using System;
using System.Collections.Generic;
using TMPro;
using UnityEngine;
using Random = UnityEngine.Random;

public class WaveManager : MonoBehaviour
{
	
	#region Statication

	public static WaveManager instance;

	private void Awake()
	{
		if (instance != null && instance != this)
		{
			Destroy(gameObject);
			return;
		}
		instance = this;
	}

	#endregion


	[System.Serializable]
	public class Wave
	{
		public Enemy[] enemies;
	}
	[Header("Player Point")]
	[SerializeField] private Transform tlPoint;
	[SerializeField] private Transform brPoint;

	[Header("Enemy Point")] 
	[SerializeField] private Transform enemyTLPoint;
	[SerializeField] private Transform enemyBRPoint;
	public Transform enemySpawnPoint;
	[Header("Waves")] 
	[SerializeField] private TextMeshProUGUI waveUI;
	public int wave = 1;
	public Wave[] waveList;
	[Header("Enemies")]
	public Transform enemyFolder;
	public List<Enemy> enemiesInPlay = new();
	[SerializeField] private float enemyCheckRadius;
	[SerializeField] private LayerMask enemyLayer;

	private void Start()
	{
		SpawnWave();
	}

	public Vector3 GetRandomPlayerPoint()
	{
		return new Vector3(Random.Range(tlPoint.position.x, brPoint.position.x),
			Random.Range(brPoint.position.y, tlPoint.position.y), 0);
	}

	private Vector3 GetRandomEnemyPoint()
	{
		Vector3 randomPoint;
		do
		{
			randomPoint = new Vector3(Random.Range(enemyTLPoint.position.x, enemyBRPoint.position.x),
				Random.Range(enemyBRPoint.position.y, enemyTLPoint.position.y), 0);
		} while (CheckEnemyOverlap(randomPoint));
		return randomPoint;
	}

	private bool CheckEnemyOverlap(Vector3 areaToCheck)
	{
		if (Physics2D.OverlapCircle(areaToCheck, enemyCheckRadius, enemyLayer))
		{
			return true;
		}

		return false;
	}

	private void SpawnWave()
	{
		waveUI.text = $"Wave: {wave}";
		foreach (Enemy enemy in waveList[wave-1].enemies)
		{
			Enemy newEnemy = Instantiate(enemy, enemyFolder);
			newEnemy.StartCoroutine(newEnemy.MoveToPosition(GetRandomEnemyPoint()));
			enemiesInPlay.Add(newEnemy);
			newEnemy.isStalled = true;
		}
		wave++;
	}

	public void UpdateKills()
	{
		if (enemiesInPlay.Count == 0)
		{
			SpawnWave();
		}
	}
}