResolver @Inject constructor(
 
     companion object {
         const val DOKKA_PARAM_PREFIX = "\$dokka."
+        val services = ServiceLocator.allServices("inbound-link-resolver").associateBy { it.name }
+        private val formatsWithDefaultResolver =
+            ServiceLocator
+                .allServices("format")
+                .filter {
+                    val desc = ServiceLocator.lookup<FormatDescriptor>(it) as? FileGeneratorBasedFormatDescriptor
+                    desc?.generatorServiceClass == FileGenerator::class
+                }.map { it.name }
+                .toSet()
     }
 }
 
@@ -177,7 +200,7 @@ class ExternalDocumentationLinkResolver @Inject constructor(
 interface InboundExternalLinkResolutionService {
     fun getPath(symbol: DeclarationDescriptor): String?
 
-    class Javadoc : InboundExternalLinkResolutionService {
+    class Javadoc(paramsMap: Map<String, List<String>>) : InboundExternalLinkResolutionService {
         override fun getPath(symbol: DeclarationDescriptor): String? {
             if (symbol is EnumEntrySyntheticClassDescriptor) {
                 return getPath(symbol.containingDeclaration)?.let { it + "#" + symbol.name.asString() }
@@ -203,7 +226,9 @@ interface InboundExternalLinkResolutionService {
         }
     }
 
-    class Dokka(val extension: String) : InboundExternalLinkResolutionService {
+    class Dokka(val paramsMap: Map<String, List<String>>) : InboundExternalLinkResolutionService {
+        val extension = paramsMap["linkExtension"]?.singleOrNull() ?: error("linkExtension not provided for Dokka resolver")
+
         override fun getPath(symbol: DeclarationDescriptor): String? {
             val leafElement = when (symbol) {
                 is CallableDescriptor, is TypeAliasDescriptor -> true
diff --git a/core/src/main/kotlin/Utilities/ServiceLocator.kt b/core/src/main/kotlin/Utilities/ServiceLocator.kt
index 71bfd21b..83c4c65c 100644
--- a/core/src/main/kotlin/Utilities/ServiceLocator.kt
+++ b/core/src/main/kotlin/Utilities/ServiceLocator.kt
@@ -14,12 +14,21 @@ class ServiceLookupException(message: String) : Exception(message)
 object ServiceLocator {
     fun <T : Any> lookup(clazz: Class<T>, category: String, implementationName: String): T {
         val descriptor = lookupDescriptor(category, implementationName)
+        return lookup(clazz, descriptor)
+    }
+
+    fun <T : Any> lookup(
+        clazz: Class<T>,
+        descriptor: ServiceDescriptor
+    ): T {
         val loadedClass = javaClass.classLoader.loadClass(descriptor.className)
         val constructor = loadedClass.constructors
-                .filter { it.parameterTypes.isEmpty() }
-                .firstOrNull() ?: throw ServiceLookupException("Class ${descriptor.className} has no corresponding constructor")
+            .filter { it.parameterTypes.isEmpty() }
+            .firstOrNull()
+                ?: throw ServiceLookupException("Class ${descriptor.className} has no corresponding constructor")
 
-        val implementationRawType: Any = if (constructor.parameterTypes.isEmpty()) constructor.newInstance() else constructor.newInstance(constructor)
+        val implementationRawType: Any =
+            if (constructor.parameterTypes.isEmpty()) constructor.newInstance() else constructor.newInstance(constructor)
 
         if (!clazz.isInstance(implementationRawType)) {
             throw ServiceLookupException("Class ${descriptor.className} is not a subtype of ${clazz.name}")
@@ -79,6 +88,7 @@ object ServiceLocator {
 }
 
 inline fun <reified T : Any> ServiceLocator.lookup(category: String, implementationName: String): T = lookup(T::class.java, category, implementationName)
+inline fun <reified T : Any> ServiceLocator.lookup(desc: ServiceDescriptor): T = lookup(T::class.java, desc)
 
 private val ZipEntry.fileName: String
     get() = name.substringAfterLast("/", name)