using UnityEngine;
using System.Collections;

namespace TowerDefenceTemplate
{
    public class Enemy : MonoBehaviour
    {
        public enum EnemyType//敵方炮車型別
        {
            Jeep,
            Tank,
            Plane
        };

        public EnemyType enemyType;//例項化炮車型別

        public EllipsoidParticleEmitter Explosion;//例項化粒子系統
 


        public float
            Health,//血量
            Speed,//行進速度
            current_health;//當前血量

        public GameObject HealthBar;//血量條

        private Transform CurrentWaypoint;//當前路點

        private Transform[] Waypoints;//所有路點

        private GameManager gameManager;//例項化遊戲管理器物件

        private
 
 int
            Award,//打死一個炮車獎勵的金幣
            WaypointIndex;//路點的索引

        private bool Dead;//判定炮車是否死亡

        void Start()
        {
            gameManager = FindObjectOfType<GameManager>();//找到GameManager指令碼
            if (gameManager == null)//異常處理
            {
                Debug.LogError("GameManager not found!"
 
);
                enabled = false;
                return;
            }
            Speed = gameManager.Waves[gameManager.CurrentWaveIndex].Speed;//獲取控制器中控制炮車行進速度
            Health = gameManager.Waves[gameManager.CurrentWaveIndex].Health;//。。。血量
            Award = gameManager.Waves[gameManager.CurrentWaveIndex].Award;//。。。獎勵
            Waypoints = gameManager.Waves[gameManager.CurrentWaveIndex].Waypoints;//。。。路點
            current_health = Health;//賦值給當前血量
            HealthBar.transform.localScale = Vector3.one;//血條不進行縮放
            CurrentWaypoint = Waypoints[WaypointIndex];//給當前路點賦值
            if (enemyType == EnemyType.Jeep)//如果炮車的型別是吉普
            {
                gameManager.JeepSound.Play();//開啟吉普車行進的音效
            }
            if (enemyType == EnemyType.Tank)
            {
                gameManager.TankSound.Play();
            }
            if (enemyType == EnemyType.Plane)
            {
                gameManager.PlaneSound.Play();
            }
        }

        void GetDamage(float damage)//得到的傷害
        {
            if (Dead)//如果沒血了
            {
                return;//結束當前方法
            }
            current_health -= damage;//減血
            HealthBar.transform.localScale = new Vector3(current_health / Health, 1, 1);//血條縮短
            if (current_health <= 0 && !Dead)//如果血量非正並且沒死
            {
                Die();//讓它死
            }
        }

        void Moving()//移動
        {
            if (!Dead)//如果沒有死
            {
                Quaternion TargetRotation = Quaternion.LookRotation(CurrentWaypoint.position - transform.position, transform.up);//定義旋轉度
                transform.rotation = Quaternion.RotateTowards(transform.rotation, TargetRotation, Time.deltaTime * 100);//讓炮車做旋轉
            }
            transform.Translate(transform.forward * Time.deltaTime * Speed, Space.World);//讓炮車向正前方向移動
            if (Vector3.Distance(transform.position, CurrentWaypoint.position) < 2f)//當炮車的位置和當前路點的距離小於2時
            {
                if ((Waypoints.Length - 1) > WaypointIndex)//當前路點索引不是最後一個索引
                {
                    NextWaypoint();//當前路點+1
                }
                else
                {
                    gameManager.DamageBase();//玩家血量減少
                    Deactivating();//消滅本波次的敵人
                }
            }
        }

        IEnumerator SinkInGround()//協同列舉器
        {
            for (float f = 0; f < 2; f += Time.deltaTime)
            {
                transform.position += new Vector3(0, -f / 5, 0);
                Speed *= (1 - f / 2);
                yield return null;
            }
        }

        IEnumerator FallDown()//協同墜落列舉器
        {
            for (float f = 0; f < 2; f += Time.deltaTime)
            {
                transform.position += new Vector3(0, -f / 5, 0);
                Speed += f / 2;
                yield return null;
            }
        }

        void NextWaypoint()//下一路點設定為當前路點
        {
            WaypointIndex += 1;
            CurrentWaypoint = Waypoints[WaypointIndex];
        }

        void Update()
        {
            Moving();//敵方炮車移動
            HealthBar.transform.position = Camera.main.WorldToScreenPoint(transform.position) + new Vector3(-30, -20, 0);//血條跟隨炮車移動
        }

        void Deactivating()
        {
            Destroy(gameObject);//消滅炮車
            Destroy(HealthBar);//銷燬血條
            for (int i = 0; i < gameManager.SpawnedEnemies.Count; i++)//遍歷本波次所有的炮車
            {
                if (gameManager.SpawnedEnemies[i].Equals(gameObject))//如果當前的炮車和空物體相等
                {
                    gameManager.SpawnedEnemies.RemoveAt(i);//炮車集合裡移除這個炮車
                }
            }
        }

        void Die()//死亡
        {
            Explosion.Emit();//粒子系統呼叫
            if (enemyType != EnemyType.Plane)//如果敵機的型別不是飛機
            {
                StartCoroutine(SinkInGround());//開始協同程式
            }
            else
            {
                StartCoroutine(FallDown());//開始協同程式，墜機
            }
            HealthBar.transform.localScale = Vector3.zero;//血條縮為0
            tag = "Dead";//標籤設定為Dead
            Dead = true;//狀態改為Dead
            gameManager.ExplosionSound.Play();//爆炸聲效
            gameManager.AddMoney(Award);//玩家的金幣增加
            Invoke("Deactivating", 2);//兩秒後執行Deactivating方法
        }
    }
}