progress

gpx-rs/src/engine/command/tools/round_trip.rs

@@ -0,0 +1,144 @@
+use crate::{Apply, CommandError, State, round_trip, update_segments};
+
+/// Makes each selected segment come back to where it started: the segments of the selected files
+/// and tracks, and the selected segments, get a reversed copy of themselves after their last
+/// trackpoint (see [`round_trip`]).
+///
+/// There is nothing to do for segments with fewer than two trackpoints, which have no way back.
+#[derive(Debug)]
+pub struct RoundTrip;
+
+impl Apply for RoundTrip {
+    fn apply(self, state: &mut State) -> Result<(), CommandError> {
+        let locations: Vec<_> = state
+            .selection
+            .segment_locations(state.files, &state.order.0)
+            .into_iter()
+            .filter(|l| state.files[&l.file_id].trk[l.trk].trkseg[l.seg].len() >= 2)
+            .collect();
+        if locations.is_empty() {
+            return Err(CommandError::NothingToDo);
+        }
+        update_segments(state, &locations, |_, segment| round_trip(segment));
+        Ok(())
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use std::collections::HashSet;
+    use std::rc::Rc;
+
+    use crate::{
+        FileId, Load, Selection, TrackSegment, end_time, engine::command::fixture::Fixture,
+    };
+
+    use super::*;
+
+    fn loaded(path: &str) -> (Fixture, FileId) {
+        let mut fx = Fixture::default();
+        let data = std::fs::read(path).unwrap();
+        Load {
+            data: &data,
+            name: "file",
+        }
+        .apply(&mut fx.state())
+        .unwrap();
+        let id = fx.order.0[0];
+        fx.selection = Selection::File {
+            file_ids: HashSet::from([id]),
+        };
+        (fx, id)
+    }
+
+    fn segments(fx: &Fixture, id: FileId) -> Vec<TrackSegment> {
+        fx.files[&id]
+            .trk
+            .iter()
+            .flat_map(|track| track.trkseg.iter().cloned())
+            .collect()
+    }
+
+    fn lngs(segment: &TrackSegment) -> Vec<f64> {
+        segment.iter().map(|p| p.coordinates.lng).collect()
+    }
+
+    #[test]
+    fn test_every_segment_of_a_file_comes_back() {
+        let (mut fx, id) = loaded("data/with_tracks_and_segments.gpx");
+        let before = segments(&fx, id);
+        RoundTrip.apply(&mut fx.state()).unwrap();
+        let after = segments(&fx, id);
+        assert_eq!(after.len(), before.len());
+        for (a, b) in after.iter().zip(&before) {
+            if b.len() < 2 {
+                assert_eq!(a.len(), b.len());
+                assert_eq!(a.rev_id, b.rev_id);
+                continue;
+            }
+            assert_eq!(a.id, b.id);
+            // the last trackpoint is not repeated
+            assert_eq!(a.len(), 2 * b.len() - 1);
+            let mut expected = lngs(b);
+            expected.extend(lngs(b).into_iter().rev().skip(1));
+            assert_eq!(lngs(a), expected);
+        }
+    }
+
+    #[test]
+    fn test_only_the_selected_segment_comes_back() {
+        let (mut fx, id) = loaded("data/with_tracks_and_segments.gpx");
+        let file = fx.files[&id].clone();
+        let trk = &file.trk[0];
+        assert!(trk.trkseg.len() >= 2);
+        fx.selection = Selection::TrackSegment {
+            file_id: id,
+            trk_id: trk.id,
+            trkseg_ids: HashSet::from([trk.trkseg[1].id]),
+        };
+        RoundTrip.apply(&mut fx.state()).unwrap();
+        let after = &fx.files[&id].trk[0];
+        assert_eq!(after.trkseg[1].len(), 2 * trk.trkseg[1].len() - 1);
+        assert_eq!(after.trkseg[0].rev_id, trk.trkseg[0].rev_id);
+    }
+
+    #[test]
+    fn test_times_go_on_from_the_end() {
+        let (mut fx, id) = loaded("data/with_time.gpx");
+        let before = segments(&fx, id).remove(0);
+        RoundTrip.apply(&mut fx.state()).unwrap();
+        let after = segments(&fx, id).remove(0);
+        let n = before.len();
+        let end = end_time(&before).unwrap();
+        assert_eq!(after.len(), 2 * n - 1);
+        // the original part is untouched
+        for i in 0..n {
+            assert_eq!(after[i].time, before[i].time);
+        }
+        // the way back goes on from the end, and lasts as long as the way there
+        for i in 1..n {
+            assert_eq!(
+                after[n - 1 + i].time.unwrap(),
+                2 * end - before[n - 1 - i].time.unwrap()
+            );
+        }
+        assert_eq!(end_time(&after), Some(2 * end - before[0].time.unwrap()));
+    }
+
+    #[test]
+    fn test_nothing_to_do_without_a_way_back() {
+        let (mut fx, id) = loaded("data/simple.gpx");
+        let before = fx.files[&id].clone();
+        fx.selection = Selection::Empty;
+        assert_eq!(
+            RoundTrip.apply(&mut fx.state()),
+            Err(CommandError::NothingToDo)
+        );
+        fx.selection = Selection::Waypoints { file_id: id };
+        assert_eq!(
+            RoundTrip.apply(&mut fx.state()),
+            Err(CommandError::NothingToDo)
+        );
+        assert!(Rc::ptr_eq(&fx.files[&id], &before));
+    }
+}