Add feed id column to path results (sequel) (#936)

* Write feedIds as separate column

feedIds are derived from boarding stops

* Add "group" column in CSV path results

For future use (see #924, for example)

src/main/java/com/conveyal/r5/analyst/cluster/PathResult.java

@@ -57,13 +57,15 @@ public class PathResult {
             "routes",
             "boardStops",
             "alightStops",
+            "feedIds",
             "rideTimes",
             "accessTime",
             "egressTime",
             "transferTime",
             "waitTimes",
             "totalTime",
-            "nIterations"
+            "nIterations",
+            "group"
     };
 
     public PathResult(AnalysisWorkerTask task, TransitLayer transitLayer) {
@@ -140,7 +142,10 @@ public ArrayList<String[]>[] summarizeIterations(Stat stat) {
                             score = thisScore;
                         }
                     }
-                    String[] row = ArrayUtils.addAll(path, transfer, waits, totalTime, String.valueOf(nIterations));
+                    String group = ""; // Reserved for future use
+                    String[] row = ArrayUtils.addAll(
+                            path, transfer, waits, totalTime, String.valueOf(nIterations), group
+                    );
                     checkState(row.length == DATA_COLUMNS.length);
                     summary[d].add(row);
                 }

src/main/java/com/conveyal/r5/transit/TransitLayer.java

@@ -873,4 +873,11 @@ public String stopString(int stopIndex, EntityRepresentation nameOrId) {
             default -> stopId;
         };
     }
+
+    /**
+     * For a supplied stopIndex in the transit layer, return the feed id (which we prepend to the GTFS stop id).
+     */
+    public String feedFromStop(int stopIndex) {
+        return stopIdForIndex.get(stopIndex) == null ? "[new]" : stopIdForIndex.get(stopIndex).split(":")[0];
+    }
 }

src/main/java/com/conveyal/r5/transit/path/RouteSequence.java

@@ -31,25 +31,39 @@ public RouteSequence(PatternSequence patternSequence, TransitLayer transitLayer)
         }
     }
 
-    /** Returns details summarizing this route sequence, using GTFS ids stored in the supplied transitLayer. */
+    /**
+     * Returns details summarizing this route sequence, using GTFS ids stored in the supplied transitLayer.
+     * @param csvOptions indicates whether names or IDs should be returned for certain fields.
+     * @return array of pipe-concatenated strings, with the route, board stop, alight stop, ride time, and feed for
+     * each transit leg, as well as the access and egress time.
+     * 
+     * If csvOptions.feedRepresentation is not null, the feed values will be R5-generated UUID for boarding stop of
+     * each leg. We are grabbing the feed ID from the stop rather than the route (which might seem like a better
+     * representative of the leg) because stops happen to have a readily available feed ID.
+     */
     public String[] detailsWithGtfsIds (TransitLayer transitLayer, CsvResultOptions csvOptions){
-        StringJoiner routeIds = new StringJoiner("|");
-        StringJoiner boardStopIds = new StringJoiner("|");
-        StringJoiner alightStopIds = new StringJoiner("|");
-        StringJoiner rideTimes = new StringJoiner("|");
+        StringJoiner routeJoiner = new StringJoiner("|");
+        StringJoiner boardStopJoiner = new StringJoiner("|");
+        StringJoiner alightStopJoiner = new StringJoiner("|");
+        StringJoiner feedJoiner = new StringJoiner("|");
+        StringJoiner rideTimeJoiner = new StringJoiner("|");
         for (int i = 0; i < routes.size(); i++) {
-            routeIds.add(transitLayer.routeString(routes.get(i), csvOptions.routeRepresentation));
-            boardStopIds.add(transitLayer.stopString(stopSequence.boardStops.get(i), csvOptions.stopRepresentation));
-            alightStopIds.add(transitLayer.stopString(stopSequence.alightStops.get(i), csvOptions.stopRepresentation));
-            rideTimes.add(String.format("%.1f", stopSequence.rideTimesSeconds.get(i) / 60f));
+            routeJoiner.add(transitLayer.routeString(routes.get(i), csvOptions.routeRepresentation));
+            boardStopJoiner.add(transitLayer.stopString(stopSequence.boardStops.get(i), csvOptions.stopRepresentation));
+            alightStopJoiner.add(transitLayer.stopString(stopSequence.alightStops.get(i), csvOptions.stopRepresentation));
+            if (csvOptions.feedRepresentation != null) {
+                feedJoiner.add(transitLayer.feedFromStop(stopSequence.boardStops.get(i)));
+            }
+            rideTimeJoiner.add(String.format("%.1f", stopSequence.rideTimesSeconds.get(i) / 60f));
         }
         String accessTime = stopSequence.access == null ? null : String.format("%.1f", stopSequence.access.time / 60f);
         String egressTime = stopSequence.egress == null ? null : String.format("%.1f", stopSequence.egress.time / 60f);
         return new String[]{
-                routeIds.toString(),
-                boardStopIds.toString(),
-                alightStopIds.toString(),
-                rideTimes.toString(),
+                routeJoiner.toString(),
+                boardStopJoiner.toString(),
+                alightStopJoiner.toString(),
+                rideTimeJoiner.toString(),
+                feedJoiner.toString(),
                 accessTime,
                 egressTime
         };