public Map<RouteDirectionStopKey, String> getStopMatches(
Map<NBRoute, Route> routeMatches,
Map<NBStop, List<Stop>> potentialStopMatches,
GtfsRelationalDao dao) {
Map<RouteDirectionStopKey, String> stopIdMappings =
new HashMap<RouteDirectionStopKey, String>();
for (Map.Entry<NBRoute, Route> entry : routeMatches.entrySet()) {
NBRoute nbRoute = entry.getKey();
Route gtfsRoute = entry.getValue();
Set<List<Stop>> stopSequences = getStopSequencesForRoute(dao, gtfsRoute);
List<Map<Stop, Integer>> stopSequenceIndices = new ArrayList<Map<Stop, Integer>>();
for (List<Stop> stopSequence : stopSequences) {
Map<Stop, Integer> index = new HashMap<Stop, Integer>();
for (int i = 0; i < stopSequence.size(); ++i) {
index.put(stopSequence.get(i), i);
}
stopSequenceIndices.add(index);
}
for (NBDirection direction : nbRoute.getDirections()) {
List<Match> matches = new ArrayList<Match>();
for (NBStop fromStop : direction.getStops()) {
List<Stop> toStops = potentialStopMatches.get(fromStop);
if (toStops.isEmpty()) {
continue;
}
Match m = new Match(fromStop, toStops);
matches.add(m);
}
Min<Assignment> m = new Min<Assignment>();
Assignment assignment = new Assignment(direction.getStops(), stopSequenceIndices);
matches = applyDirectMatchesToAssignment(matches, assignment);
recursivelyBuildAndScoreAssignment(matches, 0, assignment, m);
Assignment bestAssignment = m.getMinElement();
if (bestAssignment == null) {
throw new IllegalStateException();
}
for (NBStop stop : direction.getStops()) {
Stop gtfsStop = bestAssignment.getGtfsStopForNBStop(stop);
if (gtfsStop == null) {
continue;
}
String stopId = gtfsStop.getId().getId();
RouteDirectionStopKey key =
new RouteDirectionStopKey(nbRoute.getTag(), direction.getTag(), stop.getTag());
stopIdMappings.put(key, stopId);
}
}
}
return stopIdMappings;
}
private void recursivelyBuildAndScoreAssignment(
List<Match> matches, int depth, Assignment assignment, Min<Assignment> m) {
if (depth == matches.size()) {
double score = scoreAssignment(assignment);
if (score < m.getMinValue()) {
m.add(score, new Assignment(assignment));
}
} else {
Match match = matches.get(depth);
for (int i = 0; i < match.to.size(); ++i) {
assignment.applyMatch(match, i);
recursivelyBuildAndScoreAssignment(matches, depth + 1, assignment, m);
}
}
}