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

public class EnemySpawnScript : MonoBehaviour 
{
	public GameObject enemy;

	public float spawnRate;
	private float nextSpawnTime;

	void Update () 
	{
		if(Time.time > nextSpawnTime)
		{
			nextSpawnTime = Time.time + spawnRate;
			Instantiate (enemy, transform.position, Quaternion.identity);
		}
	}
}

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

public class EnemyControllerScript : MonoBehaviour
{
    private GameObject playerObject;
    private UnityEngine.AI.NavMeshAgent enemyNav;
    private Animator enemyAnim;

    private LayerMask playerMask = 1 << 9;
    public bool playerPresent = false;

    public float enemyHealth = 100f;

    public float enemyAttackAmount;
    public float enemyAttackRate;
    private float enemyNextAttackTime = 0f;

    void Awake()
    {
        playerObject = GameObject.FindGameObjectWithTag("Player");
        enemyNav = GetComponent<UnityEngine.AI.NavMeshAgent>();
        enemyAnim = GetComponentInChildren<Animator>();
    }

    void Update()
    {
        if(!playerPresent)
            enemyNav.SetDestination(playerObject.transform.position);
        
        EnemyAnimation();
    }

    void FixedUpdate()
    {
        playerPresent = DetectPlayer();
        AttackPlayer();
    }

    bool DetectPlayer()
    {
        Vector3 fwd = transform.TransformDirection(Vector3.forward);
        if(Physics.Raycast(transform.position, fwd, 2, playerMask))
        {
            return true;
        }
        else
        {
            return false;
        }
    }

    void AttackPlayer()
    {
        if(playerPresent && Time.time > enemyNextAttackTime)
        {
            enemyNextAttackTime = Time.time + enemyAttackRate;
            playerObject.GetComponent<PlayerStatsScript>().PlayerHealthAdjustment(-enemyAttackAmount);
        }
    }

    public void EnemyHealthAdjustment(float enemyHealthAdjustment)
    {
        enemyHealth += enemyHealthAdjustment;
        if(enemyHealth <= 0)
        {
            Destroy(gameObject);
            playerObject.GetComponent<PlayerStatsScript>().EnemiesKilledTotal();
        }
            
    }

    void EnemyAnimation ()
    {
        enemyAnim.SetBool("PlayerNear", playerPresent);
    }
}

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

public class PlayerStatsScript : MonoBehaviour
{
    public float playerHealth = 100f;
    public int enemiesKilled = 0;

    public Slider playerHealthSlider;
    public Text timerText;
    public Text enemiesKilledText;
    public Image damagePanel;

    public float damageFlashSpeed = .25f;
    public Color damageFlashColor;

    void Awake()
    {
        playerHealthSlider = GameObject.Find("HealthSlider").GetComponent<Slider>();
        timerText = GameObject.Find("TimerText").GetComponent<Text>();
        enemiesKilledText = GameObject.Find("EnemiesText").GetComponent<Text>();
        damagePanel = GameObject.Find("DamagePanel").GetComponent<Image>();
    }

    void Update()
    {
        timerText.text = "Time Alive: " + Mathf.RoundToInt(Time.time);
    }


    public void PlayerHealthAdjustment(float playerHealthAdjustment)
    {
        playerHealth += playerHealthAdjustment;
        playerHealthSlider.value = playerHealth;        

        damagePanel.color = damageFlashColor;
        StartCoroutine(DamageFlashBack());

        if(playerHealth <= 0)
        {
            GameObject.Find("GameController").GetComponent<GameControllerScript>().playerAlive = false;
            GameObject.Find("GameController").GetComponent<GameControllerScript>().PauseScreen();
        }
    }

    IEnumerator DamageFlashBack()
    {
        yield return new WaitForSeconds(damageFlashSpeed);
        damagePanel.color = Color.clear;
    }

    public void EnemiesKilledTotal()
    {
        enemiesKilled++;
        enemiesKilledText.text = "Enemies Killed: " + enemiesKilled;
    }
}