OldBlueWater/BlueWater/Assets/02.Scripts/Weapon/ParticleWeapon.cs

using System;
using System.Collections;
using UnityEngine;

// ReSharper disable once CheckNamespace
namespace BlueWaterProject
{
    public class ParticleWeapon : MonoBehaviour
    {
        public GameObject impactParticle; // Effect spawned when projectile hits a collider
        public GameObject projectileParticle; // Effect attached to the gameobject as child
        public GameObject muzzleParticle; // Effect instantly spawned when gameobject is spawned
        [Header("Adjust if not using Sphere Collider")]
        public float colliderRadius = 1f;
        [Range(0f, 1f)] // This is an offset that moves the impact effect slightly away from the point of impact to reduce clipping of the impact effect
        public float collideOffset = 0.15f;

        [SerializeField] private LayerMask targetLayer;
        [SerializeField] private float power;
        [SerializeField] private float autoDestroyTime = 5f;
        private float detectionDistance;

        private Rigidbody rb;
        private SphereCollider sphereCollider;
        private WaitForSeconds waitForSeconds;
        private RaycastHit hit;
        
        private void OnDrawGizmosSelected()
        {
            var radius = sphereCollider ? sphereCollider.radius : colliderRadius;
            var direction = rb ? rb.velocity.normalized : transform.forward;
            
            Gizmos.color = Color.red;
            Gizmos.DrawWireSphere(transform.position, radius);  // Draws the start sphere
            Gizmos.DrawLine(transform.position, transform.position + direction * detectionDistance);  // Draws the path of the SphereCast
        }

        private void Awake()
        {
            rb = GetComponent<Rigidbody>();
            sphereCollider = GetComponent<SphereCollider>();
            waitForSeconds = new WaitForSeconds(autoDestroyTime);
        }

        private void OnDestroy()
        {
            StopAllCoroutines();
        }

        private void Start()
        {
            StartCoroutine(nameof(AutoDestroy));
            
            projectileParticle = Instantiate(projectileParticle, transform.position, transform.rotation, transform) as GameObject;
            projectileParticle.transform.parent = transform;
            if (muzzleParticle)
            {
                muzzleParticle = Instantiate(muzzleParticle, transform.position, transform.rotation, transform) as GameObject;
                Destroy(muzzleParticle, 1.5f); // 2nd parameter is lifetime of effect in seconds
            }
        }
		
        private void FixedUpdate()
        {	
			if (rb.velocity.magnitude != 0)
			{
			    transform.rotation = Quaternion.LookRotation(rb.velocity); // Sets rotation to look at direction of movement
			}
			
            float radius; // Sets the radius of the collision detection
            if (sphereCollider)
                radius = sphereCollider.radius;
            else
                radius = colliderRadius;

            var direction = rb.velocity; // Gets the direction of the projectile, used for collision detection
            if (rb.useGravity)
                direction += Physics.gravity * Time.deltaTime; // Accounts for gravity if enabled
            direction = direction.normalized;

            detectionDistance = rb.velocity.magnitude * Time.deltaTime; // Distance of collision detection for this frame
            
            if (Physics.SphereCast(transform.position, radius, direction, out hit, detectionDistance, targetLayer)) // Checks if collision will happen
            {
                DestroyParticle();

                hit.transform.GetComponent<IDamageable>()?.TakeDamage(power);
            }
        }

        public void DestroyParticle()
        {
            transform.position = hit.point + (hit.normal * collideOffset); // Move projectile to point of collision
            var impactP = Instantiate(impactParticle, transform.position, Quaternion.FromToRotation(Vector3.up, hit.normal), transform) as GameObject; // Spawns impact effect

            var trails = GetComponentsInChildren<ParticleSystem>(); // Gets a list of particle systems, as we need to detach the trails
            //Component at [0] is that of the parent i.e. this object (if there is any)
            for (var i = 1; i < trails.Length; i++) // Loop to cycle through found particle systems
            {
                var trail = trails[i];

                if (trail.gameObject.name.Contains("Trail"))
                {
                    trail.transform.SetParent(null); // Detaches the trail from the projectile
                    Destroy(trail.gameObject, 2f); // Removes the trail after seconds
                }
            }

            Destroy(projectileParticle, 3f); // Removes particle effect after delay
            Destroy(impactP, 3.5f); // Removes impact effect after delay
            Destroy(gameObject); // Removes the projectile
        }

        private IEnumerator AutoDestroy()
        {
            yield return waitForSeconds;

            if (gameObject != null)
            {
                Destroy(gameObject);
            }
        }

        public void SetPower(float value) => power = value;
    }
}