using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Runtime.InteropServices;
using Toolbox.Library;
using Toolbox.Library.IO;

namespace DKCTF
{
    public class PAK : TreeNodeFile, IArchiveFile, IFileFormat, ILeaveOpenOnLoad
    {
        public FileType FileType { get; set; } = FileType.Layout;

        public bool CanSave { get; set; }
        public string[] Description { get; set; } = new string[] { "DKCTF Archive" };
        public string[] Extension { get; set; } = new string[] { "*.pak" };
        public string FileName { get; set; }
        public string FilePath { get; set; }
        public IFileInfo IFileInfo { get; set; }

        public bool CanAddFiles { get; set; }
        public bool CanRenameFiles { get; set; }
        public bool CanReplaceFiles { get; set; }
        public bool CanDeleteFiles { get; set; }

        public bool Identify(System.IO.Stream stream)
        {
            using (var reader = new Toolbox.Library.IO.FileReader(stream, true))
            {
                bool IsForm = reader.CheckSignature(4, "RFRM");
                bool FormType = reader.CheckSignature(4, "PACK", 20);

                return IsForm && FormType;
            }
        }

        public Type[] Types
        {
            get
            {
                List<Type> types = new List<Type>();
                return types.ToArray();
            }
        }

        public List<FileEntry> files = new List<FileEntry>();
        public IEnumerable<ArchiveFileInfo> Files => files;

        public void ClearFiles() { files.Clear(); }

        private PakHeader Header;
        private List<DirectoryAssetEntry> Directories = new List<DirectoryAssetEntry>();
        private List<MetaOffsetEntry> MetaOffsets = new List<MetaOffsetEntry>();
        private List<CNameTagEntry> FileNameEntries = new List<CNameTagEntry>();

        public void Load(System.IO.Stream stream)
        {
            Directories.Clear();
            MetaOffsets.Clear();
            FileNameEntries.Clear();

            using (var reader = new FileReader(stream, true))
            {
                reader.SetByteOrder(true);
                Header = reader.ReadStruct<PakHeader>();
                var ADIRChunk = reader.ReadStruct<CChunkDescriptor>();
                ReadAssetDirectoryChunk(reader, ADIRChunk);
                var METAChunk = reader.ReadStruct<CChunkDescriptor>();
                ReadMetaChunk(reader, METAChunk);
                var STRGChunk = reader.ReadStruct<CChunkDescriptor>();
                ReadFileNameChunk(reader, STRGChunk);
            }

            for (int i = 0; i < Directories.Count; i++)
            {
                files.Add(new FileEntry()
                {
                    FileData = new byte[0],
                    FileDataStream = Directories[i].Data,
                    FileName = Directories[i].Type,
                });

                /*   var file = STFileLoader.OpenFileFormat(subStream, Directories[i].ToString());
                   if (file != null && file is TreeNodeFile)
                   {
                       Nodes.Add((TreeNodeFile)file);
                   }
                   else
                   {

                   }*/
            }
        }

        private void ReadAssetDirectoryChunk(FileReader reader, CChunkDescriptor chunk)
        {
            if (chunk.ChunkType != "ADIR")
                throw new Exception("Unexpected type! Expected ADIR, got " + chunk.ChunkType);

            long pos = reader.Position;

            reader.SeekBegin(pos + chunk.DataOffset);
            uint numEntries = reader.ReadUInt32();
            for (int i = 0; i < numEntries; i++)
            {
                DirectoryAssetEntry entry = new DirectoryAssetEntry();
                entry.Read(reader);
                Directories.Add(entry);
            }

            reader.SeekBegin(pos + chunk.DataSize);
        }

        private void ReadMetaChunk(FileReader reader, CChunkDescriptor chunk)
        {
            if (chunk.ChunkType != "META")
                throw new Exception("Unexpected type! Expected META, got " + chunk.ChunkType);
            long pos = reader.Position;
            reader.SeekBegin(pos + chunk.DataOffset);
            uint numEntries = reader.ReadUInt32();
            for (int i = 0; i < numEntries; i++)
            {
                MetaOffsetEntry entry = reader.ReadStruct< MetaOffsetEntry>();
                MetaOffsets.Add(entry);
            }

            reader.SeekBegin(pos + chunk.DataSize);
        }

        private void ReadFileNameChunk(FileReader reader, CChunkDescriptor chunk)
        {
            if (chunk.ChunkType != "STRG")
                throw new Exception("Unexpected type! Expected STRG, got " + chunk.ChunkType);

            long pos = reader.Position;
            reader.SeekBegin(pos + chunk.DataOffset);
            uint numEntries = reader.ReadUInt32();
            for (int i = 0; i < numEntries; i++)
            {
             //   CNameTagEntry entry = reader.ReadStruct<CNameTagEntry>();
             //   FileNameEntries.Add(entry);
            }

            reader.SeekBegin(pos + chunk.DataSize);
        }

        public void Unload()
        {

        }

        public void Save(System.IO.Stream stream)
        {
        }

        public bool AddFile(ArchiveFileInfo archiveFileInfo)
        {
            return false;
        }

        public bool DeleteFile(ArchiveFileInfo archiveFileInfo)
        {
            return false;
        }
    }

    public class FileEntry : ArchiveFileInfo
    {

    }

    public class DirectoryAssetEntry
    {
        public string Type;
        public CObjectId FileID;

        public long Offset;
        public long Size;

        public SubStream Data;

        public void Read(FileReader reader)
        {
            Type = reader.ReadString(4, Encoding.ASCII);
            FileID = reader.ReadStruct<CObjectId>();
            Offset = reader.ReadInt64();
            Size = reader.ReadInt64();

            Data = new SubStream(reader.BaseStream, Offset,Size);
        }

        public override string ToString()
        {
            return $"{FileID.Guid.Part4.ToString()}.{Type}";
        }
    }

    [StructLayout(LayoutKind.Sequential, Pack = 1)]
    public class MetaOffsetEntry
    {
        public CObjectTag ObjectTag;
        public uint FileOffset;
    }

    [StructLayout(LayoutKind.Sequential, Pack = 1)]
    public class PakHeader
    {
        CFormDescriptor PackForm;
        CFormDescriptor TocForm;
    }

    [StructLayout(LayoutKind.Sequential, Pack = 1)]
    public class CNameTagEntry
    {
        public CObjectTag ObjectTag;
        public string Name;
    }
}