using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public class Spawner : MonoBehaviour
{
    // Reference to the Prefab to Spawn
    [SerializeField] private GameObject objectToSpawn;
    // Time interval between spawns
    public float spawnInterval = 1f;
    [SerializeField] private int maxAlive = 0;
    [SerializeField] private bool spawnOnStart = true;
    [SerializeField] private bool repeatSpawns = true;

    private readonly List<GameObject> spawned = new List<GameObject>();

    private void OnEnable()
    {
        if (spawnOnStart)
        {
            SpawnOnce();
        }
    }

    void Start()
    {
        if (repeatSpawns)
        {
            // Start the spawning process using a Coroutine
            StartCoroutine(SpawnRoutine());
        }
    }

    private IEnumerator SpawnRoutine()
    {
        // Infinite loop to keep spawning (can be modified)
        while (true)
        {
            // Wait for the specified interval
            yield return new WaitForSeconds(spawnInterval);
            if (objectToSpawn == null)
            {
                continue;
            }

            if (maxAlive > 0 && CountAlive() >= maxAlive)
            {
                continue;
            }

            SpawnOnce();
        }
    }

    private void SpawnOnce()
    {
        if (objectToSpawn == null)
        {
            return;
        }

        if (maxAlive > 0 && CountAlive() >= maxAlive)
        {
            return;
        }

        var instance = Instantiate(objectToSpawn, transform.position, Quaternion.identity);
        spawned.Add(instance);
    }

    private int CountAlive()
    {
        for (var i = spawned.Count - 1; i >= 0; i--)
        {
            if (spawned[i] == null)
            {
                spawned.RemoveAt(i);
            }
        }

        return spawned.Count;
    }
}