From 844c86cc56b538cbe368dd7fe7fadcab70398626 Mon Sep 17 00:00:00 2001
From: CollinBeczak <ctbeczak08@gmail.com>
Date: Fri, 1 Mar 2024 13:18:15 -0600
Subject: [PATCH] add support for relations in overpass queries

---
 .../provider/ChallengeProvider.scala          | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)

diff --git a/app/org/maproulette/provider/ChallengeProvider.scala b/app/org/maproulette/provider/ChallengeProvider.scala
index 5ee518f0..5d54ffd8 100644
--- a/app/org/maproulette/provider/ChallengeProvider.scala
+++ b/app/org/maproulette/provider/ChallengeProvider.scala
@@ -485,6 +485,13 @@ class ChallengeProvider @Inject() (
                                 "Element type 'way' does not match target type of '" + targetType + "'"
                               )
                             }
+                          case Some("relation") =>
+                            if (targetType != "relation") {
+                              targetTypeFailed = true
+                              throw new InvalidException(
+                                "Element type 'relation' does not match target type of '" + targetType + "'"
+                              )
+                            }
                           case Some("node") =>
                             if (targetType != "node") {
                               targetTypeFailed = true
@@ -522,6 +529,18 @@ class ChallengeProvider @Inject() (
                                 List((geom \ "lon").as[Double], (geom \ "lat").as[Double])
                               }
                               Some(Json.obj("type" -> "LineString", "coordinates" -> points))
+                            case Some("relation") =>
+                              // Relations can contain multiple geometries. Here, we're handling them similarly to ways.
+                              val geometries = (element \ "members").as[List[JsValue]].flatMap {
+                                member =>
+                                  (member \ "geometry").asOpt[List[JsValue]]
+                              }
+                              val points = geometries.flatMap { geom =>
+                                geom.map { point =>
+                                  ((point \ "lon").as[Double], (point \ "lat").as[Double])
+                                }
+                              }
+                              Some(Json.obj("type" -> "LineString", "coordinates" -> points))
                             case Some("node") =>
                               Some(
                                 Json.obj(