using System.Collections;
using UnityEngine;
using UnityEngine.Pool;
using UnityEngine.Rendering.Universal;

public class BulletHoleSpawner : MonoBehaviour {
    #region Fields

    IObjectPool<DecalProjector> decalPool;
    
    [Tooltip("Material to use for the bullet hole decal.")]
    public Material decalMaterial;
    
    [Tooltip("Layers that can receive bullet hole decals.")]
    public LayerMask decalLayers = -1;
    
    [Tooltip("Size of each decal in world units (x = width, y = height, z = depth).")]
    public Vector3 decalSize = new Vector3(0.5f, 0.5f, 0.5f);
    
    [Tooltip("Duration in seconds for the decal to fade out before being returned to the pool.")]
    public float fadeDuration = 5f;
    
    Camera cam;

    #endregion

    void Start() {
        cam = Camera.main;
        
        decalPool = new ObjectPool<DecalProjector>(
            createFunc: () => {
                GameObject go = new GameObject("DecalProjector");
                DecalProjector dp = go.AddComponent<DecalProjector>();
                go.transform.parent = this.transform;
                dp.material = decalMaterial;
                dp.fadeFactor = 1f;
                dp.fadeScale = 0.95f;
                dp.startAngleFade = 0f;
                dp.endAngleFade = 30f;
                return dp;
            },
            actionOnGet: dp => dp.gameObject.SetActive(true),
            actionOnRelease: dp => dp.gameObject.SetActive(false),
            actionOnDestroy: dp => Destroy(dp.gameObject),
            collectionCheck: false,
            defaultCapacity: 10,
            maxSize: 20
        );
    }

    void SpawnDecal(RaycastHit hit) {
        DecalProjector projector = decalPool.Get();
        
        projector.transform.position = hit.point + hit.normal * 0.01f;
        
        Quaternion normalRotation = Quaternion.LookRotation(-hit.normal, Vector3.up);
        Quaternion randomRotation = Quaternion.Euler(0, 0, Random.Range(0f, 360f));
        projector.transform.rotation = normalRotation * randomRotation;
        
        projector.size = decalSize;
        
        StartCoroutine(FadeAndRelease(projector, fadeDuration));
    }

    void Update() {
        if (Input.GetMouseButtonDown(0)) {
            Ray ray = cam.ScreenPointToRay(Input.mousePosition);

            if (Physics.SphereCast(ray, decalSize.x * 0.3f, out RaycastHit hitInfo, Mathf.Infinity, decalLayers)) {
                SpawnDecal(hitInfo);
            }
        }
    }

    IEnumerator FadeAndRelease(DecalProjector projector, float duration) {
        float time = 0f;
        float initialFade = projector.fadeFactor;

        while (time < duration) {
            if (projector == null) yield break;
            
            time += Time.deltaTime;
            float t = time / duration;
            projector.fadeFactor = Mathf.Lerp(initialFade, 0f, t);
            yield return null;
        }

        if (projector != null) {
            projector.fadeFactor = initialFade;
            decalPool.Release(projector);
        }
    }
}