WaveSpawner

using UnityEngine;
using System.Collections;
using UnityEngine.UI;

public class WaveSpawner : MonoBehaviour {

	public enum SpawnState { SPAWNING, WAITING, COUNTING }

	[System.Serializable]
	public class Wave {
		public string name;
		public Transform enemy;
		public int count;
		public float rate;
	}

	public Text countdownText;

	public Wave[] waves;
	private int nextWave = 0;

	public Transform spawnPoint;

	public float timeBetweenWaves = 5f;
	public float waveCountdown;

	private float searchCountdown = 1f;

	private SpawnState state = SpawnState.COUNTING;

	void Start() {
		waveCountdown = timeBetweenWaves;
	}

	void Update() {
		if (CameraController.inElementSelectMenu == true)
			return;
		waveCountdown = Mathf.Clamp (waveCountdown, 0f, Mathf.Infinity);
		countdownText.text = string.Format("{0:00.00}", waveCountdown);
		if (state == SpawnState.WAITING) {
			if (!EnemyIsAlive ()) {
				WaveCompleted();
			} else {
				return;
			}
		}

		if (waveCountdown <= 0) {
			if (state != SpawnState.SPAWNING) {
				StartCoroutine (SpawnWave (waves [nextWave]));
			}
		} else {
			waveCountdown -= Time.deltaTime;
		}

		if (Input.GetKeyDown("space")) {
			waveCountdown = 0;
		}
	}

	void WaveCompleted () {
		Debug.Log ("Wave Completed!");

		state = SpawnState.COUNTING;
		waveCountdown = timeBetweenWaves;

		if (nextWave + 1 > waves.Length - 1) {
			nextWave = 0;
			Debug.Log ("ALL WAVES COMPLETED! Looping...");
		} else {
			nextWave++;
		}
	}

	bool EnemyIsAlive () {
		searchCountdown -= Time.deltaTime;
		if (searchCountdown <= 0f) {
			searchCountdown = 1f;
			if (GameObject.FindGameObjectWithTag ("Enemy") == null) {
				return false;
			}
		}
		return true;
	}

	IEnumerator SpawnWave (Wave _wave) {
		Debug.Log ("Spawning Wave: " + _wave.name);
		state = SpawnState.SPAWNING;

		for (int i = 0; i < _wave.count; i++) {
			SpawnEnemy (_wave.enemy);
			yield return new WaitForSeconds (1f / _wave.rate);
		}

		state = SpawnState.WAITING;

		yield break;
	}

	void SpawnEnemy (Transform _enemy) {
		Debug.Log ("Spawning Enemy: " + _enemy.name);
		Instantiate (_enemy, spawnPoint.position, transform.rotation);
	}

}