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

public class ForcePush : MonoBehaviour
{
    Vector3 direction;
    [SerializeField] float force;
    [SerializeField] float maxForce;
    [SerializeField] float forceBuildUpAmount;
    [SerializeField] float radius;
    [SerializeField] float radiusBuildUpAmount;

    PlayerMana mana;
    [SerializeField] float manaCost;
    [SerializeField] float manaBuildUpAmount;
    [SerializeField] float cooldown;
    bool abilityReady;

    List<GameObject> enemies = new List<GameObject>();

    [SerializeField] ParticleSystem forcePushCast;

    Transform runtimeDump;

    //##########################################################################
    private void Start()
    {
        runtimeDump = GameObject.Find("RuntimeDump").transform;

        abilityReady = true;

        mana = GetComponentInParent<PlayerMana>();

        foreach (GameObject enemy in GameObject.FindGameObjectsWithTag("Enemy")) // add boss!?
        {
            enemies.Add(enemy);
        }
    }

    //##########################################################################
    private void FixedUpdate()
    {
        if(abilityReady)
        {
            BuildUp();
            Cast();
        }
    }

    //##########################################################################
    private void BuildUp()
    {
        if(Input.GetButtonDown("Fire2"))
        {
            manaCost = 0f;
        }

        if (Input.GetButton("Fire2"))
        {
            if (force < maxForce)
            {
                force += forceBuildUpAmount * Time.deltaTime;
                radius += radiusBuildUpAmount * Time.deltaTime;
                manaCost += manaBuildUpAmount * Time.deltaTime;
            }
        }
    }

    //##########################################################################
    private void Cast()
    {
        if (Input.GetButtonUp("Fire2"))
        {
            if(mana.GetMana() > manaCost)
            {
                ApplyForceToEnemies();
                abilityReady = false;
                GetComponentInParent<PlayerMana>().ReduceMana(manaCost);
                InstantiateParticleEffect();

                StartCoroutine(ReenableAbility());
            }
            else
            {
                ReenableAbility();
            }
        }

    }

    //##########################################################################
    private void ApplyForceToEnemies()
    {
        foreach (GameObject enemy in enemies)
        {
            float distanceToEnemy = Vector3.Distance(transform.position, enemy.transform.position);
            if (distanceToEnemy < radius)
            {
                enemy.GetComponent<EnemyAI>().isPushed = true;

                NavMeshAgent navMesh = enemy.GetComponent<NavMeshAgent>();
                navMesh.isStopped = true;
                navMesh.updateRotation = false;
                direction = (transform.position - enemy.transform.position) * -1f;
                navMesh.velocity = direction * (force / (distanceToEnemy * 2f));
                navMesh.speed = force / (distanceToEnemy * 2f);
                navMesh.angularSpeed = 0;
                navMesh.acceleration = force * (distanceToEnemy * 2f);

                StartCoroutine(ResetNavMeshValues(navMesh, enemy));
            }
        }
    }

    //##########################################################################
    IEnumerator ResetNavMeshValues(NavMeshAgent navMesh, GameObject enemy)
    {
        yield return new WaitForSeconds(cooldown);

        enemy.GetComponent<EnemyAI>().isPushed = false;
        navMesh.isStopped = false;
        navMesh.updateRotation = true;
        navMesh.speed = 3.5f;
        navMesh.angularSpeed = 20;
        navMesh.acceleration = 50;
    }

    //##########################################################################
    IEnumerator ReenableAbility()
    {
        yield return new WaitForSeconds(cooldown);

        force = 0f;
        radius = 0f;
        abilityReady = true;
    }

    //##########################################################################
    private void InstantiateParticleEffect()
    {
        ParticleSystem particles = Instantiate(forcePushCast, transform.position, Quaternion.identity);
        particles.transform.localScale = new Vector3(radius / 10f, radius / 10f, radius / 10f);
        particles.transform.parent = runtimeDump;
    }

}