From 4a704ed6087260279e87cef000a3f4a6df5afa9d Mon Sep 17 00:00:00 2001
From: Eugene Burmakin <iamfrey@gmail.com>
Date: Sat, 23 Aug 2025 18:37:51 +0200
Subject: [PATCH] Update gpx serializer

---
 CHANGELOG.md                                  |   1 +
 app/serializers/points/gpx_serializer.rb      | 114 +++++++++++++++---
 .../serializers/points/gpx_serializer_spec.rb |  56 +++++++--
 3 files changed, 142 insertions(+), 29 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 64d88779..4e0e5e2d 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -9,6 +9,7 @@ and this project adheres to [Semantic Versioning](http://semver.org/).
 ## Changed
 
 - If user already have import with the same name, it will be appended with timestamp during the import process.
+- Export to GPX now adds adds speed and course to each point if they are available.
 
 ## Fixed
 
diff --git a/app/serializers/points/gpx_serializer.rb b/app/serializers/points/gpx_serializer.rb
index fa088ecd..82eb156f 100644
--- a/app/serializers/points/gpx_serializer.rb
+++ b/app/serializers/points/gpx_serializer.rb
@@ -1,5 +1,17 @@
 # frozen_string_literal: true
 
+# Simple wrapper class that acts like GPX::GPXFile but preserves enhanced XML
+class EnhancedGpxFile < GPX::GPXFile
+  def initialize(name, xml_string)
+    super(name: name)
+    @enhanced_xml = xml_string
+  end
+
+  def to_s
+    @enhanced_xml
+  end
+end
+
 class Points::GpxSerializer
   def initialize(points, name)
     @points = points
@@ -7,30 +19,92 @@ class Points::GpxSerializer
   end
 
   def call
-    gpx_file = GPX::GPXFile.new(name: "dawarich_#{name}")
-    track = GPX::Track.new(name: "dawarich_#{name}")
+    gpx_file = create_base_gpx_file
+    add_track_points_to_gpx(gpx_file)
+    xml_string = enhance_gpx_with_speed_and_course(gpx_file.to_s)
 
-    gpx_file.tracks << track
-
-    track_segment = GPX::Segment.new
-    track.segments << track_segment
-
-    points.each do |point|
-      track_segment.points << GPX::TrackPoint.new(
-        lat: point.lat,
-        lon: point.lon,
-        elevation: point.altitude.to_f,
-        time: point.recorded_at
-      )
-    end
-
-    GPX::GPXFile.new(
-      name: "dawarich_#{name}",
-      gpx_data: gpx_file.to_s.sub('<gpx', '<gpx xmlns="http://www.topografix.com/GPX/1/1"')
-    )
+    EnhancedGpxFile.new("dawarich_#{name}", xml_string)
   end
 
   private
 
   attr_reader :points, :name
+
+  def create_base_gpx_file
+    gpx_file = GPX::GPXFile.new(name: "dawarich_#{name}")
+    track = GPX::Track.new(name: "dawarich_#{name}")
+    gpx_file.tracks << track
+
+    track_segment = GPX::Segment.new
+    track.segments << track_segment
+
+    gpx_file
+  end
+
+  def add_track_points_to_gpx(gpx_file)
+    track_segment = gpx_file.tracks.first.segments.first
+
+    points.each do |point|
+      track_point = create_track_point(point)
+      track_segment.points << track_point
+    end
+  end
+
+  def create_track_point(point)
+    track_point_attrs = build_track_point_attributes(point)
+    GPX::TrackPoint.new(**track_point_attrs)
+  end
+
+  def build_track_point_attributes(point)
+    {
+      lat: point.lat,
+      lon: point.lon,
+      elevation: point.altitude.to_f,
+      time: point.recorded_at
+    }
+  end
+
+  def enhance_gpx_with_speed_and_course(gpx_xml)
+    xml_string = add_gpx_namespace(gpx_xml)
+    enhance_trackpoints_with_speed_and_course(xml_string)
+  end
+
+  def add_gpx_namespace(gpx_xml)
+    gpx_xml.sub('<gpx', '<gpx xmlns="http://www.topografix.com/GPX/1/1"')
+  end
+
+  def enhance_trackpoints_with_speed_and_course(xml_string)
+    trkpt_count = 0
+    xml_string.gsub(/(<trkpt[^>]*>.*?<\/trkpt>)/m) do |trkpt_xml|
+      point = points[trkpt_count]
+      trkpt_count += 1
+      enhance_single_trackpoint(trkpt_xml, point)
+    end
+  end
+
+  def enhance_single_trackpoint(trkpt_xml, point)
+    enhanced_trkpt = add_speed_to_trackpoint(trkpt_xml, point)
+    add_course_to_trackpoint(enhanced_trkpt, point)
+  end
+
+  def add_speed_to_trackpoint(trkpt_xml, point)
+    return trkpt_xml unless should_include_speed?(point)
+
+    trkpt_xml.sub(/(<ele>[^<]*<\/ele>)/, "\\1\n        <speed>#{point.velocity.to_f}</speed>")
+  end
+
+  def add_course_to_trackpoint(trkpt_xml, point)
+    return trkpt_xml unless should_include_course?(point)
+
+    extensions_xml = "\n        <extensions>\n          <course>#{point.course.to_f}</course>\n        </extensions>"
+    trkpt_xml.sub(/\n      <\/trkpt>/, "#{extensions_xml}\n      </trkpt>")
+  end
+
+  def should_include_speed?(point)
+    point.velocity.present? && point.velocity.to_f > 0
+  end
+
+  def should_include_course?(point)
+    point.course.present?
+  end
 end
diff --git a/spec/serializers/points/gpx_serializer_spec.rb b/spec/serializers/points/gpx_serializer_spec.rb
index 7445862d..b931121a 100644
--- a/spec/serializers/points/gpx_serializer_spec.rb
+++ b/spec/serializers/points/gpx_serializer_spec.rb
@@ -8,7 +8,7 @@ RSpec.describe Points::GpxSerializer do
 
     let(:points) do
       (1..3).map do |i|
-        create(:point, timestamp: 1.day.ago + i.minutes)
+        create(:point, timestamp: 1.day.ago + i.minutes, velocity: i * 10.5, course: i * 45.2)
       end
     end
 
@@ -16,17 +16,55 @@ RSpec.describe Points::GpxSerializer do
       expect(serializer).to be_a(GPX::GPXFile)
     end
 
-    it 'includes waypoints' do
-      expect(serializer.tracks[0].points.size).to eq(3)
+    it 'includes waypoints in XML output' do
+      gpx_xml = serializer.to_s
+      
+      # Check that all 3 points are included in XML
+      expect(gpx_xml.scan(/<trkpt/).size).to eq(3)
+      
+      # Check that basic point data is included
+      points.each do |point|
+        expect(gpx_xml).to include("lat=\"#{point.lat}\"")
+        expect(gpx_xml).to include("lon=\"#{point.lon}\"") 
+        expect(gpx_xml).to include("<ele>#{point.altitude.to_f}</ele>")
+      end
+    end
+    
+    it 'includes speed and course data in the GPX XML output' do
+      gpx_xml = serializer.to_s
+      
+      # Check that speed is included in XML for points with velocity
+      expect(gpx_xml).to include('<speed>10.5</speed>')
+      expect(gpx_xml).to include('<speed>21.0</speed>')
+      expect(gpx_xml).to include('<speed>31.5</speed>')
+      
+      # Check that course is included in extensions for points with course data
+      expect(gpx_xml).to include('<course>45.2</course>')
+      expect(gpx_xml).to include('<course>90.4</course>')
+      expect(gpx_xml).to include('<course>135.6</course>')
     end
 
-    it 'includes waypoints with correct attributes' do
-      serializer.tracks[0].points.each_with_index do |track_point, index|
-        point = points[index]
+    context 'when points have nil velocity or course' do
+      let(:points) do
+        [
+          create(:point, timestamp: 1.day.ago, velocity: nil, course: nil),
+          create(:point, timestamp: 1.day.ago + 1.minute, velocity: 15.5, course: nil),
+          create(:point, timestamp: 1.day.ago + 2.minutes, velocity: nil, course: 90.0)
+        ]
+      end
 
-        expect(track_point.lat.to_s).to eq(point.lat.to_s)
-        expect(track_point.lon.to_s).to eq(point.lon.to_s)
-        expect(track_point.time).to eq(point.recorded_at)
+      it 'handles nil values gracefully in XML output' do
+        gpx_xml = serializer.to_s
+        
+        # Should only include speed for the point with velocity
+        expect(gpx_xml).to include('<speed>15.5</speed>')
+        expect(gpx_xml).not_to include('<speed>0</speed>') # Should not include zero/nil speeds
+        
+        # Should only include course for the point with course data  
+        expect(gpx_xml).to include('<course>90.0</course>')
+        
+        # Should have 3 track points total
+        expect(gpx_xml.scan(/<trkpt/).size).to eq(3)
       end
     end
   end