using UnityEngine;
using System.Collections.Generic;

public class Tower : MonoBehaviour
{
    public enum TowerTargetPriority {First, Close, Strong}
    [Header("Info")]
    public float range;
    private List<Enemy> curEnemiesInRange = new List<Enemy>();
    private Enemy curEnemy;

    public TowerTargetPriority targetPriority;
    public bool rotateTowardsTarget;

    [Header("Attacking")]
    public float attackRate;
    private float lastAttackTime;
    public GameObject projectilePrefab;
    public Transform projectileSpawnPoint;

    public int projectileDamage;
    public float projectileSpeed;

    void Update()
    {
        if(Time.time - lastAttackTime > attackRate)
        {
            lastAttackTime = Time.time;
            curEnemy = GetEnemy();
            if(curEnemy != null)
            {
                Attack();
            }
        }
    }

    Enemy GetEnemy()
    {
        curEnemiesInRange.RemoveAll(x => x == null);
        if(curEnemiesInRange.Count == 0)
        {
            return null;
        }
        if(curEnemiesInRange.Count == 1)
        {
            return curEnemiesInRange[0];
        }
        switch (targetPriority)
        {
            case TowerTargetPriority.First:
            {
                return curEnemiesInRange[0];
            }
            case TowerTargetPriority.Close:
            {
                Enemy closet = null;
                float dist = 99;
                for (int x = 0; x < curEnemiesInRange.Count; x++)
                {
                    float d = (transform.position - curEnemiesInRange[x].transform.position).sqrMagnitude;
                    if(d < dist)
                    {
                        closet = curEnemiesInRange[x];
                        dist = d;
                    }
                }
                return closet;
            }   
            case TowerTargetPriority.Strong:
            {
                Enemy strongest = null;
                int strongestHealth = 0;
                foreach (Enemy enemy in curEnemiesInRange)
                {
                    if(enemy.health > strongestHealth)
                    {
                        strongest = enemy;
                        strongestHealth = enemy.health;
                    }
                }
                return strongest;
            }
        }
        return null;
    }

    void Attack()
    {
        if(rotateTowardsTarget)
        {
            transform.LookAt(curEnemy.transform);
            transform.eulerAngles = new Vector3(0, transform.eulerAngles.y, 0);
        }
        GameObject proj = Instantiate(projectilePrefab, projectileSpawnPoint.position, Quaternion.identity);
        proj.GetComponent<Projectile>().Initialize(curEnemy, projectileDamage, projectileSpeed); 

    }
    private void OnTriggerEnter(Collider other)
    {
        if(other.CompareTag("Enemy"))
        {
            curEnemiesInRange.Add(other.GetComponent<Enemy>());
        }

    }
    private void OnTriggerExit(Collider other)
    {
        if(other.CompareTag("Enemy"))
        {
            curEnemiesInRange.Remove(other.GetComponent<Enemy>());
        }
    }
}