using System.Collections.Generic;

namespace PathfindingPCL
{
    public class DepthFirst : Algorithm
    {
        public DepthFirst(Graph _graph, IHM _ihm) : base(_graph, _ihm) {}

        protected override void Run()
        {
            // Création de la liste des noeuds non visités, et de la pile
            List<Node> notVisitedNodes = graph.NodesList();
            Stack<Node> nodesToVisit = new Stack<Node>();
            nodesToVisit.Push(graph.BeginningNode());
            notVisitedNodes.Remove(graph.BeginningNode());
            
            Node exitNode = graph.ExitNode();

            bool exitReached = false;
            // Boucle principale
            while (nodesToVisit.Count != 0 && !exitReached)
            {
                Node currentNode = nodesToVisit.Pop();
                if (currentNode.Equals(exitNode))
                {
                    // On a fini
                    exitReached = true;
                }
                else
                {
                    // On ajoute les voisins
                    foreach (Node node in graph.NodesList(currentNode))
                    {
                        if (notVisitedNodes.Contains(node))
                        {
                            notVisitedNodes.Remove(node);
                            node.Precursor = currentNode;
                            node.DistanceFromBegin = currentNode.DistanceFromBegin + graph.CostBetweenNodes(currentNode, node);
                            nodesToVisit.Push(node);
                        }
                    }
                }
            }
        }
    }
}