#include "localmap.hpp"

#include <OgreMaterialManager.h>
#include <OgreHardwarePixelBuffer.h>
#include <OgreSceneManager.h>
#include <OgreSceneNode.h>
#include <OgreCamera.h>
#include <OgreTextureManager.h>
#include <OgreRenderTexture.h>
#include <OgreViewport.h>

#include "../mwbase/environment.hpp"
#include "../mwbase/world.hpp"
#include "../mwbase/windowmanager.hpp"

#include "../mwworld/esmstore.hpp"
#include "../mwworld/cellstore.hpp"

#include "renderconst.hpp"
#include "renderingmanager.hpp"

using namespace MWRender;
using namespace Ogre;

LocalMap::LocalMap(OEngine::Render::OgreRenderer* rend, MWRender::RenderingManager* rendering) :
    mInterior(false), mCellX(0), mCellY(0)
{
    mRendering = rend;
    mRenderingManager = rendering;

    mCameraPosNode = mRendering->getScene()->getRootSceneNode()->createChildSceneNode();
    mCameraRotNode = mCameraPosNode->createChildSceneNode();
    mCameraNode = mCameraRotNode->createChildSceneNode();

    mCellCamera = mRendering->getScene()->createCamera("CellCamera");
    mCellCamera->setProjectionType(PT_ORTHOGRAPHIC);

    mCameraNode->attachObject(mCellCamera);

    mLight = mRendering->getScene()->createLight();
    mLight->setType (Ogre::Light::LT_DIRECTIONAL);
    mLight->setDirection (Ogre::Vector3(0.3, 0.3, -0.7));
    mLight->setVisible (false);
    mLight->setDiffuseColour (ColourValue(0.7,0.7,0.7));
}

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

const Ogre::Vector2 LocalMap::rotatePoint(const Ogre::Vector2& p, const Ogre::Vector2& c, const float angle)
{
    return Vector2( Math::Cos(angle) * (p.x - c.x) - Math::Sin(angle) * (p.y - c.y) + c.x,
                    Math::Sin(angle) * (p.x - c.x) + Math::Cos(angle) * (p.y - c.y) + c.y);
}

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::CellStore* cell)
{
    if (!mInterior)
    {
        /*saveTexture("Cell_"+coordStr(mCellX, mCellY)+"_fog",
            "Cell_"+coordStr(mCellX, mCellY)+"_fog.png");*/
    }
    else
    {
        Vector2 min(mBounds.getMinimum().x, mBounds.getMinimum().y);
        Vector2 max(mBounds.getMaximum().x, mBounds.getMaximum().y);
        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::CellStore* cell, float zMin, float zMax)
{
    mInterior = false;

    mCameraRotNode->setOrientation(Quaternion::IDENTITY);
    mCellCamera->setOrientation(Quaternion(Ogre::Math::Cos(Ogre::Degree(0)/2.f), 0, 0, -Ogre::Math::Sin(Ogre::Degree(0)/2.f)));

    int x = cell->getCell()->getGridX();
    int y = cell->getCell()->getGridY();

    std::string name = "Cell_"+coordStr(x, y);

    mCameraPosNode->setPosition(Vector3(0,0,0));

    render((x+0.5)*sSize, (y+0.5)*sSize, zMin, zMax, sSize, sSize, name);
}

void LocalMap::requestMap(MWWorld::CellStore* cell,
                            AxisAlignedBox bounds)
{
    // if we're in an empty cell, don't bother rendering anything
    if (bounds.isNull ())
        return;

    mInterior = true;
    mBounds = bounds;

    float zMin = mBounds.getMinimum().z;
    float zMax = mBounds.getMaximum().z;

    const Vector2& north = MWBase::Environment::get().getWorld()->getNorthVector(cell);
    Radian angle = Ogre::Math::ATan2 (north.x, north.y);
    mAngle = angle.valueRadians();

    mCellCamera->setOrientation(Quaternion::IDENTITY);
    mCameraRotNode->setOrientation(Quaternion(Math::Cos(mAngle/2.f), 0, 0, -Math::Sin(mAngle/2.f)));

    // rotate the cell and merge the rotated corners to the bounding box
    Vector2 _center(bounds.getCenter().x, bounds.getCenter().y);
    Vector3 _c1 = bounds.getCorner(AxisAlignedBox::FAR_LEFT_BOTTOM);
    Vector3 _c2 = bounds.getCorner(AxisAlignedBox::FAR_RIGHT_BOTTOM);
    Vector3 _c3 = bounds.getCorner(AxisAlignedBox::FAR_LEFT_TOP);
    Vector3 _c4 = bounds.getCorner(AxisAlignedBox::FAR_RIGHT_TOP);

    Vector2 c1(_c1.x, _c1.y);
    Vector2 c2(_c2.x, _c2.y);
    Vector2 c3(_c3.x, _c3.y);
    Vector2 c4(_c4.x, _c4.y);
    c1 = rotatePoint(c1, _center, mAngle);
    c2 = rotatePoint(c2, _center, mAngle);
    c3 = rotatePoint(c3, _center, mAngle);
    c4 = rotatePoint(c4, _center, mAngle);
    mBounds.merge(Vector3(c1.x, c1.y, 0));
    mBounds.merge(Vector3(c2.x, c2.y, 0));
    mBounds.merge(Vector3(c3.x, c3.y, 0));
    mBounds.merge(Vector3(c4.x, c4.y, 0));

    // apply a little padding
    mBounds.setMinimum (mBounds.getMinimum() - Vector3(500,500,0));
    mBounds.setMaximum (mBounds.getMaximum() + Vector3(500,500,0));

    Vector2 center(mBounds.getCenter().x, mBounds.getCenter().y);

    Vector2 min(mBounds.getMinimum().x, mBounds.getMinimum().y);
    Vector2 max(mBounds.getMaximum().x, mBounds.getMaximum().y);

    Vector2 length = max-min;

    mCameraPosNode->setPosition(Vector3(center.x, center.y, 0));

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

    mInteriorName = cell->getCell()->mName;

    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 - center.x, newcenter.y - center.y, zMin, zMax, sSize, sSize,
                cell->getCell()->mName + "_" + 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)
{
    mCellCamera->setFarClipDistance( (zhigh-zlow) + 2000 );
    mCellCamera->setNearClipDistance(50);

    mCellCamera->setOrthoWindow(xw, yw);
    mCameraNode->setPosition(Vector3(x, y, zhigh+1000));

    // disable fog (only necessary for fixed function, the shader based
    // materials already do this through local_map material configuration)
    float oldFogStart = mRendering->getScene()->getFogStart();
    float oldFogEnd = mRendering->getScene()->getFogEnd();
    Ogre::ColourValue oldFogColour = mRendering->getScene()->getFogColour();
    mRendering->getScene()->setFog(FOG_NONE);

    // set up lighting
    Ogre::ColourValue oldAmbient = mRendering->getScene()->getAmbientLight();
    mRendering->getScene()->setAmbientLight(Ogre::ColourValue(0.3, 0.3, 0.3));
    mRenderingManager->disableLights(true);
    mLight->setVisible(true);

    TexturePtr tex;
    // try loading from memory
    tex = TextureManager::getSingleton().getByName(texture);
    if (tex.isNull())
    {
        // 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(RV_Map);
        vp->setMaterialScheme("local_map");

        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;
    }

    mRenderingManager->enableLights(true);
    mLight->setVisible(false);

    // re-enable fog
    mRendering->getScene()->setFog(FOG_LINEAR, oldFogColour, 0, oldFogStart, oldFogEnd);
    mRendering->getScene()->setAmbientLight(oldAmbient);
}

void LocalMap::getInteriorMapPosition (Ogre::Vector2 pos, float& nX, float& nY, int& x, int& y)
{
    pos = rotatePoint(pos, Vector2(mBounds.getCenter().x, mBounds.getCenter().y), mAngle);

    Vector2 min(mBounds.getMinimum().x, mBounds.getMinimum().y);

    x = std::ceil((pos.x - min.x)/sSize)-1;
    y = std::ceil((pos.y - min.y)/sSize)-1;

    nX = (pos.x - min.x - sSize*x)/sSize;
    nY = 1.0-(pos.y - min.y - sSize*y)/sSize;
}

bool LocalMap::isPositionExplored (float nX, float nY, int x, int y, bool interior)
{
    std::string texName = (interior ? mInteriorName + "_" : "Cell_") + coordStr(x, y);

    if (mBuffers.find(texName) == mBuffers.end())
        return false;

    int texU = (sFogOfWarResolution-1) * nX;
    int texV = (sFogOfWarResolution-1) * nY;

    Ogre::uint32 clr = mBuffers[texName][texV * sFogOfWarResolution + texU];
    uint8 alpha = (clr >> 24);
    return alpha < 200;
}

void LocalMap::updatePlayer (const Ogre::Vector3& position, const Ogre::Quaternion& orientation)
{
    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;
    float u,v;

    Vector2 pos(position.x, position.y);

    if (mInterior)
        getInteriorMapPosition(pos, u,v, x,y);

    Vector3 playerdirection = mCameraRotNode->convertWorldToLocalOrientation(orientation).yAxis();

    if (!mInterior)
    {
        x = std::ceil(pos.x / sSize)-1;
        y = std::ceil(pos.y / sSize)-1;
        mCellX = x;
        mCellY = y;
    }
    else
    {
        MWBase::Environment::get().getWindowManager()->setInteriorMapTexture(x,y);
    }

    // convert from world coordinates to texture UV coordinates
    std::string texBaseName;
    if (!mInterior)
    {
        u = std::abs((pos.x - (sSize*x))/sSize);
        v = 1.0-std::abs((pos.y - (sSize*y))/sSize);
        texBaseName = "Cell_";
    }
    else
    {
        texBaseName = mInteriorName + "_";
    }

    MWBase::Environment::get().getWindowManager()->setPlayerPos(u, v);
    MWBase::Environment::get().getWindowManager()->setPlayerDir(playerdirection.x, playerdirection.y);

    // explore radius (squared)
    const float exploreRadius = (mInterior ? 0.1 : 0.3) * (sFogOfWarResolution-1); // explore radius from 0 to sFogOfWarResolution-1
    const float sqrExploreRadius = Math::Sqr(exploreRadius);
    const float exploreRadiusUV = exploreRadius / sFogOfWarResolution; // explore radius from 0 to 1 (UV space)

    // change the affected fog of war textures (in a 3x3 grid around the player)
    for (int mx = -1; mx<2; ++mx)
    {
        for (int my = -1; my<2; ++my)
        {

            // is this texture affected at all?
            bool affected = false;
            if (mx == 0 && my == 0) // the player is always in the center of the 3x3 grid
                affected = true;
            else
            {
                bool affectsX = (mx > 0)? (u + exploreRadiusUV > 1) : (u - exploreRadiusUV < 0);
                bool affectsY = (my > 0)? (v + exploreRadiusUV > 1) : (v - exploreRadiusUV < 0);
                affected = (affectsX && (my == 0)) || (affectsY && mx == 0) || (affectsX && affectsY);
            }

            if (!affected)
                continue;

            std::string texName = texBaseName + coordStr(x+mx,y+my*-1);

            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 + mx*(sFogOfWarResolution-1)) - u*(sFogOfWarResolution-1))
                                + Math::Sqr((texV + my*(sFogOfWarResolution-1)) - v*(sFogOfWarResolution-1));
                        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();
            }
        }
    }
}