using System;
using UnityEngine;
using UnityEngine.UI;
using UnityEngine.XR.ARFoundation;

public class TestBodyAnchorScale : MonoBehaviour
{
    [SerializeField]
    [Tooltip("The ARHumanBodyManager which will produce frame events.")]
    ARHumanBodyManager m_HumanBodyManager;

     /// <summary>
    /// Get or set the <c>ARHumanBodyManager</c>.
    /// </summary>
    public ARHumanBodyManager humanBodyManager
    {
        get { return m_HumanBodyManager; }
        set { m_HumanBodyManager = value; }
    }

    [SerializeField]
    Text m_ImageInfo;

    /// <summary>
    /// The UI Text used to display information about the image on screen.
    /// </summary>
    public Text imageInfo
    {
        get { return m_ImageInfo; }
        set { m_ImageInfo = value; }
    }

    void OnEnable()
    {
        Debug.Assert(m_ImageInfo != null, "text field is required");
        m_ImageInfo.enabled = true;

        Debug.Assert(m_HumanBodyManager != null, "Human body manager is required.");
        m_HumanBodyManager.humanBodiesChanged += OnHumanBodiesChanged;
    }

    void OnDisable()
    {
        Debug.Assert(m_ImageInfo != null, "text field is required");
        m_ImageInfo.enabled = false;

        Debug.Assert(m_HumanBodyManager != null, "Human body manager is required.");
        m_HumanBodyManager.humanBodiesChanged -= OnHumanBodiesChanged;
    }

    void OnHumanBodiesChanged(ARHumanBodiesChangedEventArgs eventArgs)
    {
        // Currently, the ARKit provider only ever produces one body anchor, so just reference the first
        float scale = ((eventArgs.added.Count > 0) ? eventArgs.added[0].estimatedHeightScaleFactor
                       : ((eventArgs.updated.Count > 0) ? eventArgs.updated[0].estimatedHeightScaleFactor
                          : Single.NaN));

        Debug.Assert(m_ImageInfo != null, "text field is required");
        m_ImageInfo.text = scale.ToString("F10");
    }
}