using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.AI;
using UnityEngine.Networking;

public class EnemyPathing : NetworkBehaviour {

    public double attackRange = 5.0;
    public float pathingUpdateTime = 0.5f;

    public NavMeshAgent unitAgent;

    private GameObject[] targets;
    [SyncVar]
    private GameObject target;
    [SyncVar]
    private NavMeshPath path;
    private float pathingCooldown = 0.0f;

    // Use this for initialization
    void Start () {
        path = new NavMeshPath();
    }

    // Update is called once per frame
    void Update () {
        //Pathfinding

        DoPathing();

    }
    private void DoPathing()
    {
        pathingCooldown += Time.deltaTime;
        if (pathingCooldown > pathingUpdateTime)
        {
            pathingCooldown -= pathingUpdateTime;

            target = FindNewTarget();

            if (target != null)
            {
                //check if target is in attack range if so attack.
                float d = GetDistance(target.transform.position);
                double dist = d;
                //print("Distance from target" + dist);
                if (dist <= attackRange)
                {
                    //attack mechanics done in different timer in update loop.
                    //stop moving to target once in range
                    if (unitAgent.hasPath)
                    {
                        unitAgent.ResetPath();
                    }
                    return;
                }
                //if target is not in range, move closer to the target.
                NavMesh.CalculatePath(unitAgent.transform.position, target.transform.position, NavMesh.AllAreas, path);
                unitAgent.path = path;
                unitAgent.destination = target.transform.position;
                    //if so move to target
                    //if not find new target
                        //check tracking range for new target
                        //if no target found, move back to spawn point

            }
        }

    }
    public GameObject FindNewTarget()
    {
        //print("Aquiriring Targets");
        targets = GameObject.FindGameObjectsWithTag("Player Hero");

        //check if it found any targets.
        if (targets.Length > 0)
        {
            if (targets.Length == 1)
            {
                //print("Only one target.");
                return targets[0];
            }
            //print("Multiple targets found.");
            List<float> distances = new List<float>();
            List<double> weights = new List<double>();
            foreach (GameObject t in targets)
            {
                //calculate the distance to the target and save it temporarily.
                float testDistance = GetDistance(t.transform.position);
                distances.Add(testDistance);
                //calculate and save the weight value.
                weights.Add(testDistance / t.GetComponentInParent<PathingData>().pathingWeight);
            }
            int bestIndex = 0;
            for (int i = 0; i < targets.Length; i++)
            {
                if (weights[i] < weights[bestIndex])
                {
                    bestIndex = i;
                }
                else if (weights[i] == weights[bestIndex])
                {
                    if (distances[i] < distances[bestIndex])
                    {
                        bestIndex = i;

                    }
                }
            }
            return targets[bestIndex];

        } else {
            print("ALL PLAYERS DEAD?!?!?!");
            return null;
        }
    }
    public float GetDistance(Vector3 t)
    {
        NavMesh.CalculatePath(unitAgent.transform.position, t, NavMesh.AllAreas, path);
        float dist = 0.0f;
        for (int i = 0; i < path.corners.Length - 1; i++)
            dist += Vector3.Distance(path.corners[i], path.corners[i + 1]);
        return dist;


    }
}