map updates

server/src/gps.rs

@@ -103,6 +103,22 @@ pub fn track_value(track: &[Pt]) -> Value {
     )
 }
 
+/// Average + maximum speed over a track (m/s), from the full-resolution samples.
+/// Max is measured over single hops (dt clamped ≥ 0.5 s so duplicate timestamps
+/// can't fabricate teleports). None when the track has no elapsed time.
+pub fn speed_stats(track: &[Pt]) -> (Option<f64>, Option<f64>) {
+    if track.len() < 2 {
+        return (None, None);
+    }
+    let elapsed = track.last().unwrap()[2] - track[0][2];
+    let avg = (elapsed > 0.0).then(|| polyline_len_m(track) / elapsed);
+    let max = track
+        .windows(2)
+        .map(|w| dist_m(w[0][0], w[0][1], w[1][0], w[1][1]) / (w[1][2] - w[0][2]).max(0.5))
+        .fold(None::<f64>, |acc, v| Some(acc.map_or(v, |a| a.max(v))));
+    (avg, max)
+}
+
 /// Cap a track at `max` points (uniform stride, always keeping the last point).
 pub fn downsample(track: Vec<Pt>, max: usize) -> Vec<Pt> {
     if track.len() <= max || max < 2 {
@@ -851,6 +867,21 @@ mod tests {
         assert_eq!(d.last(), t.last());
     }
 
+    #[test]
+    fn speed_stats_measures_avg_and_max() {
+        // ~11.13 m per second for 60 s → avg ≈ max ≈ 11.1 m/s (40 km/h).
+        let t = straight(60);
+        let (avg, max) = speed_stats(&t);
+        assert!((avg.unwrap() - 11.13).abs() < 0.1, "{avg:?}");
+        assert!((max.unwrap() - 11.13).abs() < 0.1, "{max:?}");
+        // One fast hop dominates max but barely moves avg.
+        let mut t2 = straight(60);
+        t2[30][1] += 0.0002; // extra ~22 m in that second
+        let (avg2, max2) = speed_stats(&t2);
+        assert!(max2.unwrap() > 25.0, "{max2:?}");
+        assert!(avg2.unwrap() < 13.0, "{avg2:?}");
+    }
+
     #[test]
     fn stitch_planning_rules() {
         // Healthy 1 Hz rollover (1 s gap) → nothing missing.