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

public class SpawnerController : MonoBehaviour {
    [SerializeField] private BoxCollider2D bounds;
    [SerializeField] private GameObject monsterToSpawn;

    [SerializeField] private float spawnTick;
    [SerializeField] private int maxActiveSpawns;
    [SerializeField] private int maxSpawnPerTick;

    [SerializeField] private bool isActive;

    private List<GameObject> spawns;

    private void Start() {
        spawns = new List<GameObject>();
        StartCoroutine("SpawnCoroutine");
    }

    private void Spawn() {
        Vector3 spawnPosition = new Vector3(bounds.transform.position.x + bounds.size.x * Random.Range(-0.5f, 0.5f),
                                            bounds.transform.position.y + bounds.size.y,
                                            bounds.transform.position.z);
        GameObject monster = Instantiate(monsterToSpawn);
        monster.transform.position = spawnPosition;
        spawns.Add(monster);
    }

    private IEnumerator SpawnCoroutine() {
        while (true) {
            spawns.RemoveAll(spawn => spawn == null);
            if (isActive && spawns.Count < maxActiveSpawns) {
                // TODO: Check if num active spawns is > maxActiveSpawns.
                int numSpawns = Mathf.Min(maxActiveSpawns, spawns.Count + maxSpawnPerTick) - spawns.Count;
                for (int i = 0; i < numSpawns; i++) {
                    Spawn();
                }
            }
            yield return new WaitForSeconds(spawnTick);
        }
    }
}