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

namespace UnityEngine.XR.OpenXR.Samples.ControllerSampleXRInput
{
    public class TrackingModeOriginXRInput : MonoBehaviour
    {
        [SerializeField]
        Image m_RecenteredImage;

        [SerializeField]
        Color m_RecenteredOffColor = Color.red;

        [SerializeField]
        Color m_RecenteredColor = Color.green;

        [SerializeField]
        float m_RecenteredColorResetTime = 1.0f;

        float m_LastRecenteredTime;

        [SerializeField]
        TrackingOriginModeFlags m_CurrentTrackingOriginMode;
        public TrackingOriginModeFlags currentTrackingOriginMode { get { return m_CurrentTrackingOriginMode; } }

        [SerializeField]
        Text m_CurrentTrackingOriginModeDisplay;

        [SerializeField]
        TrackingOriginModeFlags m_DesiredTrackingOriginMode;
        public TrackingOriginModeFlags desiredTrackingOriginMode { get { return m_DesiredTrackingOriginMode; } set { m_DesiredTrackingOriginMode = value; } }

        [SerializeField]
        TrackingOriginModeFlags m_SupportedTrackingOriginModes;
        public TrackingOriginModeFlags supportedTrackingOriginModes { get { return m_SupportedTrackingOriginModes; } }

        static List<XRInputSubsystem> s_InputSubsystems = new List<XRInputSubsystem>();

        private void OnEnable()
        {
            SubsystemManager.GetSubsystems(s_InputSubsystems);
            for (int i = 0; i < s_InputSubsystems.Count; i++)
            {
                s_InputSubsystems[i].trackingOriginUpdated += TrackingOriginUpdated;
            }
        }

        private void OnDisable()
        {
            SubsystemManager.GetSubsystems(s_InputSubsystems);
            for (int i = 0; i < s_InputSubsystems.Count; i++)
            {
                s_InputSubsystems[i].trackingOriginUpdated -= TrackingOriginUpdated;
            }
        }

        public void OnDesiredSelectionChanged(int newValue)
        {
            desiredTrackingOriginMode = (TrackingOriginModeFlags)(newValue == 0 ? 0 : (1 << (newValue - 1)));
        }

        private void TrackingOriginUpdated(XRInputSubsystem obj)
        {
            m_LastRecenteredTime = Time.time;
        }

        void Update()
        {
            XRInputSubsystem subsystem = null;

            SubsystemManager.GetSubsystems(s_InputSubsystems);
            if (s_InputSubsystems.Count > 0)
            {
                subsystem = s_InputSubsystems[0];
            }

            m_SupportedTrackingOriginModes = subsystem?.GetSupportedTrackingOriginModes() ?? TrackingOriginModeFlags.Unknown;

            if (m_CurrentTrackingOriginMode != m_DesiredTrackingOriginMode & m_DesiredTrackingOriginMode != TrackingOriginModeFlags.Unknown)
            {
                subsystem?.TrySetTrackingOriginMode(m_DesiredTrackingOriginMode);
            }
            m_CurrentTrackingOriginMode = subsystem?.GetTrackingOriginMode() ?? TrackingOriginModeFlags.Unknown;

            if (m_CurrentTrackingOriginModeDisplay != null)
                m_CurrentTrackingOriginModeDisplay.text = m_CurrentTrackingOriginMode.ToString();

            if (m_RecenteredImage != null)
            {
                float lerp = (Time.time - m_LastRecenteredTime) / m_RecenteredColorResetTime;
                lerp = Mathf.Clamp(lerp, 0.0f, 1.0f);
                m_RecenteredImage.color = Color.Lerp(m_RecenteredColor, m_RecenteredOffColor, lerp);
            }
        }
    }
}