using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public class AStar {

    public List<Node> openNodes;
    public List<Node> closedNodes;
    public List<Node> pathNodes;
    public int exploreCount;

    public Node finalNode;

public AStar()
    {
        openNodes = new List<Node>();
        closedNodes = new List<Node>();
        pathNodes = new List<Node>();
        exploreCount = 0;
    }

    public List<Node> ExecuteAStar(Node startNode, Node endNode)
    {
        Debug.Log("Se llama a Execute");
        Debug.Log(startNode.name);
        Debug.Log(endNode.name);
        ResetAStar();
        finalNode = endNode;

        openNodes.Add(startNode);
        startNode.weight = 0;

        Explore(startNode);

        pathNodes.Reverse();
        //Manager.instance.UpdateLists(); //esto es para ver en el inspector las listas
        if (pathNodes.Count == 0) Debug.Log("AStar failed");
        return pathNodes;
    }

    public void ResetAStar()
    {
        exploreCount = 0;
        Debug.Log("Se llama a Reset");
        foreach (Node open in openNodes)
            open.ResetNode();

        foreach (Node closed in openNodes)
            closed.ResetNode();

        foreach (Node pth in pathNodes)
        {
            pth.ResetNode();
        }

        pathNodes.Clear();
        openNodes.Clear();
        closedNodes.Clear();
    }

    private void Explore(Node toExplore)
    {
        exploreCount++;
        Debug.Log(toExplore.name + " and explore count: " + exploreCount);
        if (exploreCount > 500) return;
        Debug.Log("Se llama a Explore");
        for (int i = toExplore.neighbours.Count - 1; i >= 0; i--)  // busca en los neighbours
        {
            if (!closedNodes.Contains(toExplore.neighbours[i]))  //si no esta en closed
            {
                if (!openNodes.Contains(toExplore.neighbours[i])) //y tampoco en open
                {
                    openNodes.Add(toExplore.neighbours[i]); //lo agrega a open
                }
                float distance = toExplore.weight + toExplore.distanceToNode[i];
                if (distance < toExplore.neighbours[i].weight)
                {
                    toExplore.neighbours[i].weight = distance;
                    toExplore.neighbours[i].parent = toExplore;
                }
            }
        }

        openNodes.Remove(toExplore);
        closedNodes.Add(toExplore);

        if (toExplore == finalNode)
        {
            pathNodes.Add(toExplore);
            Debug.Log("A* encontro al final");
            Node father = toExplore.parent; //setea el primer parent, con esto va a ir pasando todo el camino
            while (father != null)
            {
                pathNodes.Add(father); //agrega al parent
               // Debug.Log("Father: " + father.name);
                father = father.parent; //pone que el parent sea su propio parent para ir al siguiente del camino hasta llegar al start
            }
        }

        else
        {
            if (openNodes.Count > 0)
            {

                Node nextToExplore = openNodes[0]; //pasa al primero de open
                float fitness = Mathf.Infinity; //punto de partida para determinar el peso del nodo

                foreach (Node item in openNodes)
                {
                    float d = Vector3.Distance(toExplore.transform.position, finalNode.transform.position); //distancia pura al nodo final
                    float h = Mathf.Abs(item.transform.position.x - finalNode.transform.position.x) + //suma las distancias por eje
                            Mathf.Abs(item.transform.position.y - finalNode.transform.position.y) +
                            Mathf.Abs(item.transform.position.z - finalNode.transform.position.z);
                    float f = d + h; //peso del nodo
                    if (fitness > f)
                    {
                        nextToExplore = item; //como arranca en infinito siempre va para ese, a no ser que haya uno con menos peso
                        fitness = f;
                    }
                }

                Explore(nextToExplore);
            }
        }
    }


}