From 77b1c8015fb0eeba3297e238ef447a494937fa45 Mon Sep 17 00:00:00 2001
From: Marwin Hochfelsner <50826859+hlfan@users.noreply.github.com>
Date: Sat, 1 Mar 2025 00:34:13 +0100
Subject: [PATCH] Add basic PWA geo protocol handler

---
 app/assets/favicons/manifest.json.erb |  8 +++++++-
 app/assets/javascripts/osm.js.erb     |  9 +++++++++
 test/javascripts/osm_test.js          | 12 ++++++++++++
 3 files changed, 28 insertions(+), 1 deletion(-)

diff --git a/app/assets/favicons/manifest.json.erb b/app/assets/favicons/manifest.json.erb
index 2e97cebc3..53fdfcc77 100644
--- a/app/assets/favicons/manifest.json.erb
+++ b/app/assets/favicons/manifest.json.erb
@@ -14,5 +14,11 @@
 	"start_url": "/",
 	"theme_color": "#7ebc6f",
 	"background_color": "#fff",
-	"display": "minimal-ui"
+	"display": "minimal-ui",
+	"protocol_handlers": [
+		{
+			"protocol": "geo",
+			"url": "/?geouri=%s"
+		}
+	]
 }
diff --git a/app/assets/javascripts/osm.js.erb b/app/assets/javascripts/osm.js.erb
index a40ae6eb8..9c38db987 100644
--- a/app/assets/javascripts/osm.js.erb
+++ b/app/assets/javascripts/osm.js.erb
@@ -63,6 +63,7 @@ OSM = {
 
   mapParams: function (search) {
     const params = OSM.params(search),
+          geoURI = URL.canParse(params.geouri) ? new URL(params.geouri) : {},
           mapParams = {};
 
     if (params.mlon && params.mlat) {
@@ -70,6 +71,11 @@ OSM = {
       mapParams.mlon = parseFloat(params.mlon);
       mapParams.mlat = parseFloat(params.mlat);
     }
+    if (geoURI.lon && geoURI.lat) {
+      mapParams.marker = true;
+      mapParams.mlon = parseFloat(geoURI.lon);
+      mapParams.mlat = parseFloat(geoURI.lat);
+    }
 
     // Old-style object parameters; still in use for edit links e.g. /edit?way=1234
     for (const type of ["node", "way", "relation", "note"]) {
@@ -100,6 +106,9 @@ OSM = {
       mapParams.lon = params.mlon;
       mapParams.lat = params.mlat;
       mapParams.zoom = params.zoom || 12;
+    } else if (geoURI.pathname) {
+      [mapParams.lat, mapParams.lon] = geoURI.pathname.split(",");
+      mapParams.zoom = geoURI.searchParams?.get("z") || (geoURI.pathname.replaceAll(/,?[-\d]+\./g, "").length / 0.6) - 2;
     } else if (loc) {
       [mapParams.lon, mapParams.lat, mapParams.zoom] = loc;
     } else if (OSM.home) {
diff --git a/test/javascripts/osm_test.js b/test/javascripts/osm_test.js
index 2f96ccb3d..6486d3cbc 100644
--- a/test/javascripts/osm_test.js
+++ b/test/javascripts/osm_test.js
@@ -82,6 +82,18 @@ describe("OSM", function () {
       expect(params).to.have.property("zoom", 16);
     });
 
+    it("parses geoURIs", function () {
+      let params = OSM.mapParams("?geouri=geo%3A57.6247%2C-3.6845");
+      expect(params).to.have.property("lat", 57.6247);
+      expect(params).to.have.property("lon", -3.6845);
+      expect(params).to.have.property("zoom", 34 / 3);
+
+      params = OSM.mapParams("?geouri=geo%3A57.6247%2C-3.6845%3Fz%3D16");
+      expect(params).to.have.property("lat", 57.6247);
+      expect(params).to.have.property("lon", -3.6845);
+      expect(params).to.have.property("zoom", 16);
+    });
+
     it("parses lat/lon/zoom from the hash", function () {
       location.hash = "#map=16/57.6247/-3.6845";
       const params = OSM.mapParams("?");