using System.Collections;
using System.Collections.Generic;
//using UnityEditor.Presets;
using UnityEngine;
using UnityEngine.AI;


namespace Beyond
{
    [RequireComponent(typeof(NavMeshAgent))]
    [RequireComponent(typeof(Animator))]
    public class Animal : MonoBehaviour
    {
        enum State { IDLE, WALK, RUN };
        State m_state;
        UnityEngine.AI.NavMeshAgent m_Agent;
        Vector3 startPosition;
        Vector3 destination;
        Animator m_Animator;
        public float StoppingDistance = 2f;
        float m_timer = 0f;
        float m_targetTime = 0f;
        public float m_wanderRange = 40f;
        public float m_minPlayerDistance = 10f;
        int m_maxTrials = 15;
        GameObject m_Player;
        // Start is called before the first frame update
        void Start()
        {
            m_Animator = GetComponent<Animator>();
            m_Agent = GetComponent<NavMeshAgent>();

            startPosition = transform.position;
            m_Agent.acceleration = 50;
            m_Agent.angularSpeed = 1000;
            m_Agent.stoppingDistance = StoppingDistance;
            SetState(State.IDLE);
            m_Player = GameObject.FindGameObjectWithTag("Player");
        }

        void SetState(State state)
        {
            m_Animator.SetInteger("Random", Random.Range(0, 2));
            switch (state)
            {
                case State.IDLE:
                    m_Animator.SetBool("IDLE", true);
                    m_Animator.SetBool("WALK", false);
                    m_Animator.SetBool("RUN", false);
                    m_targetTime = Random.Range(5f, 10f);
                    break;
                case State.WALK:
                    m_Animator.SetBool("IDLE", false);
                    m_Animator.SetBool("WALK", true);
                    m_Animator.SetBool("RUN", false);
                    if (!FindAPath(m_wanderRange, false))
                    {
                        Debug.LogError("Animal AI: didn't find a path");
                    }

                    break;
                case State.RUN:
                    m_Agent.speed = 12f;
                    m_Animator.SetBool("IDLE", false);
                    m_Animator.SetBool("WALK", false);
                    m_Animator.SetBool("RUN", true);
                    if (!FindAPath(m_wanderRange, true))
                    {
                        Debug.LogError("Animal AI: didn't find a path");
                    }
                    break;
            }
            m_timer = 0f;
            m_state = state;
        }

        void OnAnimatorMove()
        {
            m_Agent.velocity = m_Animator.deltaPosition / Time.deltaTime;
        }


        bool FindAPath(float range, bool awayFromPlayer = true)
        {
            for (int i = 0; i < m_maxTrials; i++)
            {
                Vector3 dest;
                if (awayFromPlayer)
                {
                    dest = transform.position + (transform.position - m_Player.transform.position).normalized * range;
                }
                else
                {
                    dest = startPosition;
                }
                dest += new Vector3(Random.Range(-range * .5f - 2f, range * .5f + 2f), 0, Random.Range(-range * .5f - 2f, range * .5f + 2f));
                NavMeshPath path = new NavMeshPath();
                m_Agent.CalculatePath(dest, path);
                if (path.status != NavMeshPathStatus.PathInvalid)
                {
                    m_Agent.SetPath(path);
                    destination = dest;
                    return true;
                }
            }
            return false;
        }
        // Update is called once per frame
        void Update()
        {
            switch (m_state)
            {
                case State.IDLE:
                    if (m_timer > m_targetTime)
                    {
                        SetState(State.WALK);
                    }
                    break;
                case State.WALK:
                    if (m_Agent.remainingDistance < StoppingDistance)
                    {
                        SetState(State.IDLE);
                    }
                    break;
                case State.RUN:
                    if (m_Agent.remainingDistance < StoppingDistance)
                    {
                        SetState(State.RUN);
                    }
                    break;
            }
            if (m_state != State.RUN)
            {
                float dist = (m_Player.transform.position - transform.position).magnitude;
                if (dist < m_minPlayerDistance)
                {
                    if (!FindAPath(m_wanderRange, true))
                    {
                        Debug.LogError("Animal AI: didn't find a path");
                    }
                }
            }

            m_timer += Time.deltaTime;
        }
    }
}