fix(pattern): update distance and travel times when pattern is reversed

fixes #176

Author: landonreed

lib/editor/components/pattern/TripPatternListControls.js

@@ -75,15 +75,28 @@ export default class TripPatternListControls extends Component {
       title: `Reverse trip pattern?`,
       body: `Are you sure you want to reverse this trip pattern?`,
       onConfirm: () => {
-        // Order of pattern stops is irrelevant. Stop sequence must be updated.
-        const patternStops = [...activePattern.patternStops]
-          // Reverse sort on existing stopSequence values. NOTE: Updating
-          // stop sequence for new order is handled in updatePatternStops.
-          .sort((a, b) => b.stopSequence - a.stopSequence)
-          .map((ps, i) => ({
-            ...ps,
-            stopSequence: i
-          }))
+        // Travel time will be offset by one stop (travel time for first stop
+        // should be zero).
+        let defaultTravelTime = 0
+        const {patternStops} = activePattern
+        // Store total distance from last pattern stop
+        const lastStop = patternStops[patternStops.length - 1]
+        const totalDistance = lastStop.shapeDistTraveled
+        // Clone pattern stops and reverse them, updating shape dist traveled
+        // and travel time for the new order.
+        const clonedPatternStops = [...patternStops]
+          .reverse()
+          .map((ps, i) => {
+            const patternStop = {
+              ...ps,
+              shapeDistTraveled: totalDistance - ps.shapeDistTraveled,
+              defaultTravelTime,
+              stopSequence: i
+            }
+            // Update default travel time for next iteration.
+            defaultTravelTime = ps.defaultTravelTime
+            return patternStop
+          })
         updatePatternGeometry({
           // Reverse control points
           controlPoints: clone(controlPoints).reverse(),
@@ -92,7 +105,7 @@ export default class TripPatternListControls extends Component {
             .map(seg => seg.reverse())
             .reverse()
         })
-        updatePatternStops(activePattern, patternStops)
+        updatePatternStops(activePattern, clonedPatternStops)
         saveActiveEntity('trippattern')
       }
     })