using UnityEngine;

[RequireComponent(typeof(Rigidbody))]
public class SpringyButtonPhysics : MonoBehaviour {
    public Transform buttonDirectionRoot;

    public float minX = 0f;
    public float maxX = 0f;
    public float minY = 0f;
    public float maxY = 0f;
    public float minZ = 0.005f;
    public float maxZ = 0f;


    [Header("Spring Settings")]
    public float springForce = 300f;   // how strong it returns
    public float damping = 8f;        // prevents vibration

    private Rigidbody rb;
    private Vector3 restLocalPos;

    void Start()
    {
        rb = GetComponent<Rigidbody>();
        rb.useGravity = false;

        // initial local rest position
        restLocalPos = buttonDirectionRoot.InverseTransformPoint(transform.position);
    }

    void FixedUpdate()
    {
        // 1. Local pos
        Vector3 localPos = buttonDirectionRoot.InverseTransformPoint(transform.position);

        // 2. Spring in LOCAL space
        Vector3 spring = (restLocalPos - localPos) * springForce;

        // 3. Damping also must be in LOCAL space!!
        Vector3 localVelocity = buttonDirectionRoot.InverseTransformDirection(rb.velocity);
        localVelocity *= damping;
        spring -= localVelocity;

        // 4. Convert spring to WORLD space
        Vector3 worldSpring = buttonDirectionRoot.TransformDirection(spring);

        // 5. Apply
        rb.AddForce(worldSpring, ForceMode.Acceleration);

        // --- 3. Compute new local pos after physics ---
        Vector3 newLocalPos = buttonDirectionRoot.InverseTransformPoint(transform.position);
        //Debug.Log(spring);
        // --- 4. Clamp to allowed ranges ---
        newLocalPos.x = Mathf.Clamp(newLocalPos.x, minX, maxX);
        newLocalPos.y = Mathf.Clamp(newLocalPos.y, minY, maxY);
        newLocalPos.z = Mathf.Clamp(newLocalPos.z, minZ, maxZ);

        // --- 5. Convert back to world and move via Rigidbody ---
        Vector3 worldPos = buttonDirectionRoot.TransformPoint(newLocalPos);
        rb.MovePosition(worldPos);
    }
}