1 files changed, 127 insertions, 0 deletions
diff --git a/jvm/src/main/scala/xyz/driver/core/rest/Swagger.scala b/jvm/src/main/scala/xyz/driver/core/rest/Swagger.scala
new file mode 100644
index 0000000..a3d942c
--- /dev/null
+++ b/jvm/src/main/scala/xyz/driver/core/rest/Swagger.scala
@@ -0,0 +1,127 @@
+package xyz.driver.core.rest
+
+import akka.http.scaladsl.model.{ContentType, ContentTypes, HttpEntity}
+import akka.http.scaladsl.server.Route
+import akka.http.scaladsl.server.directives.FileAndResourceDirectives.ResourceFile
+import akka.stream.ActorAttributes
+import akka.stream.scaladsl.{Framing, StreamConverters}
+import akka.util.ByteString
+import com.github.swagger.akka.SwaggerHttpService
+import com.github.swagger.akka.model._
+import com.typesafe.config.Config
+import com.typesafe.scalalogging.Logger
+import io.swagger.models.Scheme
+import io.swagger.util.Json
+
+import scala.reflect.runtime.universe
+import scala.reflect.runtime.universe.Type
+import scala.util.control.NonFatal
+
+class Swagger(
+    override val host: String,
+    override val schemes: List[Scheme],
+    version: String,
+    val apiTypes: Seq[Type],
+    val config: Config,
+    val logger: Logger)
+    extends SwaggerHttpService {
+
+  lazy val mirror = universe.runtimeMirror(getClass.getClassLoader)
+
+  override val apiClasses = apiTypes.map { tpe =>
+    mirror.runtimeClass(tpe.typeSymbol.asClass)
+  }.toSet
+
+  // Note that the reason for overriding this is a subtle chain of causality:
+  //
+  // 1. Some of our endpoints require a single trailing slash and will not
+  // function if it is omitted
+  // 2. Swagger omits trailing slashes in its generated api doc
+  // 3. To work around that, a space is added after the trailing slash in the
+  // swagger Path annotations
+  // 4. This space is removed manually in the code below
+  //
+  // TODO: Ideally we'd like to drop this custom override and fix the issue in
+  // 1, by dropping the slash requirement and accepting api endpoints with and
+  // without trailing slashes. This will require inspecting and potentially
+  // fixing all service endpoints.
+  override def generateSwaggerJson: String = {
+    import io.swagger.models.{Swagger => JSwagger}
+
+    import scala.collection.JavaConverters._
+    try {
+      val swagger: JSwagger = reader.read(apiClasses.asJava)
+
+      // Removing trailing spaces
+      swagger.setPaths(
+        swagger.getPaths.asScala
+          .map {
+            case (key, path) =>
+              key.trim -> path
+          }
+          .toMap
+          .asJava)
+
+      Json.pretty().writeValueAsString(swagger)
+    } catch {
+      case NonFatal(t) =>
+        logger.error("Issue with creating swagger.json", t)
+        throw t
+    }
+  }
+
+  override val basePath: String    = config.getString("swagger.basePath")
+  override val apiDocsPath: String = config.getString("swagger.docsPath")
+
+  override val info = Info(
+    config.getString("swagger.apiInfo.description"),
+    version,
+    config.getString("swagger.apiInfo.title"),
+    config.getString("swagger.apiInfo.termsOfServiceUrl"),
+    contact = Some(
+      Contact(
+        config.getString("swagger.apiInfo.contact.name"),
+        config.getString("swagger.apiInfo.contact.url"),
+        config.getString("swagger.apiInfo.contact.email")
+      )),
+    license = Some(
+      License(
+        config.getString("swagger.apiInfo.license"),
+        config.getString("swagger.apiInfo.licenseUrl")
+      )),
+    vendorExtensions = Map.empty[String, AnyRef]
+  )
+
+  /** A very simple templating extractor. Gets a resource from the classpath and subsitutes any `{{key}}` with a value. */
+  private def getTemplatedResource(
+      resourceName: String,
+      contentType: ContentType,
+      substitution: (String, String)): Route = get {
+    Option(this.getClass.getClassLoader.getResource(resourceName)) flatMap ResourceFile.apply match {
+      case Some(ResourceFile(url, length @ _, _)) =>
+        extractSettings { settings =>
+          val stream = StreamConverters
+            .fromInputStream(() => url.openStream())
+            .withAttributes(ActorAttributes.dispatcher(settings.fileIODispatcher))
+            .via(Framing.delimiter(ByteString("\n"), 4096, true).map(_.utf8String))
+            .map { line =>
+              line.replaceAll(s"\\{\\{${substitution._1}\\}\\}", substitution._2)
+            }
+            .map(line => ByteString(line + "\n"))
+          complete(
+            HttpEntity(contentType, stream)
+          )
+        }
+      case None => reject
+    }
+  }
+
+  def swaggerUI: Route =
+    pathEndOrSingleSlash {
+      getTemplatedResource(
+        "swagger-ui/index.html",
+        ContentTypes.`text/html(UTF-8)`,
+        "title" -> config.getString("swagger.apiInfo.title"))
+    } ~ getFromResourceDirectory("swagger-ui")
+
+}