/***************************************************************************
 *                            TileMatrixPatch.cs
 *                            -------------------
 *   begin                : May 1, 2002
 *   copyright            : (C) The RunUO Software Team
 *   email                : info@runuo.com
 *
 *   $Id$
 *
 ***************************************************************************/

/***************************************************************************
 *
 *   This program is free software; you can redistribute it and/or modify
 *   it under the terms of the GNU General Public License as published by
 *   the Free Software Foundation; either version 2 of the License, or
 *   (at your option) any later version.
 *
 ***************************************************************************/

using System.IO;
using System.Runtime.CompilerServices;

namespace Server
{
  public class TileMatrixPatch
  {
    private readonly int m_LandBlocks;
    private readonly int m_StaticBlocks;

    private StaticTile[] m_TileBuffer = new StaticTile[128];

    public TileMatrixPatch(TileMatrix matrix, int index)
    {
      if (!Enabled)
        return;

      string mapDataPath = Core.FindDataFile("mapdif{0}.mul", index);
      string mapIndexPath = Core.FindDataFile("mapdifl{0}.mul", index);

      if (File.Exists(mapDataPath) && File.Exists(mapIndexPath))
        m_LandBlocks = PatchLand(matrix, mapDataPath, mapIndexPath);

      string staDataPath = Core.FindDataFile("stadif{0}.mul", index);
      string staIndexPath = Core.FindDataFile("stadifl{0}.mul", index);
      string staLookupPath = Core.FindDataFile("stadifi{0}.mul", index);

      if (File.Exists(staDataPath) && File.Exists(staIndexPath) && File.Exists(staLookupPath))
        m_StaticBlocks = PatchStatics(matrix, staDataPath, staIndexPath, staLookupPath);
    }

    public static bool Enabled{ get; set; } = true;

    public int LandBlocks
    {
      get
      {
        lock (this)
        {
          return m_LandBlocks;
        }
      }
    }

    public int StaticBlocks
    {
      get
      {
        lock (this)
        {
          return m_StaticBlocks;
        }
      }
    }

    [MethodImpl(MethodImplOptions.Synchronized)]
    private unsafe int PatchLand(TileMatrix matrix, string dataPath, string indexPath)
    {
      using FileStream fsData = new FileStream(dataPath, FileMode.Open, FileAccess.Read, FileShare.Read);
      using FileStream fsIndex = new FileStream(indexPath, FileMode.Open, FileAccess.Read, FileShare.Read);
      BinaryReader indexReader = new BinaryReader(fsIndex);

      int count = (int)(indexReader.BaseStream.Length / 4);

      for (int i = 0; i < count; ++i)
      {
        int blockID = indexReader.ReadInt32();
        int x = blockID / matrix.BlockHeight;
        int y = blockID % matrix.BlockHeight;

        fsData.Seek(4, SeekOrigin.Current);

        LandTile[] tiles = new LandTile[64];

        fixed (LandTile* pTiles = tiles)
        {
          NativeReader.Read(fsData.SafeFileHandle.DangerousGetHandle(), pTiles, 192);
        }

        matrix.SetLandBlock(x, y, tiles);
      }

      indexReader.Close();

      return count;
    }

    [MethodImpl(MethodImplOptions.Synchronized)]
    private unsafe int PatchStatics(TileMatrix matrix, string dataPath, string indexPath, string lookupPath)
    {
      using FileStream fsData = new FileStream(dataPath, FileMode.Open, FileAccess.Read, FileShare.Read);
      using FileStream fsIndex = new FileStream(indexPath, FileMode.Open, FileAccess.Read, FileShare.Read);
      using FileStream fsLookup = new FileStream(lookupPath, FileMode.Open, FileAccess.Read, FileShare.Read);
      BinaryReader indexReader = new BinaryReader(fsIndex);
      BinaryReader lookupReader = new BinaryReader(fsLookup);

      int count = (int)(indexReader.BaseStream.Length / 4);

      TileList[][] lists = new TileList[8][];

      for (int x = 0; x < 8; ++x)
      {
        lists[x] = new TileList[8];

        for (int y = 0; y < 8; ++y)
          lists[x][y] = new TileList();
      }

      for (int i = 0; i < count; ++i)
      {
        int blockID = indexReader.ReadInt32();
        int blockX = blockID / matrix.BlockHeight;
        int blockY = blockID % matrix.BlockHeight;

        int offset = lookupReader.ReadInt32();
        int length = lookupReader.ReadInt32();
        lookupReader.ReadInt32(); // Extra

        if (offset < 0 || length <= 0)
        {
          matrix.SetStaticBlock(blockX, blockY, matrix.EmptyStaticBlock);
          continue;
        }

        fsData.Seek(offset, SeekOrigin.Begin);

        int tileCount = length / 7;

        if (m_TileBuffer.Length < tileCount)
          m_TileBuffer = new StaticTile[tileCount];

        StaticTile[] staTiles = m_TileBuffer;

        fixed (StaticTile* pTiles = staTiles)
        {
          NativeReader.Read(fsData.SafeFileHandle.DangerousGetHandle(), pTiles, length);
          StaticTile* pCur = pTiles, pEnd = pTiles + tileCount;

          while (pCur < pEnd)
          {
            lists[pCur->m_X & 0x7][pCur->m_Y & 0x7].Add(pCur->m_ID, pCur->m_Z);
            pCur = pCur + 1;
          }

          StaticTile[][][] tiles = new StaticTile[8][][];

          for (int x = 0; x < 8; ++x)
          {
            tiles[x] = new StaticTile[8][];

            for (int y = 0; y < 8; ++y)
              tiles[x][y] = lists[x][y].ToArray();
          }

          matrix.SetStaticBlock(blockX, blockY, tiles);
        }
      }

      indexReader.Close();
      lookupReader.Close();

      return count;
    }
  }
}