/*
 * author: mark joshwel
 * date: 19/6/2024
 * description: enemy AI based off <https://youtu.be/UjkSFoLxesw>
 */

using UnityEngine;
using UnityEngine.AI;

/// <summary>
///     AI patrolling, chasing and capturing behaviour for the enemy
/// </summary>
public class HerController : MonoBehaviour
{
    /// <summary>
    ///     cache variable for the walking parameter in the animator
    /// </summary>
    private static readonly int IsMoving = Animator.StringToHash("isMoving");

    /// <summary>
    ///     cache variable for the chasing parameter in the animator
    /// </summary>
    private static readonly int IsChasing = Animator.StringToHash("isChasing");

    /// <summary>
    ///     variable for the nav mesh agent that determines where the enemy can move
    /// </summary>
    public NavMeshAgent agent;

    /// <summary>
    ///     variable for the player's position
    /// </summary>
    public Transform player;

    /// <summary>
    ///     variables to distinguish player for sensing
    /// </summary>
    public LayerMask playerLayerMask;

    /// <summary>
    ///     variable specifying the capture range of the enemy
    /// </summary>
    public float captureRange;

    /// <summary>
    ///     boolean variable for the player being in attack range
    /// </summary>
    public bool playerInCaptureRange;

    /// <summary>
    ///     variable for the animator
    /// </summary>
    private Animator _anim;

    /// <summary>
    ///     variable to store game manager
    /// </summary>
    private GameManager _game;

    /// <summary>
    ///     function to set any initial values
    /// </summary>
    private void Awake()
    {
        // get the player
        player = GameObject.FindGameObjectWithTag("Player").transform;
        // get the nav mesh agent
        agent = GetComponent<NavMeshAgent>();
        // get the animator
        _anim = GetComponent<Animator>();
        // get the game manager
        _game = GameManager.Instance;
    }

    /// <summary>
    ///     function to update the enemy's behaviour
    /// </summary>
    private void Update()
    {
        // check for sight and attack range
        playerInCaptureRange = Physics.CheckSphere(transform.position, captureRange, playerLayerMask);

        if (!playerInCaptureRange) ChasePlayer();
        else CapturePlayer();
    }

    /// <summary>
    ///     function to draw/visualize the sight and attack range of the enemy
    /// </summary>
    private void OnDrawGizmosSelected()
    {
        Gizmos.color = Color.red;
        Gizmos.DrawWireSphere(transform.position, captureRange);
    }

    /// <summary>
    ///     function to chase the player
    /// </summary>
    private void ChasePlayer()
    {
        // start chasing animation
        _anim.SetBool(IsMoving, true);
        _anim.SetBool(IsChasing, true);
        // aim at the player
        agent.SetDestination(player.position);
    }

    /// <summary>
    ///     function that captures the player and signals the game manager appropriately
    /// </summary>
    private void CapturePlayer()
    {
        // signal the game manager to show the 'caught!' menu
        if (_game.Paused) return;

        Debug.Log("captured...");
        _game.SetDisplayState(GameManager.DisplayState.ScreenCaughtMenu);

        // // stop any moving animations
        // _anim.SetBool(IsChasing, false);
        // _anim.SetBool(IsMoving, false);
        // // don't move the enemy
        // agent.SetDestination(transform.position);
        // // look at me!
        // transform.LookAt(player);
    }
}