1 files changed, 55 insertions, 2 deletions
diff --git a/src/main/scala/xyz/driver/core/rest/DriverRoute.scala b/src/main/scala/xyz/driver/core/rest/DriverRoute.scala
index 5f961b6..5647818 100644
--- a/src/main/scala/xyz/driver/core/rest/DriverRoute.scala
+++ b/src/main/scala/xyz/driver/core/rest/DriverRoute.scala
@@ -7,6 +7,7 @@ import akka.http.scaladsl.model.StatusCodes
 import akka.http.scaladsl.model.headers._
 import akka.http.scaladsl.server.Directives._
 import akka.http.scaladsl.server.{Directive0, ExceptionHandler, RequestContext, Route}
+import com.typesafe.config.Config
 import com.typesafe.scalalogging.Logger
 import org.slf4j.MDC
 import xyz.driver.core.rest
@@ -16,17 +17,69 @@ import scala.compat.Platform.ConcurrentModificationException
 
 trait DriverRoute {
   def log: Logger
+  def config: Config
 
   def route: Route
 
   def routeWithDefaults: Route = {
-    (defaultResponseHeaders & handleExceptions(ExceptionHandler(exceptionHandler)))(route)
+    (defaultResponseHeaders & handleExceptions(ExceptionHandler(exceptionHandler))) {
+      route ~ defaultOptionsRoute
+    }
+  }
+
+  protected lazy val allowedCorsDomainSuffixes: Set[HttpOrigin] = {
+    import scala.collection.JavaConverters._
+    config
+      .getConfigList("application.cors.allowedOrigins")
+      .asScala
+      .map { c =>
+        HttpOrigin(c.getString("scheme"), Host(c.getString("hostSuffix")))
+      }(scala.collection.breakOut)
+  }
+
+  protected lazy val defaultCorsAllowedMethods: Set[HttpMethod] = {
+    import scala.collection.JavaConverters._
+    config.getStringList("application.cors.allowedMethods").asScala.toSet.flatMap(HttpMethods.getForKey)
+  }
+
+  protected lazy val defaultCorsAllowedOrigin: Origin =
+    Origin(allowedCorsDomainSuffixes.to[collection.immutable.Seq])
+
+  protected def corsAllowedOriginHeader(origin: Option[Origin]): HttpHeader = {
+    val allowedOrigin =
+      origin
+        .filter { requestOrigin =>
+          allowedCorsDomainSuffixes.exists { allowedOriginSuffix =>
+            requestOrigin.origins.exists(o =>
+              o.scheme == allowedOriginSuffix.scheme &&
+                o.host.host.address.endsWith(allowedOriginSuffix.host.host.address()))
+          }
+        }
+        .getOrElse(defaultCorsAllowedOrigin)
+
+    `Access-Control-Allow-Origin`(HttpOriginRange(allowedOrigin.origins: _*))
+  }
+
+  protected def respondWithAllCorsHeaders: Directive0 = {
+    respondWithCorsAllowedHeaders tflatMap { _ =>
+      respondWithCorsAllowedMethodHeaders(defaultCorsAllowedMethods) tflatMap { _ =>
+        optionalHeaderValueByType[Origin](()) flatMap { origin =>
+          respondWithHeader(corsAllowedOriginHeader(origin))
+        }
+      }
+    }
+  }
+
+  protected def defaultOptionsRoute: Route = options {
+    respondWithAllCorsHeaders {
+      complete("OK")
+    }
   }
 
   protected def defaultResponseHeaders: Directive0 = {
     extractRequest flatMap { request =>
       val tracingHeader = RawHeader(ContextHeaders.TrackingIdHeader, rest.extractTrackingId(request))
-      respondWithHeader(tracingHeader) & respondWithCorsHeaders
+      respondWithHeader(tracingHeader) & respondWithAllCorsHeaders
     }
   }