using System;
using System.Collections.Generic;
#if UNITY_EDITOR
using UnityEditor;
#endif
using UnityEngine;
using UnityEngine.Rendering;

namespace Assets.ThoMagic.Renderer
{
    [ExecuteAlways]
    [DisallowMultipleComponent]
    public class TileObjectRenderer : MonoBehaviour
    {
        /// <summary>
        /// This event is called after this detail renderer is initialized.
        /// </summary>
        public event EventHandler<TileObjectRenderer> Initialized;

        [NonSerialized]
        private bool isInitialized = false;


        [Tooltip("Delay the initialization of ThoMagic Renderer until the first LateUpdate event")]
        [SerializeField]
        private bool _delayInitialize = true;

        private bool CanInitialize() => isActiveAndEnabled;

        [NonSerialized]
        private TileObjectStreamer tileObjectStreamer;

        private void Awake()
        {
            //Load resources

        }

        private void OnEnable()
        {
            if (_delayInitialize && Application.isPlaying || (isInitialized || !CanInitialize()))
                return;
            Initialize();
        }

        private void Start()
        {
            if (_delayInitialize && Application.isPlaying || (isInitialized || !CanInitialize()))
                return;
            Initialize();
        }

        private void OnDisable()
        {
            if (!isInitialized)
                return;
            Destroy();
        }

        private void OnDestroy()
        {
            if (!isInitialized)
                return;
            Destroy();
        }

        private void Initialize()
        {
            if (isInitialized)
                return;

            if (tileObjectStreamer == null)
                tileObjectStreamer = new TileObjectStreamer(gameObject);

            tileObjectStreamer?.Load();          

            if (Initialized != null)
                Initialized(this, this);

            isInitialized = true;

#if UNITY_EDITOR
            SceneView.lastActiveSceneView?.Repaint();

            RenderPipelineManager.endContextRendering -= OnBeginContextRendering;
            RenderPipelineManager.endContextRendering += OnBeginContextRendering;
#endif
        }

#if UNITY_EDITOR
        private void OnBeginContextRendering(
          ScriptableRenderContext context,
          List<Camera> cameras)
        {
            //LateUpdate();
        }
#endif
        private void LateUpdate()
        {
            if (!isInitialized && CanInitialize())
                Initialize();

            if (!isInitialized)
                return;

            tileObjectStreamer?.LateUpdate();
        }

        private void Destroy()
        {
            if (!isInitialized)
                return;

            try
            {
                tileObjectStreamer?.Destroy();
            }
            catch { }
            tileObjectStreamer = null;

            isInitialized = false;

#if UNITY_EDITOR
            RenderPipelineManager.endContextRendering -= OnBeginContextRendering;
#endif
        }

        private void OnTransformChildrenChanged()
        {
            tileObjectStreamer?.MarkDirty();
        }
    }
}