using CodeWalker.Core.Utils;
using CodeWalker.World;
using CommunityToolkit.HighPerformance;
using System;
using System.Collections.Concurrent;
using System.Collections.Generic;
using System.Diagnostics;
using System.IO;
using System.Linq;
using System.Runtime.CompilerServices;
using System.Runtime.InteropServices;
using System.Text;
using System.Threading;
using System.Threading.Tasks;
using System.Xml;
using System.Xml.Linq;

namespace CodeWalker.GameFiles
{
    public class RpfManager
    {
        private static RpfManager _instance = new RpfManager();
        public static RpfManager GetInstance()
        {
            return _instance ??= new RpfManager();
        }
        //for caching and management of RPF file data.

        public string Folder { get; private set; }
        public string[] ExcludePaths { get; set; }
        public bool EnableMods { get; set; }
        public bool BuildExtendedJenkIndex { get; set; } = true;
        public event Action<string> UpdateStatus;
        public event Action<string> ErrorLog;

        public List<RpfFile> BaseRpfs { get; private set; }
        public List<RpfFile> ModRpfs { get; private set; }
        public List<RpfFile> DlcRpfs { get; private set; }
        public List<RpfFile> AllRpfs { get; private set; }
        public List<RpfFile> DlcNoModRpfs { get; private set; }
        public List<RpfFile> AllNoModRpfs { get; private set; }
        public Dictionary<string, RpfFile> RpfDict { get; private set; }
        public Dictionary<string, RpfEntry> EntryDict { get; private set; }
        public Dictionary<string, RpfFile> ModRpfDict { get; private set; }
        public Dictionary<string, RpfEntry> ModEntryDict { get; private set; }

        public volatile bool IsInited = false;

        private const int DefaultEntryDictCapacity = 354878;
        private const int DefaultRpfDictCapacity = 4650;

        public void Init(string folder, Action<string> updateStatus, Action<string> errorLog, bool rootOnly = false, bool buildIndex = true)
        {
            using var timer = new DisposableTimer("RpfManager.Init");
            UpdateStatus += updateStatus;
            ErrorLog += errorLog;

            string replpath = folder + "\\";
            var sopt = rootOnly ? SearchOption.TopDirectoryOnly : SearchOption.AllDirectories;
            string[] allfiles = Directory.GetFiles(folder, "*.rpf", sopt);

            BaseRpfs = new List<RpfFile>(1300);
            ModRpfs = new List<RpfFile>(0);
            DlcRpfs = new List<RpfFile>(3500);
            AllRpfs ??= new List<RpfFile>(0);
            DlcNoModRpfs = new List<RpfFile>(3500);
            AllNoModRpfs = new List<RpfFile>(5000);
            RpfDict = new Dictionary<string, RpfFile>(StringComparer.OrdinalIgnoreCase);
            EntryDict = new Dictionary<string, RpfEntry>(StringComparer.OrdinalIgnoreCase);
            ModRpfDict = new Dictionary<string, RpfFile>(StringComparer.OrdinalIgnoreCase);
            ModEntryDict = new Dictionary<string, RpfEntry>(StringComparer.OrdinalIgnoreCase);

            FileCounts _fileCounts = default;

            var rpfs = new ConcurrentBag<RpfFile>();
            Parallel.ForEach(allfiles, (rpfpath) =>
            {
                try
                {
                    RpfFile rf = new RpfFile(rpfpath, rpfpath.Replace(replpath, ""));

                    if (ExcludePaths is not null)
                    {
                        bool excl = false;
                        foreach(var path in ExcludePaths)
                        {
                            if (rf.Path.StartsWith(path, StringComparison.OrdinalIgnoreCase))
                            {
                                excl = true;
                                break;
                            }
                        }
                        if (excl)
                            return; //skip files in exclude paths.
                    }

                    rf.ScanStructure(updateStatus, errorLog, out var fileCounts);

                    lock(this)
                    {
                        _fileCounts += fileCounts;
                    }

                    if (rf.LastException != null) //incase of corrupted rpf (or renamed NG encrypted RPF)
                    {
                        Console.WriteLine(rf.LastException);
                        return;
                    }

                    rpfs.Add(rf);
                }
                catch (Exception ex)
                {
                    Console.WriteLine(ex);
                    errorLog?.Invoke($"{rpfpath}: {ex}");
                }
            });

            static int calculateSum(RpfFile rpf)
            {
                return rpf.AllEntries?.Count ?? 0 + rpf.Children?.Sum(calculateSum) ?? 0;
            }

            AllRpfs.EnsureCapacity((int)_fileCounts.Rpfs);
            RpfDict.EnsureCapacity((int)_fileCounts.Rpfs);
            AllNoModRpfs.EnsureCapacity((int)_fileCounts.Rpfs);
            EntryDict.EnsureCapacity((int)_fileCounts.Rpfs + (int)_fileCounts.Files);

            foreach (var rpf in rpfs)
            {
                AddRpfFile(rpf, false, false);
            }

            if (buildIndex)
            {
                Task.Run(() =>
                {
                    updateStatus?.Invoke("Building jenkindex...");
                    BuildBaseJenkIndex();
                    IsInited = true;
                    updateStatus?.Invoke("Scan complete");
                });
            }
            else
            {
                updateStatus?.Invoke("Scan complete");
                IsInited = true;
            }

            Console.WriteLine($"fileCounts: {_fileCounts}");
            Console.WriteLine($"AllRpfs: {AllRpfs.Count}; RpfDict: {RpfDict.Count}; EntryDict: {EntryDict.Count}; BaseRpfs: {BaseRpfs.Count}; ModRpfs: {ModRpfs.Count}; DlcRpfs: {DlcRpfs.Count}; DlcNoModRpfs: {DlcNoModRpfs.Count}; AllNoModRpfs: {AllNoModRpfs.Count}; ModRpfDict: {ModRpfDict.Count}; ModEntryDict: {ModEntryDict.Count}");
        }

        public void Init(List<RpfFile> allRpfs)
        {
            using var _ = new DisposableTimer("RpfManager.Init");
            //fast init used by RPF explorer's File cache
            AllRpfs = allRpfs;

            BaseRpfs = new List<RpfFile>();
            ModRpfs = new List<RpfFile>();
            DlcRpfs = new List<RpfFile>();
            DlcNoModRpfs = new List<RpfFile>();
            AllNoModRpfs = new List<RpfFile>();
            RpfDict = new Dictionary<string, RpfFile>(DefaultRpfDictCapacity, StringComparer.OrdinalIgnoreCase);
            EntryDict = new Dictionary<string, RpfEntry>(DefaultEntryDictCapacity, StringComparer.OrdinalIgnoreCase);
            ModRpfDict = new Dictionary<string, RpfFile>(StringComparer.OrdinalIgnoreCase);
            ModEntryDict = new Dictionary<string, RpfEntry>(StringComparer.OrdinalIgnoreCase);
            foreach (var rpf in allRpfs)
            {
                RpfDict[rpf.Path] = rpf;
                if (rpf.AllEntries == null)
                    continue;
                foreach (var entry in rpf.AllEntries)
                {
                    EntryDict[entry.Path] = entry;
                }
            }

            Console.WriteLine($"RpfDict: {RpfDict.Count}; EntryDict: {EntryDict.Count}");

            Task.Run(() =>
            {
                BuildBaseJenkIndex();
                IsInited = true;
            });
        }


        private void AddRpfFile(RpfFile file, bool isdlc, bool ismod)
        {
            if (file.AllEntries is null && file.Children is null)
                return;

            isdlc = isdlc || (file.Name.EndsWith(".rpf", StringComparison.OrdinalIgnoreCase) && (file.Name.StartsWith("dlc", StringComparison.OrdinalIgnoreCase) || file.Name.Equals("update.rpf", StringComparison.OrdinalIgnoreCase)));
            ismod = ismod || (file.Path.StartsWith("mods\\", StringComparison.OrdinalIgnoreCase));

            if (file.AllEntries is not null)
            {
                AllRpfs.Add(file);
                if (!ismod)
                {
                    AllNoModRpfs.Add(file);
                }
                if (isdlc)
                {
                    DlcRpfs.Add(file);
                    if (!ismod)
                    {
                        DlcNoModRpfs.Add(file);
                    }
                }
                else
                {
                    if (ismod)
                    {
                        ModRpfs.Add(file);
                    }
                    else
                    {
                        BaseRpfs.Add(file);
                    }
                }
                if (ismod)
                {
                    ModRpfDict[file.Path.Substring(5)] = file;
                }

                RpfDict[file.Path] = file;

                foreach (RpfEntry entry in file.AllEntries)
                {
                    try
                    {
                        if (!string.IsNullOrEmpty(entry.Name))
                        {
                            if (ismod)
                            {
                                ModEntryDict[entry.Path] = entry;
                                ModEntryDict[entry.Path.Substring(5)] = entry;
                            }
                            else
                            {
                                _ = EntryDict.TryAdd(entry.Path, entry);
                            }

                        }
                    }
                    catch (Exception ex)
                    {
                        file.LastError = ex.ToString();
                        file.LastException = ex;
                        ErrorLog?.Invoke($"{entry.Path}: {ex}");
                    }
                }
            }

            if (file.Children is not null)
            {
                foreach (RpfFile cfile in file.Children)
                {
                    AddRpfFile(cfile, isdlc, ismod);
                }
            }
        }


        public RpfFile? FindRpfFile(string path) => FindRpfFile(path, false);


        public RpfFile? FindRpfFile(string path, bool exactPathOnly)
        {
            if (EnableMods && ModRpfDict.TryGetValue(path, out RpfFile? file))
            {
                return file;
            }

            if (RpfDict.TryGetValue(path, out file))
            {
                return file;
            }

            foreach (RpfFile tfile in AllRpfs)
            {
                if (!exactPathOnly && tfile.Name.Equals(path, StringComparison.OrdinalIgnoreCase))
                {
                    return tfile;
                }
                if (tfile.Path.Equals(path, StringComparison.OrdinalIgnoreCase))
                {
                    return tfile;
                }
            }

            return file;
        }


        public RpfEntry? GetEntry(string path)
        {
            if (EnableMods && ModEntryDict.TryGetValue(path, out RpfEntry? entry))
            {
                return entry;
            }
            EntryDict.TryGetValue(path, out entry);
            if (entry is null)
            {
                path = path.Replace("/", "\\");
                path = path.Replace("common:", "common.rpf");
                if (EnableMods && ModEntryDict.TryGetValue(path, out entry))
                {
                    return entry;
                }
                EntryDict.TryGetValue(path, out entry);
            }
            return entry;
        }
        public byte[]? GetFileData(string path)
        {
            byte[]? data = null;
            if (GetEntry(path) is RpfFileEntry entry)
            {
                data = entry.File.ExtractFile(entry);
            }
            return data;
        }
        public string GetFileUTF8Text(string path)
        {
            byte[]? bytes = GetFileData(path);
            var text = TextUtil.GetUTF8Text(bytes);

            return text;
        }

        public StreamReader GetFileUTF8TextStream(string path)
        {
            byte[]? bytes = GetFileData(path);

            return new StreamReader(bytes.AsMemory().AsStream(), new UTF8Encoding(false), true); ;
        }

        public XmlDocument GetFileXml(string path)
        {
            XmlDocument doc = new XmlDocument();
            string text = GetFileUTF8Text(path);
            if (!string.IsNullOrEmpty(text))
            {
                doc.LoadXml(text);
            }

            return doc;
        }

        public XmlReader GetFileXmlReader(string path, XmlNameTable nameTable)
        {
            var text = GetFileUTF8TextStream(path);

            var reader = XmlReader.Create(text, new XmlReaderSettings { NameTable = nameTable });

            return reader;
        }

        public XmlReader GetFileXmlReader(string path)
        {
            var text = GetFileUTF8TextStream(path);

            var reader = XmlReader.Create(text);

            return reader;
        }

        public T? GetFile<T>(string path) where T : class, PackedFile, new()
        {
            if (GetEntry(path) is not RpfFileEntry entry)
                return null;

            return GetFile<T>(entry);
        }
        public static T? GetFile<T>(RpfEntry e) where T : class, PackedFile, new()
        {
            if (e is not RpfFileEntry entry)
                return null;

            byte[]? data = entry.File.ExtractFile(entry);
            T? file = null;
            if (data is not null)
            {
                file = new T();
                file.Load(data, entry);
            }
            return file;
        }

        public ValueTask<T?> GetFileAsync<T>(string path) where T : class, PackedFile, new()
        {
            RpfFileEntry? entry = GetEntry(path) as RpfFileEntry;

            if (entry is null)
                return ValueTask.FromResult((T?)null);

            return GetFileAsync<T>(entry);
        }

        public static async ValueTask<T?> GetFileAsync<T>(RpfEntry e) where T : class, PackedFile, new()
        {
            if (e is not RpfFileEntry entry)
                return null;

            try
            {
                byte[]? data = await entry.File.ExtractFileAsync(entry);
                T? file = null;
                if (data is not null && data.Length > 0)
                {
                    file = new T();
                    file.Load(data, entry);
                }
                return file;
            }
            catch(Exception ex)
            {
                Console.WriteLine(ex);
                throw;
            }
        }
        public bool LoadFile<T>(T file, RpfEntry e) where T : class, PackedFile
        {
            byte[]? data = null;
            RpfFileEntry? entry = e as RpfFileEntry;
            if (entry is not null)
            {
                data = entry.File.ExtractFile(entry);
            }

            if (data is not null && data.Length > 0)
            {
                try
                {
                    file.Load(data, entry);
                    return true;
                }
                catch(Exception ex)
                {
                    Console.WriteLine($"Error occured while loading {e.Name} at {e.Path}:\n{ex}");
                    throw;
                }
            }
            return false;
        }

        public async ValueTask<bool> LoadFileAsync<T>(T file, RpfEntry e) where T : class, PackedFile
        {
            byte[]? data = null;
            RpfFileEntry? entry = e as RpfFileEntry;
            if (entry is not null)
            {
                data = await entry.File.ExtractFileAsync(entry);
            }
            if (data is not null && data.Length > 0)
            {
                try
                {
                    file.Load(data, entry);
                    return true;
                }
                catch(Exception ex)
                {
                    Console.WriteLine($"Error occured while loading {e.Name} at {e.Path}:\n{ex}");
                    throw;
                }
            }
            return false;
        }

        private ConcurrentDictionary<string, int> counts = new ConcurrentDictionary<string, int>();
        private string[] stringLookup;

        [SkipLocalsInit]
        public void AddAllLods(string name)
        {
            var idx = name.LastIndexOf('_');
            if (idx > 0)
            {
                var str1 = name.AsSpan(0, idx);
                var idx2 = str1.LastIndexOf('_');
                if (idx2 > 0)
                {
                    // Filter some peds and clothing models (ydd's) which don't have LOD hashes we're interested in.
                    // This saves about 50% of the time it takes to do initial hashing
                    var str2 = str1.Slice(0, idx2 + 1).ToString();
                    if (str2.Length <= 2)
                    {
                        return;
                    }
                    var ignore = str2 switch
                    {
                        "p_" => true,
                        "s_m_y_" => true,
                        "s_m_" => true,
                        "s_m_m_" => true,
                        "s_f_y_" => true,
                        "a_m_y_" => true,
                        "ig_" => true,
                        "u_m_y_" => true,
                        "u_m_m_" => true,
                        "u_m_" => true,
                        "minimap_" => true,
                        "a_" => true,
                        "u_f_" => true,
                        "csb_" => true,
                        "g_m_y_" => true,
                        "a_f_m_" => true,
                        "a_m_m_" => true,
                        "g_m_m_" => true,
                        "mp_m_" => true,
                        "mp_f_" => true,
                        "mp_" => true,
                        "a_f_y_" => true,
                        var str when str.StartsWith("accs_") => true,
                        var str when str.StartsWith("decl_") => true,
                        var str when str.StartsWith("berd_") => true,
                        var str when str.StartsWith("hair_") => true,
                        var str when str.StartsWith("teef_") => true,
                        var str when str.StartsWith("lowr_") => true,
                        var str when str.StartsWith("jbib_") => true,
                        var str when str.StartsWith("hand_") => true,
                        var str when str.StartsWith("feet_") => true,
                        var str when str.StartsWith("task_") => true,
                        var str when str.StartsWith("head_") => true,
                        var str when str.StartsWith("uppr_") => true,
                        _ => false,
                    };
                    if (ignore)
                        return;

                    Span<char> buff = stackalloc char[str2.Length + 2 + 4];
                    str2.CopyTo(buff.Slice(0, str2.Length));
                    stackalloc char[] { 'l', 'o', 'd' }.CopyTo(buff.Slice(str2.Length, 3));
                    //Console.WriteLine(buff.Slice(0, str2.Length + 3).ToString());
                    JenkIndex.EnsureLower(buff.Slice(0, str2.Length + 3));
                    const int maxi = 99;

                    stackalloc char[] { '0', '0', '_', 'l', 'o', 'd' }.CopyTo(buff.Slice(str2.Length, 6));

                    if (stringLookup is null)
                    {
                        stringLookup = new string[maxi + 1];
                        for (int i = 0; i <= maxi; i++)
                        {
                            stringLookup[i] = i.ToString().PadLeft(2, '0');
                        }
                    }

                    for (int i = 1; i <= maxi; i++)
                    {
                        stringLookup[i].AsSpan().CopyTo(buff.Slice(str2.Length, 2));

                        var hash = JenkHash.GenHashLower(buff);

                        //Console.WriteLine(buff.ToString());
                        //JenkIndex.Ensure(buff);
                        JenkIndex.Ensure(str2, hash);
                    }
                }
            }
        }

        [SkipLocalsInit]
        private void parseAwc(string path)
        {
            var enumerator = path.ReverseEnumerateSplit('\\');
            if (enumerator.MoveNext())
            {
                ReadOnlySpan<char> fn = enumerator.Current;
                if (enumerator.MoveNext())
                {
                    ReadOnlySpan<char> fd = enumerator.Current;

                    fn = fn.Slice(0, fn.Length - 4);

                    if (fd.EndsWith(['.', 'r', 'p', 'f'], StringComparison.OrdinalIgnoreCase))
                    {
                        fd = fd.Slice(0, fd.Length - 4);
                    }

                    Span<char> hpath = stackalloc char[fd.Length + fn.Length + 1];

                    fd.CopyTo(hpath);
                    hpath[fd.Length] = '/';
                    fn.CopyTo(hpath.Slice(fd.Length + 1));
                    JenkIndex.EnsureLower(hpath);
                }
            }
        }

        public void BuildBaseJenkIndex()
        {
            var yddFiles = new ConcurrentBag<string>();
            using var timer = new DisposableTimer("BuildBaseJenkIndex");
            Parallel.ForEach(AllRpfs, new ParallelOptions { MaxDegreeOfParallelism = 4 }, [SkipLocalsInit] (file) =>
            {
                try
                {
                    JenkIndex.Ensure(file.Name);
                    foreach (RpfEntry entry in file.AllEntries)
                    {
                        var name = entry.Name;
                        if (string.IsNullOrEmpty(name))
                            continue;
                        //JenkIndex.Ensure(entry.Name);
                        //JenkIndex.Ensure(nlow);
                        var nameWithoutExtension = entry.ShortName;
                        JenkIndex.EnsureBoth(nameWithoutExtension);

                        //if (ind < entry.Name.Length - 2)
                        //{
                        //    JenkIndex.Ensure(entry.Name.Substring(0, ind) + ".#" + entry.Name.Substring(ind + 2));
                        //    JenkIndex.Ensure(entry.NameLower.Substring(0, ind) + ".#" + entry.NameLower.Substring(ind + 2));
                        //}
                        if (BuildExtendedJenkIndex)
                        {
                            if (name.EndsWith(".ydr", StringComparison.OrdinalIgnoreCase))// || nlow.EndsWith(".yft")) //do yft's get lods?
                            {
                                var sname = entry.ShortName;
                                var nameLod = $"{sname}_lod";
                                JenkIndex.EnsureLower(nameLod);
                                JenkIndex.EnsureLower($"{nameLod}a");
                                JenkIndex.EnsureLower($"{nameLod}b");
                            }
                            else if (name.EndsWith(".ydd", StringComparison.OrdinalIgnoreCase))
                            {
                                if (name.EndsWith("_children.ydd", StringComparison.OrdinalIgnoreCase))
                                {
                                    var strn = entry.Name.Substring(0, name.Length - 13);
                                    JenkIndex.EnsureLower(strn);
                                    var nameChildrenLod = $"{strn}_lod";
                                    JenkIndex.EnsureLower(nameChildrenLod);
                                    JenkIndex.EnsureLower($"{nameChildrenLod}a");
                                    JenkIndex.EnsureLower($"{nameChildrenLod}b");
                                }

                                yddFiles.Add(name);
                                //var idx = name.LastIndexOf('_');
                                //if (idx > 0)
                                //{
                                //    var str1 = name.Substring(0, idx);
                                //    var idx2 = str1.LastIndexOf('_');
                                //    if (idx2 > 0)
                                //    {
                                //        var str2 = str1.Substring(0, idx2);
                                //        JenkIndex.EnsureLower(str2 + "_lod");
                                //        var maxi = 100;

                                //        for (int i = 1; i <= maxi; i++)
                                //        {
                                //            var str3 = str2 + '_' + i.ToString().PadLeft(2, '0') + "_lod";
                                //            //JenkIndex.Ensure(str3);
                                //            JenkIndex.EnsureLower(str3);
                                //        }
                                //    }
                                //}
                                //AddAllLods(name);
                            }
                            else if(name.EndsWith(".sps", StringComparison.OrdinalIgnoreCase))
                            {
                                JenkIndex.EnsureLower(entry.Name);//for shader preset filename hashes!
                            }
                            else if(name.EndsWith(".awc", StringComparison.OrdinalIgnoreCase)) //create audio container path hashes...
                            {
                                parseAwc(entry.Path);
                            }
                            else if(name.EndsWith(".nametable", StringComparison.OrdinalIgnoreCase))
                            {
                                if (entry is RpfBinaryFileEntry binfe)
                                {
                                    byte[] rawData = file.ExtractFile(binfe);
                                    if (rawData != null)
                                    {
                                        foreach(var bytes in rawData.AsSpan().EnumerateSplit((byte)0))
                                        {
                                            string str = Encoding.ASCII.GetString(bytes);
                                            if (!string.IsNullOrEmpty(str))
                                            {
                                                //JenkIndex.Ensure(str);

                                                JenkIndex.EnsureLower(str);

                                                ////DirMod_Sounds_ entries apparently can be used to infer SP audio strings
                                                ////no luck here yet though
                                                //if (strl.StartsWith("dirmod_sounds_") && (strl.Length > 14))
                                                //{
                                                //    strl = strl.Substring(14);
                                                //    JenkIndex.Ensure(strl);
                                                //}
                                            }
                                        }
                                        //int startIndex = 0;
                                        //for (int i = 0; i < rawData.Length; i++)
                                        //{
                                        //    byte c = rawData[i];
                                        //    if (c == 0)
                                        //    {
                                        //        string str = Encoding.ASCII.GetString(rawData.AsSpan(startIndex, i - startIndex));
                                        //        if (!string.IsNullOrEmpty(str))
                                        //        {
                                        //            //JenkIndex.Ensure(str);

                                        //            JenkIndex.EnsureLower(str);

                                        //            ////DirMod_Sounds_ entries apparently can be used to infer SP audio strings
                                        //            ////no luck here yet though
                                        //            //if (strl.StartsWith("dirmod_sounds_") && (strl.Length > 14))
                                        //            //{
                                        //            //    strl = strl.Substring(14);
                                        //            //    JenkIndex.Ensure(strl);
                                        //            //}
                                        //        }
                                        //        startIndex = i + 1;
                                        //    }
                                        //}
                                    }
                                }
                            }
                        }
                    }

                }
                catch(Exception err)
                {
                    ErrorLog?.Invoke(err.ToString());
                    Console.WriteLine(err.ToString());
                    //failing silently!! not so good really
                }
            });
            //foreach (RpfFile file in AllRpfs)
            //{
                
            //}

            for (int i = 0; i < 100; i++)
            {
                JenkIndex.Ensure(i.ToString("00"));
            }

            _ = Task.Run(() => {
                using var timer2 = new DisposableTimer("BuildBaseJenkIndex -> AddAllLods");
                foreach (var name in yddFiles)
                {
                    AddAllLods(name);
                }
            });

            //Task.Run(() =>
            //{
            //    foreach (var count in counts.OrderBy(p => p.Value))
            //    {
            //        Console.WriteLine($"{count.Key,30}: {count.Value,3}");
            //    }
            //});
        }

    }
}