using UnityEngine;
using UnityEngine.EventSystems;

/// <summary>
/// Fitur:
///   • Single touch / mouse drag  → rotate
///   • Two-finger pinch           → zoom in/out
///   • Two-finger drag            → pan/geser
///   • Mouse scroll wheel         → zoom in/out
/// </summary>
public class FreeInteract : MonoBehaviour
{
    [Header("Interaction Settings")]
    public float rotateSpeed      = 0.3f;
    public float pinchSensitivity = 0.005f;
    public float panSensitivity   = 0.01f;
    public float scrollSensitivity = 0.3f;
    public Vector2 scaleRange     = new Vector2(0.4f, 3.0f);

    private Vector3 originalScale;
    private float   scaleMultiplier = 1f;

    private float lastPinchDist    = 0f;
    private bool  pinchInitialized = false;
    private bool  isDragging       = false;

    void Start()
    {
        originalScale = transform.localScale;
        if (originalScale == Vector3.zero) originalScale = Vector3.one;
    }

    void Update()
    {
        // Abaikan kalau klik/tap kena UI
        if (EventSystem.current != null && EventSystem.current.IsPointerOverGameObject()) return;

        HandleTouch();
        HandleMouse();
    }

    void HandleTouch()
    {
        int touchCount = Input.touchCount;

        if (touchCount == 1)
        {
            pinchInitialized = false;
            Touch t = Input.GetTouch(0);

            if (EventSystem.current != null && EventSystem.current.IsPointerOverGameObject(t.fingerId)) return;

            if (t.phase == TouchPhase.Moved)
                RotateObject(t.deltaPosition.x, t.deltaPosition.y);
        }
        else if (touchCount >= 2)
        {
            Touch t1 = Input.GetTouch(0);
            Touch t2 = Input.GetTouch(1);

            // Pinch zoom
            float currentDist = Vector2.Distance(t1.position, t2.position);
            if (!pinchInitialized || t1.phase == TouchPhase.Began || t2.phase == TouchPhase.Began)
            {
                lastPinchDist    = currentDist;
                pinchInitialized = true;
            }
            else
            {
                float delta = currentDist - lastPinchDist;
                ApplyScaleDelta(delta * pinchSensitivity);
                lastPinchDist = currentDist;
            }

            // Two-finger pan (hanya kalau arah sama)
            if (t1.phase == TouchPhase.Moved || t2.phase == TouchPhase.Moved)
            {
                Vector2 avgDelta = (t1.deltaPosition + t2.deltaPosition) * 0.5f;
                if (Vector2.Dot(t1.deltaPosition.normalized, t2.deltaPosition.normalized) > 0.5f)
                {
                    Vector3 worldDelta = Camera.main.transform.TransformDirection(
                        new Vector3(avgDelta.x, avgDelta.y, 0f) * panSensitivity
                    );
                    transform.position += worldDelta;
                }
            }
        }
    }

    void HandleMouse()
    {
        if (Input.GetMouseButtonDown(0)) isDragging = true;
        if (Input.GetMouseButtonUp(0))   isDragging = false;

        if (isDragging && Input.GetMouseButton(0))
        {
            float dx = Input.GetAxis("Mouse X");
            float dy = Input.GetAxis("Mouse Y");
            RotateObject(dx * 10f, dy * 10f); // *10 karena Mouse X satuan berbeda dari pixel
        }

        float scroll = Input.GetAxis("Mouse ScrollWheel");
        if (Mathf.Abs(scroll) > 0.001f)
            ApplyScaleDelta(scroll * scrollSensitivity);
    }

    void RotateObject(float deltaX, float deltaY)
    {
        float rotY = -deltaX * rotateSpeed;
        float rotX =  deltaY * rotateSpeed;
        transform.Rotate(Camera.main.transform.up,    rotY, Space.World);
        transform.Rotate(Camera.main.transform.right, rotX, Space.World);
    }

    void ApplyScaleDelta(float delta)
    {
        scaleMultiplier = Mathf.Clamp(scaleMultiplier + delta, scaleRange.x, scaleRange.y);
        transform.localScale = originalScale * scaleMultiplier;
    }
}