From b3de2e25f1953f3c30ae86dbedc94f4948738760 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Matt=C3=A9o=20Delabre?= <spam@delab.re>
Date: Mon, 13 Jan 2020 15:01:07 +0100
Subject: [PATCH] Prevent using ways in the wrong direction

---
 back/data.js | 14 ++++++++++----
 1 file changed, 10 insertions(+), 4 deletions(-)

diff --git a/back/data.js b/back/data.js
index c0a306b..176879f 100644
--- a/back/data.js
+++ b/back/data.js
@@ -78,7 +78,11 @@ out body qt;
 
         for (let id of rawWays)
         {
-            const {type, nodes} = elements[id];
+            const {type, nodes, tags} = elements[id];
+            const canGoBackward = (
+                tags.oneway !== 'yes'
+                || parseInt(tags['lanes:psv:backward'], 10) > 0
+            );
 
             if (type === 'way' && nodes.length >= 1)
             {
@@ -93,14 +97,16 @@ out body qt;
                 {
                     if (!nodeNeighbors.has(node))
                     {
-                        nodeNeighbors.set(node, new Set([previousNode]));
+                        nodeNeighbors.set(node, new Set());
                     }
-                    else
+
+                    nodeNeighbors.get(previousNode).add(node);
+
+                    if (canGoBackward)
                     {
                         nodeNeighbors.get(node).add(previousNode);
                     }
 
-                    nodeNeighbors.get(previousNode).add(node);
                     previousNode = node;
                 }
             }