/* FasTC
 * Copyright (c) 2013 University of North Carolina at Chapel Hill.
 * All rights reserved.
 *
 * Permission to use, copy, modify, and distribute this software and its
 * documentation for educational, research, and non-profit purposes, without
 * fee, and without a written agreement is hereby granted, provided that the
 * above copyright notice, this paragraph, and the following four paragraphs
 * appear in all copies.
 *
 * Permission to incorporate this software into commercial products may be
 * obtained by contacting the authors or the Office of Technology Development
 * at the University of North Carolina at Chapel Hill <otd@unc.edu>.
 *
 * This software program and documentation are copyrighted by the University of
 * North Carolina at Chapel Hill. The software program and documentation are
 * supplied "as is," without any accompanying services from the University of
 * North Carolina at Chapel Hill or the authors. The University of North
 * Carolina at Chapel Hill and the authors do not warrant that the operation of
 * the program will be uninterrupted or error-free. The end-user understands
 * that the program was developed for research purposes and is advised not to
 * rely exclusively on the program for any reason.
 *
 * IN NO EVENT SHALL THE UNIVERSITY OF NORTH CAROLINA AT CHAPEL HILL OR THE
 * AUTHORS BE LIABLE TO ANY PARTY FOR DIRECT, INDIRECT, SPECIAL, INCIDENTAL,
 * OR CONSEQUENTIAL DAMAGES, INCLUDING LOST PROFITS, ARISING OUT OF THE USE OF
 * THIS SOFTWARE AND ITS DOCUMENTATION, EVEN IF THE UNIVERSITY OF NORTH CAROLINA
 * AT CHAPEL HILL OR THE AUTHORS HAVE BEEN ADVISED OF THE POSSIBILITY OF SUCH
 * DAMAGE.
 *
 * THE UNIVERSITY OF NORTH CAROLINA AT CHAPEL HILL AND THE AUTHORS SPECIFICALLY
 * DISCLAIM ANY WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE AND ANY 
 * STATUTORY WARRANTY OF NON-INFRINGEMENT. THE SOFTWARE PROVIDED HEREUNDER IS ON
 * AN "AS IS" BASIS, AND THE UNIVERSITY  OF NORTH CAROLINA AT CHAPEL HILL AND
 * THE AUTHORS HAVE NO OBLIGATIONS TO PROVIDE MAINTENANCE, SUPPORT, UPDATES, 
 * ENHANCEMENTS, OR MODIFICATIONS.
 *
 * Please send all BUG REPORTS to <pavel@cs.unc.edu>.
 *
 * The authors may be contacted via:
 *
 * Pavel Krajcevski
 * Dept of Computer Science
 * 201 S Columbia St
 * Frederick P. Brooks, Jr. Computer Science Bldg
 * Chapel Hill, NC 27599-3175
 * USA
 * 
 * <http://gamma.cs.unc.edu/FasTC/>
 */

#include "FasTC/BPTCCompressor.h"

#include "CompressionMode.h"
#undef DBL_MAX
#include "FasTC/BitStream.h"
#include "FasTC/TexCompTypes.h"

#include <iostream>
#include <sstream>
#include <cstring>

#include "avpcl.h"

namespace BPTCC {

  void GetBlock(uint32 x, uint32 y, uint32 width, const uint32 *pixels, Tile &t) {
    for(uint32 j = 0; j < 4; j++)
    for(uint32 i = 0; i < 4; i++) {
      uint32 pixel = pixels[(y+j)*width + (x+i)];
      t.data[j][i].X() = pixel & 0xFF;
      t.data[j][i].Y() = (pixel >> 8) & 0xFF;
      t.data[j][i].Z() = (pixel >> 16) & 0xFF;
      t.data[j][i].W() = (pixel >> 24) & 0xFF;
    }
  }

  class BlockLogger {
   public:
    BlockLogger(uint64 blockIdx, std::ostream &os)
      : m_BlockIdx(blockIdx), m_Stream(os) { }

    template<typename T>
    friend std::ostream &operator<<(const BlockLogger &bl, const T &v);

    uint64 m_BlockIdx;
    std::ostream &m_Stream;
  };

  template<typename T>
  std::ostream &operator<<(const BlockLogger &bl, const T &v) {
    std::stringstream ss;
    ss << bl.m_BlockIdx << ": " << v;
    return bl.m_Stream << ss.str();
  }

  template<typename T>
  static void PrintStat(const BlockLogger &lgr, const char *stat, const T &v) {
    std::stringstream ss;
    ss << stat << " -- " << v << std::endl;
    lgr << ss.str();
  }

  // Compress an image using BC7 compression. Use the inBuf parameter to point
  // to an image in 4-byte RGBA format. The width and height parameters specify
  // the size of the image in pixels. The buffer pointed to by outBuf should be
  // large enough to store the compressed image. This implementation has an 4:1
  // compression ratio.
  void CompressNVTT(const FasTC::CompressionJob &cj) {
    const uint32 *inPixels = reinterpret_cast<const uint32 *>(cj.InBuf());
    const uint32 kBlockSz = GetBlockSize(FasTC::eCompressionFormat_BPTC);
    uint8 *outBuf = cj.OutBuf() + cj.CoordsToBlockIdx(cj.XStart(), cj.YStart()) * kBlockSz;

    uint32 startX = cj.XStart();
    const uint32 endY = std::min(cj.YEnd(), cj.Height() - 4);
    for(uint32 j = cj.YStart(); j <= endY; j += 4) {
      const uint32 endX = j == cj.YEnd()? cj.XEnd() : cj.Width();
      for(uint32 i = startX; i < endX; i += 4) {

        Tile block(4, 4);
        GetBlock(i, j, cj.Width(), inPixels, block);
        AVPCL::compress(block, reinterpret_cast<char *>(outBuf), NULL);

        outBuf += kBlockSz;
      }
      startX = 0;
    }
  }

  typedef double (*ModeCompressFunc)(const Tile &, char* out);
  static ModeCompressFunc kModeFuncs[8] = {
    AVPCL::compress_mode0,
    AVPCL::compress_mode1,
    AVPCL::compress_mode2,
    AVPCL::compress_mode3,
    AVPCL::compress_mode4,
    AVPCL::compress_mode5,
    AVPCL::compress_mode6,
    AVPCL::compress_mode7
  };

  double CompressMode(uint32 mode, const Tile &t, char *out, BlockLogger &log) {
    std::stringstream ss;
    ss << "Mode_" << mode << "_error";
    double mse = kModeFuncs[mode](t, out);
    PrintStat(log, ss.str().c_str(), mse);

    FasTC::BitStreamReadOnly strm(reinterpret_cast<uint8 *>(out));
    while(!strm.ReadBit());

    const CompressionMode::Attributes *attrs =
      CompressionMode::GetAttributesForMode(mode);
    const uint32 nSubsets = attrs->numSubsets;

    ss.str("");
    ss << "Mode_" << mode << "_shape";

    uint32 shapeIdx = 0;
    if ( nSubsets > 1 ) {
      shapeIdx = strm.ReadBits(mode == 0? 4 : 6);
      PrintStat(log, ss.str().c_str(), shapeIdx);
    } else {
      PrintStat(log, ss.str().c_str(), -1);
    }

    return mse;
  }

  void CompressNVTTWithStats(const FasTC::CompressionJob &cj, std::ostream *logStream) {
    const uint32 *inPixels = reinterpret_cast<const uint32 *>(cj.InBuf());
    const uint32 kBlockSz = GetBlockSize(FasTC::eCompressionFormat_BPTC);
    uint8 *outBuf = cj.OutBuf() + cj.CoordsToBlockIdx(cj.XStart(), cj.YStart()) * kBlockSz;

    uint32 startX = cj.XStart();
    const uint32 endY = std::min(cj.YEnd(), cj.Height() - 4);
    for(uint32 j = cj.YStart(); j <= endY; j += 4) {
      const uint32 endX = j == cj.YEnd()? cj.XEnd() : cj.Width();
      for(uint32 i = startX; i < endX; i += 4) {

        Tile block(4, 4);
        GetBlock(i, j, cj.Width(), inPixels, block);

        if(logStream) {
          BlockLogger logger(cj.CoordsToBlockIdx(i, j), *logStream);

          char tempblock[16];
          double msebest = 1e30;
          for(uint32 mode = 0; mode < 8; mode++) {
            double mse_mode = CompressMode(mode, block, tempblock, logger);
            if(mse_mode < msebest) {
              msebest = mse_mode;
              memcpy(outBuf, tempblock, AVPCL::BLOCKSIZE);
            }
          }
        } else {
          AVPCL::compress(block, reinterpret_cast<char *>(outBuf), NULL);          
        }

        outBuf += 16;
      }

      startX = 0;
    }
  }

}  // namespace BC7C