using UnityEngine;

/// <summary>
/// Attach to each selectable layer child.
/// Supports:
///   • Single touch / mouse drag  → rotate
///   • Two-finger pinch           → scale (zoom in/out)
///   • Two-finger drag            → pan (move)
///   • Mouse scroll wheel         → scale (zoom in/out)
///   • Animator on this object    → animation plays and can be scaled/moved freely
/// </summary>
public class LayerInteract : MonoBehaviour
{
    // ---------------------------------------------------------------
    // Inspector
    // ---------------------------------------------------------------
    [Header("Layer Info")]
    public string   layerTitle       = "Nama Layer";
    [TextArea]
    public string   layerDescription = "Deskripsi layer ini...";
    public int      narasiClipIndex  = -1; // index AudioClip di LayerInfoPanel.narasiClips

    [Header("Interaction Settings")]
    [Tooltip("Rotation speed multiplier for touch/mouse drag.")]
    public float rotateSpeed   = 0.3f;
    [Tooltip("Pinch zoom sensitivity.")]
    public float pinchSensitivity = 0.005f;
    [Tooltip("Pan (two-finger move) sensitivity.")]
    public float panSensitivity  = 0.01f;
    [Tooltip("Mouse scroll wheel sensitivity.")]
    public float scrollSensitivity = 0.3f;
    [Tooltip("Min / max scale multiplier relative to original scale.")]
    public Vector2 scaleRange = new Vector2(0.4f, 3.0f);

    // ---------------------------------------------------------------
    // Private state
    // ---------------------------------------------------------------
    private LayerSelector selector;
    private bool isSelected   = false;
    private bool justSelected = false;   // skip first-frame drag after tap

    // Scale tracking
    private Vector3 originalScale;       // scale when SetSelected(true) is called
    private float   scaleMultiplier = 1f;

    // Pinch state
    private float lastPinchDist  = 0f;
    private bool  pinchInitialized = false;

    // Animator support
    private Animator animator;

    // ---------------------------------------------------------------
    // Unity lifecycle
    // ---------------------------------------------------------------
    void Awake()
    {
        // Cache Animator if present (e.g., tectonic plate animation)
        animator = GetComponent<Animator>();
        // Ensure a collider exists for raycasting
        if (GetComponent<Collider>() == null)
            gameObject.AddComponent<SphereCollider>();
    }

    void Start()
    {
        selector = GetComponentInParent<LayerSelector>();
        if (selector == null)
            Debug.LogError($"[LayerInteract] {gameObject.name}: LayerSelector not found in parent!");
    }

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

        HandleTouchInput();
        HandleMouseInput();

        justSelected = false;
    }

    // ---------------------------------------------------------------
    // Input handling
    // ---------------------------------------------------------------

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

        if (touchCount == 1)
        {
            pinchInitialized = false;   // reset pinch when back to one finger

            Touch t = Input.GetTouch(0);
            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;
            }

            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 HandleMouseInput()
    {
        // Rotate with left mouse button drag (skip the frame of selection)
        if (Input.GetMouseButton(0) && !justSelected)
        {
            float dx = Input.GetAxis("Mouse X");
            float dy = Input.GetAxis("Mouse Y");
            RotateObject(dx * (1f / rotateSpeed), dy * (1f / rotateSpeed));
            // Note: Mouse X/Y are already in a "delta" unit, so we scale them separately
        }

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

    // ---------------------------------------------------------------
    // Helpers
    // ---------------------------------------------------------------

    /// <param name="deltaX">Horizontal delta in screen pixels (or axis value).</param>
    /// <param name="deltaY">Vertical delta in screen pixels (or axis value).</param>
    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;
    }

    // ---------------------------------------------------------------
    // Selection API
    // ---------------------------------------------------------------

    void OnMouseDown() { TapSelect(); }

    public void TapSelect()
    {
        if (selector == null)
        {
            selector = GetComponentInParent<LayerSelector>();
            if (selector == null) return;
        }

        // Only select if nothing is currently selected
        if (selector.selectedLayer == null)
        {
            selector.SelectLayer(this.transform);
            justSelected = true;
        }
    }

    public void SetSelected(bool val)
    {
        isSelected = val;

        if (val)
        {
            originalScale    = transform.localScale;
            if (originalScale == Vector3.zero) originalScale = Vector3.one;
            scaleMultiplier  = 1f;
            pinchInitialized = false;

            // Resume animation if present
            if (animator != null) animator.enabled = true;
        }
        else
        {
            scaleMultiplier  = 1f;
            pinchInitialized = false;

        }
    }
}