/*************************************************************************
 *  Copyright © 2018-2023 Liwen All rights reserved.
 *------------------------------------------------------------------------
 *  File         :  LoadPagedLodFromFileManager.cs
 *  Description  :  Load root tile file and initialize child lod config.
 *------------------------------------------------------------------------
 *  Author       :  Liwen
 *  Version      :  1.0.0
 *  Date         :  1/5/2019
 *  Description  :  Initial development version.
 *************************************************************************/

using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using System.IO;
using System;
using UnityEngine.EventSystems;
using UnityEngine.Scripting;
using System.Runtime.InteropServices;
using System.Runtime.Serialization.Formatters.Binary;

namespace AIPagedLod
{
    [System.Serializable]
    public class LoadPagedLodFromFileConfig
    {
        /////////////////////////////editor parameter///////////////////////
        public string mDataName = string.Empty;
        public string mDataPath = string.Empty;
        public int mStartLevel = -1;
        //public int mMeshLayer = -1;
        public int mLoadPagedLodCount = 6;
        public bool mLoadStartLevelFlag = false;
        public int mStartLoadLevel = 17;
        public bool mIsDaJiangData = false;
        public bool mIsGenerateCollider = false;
        /////////////////////////////runtime parameter///////////////////////
        public bool mIsUpdate = true;
        public string mBaseUrl;
    }

    public class LoadPagedLodFromFileManager : MonoBehaviour
    {
        public LoadPagedLodFromFileConfig mConfig = new LoadPagedLodFromFileConfig();
        public List<PagedLod> mPagedLodList = null;
        public static Vector3 mCameraPosition = Vector3.zero;

        private void Start()
        {
        }

        void InitPagedLodList()
        {
            mPagedLodList = new List<PagedLod>(GetComponentsInChildren<PagedLod>(true));
            for (int i = 0; i < mPagedLodList.Count; ++i)
            {
#if  !UNITY_WEBGL && UNITY_ANDROID
                if (PagedLodConfig.mInstance.mTileDataType == TileDataType.B3DM)
                {
                    mPagedLodList[i].LoadTileSetJsonFile();
                }
#endif
                mPagedLodList[i].mIsRootTile = true;
                mPagedLodList[i].RecaculateBounds();
                mPagedLodList[i].InitBasicInfoDictFromList();
            }
        }

        public string GetDataPath()
        {
            if (PagedLodConfig.mInstance != null && PagedLodConfig.mInstance.mDataPathDict.ContainsKey(mConfig.mDataName))
            {
                return PagedLodConfig.mInstance.mDataPathDict[mConfig.mDataName].mDataPath;
            }
            string dataPath = mConfig.mDataPath;
            if(!Directory.Exists(dataPath)) //数据路径不存在则停止更新
            {
                mConfig.mIsUpdate = false;
            }
            return dataPath;
        }

        void Update()
        {
            if (mConfig.mIsUpdate)
            {
                if (mPagedLodList.Count == 0)
                {
                    InitPagedLodList();
                }

                UpdatePagedLod(mPagedLodList);
            }
        }

        private void LateUpdate()
        {
            if (Input.GetKeyDown(KeyCode.Escape))
            {
                Application.Quit();
            }
        }

        public static int SortLodByDistance(PagedLod left, PagedLod right)
        {
            if(left.mIsVisiable && right.mIsVisiable)
            {
                float d1 = Vector3.Distance(left.mWorldCenter, mCameraPosition);
                float d2 = Vector3.Distance(right.mWorldCenter, mCameraPosition);
                if (d1 < d2)
                    return 1;
                else if (d1 > d2)
                    return -1;
                else
                    return 0;
            }
            else
            {
                //根据是否可见    
                if (left.mIsVisiable && !right.mIsVisiable)
                    return 1;
                else if (!right.mIsVisiable && right.mIsVisiable)
                    return -1;
                else
                    return 0;
            }
        }

        public static void UpdatePagedLod(List<PagedLod> pagedLodList)
        {
            mCameraPosition = Camera.main.transform.position;
            if (!PagedLodUpdateController.IsUpdateEnabled()) return;
#if UNITY_WEBGL || UNITY_ANDROID
            pagedLodList.Sort(SortLodByDistance);
            TraverseUpdateDepthFirst(pagedLodList);
#else
            PagedLodThreadPool.RunAsync(() =>
            {
                pagedLodList.Sort(SortLodByDistance);
                PagedLodThreadPool.QueueOnMainThread(() =>
                {
                    TraverseUpdateDepthFirst(pagedLodList);
                });
            });
#endif
        }

        public static void TraverseUpdateBreadthFirst(List<PagedLod> pagedLodList)
        {
            Queue<PagedLod> tileQueue = new Queue<PagedLod>();
            for (int i = 0; i < pagedLodList.Count; ++i)
            {
                tileQueue.Enqueue(pagedLodList[i]);
            }

            while (tileQueue.Count > 0)
            {
                PagedLod currentTile = tileQueue.Dequeue();
                bool isUpdateChild = currentTile.UpdatePagedLod();
                if (isUpdateChild)
                {
                    for (int i = 0; i < currentTile.mChildTileList.Count; ++i)
                    {
                        PagedLod childPagedLod = currentTile.mChildTileList[i].mPagedLod;
                        if (childPagedLod != null)
                        {
                            tileQueue.Enqueue(childPagedLod);
                        }
                    }
                }
            }
        }

        //深度优先遍历四叉树
        public static void TraverseUpdateDepthFirst(List<PagedLod> pagedLodList)
        {
            Stack<PagedLod> tileStack =new Stack<PagedLod>();
            for (int i = 0; i < pagedLodList.Count; ++i)
            {
                tileStack.Push(pagedLodList[i]);
            }
            while (tileStack.Count > 0)
            {
                PagedLod currentTile = tileStack.Pop();
                bool isUpdateChild = currentTile.UpdatePagedLod();
                if (isUpdateChild)
                {
                    for (int i = 0; i < currentTile.mChildTileList.Count; ++i)
                    {
                        PagedLod childPagedLod = currentTile.mChildTileList[i].mPagedLod;
                        if (childPagedLod != null)
                        {
                            tileStack.Push(childPagedLod);
                        }
                    }
                }
            }
        }

        public static int GetTileFileLevel(string tileDirName, string tileFileName)
        {
            string tileFileBaseName = tileFileName.Replace(PagedLodConfig.mInstance.GetFileSufix(), "");
            if (tileFileBaseName == tileDirName) return -1;

            string tempTileDirName = tileDirName + "_";
            if (tileFileBaseName.Contains(tempTileDirName))
            {
                string strLevel = tileFileBaseName.Replace(tempTileDirName, "");
                strLevel = strLevel.Replace("L", "");
                string[] tempArray = strLevel.Split('_');
                if (tempArray.Length > 0)
                {
                    return int.Parse(tempArray[0]);
                }
            }
            return -1;
        }

        public static int GetDataStartLevel(string dataPath)
        {
#if !UNITY_WEBGL && !UNITY_ANDROID
            if (!Directory.Exists(dataPath)) return 0;
            DirectoryInfo dataDir = new DirectoryInfo(dataPath);
            List<DirectoryInfo> dirInfos = new List<DirectoryInfo>(dataDir.GetDirectories());
            foreach (var tileDir in dirInfos)
            {
                foreach (var fileInfo in tileDir.GetFiles("*"+ PagedLodConfig.mInstance.GetFileSufix()))
                {
                    int level = GetTileFileLevel(tileDir.Name, fileInfo.Name);
                    if (level > 0)
                    {
                        return level - 1;
                    }
                }
            }
#endif
            return -1;
        }
        //编辑器初始化加载数据
        //运行时初始化加载数据
        public static PagedLod LoadPagedLod(PagedLodFileLoader loader,Transform parent)
        {
            GameObject tileObj = new GameObject();
            tileObj.name = loader.mTileName;
            tileObj.transform.SetParent(parent);
            tileObj.transform.localPosition = Vector3.zero;
            tileObj.transform.localRotation = Quaternion.identity;
            tileObj.transform.localScale = Vector3.one;

            PagedLod pagedLod = tileObj.AddComponent<PagedLod>();
            pagedLod.mSelfLevel = loader.mLevel;
            pagedLod.mTileDirPath = loader.mTileDirPath;
            pagedLod.LoadRenderNode(loader);         
            return pagedLod;
        }

        public static void GenerateColliderObject(PagedLod pagedLod)
        {
            GameObject tileCollider = new GameObject("TileCollider");
            tileCollider.transform.SetParent(pagedLod.transform);
            tileCollider.transform.localPosition = Vector3.zero;
            tileCollider.transform.localRotation = Quaternion.identity;
            tileCollider.transform.localScale = Vector3.one;
            MeshFilter[] meshFilters = pagedLod.GetComponentsInChildren<MeshFilter>();
            for (int i = 0; i < meshFilters.Length; ++i)
            {
                GameObject meshColliderObj = new GameObject("MeshCollider");
                meshColliderObj.transform.SetParent(tileCollider.transform);
                meshColliderObj.transform.localPosition = Vector3.zero;
                meshColliderObj.transform.localRotation = Quaternion.identity;
                meshColliderObj.transform.localScale = Vector3.one;
                MeshCollider meshCollider = meshColliderObj.AddComponent<MeshCollider>();
                meshCollider.sharedMesh = meshFilters[i].sharedMesh;
                meshColliderObj.layer = PagedLodConfig.mInstance == null ? 8 : PagedLodConfig.mInstance.mMeshLayer;
            }
        }
    }
}