public virtual double CalculateWeight(ITransit transit, TimeSpan departureTime) => _underlyingWeightCalculator.CalculateWeight(transit, departureTime);
public IPath FindFastestPath(AStarNode startingNode, AStarNode endingNode, TimeSpan departureTime)
{
var visitedNodes = new HashSet <AStarNode>();
var nodesToVisit = new SimplePriorityQueue <AStarNode>();
var temporaryArrivalTimes = new Dictionary <INode, TimeSpan>();
nodesToVisit.Enqueue(startingNode, 0);
temporaryArrivalTimes[startingNode] = departureTime;
startingNode.Weight = 0;
startingNode.HeuristicWeight = 0;
while (nodesToVisit.Count > 0)
{
var currentNode = nodesToVisit.Dequeue();
if (currentNode == endingNode)
{
break;
}
foreach (var transit in currentNode.Transits)
{
var endNode = (AStarNode)transit.EndNode;
var potentialWeight = _weightCalculator.CalculateWeight(transit, temporaryArrivalTimes[currentNode]) + currentNode.Weight;
var potentialHeuristic = _heuristicCalculator.CalculateWeight(transit, temporaryArrivalTimes[currentNode]);
var weightUpdated = false;
if (potentialWeight < endNode.Weight)
{
weightUpdated = true;
endNode.Weight = potentialWeight;
endNode.HeuristicWeight = potentialHeuristic;
endNode.FastestTransit = transit;
var intermediateDepartureTime = transit.Transport.GetClosestDepartureTime(currentNode.Location, temporaryArrivalTimes[currentNode]);
temporaryArrivalTimes[endNode] = intermediateDepartureTime + transit.Transport.TravelTime(transit.StartNode.Location, transit.EndNode.Location, intermediateDepartureTime);
transit.DepartureTime = intermediateDepartureTime;
transit.ArrivalTime = temporaryArrivalTimes[endNode];
}
if (!visitedNodes.Contains(endNode))
{
var isInVisitList = nodesToVisit.Contains(endNode);
if (!isInVisitList)
{
nodesToVisit.EnqueueWithoutDuplicates(endNode, (float)endNode.TotalWeight);
}
else if (isInVisitList && weightUpdated)
{
nodesToVisit.UpdatePriority(endNode, (float)endNode.TotalWeight);
}
}
}
visitedNodes.Add(currentNode);
}
return(BacktrackPath(endingNode));
}