using System;
using UnityEngine;
using UnityEngine.XR.ARFoundation;
#if UNITY_IOS
using UnityEngine.XR.ARKit;
#endif

/// <summary>
/// This example shows how to activate the [ARCoachingOverlayView](https://developer.apple.com/documentation/arkit/arcoachingoverlayview)
/// </summary>
[RequireComponent(typeof(ARSession))]
public class ARKitCoachingOverlay : MonoBehaviour
{
    // Duplicate the ARCoachingGoal enum so that we can use it on a serialized field
    enum CoachingGoal
    {
        Tracking,
        HorizontalPlane,
        VerticalPlane,
        AnyPlane
    }

    [SerializeField]
    [Tooltip("The coaching goal associated with the coaching overlay.")]
#if !UNITY_IOS
    #pragma warning disable CS0414
#endif
    CoachingGoal m_Goal = CoachingGoal.Tracking;
#if !UNITY_IOS
    #pragma warning restore CS0414
#endif

#if UNITY_IOS
    /// <summary>
    /// The [ARCoachingGoal](https://developer.apple.com/documentation/arkit/arcoachinggoal) associated with the coaching overlay
    /// </summary>
    public ARCoachingGoal goal
    {
        get
        {
            if (GetComponent<ARSession>().subsystem is ARKitSessionSubsystem sessionSubsystem)
            {
                return sessionSubsystem.coachingGoal;
            }
            else
            {
                return (ARCoachingGoal)m_Goal;
            }
        }

        set
        {
            m_Goal = (CoachingGoal)value;
            if (supported && GetComponent<ARSession>().subsystem is ARKitSessionSubsystem sessionSubsystem)
            {
                sessionSubsystem.coachingGoal = value;
            }
        }
    }
#endif

    [SerializeField]
    [Tooltip("Whether the coaching overlay activates automatically.")]
    bool m_ActivatesAutomatically = true;

    /// <summary>
    /// Whether the coaching overlay activates automatically
    /// </summary>
    public bool activatesAutomatically
    {
        get
        {
#if UNITY_IOS
            if (supported && GetComponent<ARSession>().subsystem is ARKitSessionSubsystem sessionSubsystem)
            {
                return sessionSubsystem.coachingActivatesAutomatically;
            }
#endif
            return m_ActivatesAutomatically;
        }

        set
        {
            m_ActivatesAutomatically = value;

#if UNITY_IOS
            if (supported && GetComponent<ARSession>().subsystem is ARKitSessionSubsystem sessionSubsystem)
            {
                sessionSubsystem.coachingActivatesAutomatically = value;
            }
#endif
        }
    }

    /// <summary>
    /// Whether the [ARCoachingGoal](https://developer.apple.com/documentation/arkit/arcoachinggoal) is supported.
    /// </summary>
    public bool supported
    {
        get
        {
#if UNITY_IOS
            return ARKitSessionSubsystem.coachingOverlaySupported;
#else
            return false;
#endif
        }
    }

    void OnEnable()
    {
#if UNITY_IOS
        if (supported && GetComponent<ARSession>().subsystem is ARKitSessionSubsystem sessionSubsystem)
        {
            sessionSubsystem.coachingGoal = (ARCoachingGoal)m_Goal;
            sessionSubsystem.coachingActivatesAutomatically = m_ActivatesAutomatically;
        }
        else
#endif
        {
            Debug.LogError("ARCoachingOverlayView is not supported by this device.");
        }
    }

    /// <summary>
    /// Activates the [ARCoachingGoal](https://developer.apple.com/documentation/arkit/arcoachinggoal)
    /// </summary>
    /// <param name="animated">If <c>true</c>, the coaching overlay is animated, e.g. fades in. If <c>false</c>, the coaching overlay appears instantly, without any transition.</param>
    public void ActivateCoaching(bool animated)
    {
#if UNITY_IOS
        if (supported && GetComponent<ARSession>().subsystem is ARKitSessionSubsystem sessionSubsystem)
        {
            sessionSubsystem.SetCoachingActive(true, animated ? ARCoachingOverlayTransition.Animated : ARCoachingOverlayTransition.Instant);
        }
        else
#endif
        {
            throw new NotSupportedException("ARCoachingOverlay is not supported");
        }
    }
}