using System;
using System.Collections;
using UnityEngine;
using UnityEngine.AI;

public class EnemyManager : MonoBehaviour
{
    private float moveSpeed;
    private NavMeshAgent agent;
    private GameObject player;
    public GameObject bulletPrefb;
    public Transform firePoint;
    private int count;
    public GameObject effectPrefab1;
    public GameObject effectPrefab2;
    private int HP;
    private float searchRange;
    private GameObject[] safeZone;
    private GameObject[] enemies;

    public enum State
    {
        Normal,
        Attack,
        Escape,
    }

    public State mode;

    void Start()
    {
        moveSpeed = 1.5f;
        agent = GetComponent<NavMeshAgent>();
        player = GameObject.Find("Player");

        HP = 5;
        StartCoroutine(HPRecovery());

        searchRange = 10;

        safeZone = GameObject.FindGameObjectsWithTag("SafeZone");

        // ゲーム開始時点はノーマルモード
        mode = State.Normal;
    }

    void Update()
    {
        switch (mode)
        {
            default:

            // ノーマルモードの時にやること
            case State.Normal:
                MoveAround();
                Search();
                break;

            // 攻撃モードの時にやること
            case State.Attack:
                FireBullet();
                Chase();
                Call();
                break;

            // 離脱モードの時にやること
            case State.Escape:
                RunAway();
                break;
        }
    }

    // 追跡
    void Chase()
    {
        agent.destination = player.transform.position;
        agent.stoppingDistance = 5f;
    }
    // 巡回
    void MoveAround()
    {
        transform.Translate(Vector3.forward * Time.deltaTime * moveSpeed);

        RaycastHit hit;
        Ray ray = new Ray(transform.position, transform.forward);

        if (Physics.Raycast(ray, out hit, 1))
        {
            GameObject target = hit.collider.gameObject;

            if (target.CompareTag("UTurn"))
            {
                transform.localRotation = Quaternion.Euler(0, transform.eulerAngles.y + 180, 0);
            }
            else if (target.CompareTag("LTurn"))
            {
                transform.localRotation = Quaternion.Euler(0, transform.eulerAngles.y + 270, 0);
            }
            else if (target.CompareTag("RTurn"))
            {
                transform.localRotation = Quaternion.Euler(0, transform.eulerAngles.y + 90, 0);
            }
        }
    }
    // 攻撃（ショット）
    void FireBullet()
    {
        transform.LookAt(player.transform.position);

        count += 1;

        if (count % 250 == 0)
        {
            GameObject bullet = Instantiate(bulletPrefb, firePoint.position, Quaternion.identity);
            Rigidbody bulletRb = bullet.GetComponent<Rigidbody>();
            bulletRb.AddForce(transform.forward * 1000);
            Destroy(bullet, 5.0f);
        }
    }
    // 体力（HP）
    void OnTriggerEnter(Collider other)
    {
        if (other.CompareTag("Omizu"))
        {
            HP -= 1;

            // HPが２以下になったら離脱モードに移行する
            if (HP < 3)
            { 
                mode = State.Escape;
            }

            if (HP > 0)
            {
                GameObject effect1 = Instantiate(effectPrefab1, transform.position, Quaternion.identity);
                Destroy(effect1, 0.75f);
            }
            else
            {
                GameObject effect2 = Instantiate(effectPrefab2, transform.position, Quaternion.identity);
                Destroy(effect2, 0.75f);
                Destroy(gameObject);
            }
        }
    }
    // 体力回復
    private IEnumerator HPRecovery()
    {
        while (true)
        {
            HP += 1;

            if (HP > 5)
            {
                HP = 5;
            }

            yield return new WaitForSeconds(3);
        }
    }
    // 索敵
    void Search()
    {
        RaycastHit hit;
        Ray ray = new Ray(transform.position, transform.forward);

        if (Physics.Raycast(ray, out hit, searchRange))
        {
            GameObject target = hit.collider.gameObject;

            if (target.CompareTag("PlayerBody"))
            {
                // プレーヤーを発見したら攻撃モードに移行
                mode = State.Attack;
            }
        }
    }
    // 逃げる
    void RunAway()
    {
        GameObject farthestZone = null;
        float maxDistance = 0f;

        // すべてのSafeZoneをチェックして、一番遠いものを探す
        foreach (GameObject zone in safeZone)
        {
            // 自分とsafezoneの距離をチェックして、一番遠いものを探す
            float distance = Vector3.Distance(transform.position, zone.transform.position);

            // 今までの最大距離より遠ければ、それを暫定1位にする
            if (distance > maxDistance)
            {
                maxDistance = distance;
                farthestZone = zone;
            }
        }

        // 見つかった一番遠いZoneを目的地に設定
        agent.destination = farthestZone.transform.position;
        agent.stoppingDistance = 0f;

        // 10秒経過したら「攻撃モード」に戻す
        Invoke("AttackMode", 10f);
    }
    // 仲間を呼ぶ
    void Call()
    {
        enemies = GameObject.FindGameObjectsWithTag("Enemy");

        foreach (GameObject g in enemies)
        {
            EnemyManager em = g.GetComponent<EnemyManager>();
            em.mode = State.Attack;
        }
    }
    // 攻撃モードに戻る
    void AttackMode()
    {
        mode = State.Attack;
    }
}