/**
* Gets the shortest route between two baggage points.
*
* @param source The baggage point from which the bag has to be routed.
* @param destination The baggage point to which the bag has to be routed.
* @return A String holding a delimiter-separated list of baggage points that forms the shortest
* route.
*/
public String route(BaggagePoint source, BaggagePoint destination) {
ArgumentValidator.assertNotNull("Baggage point source", source);
ArgumentValidator.assertNotNull("Baggage point destination", destination);
if (!shortestPathsNetwork.containsKey(source)) {
throw new IllegalArgumentException(
String.format("Baggage point source %s cannot be found.", source.getId()));
}
if (!shortestPathsNetwork.containsKey(destination)) {
throw new IllegalArgumentException(
String.format("Baggage point destination %s cannot be found.", destination.getId()));
}
String shortestRoute;
if (source.equals(destination)) {
List<BaggagePoint> path = new ArrayList<BaggagePoint>();
path.add(source);
path.add(source);
shortestRoute = new ShortestRoute(0d, path).toString();
} else {
if (shortestPathsNetwork.get(source).containsKey(destination)) {
shortestRoute = shortestPathsNetwork.get(source).get(destination).toString();
} else {
shortestRoute =
String.format(
"%s %s : %s",
source.getId(), destination.getId(), OUTPUT_DISTANCE_FOR_UNCONNECTED_POINTS);
}
}
return shortestRoute;
}
private Map<BaggagePoint, ShortestRoute> getSavedShortestPaths(BaggagePoint baggagePoint) {
Map<BaggagePoint, ShortestRoute> savedShortestPaths;
if (shortestPathsNetwork.containsKey(baggagePoint)) {
savedShortestPaths = shortestPathsNetwork.get(baggagePoint);
LOGGER.fine("Entry exists for shortest paths for : " + baggagePoint.getId());
} else {
savedShortestPaths = new HashMap<BaggagePoint, ShortestRoute>();
shortestPathsNetwork.put(baggagePoint, savedShortestPaths);
LOGGER.fine("Added entry for shortest path for : " + baggagePoint.getId());
}
return savedShortestPaths;
}
private void saveShortestPath(
Map<BaggagePoint, ShortestRoute> savedShortestPaths,
BaggagePoint destination,
List<BaggagePoint> path,
double distance) {
if (savedShortestPaths.containsKey(destination)) {
LOGGER.fine("Entry exists for shortest path to : " + destination.getId());
ShortestRoute savedShortestPath = savedShortestPaths.get(destination);
if (savedShortestPath.distance > distance) {
savedShortestPath.distance = distance;
savedShortestPath.path = path;
}
} else {
LOGGER.fine("Adding entry for shortest path to : " + destination.getId());
savedShortestPaths.put(destination, new ShortestRoute(distance, path));
}
}
@Override
public String toString() {
StringBuffer shortestPath = new StringBuffer();
if (null != path) {
for (BaggagePoint baggagePoint : path) {
shortestPath.append(String.format("%s ", baggagePoint.getId()));
}
shortestPath.append(String.format(": %s", decimalFormat.format(distance)));
}
return shortestPath.toString();
}