using OSMDatastructure;
using OSMDatastructure.Graph;

namespace Pathfinding;

public static partial class Pathfinder
{

    private static ValueTuple<OsmNode?, OsmNode?> SetupNodes(Coordinates startCoordinates, Coordinates goalCoordinates, RegionManager regionManager )
    {
        ValueTuple<OsmNode?, OsmNode?> retTuple = new();
        retTuple.Item1 = regionManager.ClosestNodeToCoordinates(startCoordinates, Tag.SpeedType.road);
        retTuple.Item2 = regionManager.ClosestNodeToCoordinates(goalCoordinates, Tag.SpeedType.road);
        if (retTuple.Item1 is null || retTuple.Item2 is null)
            return retTuple;
        retTuple.Item1.currentPathWeight = 0;
        retTuple.Item1.currentPathLength = 0;
        retTuple.Item1.directDistanceToGoal =  Utils.DistanceBetween(retTuple.Item1, retTuple.Item2);
        return retTuple;
    }

    private static double EdgeWeight(OsmNode node1, OsmEdge edge, Tag.SpeedType vehicle, RegionManager regionManager)
    {
        OsmNode? node2 = regionManager.GetNode(edge.neighborId, edge.neighborRegion);
        if (node2 is null)
            return double.MaxValue;
        double distance = Utils.DistanceBetween(node1, node2);
        double speed = regionManager.GetSpeedForEdge(node1, edge.wayId, vehicle);
        if (speed is 0)
            return double.MaxValue;
        return distance / speed;
    }
}