/*
--------------------------------------------------------------------------------
This source file is part of SkyX.
Visit http://www.paradise-studios.net/products/skyx/

Copyright (C) 2009-2012 Xavier Verguín González < xavyiy@gmail.com>

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

This program is distributed in the hope that it will be useful, but WITHOUT
ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details.

You should have received a copy of the GNU Lesser General Public License along with
this program; if not, write to the Free Software Foundation, Inc., 59 Temple
Place - Suite 330, Boston, MA 02111-1307, USA, or go to
http://www.gnu.org/copyleft/lesser.txt.
--------------------------------------------------------------------------------
*/

#include <vector>

#include <OgrePixelFormat.h>
#include "VClouds/DataManager.h"

#include "VClouds/VClouds.h"
#include "VClouds/Ellipsoid.h"

namespace SkyX { namespace VClouds
{
  DataManager::DataManager(VClouds *vc)
    : mVClouds(vc)
      , mCellsCurrent(0)
      , mCellsTmp(0)
      , mFFRandom(0)
      , mNx(0), mNy(0), mNz(0)
      , mCurrentTransition(0)
      , mUpdateTime(10.0f)
      , mStep(0), mXStart(0), mXEnd(0)
      , mMaxNumberOfClouds(250)
      , mVolTexToUpdate(true)
      , mCreated(false)
  {
    for (int k = 0; k < 2; k++)
    {
      mVolTextures[k].setNull();
    }
  }

  DataManager::~DataManager()
  {
    remove();
  }

  void DataManager::remove()
  {
    if (!mCreated)
    {
      return;
    }

    for (int k = 0; k < 2; k++)
    {
      Ogre::TextureManager::getSingleton().remove(mVolTextures[k]->getName());
      mVolTextures[k].setNull();
    }

    _delete3DCellArray(mCellsCurrent, mNx, mNy);
    _delete3DCellArray(mCellsTmp, mNx, mNy);

    delete mFFRandom;

    mNx = mNy = mNz = 0;

    mCreated = false;
  }

  void DataManager::update(const Ogre::Real &timeSinceLastFrame)
  {
    if (mVolTexToUpdate)
    {
      mCurrentTransition += timeSinceLastFrame;

      mXEnd = static_cast < int>((mCurrentTransition / mUpdateTime)*4*mNx);
      if (mXEnd > 4*mNx)
      {
        mXEnd = 4*mNx;
      }

      if (mXEnd/mNx != mXStart/mNx)
      {
        for (int k = mStep; k <= mXEnd/mNx; k++)
        {
          _performCalculations(mNx, mNy, mNz, k, mXStart%mNx,
              (mXEnd/mNx != k) ? mNx : mXEnd%mNx);
          mXStart = 0;
        }
      }
      else
      {
        if (mXStart != mXEnd)
        {
          _performCalculations(mNx, mNy, mNz, mXEnd/mNx,
              mXStart%mNx, mXEnd%mNx);
        }
      }

      mStep = mXEnd/mNx;
      mXStart = mXEnd;

      if (mCurrentTransition >= mUpdateTime)
      {
        _updateVolTextureData(mCellsCurrent, VOL_TEX0, mNx, mNy, mNz);

        mCurrentTransition = mUpdateTime;
        mVolTexToUpdate = !mVolTexToUpdate;
        mStep = mXStart = mXEnd = 0;
      }
    }
    else
    {
      mCurrentTransition -= timeSinceLastFrame;

      mXEnd = static_cast < int>(((mUpdateTime-mCurrentTransition) /
            mUpdateTime)*4*mNx);
      if (mXEnd < 0)
      {
        mXEnd = 0;
      }

      if (mXEnd/mNx != mXStart/mNx)
      {
        for (int k = mStep; k <= mXEnd/mNx; k++)
        {
          _performCalculations(mNx, mNy, mNz, k, mXStart%mNx,
              (mXEnd/mNx != k) ? mNx : mXEnd%mNx);
          mXStart = 0;
        }
      }
      else
      {
        if (mXStart != mXEnd)
        {
          _performCalculations(mNx, mNy, mNz, mXEnd/mNx,
              mXStart%mNx, mXEnd%mNx);
        }
      }

      mStep = mXEnd/mNx;
      mXStart = mXEnd;

      if (mCurrentTransition <= 0)
      {
        _updateVolTextureData(mCellsCurrent, VOL_TEX1, mNx, mNy, mNz);

        mCurrentTransition = 0;
        mVolTexToUpdate = !mVolTexToUpdate;
        mStep = mXStart = mXEnd = 0;
      }
    }
  }

  void DataManager::create(const int &nx, const int &ny, const int &nz)
  {
    remove();

    mNx = nx;
    mNy = ny;
    mNz = nz;

    mFFRandom = new FastFakeRandom(1024, 0, 1);

    _initData(nx, ny, nz);

    for (int k = 0; k < 2; k++)
    {
      _createVolTexture(static_cast < VolTextureId>(k), nx, ny, nz);
    }

    _updateVolTextureData(mCellsCurrent, VOL_TEX0, mNx, mNy, mNz);
    _updateVolTextureData(mCellsCurrent, VOL_TEX1, mNx, mNy, mNz);

    mCreated = true;
  }

  void DataManager::forceToUpdateData()
  {
    // Finish current update process
    _performCalculations(mNx, mNy, mNz, mStep, mXStart%mNx, mNx);
    for (int k = mStep+1; k < 4; k++)
    {
      _performCalculations(mNx, mNy, mNz, k, 0, mNx);
    }
    mStep = mXStart = mXEnd = 0;

    if (mVolTexToUpdate)
    {
      _updateVolTextureData(mCellsCurrent, VOL_TEX0, mNx, mNy, mNz);
      mCurrentTransition = mUpdateTime;
    }
    else
    {
      _updateVolTextureData(mCellsCurrent, VOL_TEX1, mNx, mNy, mNz);
      mCurrentTransition = 0;
    }

    mVolTexToUpdate = !mVolTexToUpdate;
  }

  void DataManager::_initData(const int& nx, const int& ny, const int& nz)
  {
    mCellsCurrent = _create3DCellArray(nx, ny, nz);
    mCellsTmp   = _create3DCellArray(nx, ny, nz, false);
  }

  DataManager::Cell *** DataManager::_create3DCellArray(const int& nx,
      const int& ny, const int& nz, const bool& init)
  {
    Cell ***c = new Cell** [nx];

    int u, v, w;

    for (u = 0; u < nx; u++)
    {
      c[u] = new Cell* [ny];

      for (v = 0; v < ny; v++)
      {
        c[u][v] = new Cell[nz];
      }
    }

    if (!init)
    {
      return c;
    }

    for (u = 0; u < nx; u++)
    {
      for (v = 0; v < ny; v++)
      {
        for (w = 1; w < nz; w++)
        {
          c[u][v][w].act = false;
          c[u][v][w].cld = false;
          c[u][v][w].hum = false;

          c[u][v][w].pact = 0;
          c[u][v][w].pext = 1;
          c[u][v][w].phum = 0;

          c[u][v][w].dens = 0.0f;
          c[u][v][w].light = 1.0f;
        }
      }
    }

    return c;
  }

  void DataManager::_delete3DCellArray(Cell ***c, const int& nx, const int& ny)
  {
    int u, v;

    for (u = 0; u < nx; u++)
    {
      for (v = 0; v < ny; v++)
      {
        delete [] c[u][v];
      }

      delete [] c[u];
    }

    delete [] c;
  }

  void DataManager::_copy3DCellArraysData(Cell ***src, Cell ***dest,
      const int& nx, const int& ny, const int& nz)
  {
    int u, v, w;

    for (u = 0; u < nx; u++)
    {
      for (v = 0; v < ny; v++)
      {
        for (w = 0; w < nz; w++)
        {
          dest[u][v][w].act = src[u][v][w].act;
          dest[u][v][w].cld = src[u][v][w].cld;
          dest[u][v][w].hum = src[u][v][w].hum;

          dest[u][v][w].pact = src[u][v][w].pact;
          dest[u][v][w].pext = src[u][v][w].pext;
          dest[u][v][w].phum = src[u][v][w].phum;

          dest[u][v][w].dens = src[u][v][w].dens;
          dest[u][v][w].light = src[u][v][w].light;
        }
      }
    }
  }

  void DataManager::setWheater(const float& Humidity,
      const float& AverageCloudsSize, const bool& delayedResponse)
  {
    int numberofclouds = static_cast < int>(Humidity * mMaxNumberOfClouds);
    Ogre::Vector3 maxcloudsize = AverageCloudsSize*
      Ogre::Vector3(mNx/14, mNy/14,
          static_cast < int>(static_cast < float>(mNz)/2.75));

    // Update old clouds with new parameters
    Ogre::Vector3 currentdimensions, currentPosition;
    std::vector < Ellipsoid*>::const_iterator mEllipsoidsIt;

    for (mEllipsoidsIt = mEllipsoids.begin();
        mEllipsoidsIt != mEllipsoids.end(); mEllipsoidsIt++)
    {
      // Update size
      currentdimensions = (*mEllipsoidsIt)->getDimensions();

      if (currentdimensions.x / maxcloudsize.x < 0.5 ||
          currentdimensions.x / maxcloudsize.x > 2)
      {
        currentdimensions.x = maxcloudsize.x +
          Ogre::Math::RangeRandom(-0.2, 0.2)*maxcloudsize.x;
      }
      if (currentdimensions.y / maxcloudsize.y < 0.5 ||
          currentdimensions.y / maxcloudsize.y > 2)
      {
        currentdimensions.y = maxcloudsize.y +
          Ogre::Math::RangeRandom(-0.2, 0.2)*maxcloudsize.y;
      }
      if (currentdimensions.z / maxcloudsize.z < 0.5 ||
          currentdimensions.z / maxcloudsize.z > 2)
      {
        currentdimensions.z = maxcloudsize.z +
          Ogre::Math::RangeRandom(-0.2, 0.15)*maxcloudsize.z;
      }

      (*mEllipsoidsIt)->setDimensions(currentdimensions);

      // Update position
      currentPosition = (*mEllipsoidsIt)->getPosition();
      (*mEllipsoidsIt)->setPosition(
          Ogre::Vector3(currentPosition.x, currentPosition.y,
            static_cast < int>(Ogre::Math::RangeRandom(currentdimensions.z+2,
                mNz-currentdimensions.z-2))));
    }

    // Remove some clouds if needed
    while (static_cast < unsigned int>(numberofclouds) < mEllipsoids.size())
    {
      mEllipsoids.pop_back();
    }

    // Add new clouds if needed
    Ogre::Vector3 newclouddimensions;
    while (static_cast < unsigned int>(numberofclouds) > mEllipsoids.size())
    {
      newclouddimensions = maxcloudsize *
        Ogre::Vector3(Ogre::Math::RangeRandom(0.5, 2),
            Ogre::Math::RangeRandom(0.5, 2), Ogre::Math::RangeRandom(0.75, 1));

      addEllipsoid(new Ellipsoid(newclouddimensions.x, newclouddimensions.y,
            newclouddimensions.z, mNx, mNy, mNz,
            (int)Ogre::Math::RangeRandom(0, mNx),
            (int)Ogre::Math::RangeRandom(0, mNy),
            static_cast < int>(Ogre::Math::RangeRandom(
                newclouddimensions.z+2, mNz-newclouddimensions.z-2)),
            Ogre::Math::RangeRandom(1, 5.0f)), false);
    }

    _updateProbabilities(mCellsCurrent, mNx, mNy, mNz, delayedResponse);

    if (!delayedResponse)
    {
      for (int k = 0; k < 4; k++)
      {
        _performCalculations(mNx, mNy, mNz, k, 0, mNx);
      }
      mStep = mXStart = mXEnd = 0;

      _updateVolTextureData(mCellsCurrent, VOL_TEX0, mNx, mNy, mNz);
      _updateVolTextureData(mCellsCurrent, VOL_TEX1, mNx, mNy, mNz);
    }
  }

  void DataManager::addEllipsoid(Ellipsoid *e, const bool& UpdateProbabilities)
  {
    mEllipsoids.push_back(e);

    if (UpdateProbabilities)
    {
      e->updateProbabilities(mCellsCurrent, mNx, mNy, mNz);
    }
  }

  void DataManager::_clearProbabilities(Cell*** c, const int& nx,
      const int& ny, const int& nz, const bool& clearData)
  {
    int u, v, w;

    for (u = 0; u < nx; u++)
    {
      for (v = 0; v < ny; v++)
      {
        for (w = 0; w < nz; w++)
        {
          c[u][v][w].pact = 0;
          c[u][v][w].pext = 1;
          c[u][v][w].phum = 0;

          if (clearData)
          {
            c[u][v][w].act = false;
            c[u][v][w].cld = false;
            c[u][v][w].hum = false;

            c[u][v][w].dens = 0;
            c[u][v][w].light = 0;
          }
        }
      }
    }
  }

  void DataManager::_updateProbabilities(Cell*** c, const int& nx,
      const int& ny, const int& nz, const bool& delayedResponse)
  {
    _clearProbabilities(c, nx, ny, nz, !delayedResponse);

    std::vector < Ellipsoid*>::const_iterator mEllipsoidsIt;

    for (mEllipsoidsIt = mEllipsoids.begin();
        mEllipsoidsIt != mEllipsoids.end(); mEllipsoidsIt++)
    {
      (*mEllipsoidsIt)->updateProbabilities(c, nx, ny, nz, delayedResponse);
    }
  }

  Ogre::Real DataManager::_getLightAbsorcionAt(Cell*** c, const int& nx,
      const int& ny, const int& nz, const int& x, const int& y, const int& z,
      const Ogre::Vector3& d, const float& att) const
  {
    Ogre::Real step = 1, factor = 1;
    Ogre::Vector3 negD = -d;
    int xLocal = x;
    int yLocal = y;
    int zLocal = z;
    bool outOfBounds = false;
    int u, v, uu, vv,
        current_iteration = 0, max_iterations = 8;

    while (!outOfBounds)
    {
      if (zLocal >= nz || zLocal < 0 || factor <= 0 ||
          current_iteration >= max_iterations)
      {
        outOfBounds = true;
      }
      else
      {
        u = xLocal;
        v = yLocal;

        uu = (u < 0) ? (u + nx) : u;
        if (u >= nx)
          uu -= nx;

        vv = (v < 0) ? (v + ny) : v;
        if (v >= ny)
          vv -= ny;

        factor -= c[uu][vv][zLocal].dens * att * (1 -
            static_cast<float>(current_iteration)/max_iterations);

        xLocal += step * negD.x;
        yLocal += step * negD.y;
        zLocal += step * negD.z;

        current_iteration++;
      }
    }

    return Ogre::Math::Clamp < Ogre::Real>(factor, 0, 1);
  }

  void DataManager::_performCalculations(const int& nx, const int& ny,
      const int& nz, const int& step, const int& xStart, const int& xEnd)
  {
    int u, v, w;

    switch (step)
    {
      case 0:
        {
          for (u = xStart; u < xEnd; u++)
          {
            for (v = 0; v < ny; v++)
            {
              for (w = 0; w < nz; w++)
              {
                // ti+1            ti
                mCellsCurrent[u][v][w].hum = mCellsCurrent[u][v][w].hum ||
                  (mFFRandom->get() < mCellsCurrent[u][v][w].phum);
                mCellsCurrent[u][v][w].cld = mCellsCurrent[u][v][w].cld &&
                  (mFFRandom->get() > mCellsCurrent[u][v][w].pext);
                mCellsCurrent[u][v][w].act = mCellsCurrent[u][v][w].act ||
                  (mFFRandom->get() < mCellsCurrent[u][v][w].pact);

                // Copy act in the temporal buffer, for _fact(...)
                mCellsTmp[u][v][w].act = mCellsCurrent[u][v][w].act;
              }
            }
          }
        }
        break;
      case 1:
        {
          for (u = xStart; u < xEnd; u++)
          {
            for (v = 0; v < ny; v++)
            {
              for (w = 0; w < nz; w++)
              {
                // ti+1            ti
                mCellsCurrent[u][v][w].hum =  mCellsCurrent[u][v][w].hum &&
                  !mCellsCurrent[u][v][w].act;
                mCellsCurrent[u][v][w].cld =  mCellsCurrent[u][v][w].cld ||
                  mCellsCurrent[u][v][w].act;
                mCellsCurrent[u][v][w].act = !mCellsCurrent[u][v][w].act &&
                  mCellsCurrent[u][v][w].hum &&
                  _fact(mCellsTmp, nx, ny, nz, u, v, w);
              }
            }
          }
        }
        break;
      case 2:
        {
          // Continous density
          for (u = xStart; u < xEnd; u++)
          {
            for (v = 0; v < ny; v++)
            {
              for (w = 0; w < nz; w++)
              {
                mCellsCurrent[u][v][w].dens = _getDensityAt(mCellsCurrent,
                    nx, ny, nz, u, v, w, 1/*TODOOOO!!!*/, 1.15f);
                // mCellsCurrent[u][v][w].dens =
                // _getDensityAt(mCellsCurrent,u,v,w);
              }
            }
          }
        }
        break;
      case 3:
        {
          // Light scattering
          Ogre::Vector3 SunDir = Ogre::Vector3(mVClouds->getSunDirection().x,
              mVClouds->getSunDirection().y, mVClouds->getSunDirection().z);

          for (u = xStart; u < xEnd; u++)
          {
            for (v = 0; v < ny; v++)
            {
              for (w = 0; w < nz; w++)
              {
                mCellsCurrent[u][v][w].light = _getLightAbsorcionAt(
                    mCellsCurrent, nx, ny, nz, u, v, w, SunDir,
                    0.15f/*TODO!!!!*/);
              }
            }
          }
        }
        break;
      default:
        break;
    }
  }

  bool DataManager::_fact(Cell ***c, const int& nx, const int& ny,
      const int& nz, const int& x, const int& y, const int& z) const
  {
    bool i1m, j1m, k1m,
    i1r, j1r, k1r,
    i2r, i2m, j2r, j2m, k2r;

    i1m = ((x+1) >= nx) ? c[0][y][z].act : c[x+1][y][z].act;
    j1m = ((y+1) >= ny) ? c[x][0][z].act : c[x][y+1][z].act;
    k1m = ((z+1) >= nz) ? false : c[x][y][z+1].act;

    i1r = ((x-1) < 0) ? c[nx-1][y][z].act : c[x-1][y][z].act;
    j1r = ((y-1) < 0) ? c[x][ny-1][z].act : c[x][y-1][z].act;
    k1r = ((z-1) < 0) ? false : c[x][y][z-1].act;

    i2r = ((x-2) < 0) ? c[nx-2][y][z].act : c[x-2][y][z].act;
    j2r = ((y-2) < 0) ? c[x][ny-2][z].act : c[x][y-2][z].act;
    k2r = ((z-2) < 0) ? false : c[x][y][z-2].act;

    i2m = ((x+2) >= nx) ? c[1][y][z].act : c[x+2][y][z].act;
    j2m = ((y+2) >= ny) ? c[x][1][z].act : c[x][y+2][z].act;

    return i1m || j1m || k1m || i1r || j1r || k1r || i2r ||
           i2m || j2r || j2m || k2r;
  }

  float DataManager::_getDensityAt(Cell ***c, const int& nx,
      const int& ny, const int& nz, const int& x, const int& y, const int& z,
      const int& r, const float& strength) const
  {
    int zr = ((z-r) < 0) ? 0 : z-r;
    int zm = ((z+r) >= nz) ? nz : z+r;
    int u, uu, v, vv, w;
    int clouds = 0, div = 0;

    for (u = x-r; u <= x+r; u++)
    {
      for (v = y-r; v <= y+r; v++)
      {
        for (w = zr; w < zm; w++)
        {
          // x/y Seamless!
          uu = (u < 0) ? (u + nx) : u;
          if (u >= nx) { uu -= nx; }
          vv = (v < 0) ? (v + ny) : v;
          if (v >= ny) { vv -= ny; }

          clouds += c[uu][vv][w].cld ? 1 : 0;
          div++;
        }
      }
    }

    return Ogre::Math::Clamp < float>(strength*((float)clouds)/div, 0, 1);
  }

  float DataManager::_getDensityAt(Cell ***c, const int& x,
      const int& y, const int& z) const
  {
    return c[x][y][z].cld ? 1.0f : 0.0f;
  }

  void DataManager::_createVolTexture(const VolTextureId& TexId, const int& nx,
      const int& ny, const int& nz)
  {
    mVolTextures[static_cast < int>(TexId)]
      = Ogre::TextureManager::getSingleton().
      createManual("_SkyX_VolCloudsData"+Ogre::StringConverter::toString(TexId),
          SKYX_RESOURCE_GROUP,
          Ogre::TEX_TYPE_3D,
          nx, ny, nz, 0,
          Ogre::PF_BYTE_RGB);

    mVolTextures[static_cast < int>(TexId)]->load();

    static_cast < Ogre::MaterialPtr>(
        Ogre::MaterialManager::getSingleton().getByName("SkyX_VolClouds"))
      ->getTechnique(0)->getPass(0)->getTextureUnitState(
          static_cast < int>(TexId))
      ->setTextureName("_SkyX_VolCloudsData" +
          Ogre::StringConverter::toString(TexId), Ogre::TEX_TYPE_3D);
    static_cast < Ogre::MaterialPtr>(
        Ogre::MaterialManager::getSingleton().getByName(
          "SkyX_VolClouds_Lightning"))
      ->getTechnique(0)->getPass(0)->getTextureUnitState(
          static_cast < int>(TexId))
      ->setTextureName("_SkyX_VolCloudsData" +
          Ogre::StringConverter::toString(TexId), Ogre::TEX_TYPE_3D);
  }

  void DataManager::_updateVolTextureData(Cell ***c, const VolTextureId& TexId,
      const int& /*nx*/, const int& /*ny*/, const int& /*nz*/)
  {
    Ogre::HardwarePixelBufferSharedPtr buffer =
      mVolTextures[TexId]->getBuffer(0, 0);

    buffer->lock(Ogre::HardwareBuffer::HBL_DISCARD);
    const Ogre::PixelBox &pb = buffer->getCurrentLock();

    Ogre::uint32 *pbptr = static_cast < Ogre::uint32*>(pb.data);
    size_t x, y, z;

    for (z = pb.front; z < pb.back; z++)
    {
      for (y = pb.top; y < pb.bottom; y++)
      {
        for (x = pb.left; x < pb.right; x++)
        {
          Ogre::uint8 *ptr = (Ogre::uint8 *)pb.data +
                             (x + y * pb.rowPitch + z * pb.slicePitch) *
                                 Ogre::PixelUtil::getNumElemBytes(pb.format);

          Ogre::PixelUtil::packColour(c[x][y][z].dens/* TODO!!!! */,
              c[x][y][z].light, 0, 0, pb.format, ptr);
        }
        pbptr += pb.rowPitch;
      }
      pbptr += pb.getSliceSkip();
    }
    buffer->unlock();
  }
}
}
