#include "localmap.hpp"
#include "renderingmanager.hpp"

#include "../mwworld/environment.hpp"
#include "../mwgui/window_manager.hpp"

#include <OgreOverlayManager.h>
#include <OgreMaterialManager.h>

using namespace MWRender;
using namespace Ogre;

LocalMap::LocalMap(OEngine::Render::OgreRenderer* rend, MWWorld::Environment* env)
{
    mRendering = rend;
    mEnvironment = env;
    
    mCellCamera = mRendering->getScene()->createCamera("CellCamera");
    mCellCamera->setProjectionType(PT_ORTHOGRAPHIC);
    // look down -y
    const float sqrt0pt5 = 0.707106781;
    mCellCamera->setOrientation(Quaternion(sqrt0pt5, -sqrt0pt5, 0, 0));
}

LocalMap::~LocalMap()
{
    deleteBuffers();
}

void LocalMap::deleteBuffers()
{
    mBuffers.clear();
}

void LocalMap::saveTexture(const std::string& texname, const std::string& filename)
{
    TexturePtr tex = TextureManager::getSingleton().getByName(texname);
    if (tex.isNull()) return;
    HardwarePixelBufferSharedPtr readbuffer = tex->getBuffer();
    readbuffer->lock(HardwareBuffer::HBL_NORMAL );
    const PixelBox &readrefpb = readbuffer->getCurrentLock();    
    uchar *readrefdata = static_cast<uchar*>(readrefpb.data);        

    Image img;
    img = img.loadDynamicImage (readrefdata, tex->getWidth(),
        tex->getHeight(), tex->getFormat());    
    img.save("./" + filename);

    readbuffer->unlock();
}

std::string LocalMap::coordStr(const int x, const int y)
{
    return StringConverter::toString(x) + "_" + StringConverter::toString(y);
}

void LocalMap::saveFogOfWar(MWWorld::Ptr::CellStore* cell)
{
    if (!mInterior)
    {
        /*saveTexture("Cell_"+coordStr(mCellX, mCellY)+"_fog",
            "Cell_"+coordStr(mCellX, mCellY)+"_fog.png");*/
    }
    else
    {
        Vector2 min(mBounds.getMinimum().x, mBounds.getMinimum().z);
        Vector2 max(mBounds.getMaximum().x, mBounds.getMaximum().z);
        /// \todo why is this workaround needed?
        min *= 1.3;
        max *= 1.3;
        Vector2 length = max-min;
        
        // divide into segments
        const int segsX = std::ceil( length.x / sSize );
        const int segsY = std::ceil( length.y / sSize );

        for (int x=0; x<segsX; ++x)
        {
            for (int y=0; y<segsY; ++y)
            {
                /*saveTexture(
                    mInteriorName + "_" + coordStr(x,y) + "_fog",
                    mInteriorName + "_" + coordStr(x,y) + "_fog.png");*/
            }
        }
    }
}

void LocalMap::requestMap(MWWorld::Ptr::CellStore* cell)
{
    mInterior = false;

    std::string name = "Cell_"+coordStr(cell->cell->data.gridX, cell->cell->data.gridY);

    int x = cell->cell->data.gridX;
    int y = cell->cell->data.gridY;

    render((x+0.5)*sSize, (-y-0.5)*sSize, -10000, 10000, sSize, sSize, name);
}

void LocalMap::requestMap(MWWorld::Ptr::CellStore* cell,
                            AxisAlignedBox bounds)
{
    mInterior = true;
    mBounds = bounds;
    
    Vector2 z(bounds.getMaximum().y, bounds.getMinimum().y);
    Vector2 min(bounds.getMinimum().x, bounds.getMinimum().z);
    Vector2 max(bounds.getMaximum().x, bounds.getMaximum().z);

    /// \todo why is this workaround needed?
    min *= 1.3;
    max *= 1.3;

    Vector2 length = max-min;
    Vector2 center(bounds.getCenter().x, bounds.getCenter().z);

    // divide into segments
    const int segsX = std::ceil( length.x / sSize );
    const int segsY = std::ceil( length.y / sSize );

    mInteriorName = cell->cell->name;

    for (int x=0; x<segsX; ++x)
    {
        for (int y=0; y<segsY; ++y)
        {
            Vector2 start = min + Vector2(sSize*x,sSize*y);
            Vector2 newcenter = start + 4096;

            render(newcenter.x, newcenter.y, z.y, z.x, sSize, sSize,
                cell->cell->name + "_" + coordStr(x,y));
        }
    }
}

void LocalMap::render(const float x, const float y,
                    const float zlow, const float zhigh,
                    const float xw, const float yw, const std::string& texture)
{
    // disable fog
    // changing FOG_MODE is not a solution when using shaders, thus we have to push linear start/end
    const float fStart = mRendering->getScene()->getFogStart();
    const float fEnd = mRendering->getScene()->getFogEnd();
    const ColourValue& clr = mRendering->getScene()->getFogColour();
    mRendering->getScene()->setFog(FOG_LINEAR, clr, 0, 1000000, 10000000);

    // make everything visible
    mRendering->getScene()->setAmbientLight(ColourValue(1,1,1));

    mCellCamera->setPosition(Vector3(x, zhigh+100000, y));
    //mCellCamera->setFarClipDistance( (zhigh-zlow) * 1.1 );
    mCellCamera->setFarClipDistance(0); // infinite

    mCellCamera->setOrthoWindow(xw, yw);

    TexturePtr tex;
    // try loading from memory
    tex = TextureManager::getSingleton().getByName(texture);
    if (tex.isNull())
    {
        // try loading from disk
        //if (boost::filesystem::exists(texture+".jpg"))
        //{
            /// \todo
        //}
        //else
        {
            // render
            tex = TextureManager::getSingleton().createManual(
                            texture,
                            ResourceGroupManager::DEFAULT_RESOURCE_GROUP_NAME,
                            TEX_TYPE_2D,
                            xw*sMapResolution/sSize, yw*sMapResolution/sSize, 
                            0,
                            PF_R8G8B8,
                            TU_RENDERTARGET);

            RenderTarget* rtt = tex->getBuffer()->getRenderTarget();
            rtt->setAutoUpdated(false);
            Viewport* vp = rtt->addViewport(mCellCamera);
            vp->setOverlaysEnabled(false);
            vp->setShadowsEnabled(false);
            vp->setBackgroundColour(ColourValue(0, 0, 0));
            //vp->setVisibilityMask( ... );

            rtt->update();

            // create "fog of war" texture
            TexturePtr tex2 = TextureManager::getSingleton().createManual(
                            texture + "_fog",
                            ResourceGroupManager::DEFAULT_RESOURCE_GROUP_NAME,
                            TEX_TYPE_2D,
                            xw*sFogOfWarResolution/sSize, yw*sFogOfWarResolution/sSize, 
                            0,
                            PF_A8R8G8B8,
                            TU_DYNAMIC_WRITE_ONLY_DISCARDABLE);

            // create a buffer to use for dynamic operations
            std::vector<uint32> buffer;
            buffer.resize(sFogOfWarResolution*sFogOfWarResolution);

            // initialize to (0, 0, 0, 1)
            for (int p=0; p<sFogOfWarResolution*sFogOfWarResolution; ++p)
            {
                buffer[p] = (255 << 24);
            }

            memcpy(tex2->getBuffer()->lock(HardwareBuffer::HBL_DISCARD), &buffer[0], sFogOfWarResolution*sFogOfWarResolution*4);
            tex2->getBuffer()->unlock();

            mBuffers[texture] = buffer;

            // save to cache for next time
            //rtt->writeContentsToFile("./" + texture + ".jpg");
        }
    }
    

    // re-enable fog
    mRendering->getScene()->setFog(FOG_LINEAR, clr, 0, fStart, fEnd);
}

void LocalMap::updatePlayer (const Ogre::Vector3& position, const Ogre::Vector3& direction)
{
    if (sFogOfWarSkip != 0)
    {
        static int count=0;
        if (++count % sFogOfWarSkip != 0)
            return;
    }

    // retrieve the x,y grid coordinates the player is in 
    int x,y;
    Vector2 pos(position.x, position.z);
    if (!mInterior)
    {
        x = std::ceil(pos.x / sSize)-1;
        y = std::ceil(-pos.y / sSize)-1;
        mCellX = x;
        mCellY = y;
    }
    else
    {
        Vector2 min(mBounds.getMinimum().x, mBounds.getMinimum().z);
        min *= 1.3;
        
        x = std::ceil((pos.x - min.x)/sSize)-1;
        y = std::ceil((pos.y - min.y)/sSize)-1;

        mEnvironment->mWindowManager->setInteriorMapTexture(x,y);
    }

    // convert from world coordinates to texture UV coordinates
    float u,v;
    std::string texName;
    if (!mInterior)
    {
        u = std::abs((pos.x - (sSize*x))/sSize);
        v = 1-std::abs((pos.y + (sSize*y))/sSize);
        texName = "Cell_"+coordStr(x,y);

    }
    else
    {
        Vector2 min(mBounds.getMinimum().x, mBounds.getMinimum().z);
        min *= 1.3;

        u = (pos.x - min.x - sSize*x)/sSize;
        v = (pos.y - min.y - sSize*y)/sSize;

        texName = mInteriorName + "_" + coordStr(x,y);
    }
    mEnvironment->mWindowManager->setPlayerPos(u, v);
    mEnvironment->mWindowManager->setPlayerDir(direction.x, -direction.z);

    // explore radius (squared)
    const float sqrExploreRadius = 0.01 * sFogOfWarResolution*sFogOfWarResolution;

    // get the appropriate fog of war texture
    TexturePtr tex = TextureManager::getSingleton().getByName(texName+"_fog");
    if (!tex.isNull())
    {
        // get its buffer
        if (mBuffers.find(texName) == mBuffers.end()) return;
        int i=0;
        for (int texV = 0; texV<sFogOfWarResolution; ++texV)
        {
            for (int texU = 0; texU<sFogOfWarResolution; ++texU)
            {
                float sqrDist = Math::Sqr(texU - u*sFogOfWarResolution) + Math::Sqr(texV - v*sFogOfWarResolution);
                uint32 clr = mBuffers[texName][i];
                uint8 alpha = (clr >> 24);
                alpha = std::min( alpha, (uint8) (std::max(0.f, std::min(1.f, (sqrDist/sqrExploreRadius)))*255) );
                mBuffers[texName][i] = (uint32) (alpha << 24);

                ++i;
            }
        }

        // copy to the texture
        memcpy(tex->getBuffer()->lock(HardwareBuffer::HBL_DISCARD), &mBuffers[texName][0], sFogOfWarResolution*sFogOfWarResolution*4);
        tex->getBuffer()->unlock();
    }
}
