using System;
using System.Collections.Generic;
using UnityEngine.XR.ARSubsystems;

namespace UnityEngine.XR.ARFoundation
{
    /// <summary>
    /// Manages reference points.
    /// </summary>
    /// <remarks>
    /// <para>Use this component to programmatically add, remove, or query for
    /// reference points. Reference points are <c>Pose</c>s in the world
    /// which will be periodically updated by an AR device as its understanding
    /// of the world changes.</para>
    /// <para>Subscribe to changes (added, updated, & removed) via the
    /// <see cref="ARReferencePointManager.referencePointsChanged"/> event.</para>
    /// </remarks>
    /// <seealso cref="ARTrackableManager{TSubsystem, TSubsystemDescriptor, TSessionRelativeData, TTrackable}"/>
    [DisallowMultipleComponent]
    [RequireComponent(typeof(ARSessionOrigin))]
    [HelpURL("https://docs.unity3d.com/Packages/com.unity.xr.arfoundation@3.0/api/UnityEngine.XR.ARFoundation.ARReferencePointManager.html")]
    [Obsolete("ARReferencePointManager has been deprecated. Use ARAnchorManager instead (UnityUpgradable) -> UnityEngine.XR.ARFoundation.ARAnchorManager", true)]
    public sealed class ARReferencePointManager : ARTrackableManager<
        XRReferencePointSubsystem,
        XRReferencePointSubsystemDescriptor,
        XRReferencePoint,
        ARReferencePoint>
    {
        [SerializeField]
        [Tooltip("If not null, instantiates this prefab for each instantiated reference point.")]
        GameObject m_ReferencePointPrefab;

        /// <summary>
        /// Getter/setter for the Reference Point Prefab.
        /// </summary>

        [Obsolete("ARReferencePointManger.referencePointPrefab has been renamed. Use ARAnchorManager.anchorPrefab instead (UnityUpgradable) -> UnityEngine.XR.ARFoundation.ARAnchorManager.anchorPrefab", true)]
        public GameObject referencePointPrefab
        {
            get { return m_ReferencePointPrefab; }
            set { m_ReferencePointPrefab = value; }
        }

        /// <summary>
        /// Invoked once per frame to communicate changes to reference points, including
        /// new reference points, the update of existing reference points, and the removal
        /// of previously existing reference points.
        /// </summary>
        [Obsolete("ARReferencePointManger.referencePointsChanged has been renamed. Use ARAnchorManager.anchorsChanged instead (UnityUpgradable) -> UnityEngine.XR.ARFoundation.ARAnchorManager.anchorsChanged", true)]
        public event Action<ARReferencePointsChangedEventArgs> referencePointsChanged;

        /// <summary>
        /// Attempts to add an <see cref="ARReferencePoint"/> with the given <c>Pose</c>.
        /// </summary>
        /// <remarks>
        /// If <see cref="ARTrackableManager{TSubsystem, TSubsystemDescriptor, TSessionRelativeData, TTrackable}.prefab"/>
        /// is not null, a new instance of that prefab will be instantiated. Otherwise, a
        /// new <c>GameObject</c> will be created. In either case, the resulting
        /// <c>GameObject</c> will have an <see cref="ARReferencePoint"/> component on it.
        /// </remarks>
        /// <param name="pose">The pose, in Unity world space, of the <see cref="ARReferencePoint"/>.</param>
        /// <returns>A new <see cref="ARReferencePoint"/> if successful, otherwise <c>null</c>.</returns>
        [Obsolete("ARReferencePointManger.AddReferencePoint() has been deprecated. Use ARAnchorManager.AddAnchor() instead (UnityUpgradable) -> UnityEngine.XR.ARFoundation.ARAnchorManager.AddAnchor(*)", true)]        
        public ARReferencePoint AddReferencePoint(Pose pose)
        {
            if (!enabled)
                throw new InvalidOperationException("Cannot create a reference point from a disabled reference point manager.");

            if (subsystem == null)
                throw new InvalidOperationException("Reference point manager has no subsystem. Enable the manager first.");

            var sessionRelativePose = sessionOrigin.trackablesParent.InverseTransformPose(pose);

            // Add the reference point to the XRReferencePointSubsystem
            XRReferencePoint sessionRelativeData;
            if (subsystem.TryAddReferencePoint(sessionRelativePose, out sessionRelativeData))
                return CreateTrackableImmediate(sessionRelativeData);

            return null;
        }

        /// <summary>
        /// Attempts to create a new reference point that is attached to an existing <see cref="ARPlane"/>.
        /// </summary>
        /// <param name="plane">The <see cref="ARPlane"/> to which to attach.</param>
        /// <param name="pose">The initial <c>Pose</c>, in Unity world space, of the reference point.</param>
        /// <returns>A new <see cref="ARReferencePoint"/> if successful, otherwise <c>null</c>.</returns>
        [Obsolete("ARReferencePointManger.AttachReferencePoint() has been deprecated. Use ARAnchorManager.AttachAnchor() instead (UnityUpgradable) -> UnityEngine.XR.ARFoundation.ARAnchorManager.AttachAnchor(*)", true)]        
        public ARReferencePoint AttachReferencePoint(ARPlane plane, Pose pose)
        {
            if (!enabled)
                throw new InvalidOperationException("Cannot create a reference point from a disabled reference point manager.");

            if (subsystem == null)
                throw new InvalidOperationException("Reference point manager has no subsystem. Enable the manager first.");

            if (plane == null)
                throw new ArgumentNullException("plane");

            var sessionRelativePose = sessionOrigin.trackablesParent.InverseTransformPose(pose);
            XRReferencePoint sessionRelativeData;
            if (subsystem.TryAttachReferencePoint(plane.trackableId, sessionRelativePose, out sessionRelativeData))
                return CreateTrackableImmediate(sessionRelativeData);

            return null;
        }

        /// <summary>
        /// Attempts to remove an <see cref="ARReferencePoint"/>.
        /// </summary>
        /// <param name="referencePoint">The reference point you wish to remove.</param>
        /// <returns>
        /// <c>True</c> if the reference point was successfully removed.
        /// <c>False</c> usually means the reference point is not longer tracked by the system.
        /// </returns>
        [Obsolete("ARReferencePointManger.RemoveReferencePoint() has been deprecated. Use ARAnchorManager.RemoveAnchor() instead (UnityUpgradable) -> UnityEngine.XR.ARFoundation.ARAnchorManager.RemoveAnchor(*)", true)]        
        public bool RemoveReferencePoint(ARReferencePoint referencePoint)
        {
            if (!enabled)
                throw new InvalidOperationException("Cannot create a reference point from a disabled reference point manager.");

            if (subsystem == null)
                throw new InvalidOperationException("Reference point manager has no subsystem. Enable the manager first.");

            if (referencePoint == null)
                throw new ArgumentNullException("referencePoint");

            if (subsystem.TryRemoveReferencePoint(referencePoint.trackableId))
            {
                DestroyPendingTrackable(referencePoint.trackableId);
                return true;
            }

            return false;
        }

        /// <summary>
        /// Gets the <see cref="ARReferencePoint"/> with given <paramref name="trackableId"/>,
        /// or <c>null</c> if it does not exist.
        /// </summary>
        /// <param name="trackableId">The <see cref="TrackableId"/> of the <see cref="ARReferencePoint"/> to retrieve.</param>
        /// <returns>The <see cref="ARReferencePoint"/> with <paramref name="trackableId"/> or <c>null</c> if it does not exist.</returns>
        [Obsolete("ARReferencePointManger.GetReferencePoint() has been deprecated. Use ARAnchorManager.GetAnchor() instead (UnityUpgradable) -> UnityEngine.XR.ARFoundation.ARAnchorManager.GetAnchor(*)", true)]        
        public ARReferencePoint GetReferencePoint(TrackableId trackableId)
        {
            ARReferencePoint referencePoint;
            if (m_Trackables.TryGetValue(trackableId, out referencePoint))
                return referencePoint;

            return null;
        }

        protected override GameObject GetPrefab()
        {
            return m_ReferencePointPrefab;
        }

        protected override string gameObjectName
        {
            get { return "ReferencePoint"; }
        }

        protected override void OnTrackablesChanged(
            List<ARReferencePoint> addedPoints,
            List<ARReferencePoint> updatedPoints,
            List<ARReferencePoint> removedPoints)
        {
            if (referencePointsChanged != null)
            {
                referencePointsChanged(
                    new ARReferencePointsChangedEventArgs(
                        addedPoints,
                        updatedPoints,
                        removedPoints));
            }
        }
    }
}