using UnityEngine;

[ExecuteAlways]
[RequireComponent(typeof(LineRenderer))]
public class LaserBeam : MonoBehaviour
{
    [Header("Laser Settings")]
    public float maxDistance = 20f;
    public LayerMask collisionMask = ~0;

    [Header("Laser Appearance")]
    public Color laserColor = Color.red;
    public float laserWidth = 0.05f;
    public float emissionStrength = 5f;
    public float scrollSpeed = 1f;

    private LineRenderer line;

    void Reset()
    {
        SetupLaserRenderer();
    }

    void Awake()
    {
        SetupLaserRenderer();
    }

    void Update()
    {
        if (!line) return;

        Vector3 start = transform.position;
        Vector3 direction = transform.forward;

        RaycastHit hit;
        Vector3 end;

        if (Physics.Raycast(start, direction, out hit, maxDistance, collisionMask))
        {
            end = hit.point;
        }
        else
        {
            end = start + direction * maxDistance;
        }

        line.SetPosition(0, start);
        line.SetPosition(1, end);
    }

    [ContextMenu("Setup Laser Renderer")]
    public void SetupLaserRenderer()
    {
        line = GetComponent<LineRenderer>();
        if (line == null)
            line = gameObject.AddComponent<LineRenderer>();

        line.positionCount = 2;
        line.useWorldSpace = true;
        line.loop = false;
        line.shadowCastingMode = UnityEngine.Rendering.ShadowCastingMode.Off;
        line.receiveShadows = false;
        line.widthMultiplier = laserWidth;

        // Try to load the custom shader
        Shader laserShader = Shader.Find("Custom/EmissiveLaser");
        if (laserShader != null)
        {
            Material laserMat = new Material(laserShader);
            laserMat.SetColor("_Color", laserColor);
            laserMat.SetFloat("_Emission", emissionStrength);
            laserMat.SetFloat("_ScrollSpeed", scrollSpeed);
            line.material = laserMat;
        }
        else
        {
            Debug.LogWarning("Custom/EmissiveLaser shader not found. Using fallback material.");
            line.material = new Material(Shader.Find("Sprites/Default"));
            line.material.color = laserColor;
        }

        line.startColor = laserColor;
        line.endColor = laserColor;
    }
}