/// <summary>
/// Initializes a new instance of the <see cref="RoutePathElement"/> class.
/// </summary>
/// <param name="room">The room of this element.</param>
/// <param name="previous">The previous <see cref="RoutePathElement"/>.</param>
public RoutePathElement([NotNull] RoomViewModel room, [NotNull] RoutePathElement previous)
{
Assert.ArgumentNotNull(room, "room");
Assert.ArgumentNotNull(previous, "previous");
Room = room;
Previous = previous;
}
public static IEnumerable <RoomViewModel> FindRouteToRoom([NotNull] RoomViewModel currentRoom, [NotNull] RoomViewModel roomToNavigateTo, IEnumerable <RoomColor> roomColorsToSkip = null)
{
Assert.ArgumentNotNull(currentRoom, "currentRoom");
Assert.ArgumentNotNull(roomToNavigateTo, "roomToNavigateTo");
if (currentRoom == roomToNavigateTo)
{
return(Enumerable.Empty <RoomViewModel>());
}
var visitedRooms = new HashSet <RoomViewModel>();
var pathQueue = new Queue <RoutePathElement>();
var currentElement = new RoutePathElement(currentRoom);
while (true)
{
if (currentElement.Room == roomToNavigateTo)
{
break;
}
foreach (var exit in currentElement.Room.Exits)
{
if (exit.Room == null)
{
continue;
}
if (!visitedRooms.Contains(exit.Room))
{
bool skipRoom = roomColorsToSkip?.Any(roomColor => exit.Room.Color == roomColor) == true;
if (skipRoom)
{
continue;
}
pathQueue.Enqueue(new RoutePathElement(exit.Room, currentElement));
visitedRooms.Add(exit.Room);
}
}
if (pathQueue.Count == 0)
{
return(Enumerable.Empty <RoomViewModel>());
}
currentElement = pathQueue.Dequeue();
}
var result = new List <RoomViewModel>();
while (currentElement.Previous != null)
{
result.Add(currentElement.Room);
currentElement = currentElement.Previous;
}
result.Reverse();
return(result);
}