// Patrol.cs
using UnityEngine;
using UnityEngine.AI;
using System.Collections;

public enum RobotState
{
    Idle,
    Patrol,
    Chase,
    Attack,
}
public class Patrol : MonoBehaviour
{
    [SerializeField] private GameObject sight;
    public Transform[] points;
    private int destPoint = 0;
    private NavMeshAgent agent;
    public bool hasPlayerLock;
    private Transform player;
    private float switchTimer;
    [SerializeField] private float idleWaitTime = 3.0f;
    [SerializeField] private float attackTime = 1.0f;
    [SerializeField] private float attackDistance = 2.0f;
    public RobotState state;


    void Start()
    {
        state = RobotState.Idle;
        switchTimer = idleWaitTime;
        player = GameObject.FindGameObjectWithTag( "Player" ).transform;
        agent = GetComponent<NavMeshAgent>();

        // Disabling auto-braking allows for continuous movement
        // between points (ie, the agent doesn't slow down as it
        // approaches a destination point).
        agent.autoBraking = true;

        GotoNextPoint();
    }


    void GotoNextPoint()
    {
        // Returns if no points have been set up
        if( points.Length == 0 )
            return;

        // Set the agent to go to the currently selected destination.
        agent.destination = points[destPoint].position;

        // Choose the next point in the array as the destination,
        // cycling to the start if necessary.
        destPoint = ( destPoint + 1 ) % points.Length;
    }


    void Update()
    {
        switch( state )
        {
            case RobotState.Idle:
                switchTimer -= Time.deltaTime;
                agent.destination = transform.position;
                break;
            case RobotState.Attack:
                switchTimer -= Time.deltaTime;
                break;
            case RobotState.Chase:
                agent.destination = player.position;
                break;
            case RobotState.Patrol:
                if( !agent.pathPending && agent.remainingDistance < 0.5f )
                    GotoNextPoint();
                break;
            default:
                break;
        }

        DetermineState();

        //Debug.Log( state + ", " + switchTimer );

    }

    private void DetermineState()
    {

        hasPlayerLock = sight.GetComponent<CombatantSight>().hasPlayerLock; // if the sight system has the player, so does the turret
        float dist = Vector3.Distance(player.position, transform.position );

        switch( state )
        {
            case RobotState.Idle:
                if( switchTimer < 0 )
                    state = RobotState.Patrol;
                if( hasPlayerLock )
                    state = RobotState.Chase;
                break;
            case RobotState.Attack:
                if( switchTimer < 0 )
                    Attack();
                break;
            case RobotState.Chase:
                if( !hasPlayerLock )
                {
                    state = RobotState.Idle;
                    switchTimer = idleWaitTime;
                }

                if( dist < attackDistance )
                {
                    state = RobotState.Attack;
                    switchTimer = attackTime;
                }

                break;
            case RobotState.Patrol:
                if( hasPlayerLock )
                    state = RobotState.Chase;
                break;
            default:
                break;
        }
    }

    private void Attack()
    {
        // Do Attack Stuff Here
        state = RobotState.Idle;
        switchTimer = idleWaitTime;
    }
}