using UnityEngine;

public class RootCrawler : MonoBehaviour
{
    public Transform target;
    public float maxHeight = 2f;
    public float crawlingSpeed = 0.4f;
    public float radius = 0.5f;
    public float rotationSpeed = 5f;
    public float noiseStrength = 0.06f;
    public float noiseFrequency = 1.5f;
    public int resolution = 80;

    private float currentHeight = 0f;
    private float noiseOffset;
    private LineRenderer line;
    private float angleOffset = 0f;

    void Start()
    {
        line = GetComponent<LineRenderer>();
        noiseOffset = Random.Range(0f, 100f);
    }

    void Update()
    {
        if (target == null) 
            return;

        currentHeight += Time.deltaTime * crawlingSpeed;
        currentHeight = Mathf.Clamp(currentHeight, 0f, maxHeight);

        angleOffset += Time.deltaTime * 2f;

        int currentResolution = Mathf.Max(2, Mathf.RoundToInt((currentHeight / maxHeight) * resolution));
        line.positionCount = currentResolution;

        for (int i = 0; i < currentResolution; i++) {
            float t = (float)i / (currentResolution - 1);
            float h = t * currentHeight;
            float angle = t * rotationSpeed * maxHeight / crawlingSpeed + angleOffset;

            float r = Mathf.Lerp(radius, radius * 0.5f, t);

            float noiseX = (Mathf.PerlinNoise(noiseOffset + h * noiseFrequency, 0f) - 0.5f) * noiseStrength;
            float noiseZ = (Mathf.PerlinNoise(0f, noiseOffset + h * noiseFrequency) - 0.5f) * noiseStrength;

            float x = Mathf.Cos(angle) * r + noiseX;
            float z = Mathf.Sin(angle) * r + noiseZ;

            line.SetPosition(i, target.position + new Vector3(x, h - 0.8f, z));
        }
        float rotationMultiplier = 1f - (currentHeight / maxHeight);
        angleOffset += Time.deltaTime * 2f * (rotationMultiplier + 0.1f);
    }
}