using System;
using System.IO;
using System.Diagnostics;
using System.Text;
using Hack.Xenosaga.Common;

namespace Hack.Xenosaga.Process
{
    class Unpack
    {
        private static BinaryWriter _bw;
        private const string _listExtension = ".lst";
        private const string _copyright = "Hacked by BahaBulle (c)2016\0";
        private const int _sectorSize = 0x800;
        private const int _maxSizeFile = 0x40000000;
        
        private struct element
        {
            public bool isDirectory;
            public bool isCompressed;
            public byte level;
            public string name;
            public UInt32 sector;
            public UInt32 position;
            public UInt32 sizeIn;
            public UInt32 sizeOut;
        }


        #region Private methods

        private static int getIdFile(UInt32 position, int indexSize)
        {
            double d = (position - indexSize) / _maxSizeFile;

            return (int)Math.Floor(d) + 1;
        }

        private static bool readElement(BinaryReader br, ref element e)
        {
            byte size = br.ReadByte();
            if (size == 0)
                return false;

            if ((size & 0x80) != 0)
            {
                size -= 2;
                e.isDirectory = true;
                e.level = br.ReadByte();
                e.name = Encoding.ASCII.GetString(br.ReadBytes(size & 0x7F));
            }
            else
            {
                size--;
                e.isDirectory = false;
                e.level = 0;
                e.name = Encoding.ASCII.GetString(br.ReadBytes(size & 0x3F));
                e.sector = br.ReadUInt16() + (uint)br.ReadByte() * 0x10000;
                e.position = e.sector * _sectorSize;
                e.sizeIn = br.ReadUInt32();
                if ((size & 0x40) != 0)
                {
                    e.sizeOut = br.ReadUInt16() + (uint)br.ReadByte() * 0x10000;
                    e.isCompressed = true;
                }
                else
                {
                    e.sizeOut = e.sizeIn;
                    e.isCompressed = false;
                }
            }

            return true;
        }

        private static byte readIndex(string asIndexName, listPathElement path)
        {
            byte bIndexNbSector = 0;
            int num = 0;
            int level;

            using (BinaryReader brIndex = new BinaryReader(File.Open(asIndexName, FileMode.Open)))
            {
                pathElement current = new pathElement(true);

                bIndexNbSector = brIndex.ReadByte();

                element e = new element();
                while (readElement(brIndex, ref e))
                {
                    level = e.level;

                    while (e.level-- > 0)
                        current = current.Parent;

                    pathElement entry = new pathElement(e.isDirectory) { Name = e.name, Position = e.position, Sector = e.sector, SizeIn = e.sizeIn, SizeOut = e.sizeOut, Id = num++, Level = level, IsCompressed = e.isCompressed };
                    current.addEntry(entry);
                    path.addToIndex(entry);

                    if (e.isDirectory)
                        current = entry;
                }
            }

            return bIndexNbSector;
        }

        private static void writeIndex(string as_file, byte ai_nbSector, listPathElement index)
        {
            index.SortById();

            using (BinaryWriter bwIndex = new BinaryWriter(File.Open(Variables.dirPack + as_file, FileMode.Create)))
            {
                bwIndex.Write(ai_nbSector);

                foreach (pathElement entryPath in index.getEntries())
                {
                    if (entryPath.Name != "")
                    {
                        if (entryPath.IsDirectory)
                        {
                            bwIndex.Write((byte)(entryPath.Name.Length + 0x82));
                            bwIndex.Write((byte)entryPath.Level);
                            bwIndex.Write(entryPath.Name.ToCharArray());
                        }
                        else
                        {
                            if (entryPath.IsCompressed)
                                bwIndex.Write((byte)(entryPath.Name.Length + 0x41));
                            else
                                bwIndex.Write((byte)(entryPath.Name.Length + 1));

                            bwIndex.Write(entryPath.Name.ToCharArray());
                            bwIndex.Write((UInt16)entryPath.Sector);
                            bwIndex.Write((byte)(entryPath.Sector / 0x10000));
                            bwIndex.Write((UInt32)entryPath.SizeIn);

                            if (entryPath.IsCompressed)
                            {
                                bwIndex.Write((UInt16)entryPath.SizeOut);
                                bwIndex.Write((byte)(entryPath.SizeOut / 0x10000));
                            }
                        }
                    }
                }

                bwIndex.Write((byte)0);

                int size = (int)bwIndex.BaseStream.Length;
                padding(bwIndex, ref size);
            }
        }

        private static void padding(BinaryWriter a_bw, ref int size)
        {
            char[] hack = _copyright.ToCharArray();

            int id = 0;
            while (size % _sectorSize != 0)
            {
                a_bw.Write(hack[id++]);
                size++;

                if (id >= hack.Length)
                    id = 0;
            }
        }

        private static int AddFileToStream(string pathname, ref int num, BinaryReader br, int size, bool regroup)
        {
            if (_bw == null)
                _bw = new BinaryWriter(File.Open(string.Format("{0}{1:00}", pathname, num), FileMode.Create));
            
            long pos = _bw.BaseStream.Position;
            int size_rest = _maxSizeFile - (int)_bw.BaseStream.Length;

            if (!regroup && size > size_rest)
            {
                _bw.Write(br.ReadBytes(size_rest), 0, size_rest);
                _bw.Close();
                _bw.Dispose();

                num++;
                _bw = new BinaryWriter(File.Open(string.Format("{0}{1:00}", pathname, num), FileMode.Create));

                _bw.Write(br.ReadBytes(size - size_rest), 0, size - size_rest);
            }
            else
                _bw.Write(br.ReadBytes(size), 0, size);

            padding(_bw, ref size);

            return size;
        }

        private static int findFile(pathElement entry, string numberFile)
        {
            // Check if the file is in the INSERT directory
            if (File.Exists(Variables.dirInsert + entry.Name))
                return 1;

            // Check if the file is in the UNPACK directory
            if (File.Exists(Variables.dirUnpack + numberFile + entry.FullPath))
                return 2;

            // Otherwise, get the file from iso files
            return -1;
        }

        #endregion

        #region Public methods

        /// <summary>
        /// Unpack all files from an index
        /// </summary>
        /// <param name="indexName">Pathname of the index</param>
        public static void unpackIsoFiles(string indexName)
        {
            BinaryReader br = null;
            byte bIndexNbSector = 0;
            int numFileIndex;
            int numFileOpen = -1;
            int iIndexSize = 0;
            string fileNameBase = Path.GetFileNameWithoutExtension(indexName);

            int.TryParse(Path.GetExtension(indexName).Substring(1), out numFileIndex);
            string directoryName = Variables.dirUnpack + string.Format("{0:D2}", numFileIndex);

            listPathElement index = new listPathElement();

            Trace.Write(string.Format("Reading index ({0}) : ", indexName));

            // Lecture de l'index
            try
            {
                bIndexNbSector = readIndex(indexName, index);
                index.SortBySector();
            }
            catch (Exception ex)
            {
                Trace.WriteLine(string.Format("ERROR : {0}", ex.Message));
                return;
            }
            Trace.WriteLine("OK");

            iIndexSize = bIndexNbSector * _sectorSize;

            try
            {
                Trace.WriteLine("Extracting files");
                Trace.Indent();

                foreach (pathElement entryPath in index.getEntries())
                {
                    if (!entryPath.IsDirectory)
                    {
                        Trace.WriteLine(string.Format("Create file {0}", entryPath.FullPath));
                        Directory.CreateDirectory(directoryName + Path.GetDirectoryName(entryPath.FullPath));

                        int id = getIdFile(entryPath.Position, iIndexSize) + numFileIndex;

                        double pos = (entryPath.Position - iIndexSize) % _maxSizeFile;

                        if (numFileOpen == -1 || numFileOpen != id)
                        {
                            if (br != null)
                            {
                                br.Close();
                                br.Dispose();
                            }

                            br = new BinaryReader(File.Open(string.Format("{0}.{1:D2}", fileNameBase, id), FileMode.Open));
                            numFileOpen = id;
                        }

                        br.BaseStream.Seek((int)pos, SeekOrigin.Begin);

                        int size_rest = (int)br.BaseStream.Length - (int)pos;
                        using (BinaryWriter bw = new BinaryWriter(File.Open(directoryName + entryPath.FullPath, FileMode.Create)))
                        {
                            if (size_rest >= entryPath.SizeIn)
                                bw.Write(br.ReadBytes((int)entryPath.SizeIn));
                            else
                            {
                                bw.Write(br.ReadBytes(size_rest));
                                int num = id + 1;

                                if (br != null)
                                {
                                    br.Close();
                                    br.Dispose();
                                }

                                br = new BinaryReader(File.Open(string.Format("{0}.{1:D2}", fileNameBase, num), FileMode.Open));
                                numFileOpen = num;

                                bw.Write(br.ReadBytes((int)entryPath.SizeIn - size_rest));
                            }
                        }
                    }
                }
            }
            catch (Exception ex)
            {
                Trace.WriteLine(string.Format("==> ERROR : {0}", ex.Message));
                return;
            }
            finally
            {
                Trace.Unindent();
            }
        }

        /// <summary>
        /// Pack all files to index
        /// </summary>
        /// <param name="indexName">Pathname of the index</param>
        /// <param name="regroup">Used to know if the program pack files in 1 ou more files</param>
        public static void packIsoFiles(string indexName, bool regroup)
        {
            BinaryReader br = null;
            byte bIndexNbSector = 0;
            long l_sector = 0;
            long l_position = 0;
            int iIndexSize = 0;
            int numFileIndex;
            int numFileWrite = -1;
            int idSave = -1;
            int.TryParse(Path.GetExtension(indexName).Substring(1), out numFileIndex);

            string fileNameBase = Path.GetFileNameWithoutExtension(indexName);
            string filename = "";
            string directoryUnpackName = Variables.dirUnpack + string.Format("{0:D2}", numFileIndex);

            listPathElement index = new listPathElement();

            Trace.Write(string.Format("Reading index ({0}) : ", indexName));

            // Lecture de l'index
            try
            {
                bIndexNbSector = readIndex(indexName, index);
                index.SortBySector();
            }
            catch (Exception ex)
            {
                Trace.WriteLine(string.Format("ERROR : {0}", ex.Message));
                return;
            }

            l_sector += bIndexNbSector;
            iIndexSize = bIndexNbSector * _sectorSize;
            l_position += iIndexSize;

            numFileWrite = numFileIndex + 1;
            try
            {
                Trace.WriteLine("Inserting files");
                Trace.Indent();

                string s_pathname = string.Format("{0}{1}.", Variables.dirPack, fileNameBase);
                Directory.CreateDirectory(Variables.dirPack);

                foreach (pathElement entryPath in index.getEntries())
                {
                    if (!entryPath.IsDirectory)
                    {
                        long size = 0;

                        int idFile = findFile(entryPath, string.Format("{0:D2}", numFileIndex));

                        if (idFile == 1 || idFile == 2)
                        {
                            if (idFile == 1)
                            {
                                Trace.WriteLine(string.Format("From {0} : file {1}", Variables.dirInsert, entryPath.FullPath));

                                filename = Variables.dirInsert + entryPath.Name;
                            }
                            else
                            {
                                Trace.WriteLine(string.Format("From {0} : file {1}", Variables.dirUnpack, entryPath.FullPath));

                                filename = directoryUnpackName + entryPath.FullPath;
                            }

                            using (BinaryReader brFile = new BinaryReader(File.Open(filename, FileMode.Open)))
                            {
                                size = brFile.BaseStream.Length;

                                if (entryPath.IsCompressed)
                                {
                                    // Compression du fichier
                                    entryPath.SizeIn = (UInt32)size;
                                    //entryPath.SizeOut = entryPath.SizeIn;
                                }
                                else
                                {
                                    entryPath.SizeIn = (UInt32)size;
                                    //entryPath.SizeOut = entryPath.SizeIn;
                                }

                                int size_new = AddFileToStream(s_pathname, ref numFileWrite, brFile, (int)size, regroup);

                                entryPath.Position = (UInt32)l_position;
                                entryPath.Sector = entryPath.Position / _sectorSize;
                                l_position += size_new;
                            }
                        }
                        else
                        {
                            int id = getIdFile(entryPath.Position, iIndexSize) + numFileIndex;
                            filename = string.Format("{0}.{1:D2}", fileNameBase, id);

                            Trace.WriteLine(string.Format("From {0} : file {1}", filename, entryPath.FullPath));

                            size = entryPath.SizeIn;

                            double pos = (entryPath.Position - iIndexSize) % _maxSizeFile;

                            int size_new = 0;

                            if (br != null && id != idSave)
                            {
                                br.Close();
                                br.Dispose();
                                br = null;
                            }

                            if (br == null)
                            {
                                br = new BinaryReader(File.Open(filename, FileMode.Open));
                                idSave = id;
                            }

                            br.BaseStream.Seek((int)pos, SeekOrigin.Begin);

                            int size_rest = (int)br.BaseStream.Length - (int)pos;

                            if (size_rest >= size)
                                size_new = AddFileToStream(s_pathname, ref numFileWrite, br, (int)size, regroup);
                            else
                            {
                                int sizeTemp = AddFileToStream(s_pathname, ref numFileWrite, br, size_rest, regroup);
                                int num = id + 1;
                                size_new = sizeTemp;

                                if (br != null)
                                {
                                    br.Close();
                                    br.Dispose();
                                }

                                filename = string.Format("{0}.{1:D2}", fileNameBase, num);
                                br = new BinaryReader(File.Open(filename, FileMode.Open));
                                idSave = num;

                                sizeTemp = AddFileToStream(s_pathname, ref numFileWrite, br, (int)entryPath.SizeIn - size_rest, regroup);
                                size_new += sizeTemp;
                            }

                            entryPath.Position = (UInt32)l_position;
                            entryPath.Sector = entryPath.Position / _sectorSize;
                            l_position += size_new;
                        }
                    }
                }

                _bw.Close();
                _bw.Dispose();

                writeIndex(indexName, bIndexNbSector, index);
            }
            catch (Exception ex)
            {
                Trace.WriteLine(string.Format("==> ERROR : {0}", ex.Message));
                return;
            }
            finally
            {
                Trace.Unindent();
            }
        }

        /// <summary>
        /// List files of an index
        /// </summary>
        /// <param name="indexName">Pathname of the index</param>
        public static void listFiles(string indexName)
        {
            string outputName;
            byte bIndexNbSector = 0;
            int iIndexSize;
            int numFile;
            int.TryParse(Path.GetExtension(indexName).Substring(1), out numFile);

            listPathElement index = new listPathElement();

            Trace.Write(string.Format("Reading index file ({0}) : ", indexName));

            try
            {
                Directory.CreateDirectory(Variables.dirUnpack);
                outputName = string.Format("{0}{1}{2}", Variables.dirUnpack, indexName, _listExtension);

                using (StreamWriter sw = new StreamWriter(outputName))
                {
                    Functions.ManageListener(false, true, sw);

                    bIndexNbSector = readIndex(indexName, index);
                    index.SortBySector();
                    iIndexSize = bIndexNbSector * _sectorSize;

                    foreach (pathElement entryPath in index.getEntries())
                    {
                        if (!entryPath.IsDirectory)
                        {
                            double d = (entryPath.Position - iIndexSize) / _maxSizeFile;
                            int id = (int)Math.Floor(d) + 1;

                            Trace.WriteLine(string.Format("{0,-36}Sector={1,-15}SizeIn={2,-15}SizeOut={3,-15}File=xenosaga.{4:D2}", entryPath.FullPath, entryPath.Sector, entryPath.SizeIn, entryPath.SizeOut, id + numFile));
                        }
                    }

                    Functions.ManageListener(true, false);
                }

                Trace.WriteLine("OK");
            }
            catch (Exception ex)
            {
                Trace.WriteLine(string.Format("ERROR : {0}", ex.Message));
                return;
            }
        }

        #endregion
    }
}