using UnityEngine;

public class EnemyHealth : MonoBehaviour
{
    public int startingHealth = 100;
    public int currentHealth;
    public float sinkSpeed = 2.5f;
    public int scoreValue = 10;
    public AudioClip deathClip;


    Animator anim;
    AudioSource enemyAudio;
    ParticleSystem hitParticles;
    CapsuleCollider capsuleCollider;
    bool isDead;
    bool isSinking;


    void Awake ()
    {
        anim = GetComponent <Animator> ();
        enemyAudio = GetComponent <AudioSource> ();
        hitParticles = GetComponentInChildren <ParticleSystem> ();
        capsuleCollider = GetComponent <CapsuleCollider> ();

        currentHealth = startingHealth;
    }


    void Update ()
    {
        if(isSinking)
        {
            transform.Translate (-Vector3.up * sinkSpeed * Time.deltaTime);
        }
    }


    public void TakeDamage (int amount, Vector3 hitPoint)
    {
        if(isDead)
            return;

        enemyAudio.Play ();

        currentHealth -= amount;

        hitParticles.transform.position = hitPoint;
        hitParticles.Play();

        if(currentHealth <= 0)
        {
            Death ();
        }
    }


    void Death ()
    {
        isDead = true;

        capsuleCollider.isTrigger = true;

        anim.SetTrigger ("Dead");

        enemyAudio.clip = deathClip;
        enemyAudio.Play ();
    }


    public void StartSinking()
    {
        // Find and disable the Nav Mesh Agent.
        GetComponent<NavMeshAgent>().enabled = false;

        // Find the rigidbody component and make it kinematic (since we use Translate to sink the enemy).
        GetComponent<Rigidbody>().isKinematic = true;

        // The enemy should no sink.
        isSinking = true;

        // Increase the score by the enemy's score value.
        ScoreManager.score += scoreValue;

        // After 2 seconds destory the enemy.
        Destroy(gameObject, 2f);
    }
}