#include <string>

#include "Engine.h"

#include "UserInterface.h"
#include "Utility.h"
#include "View.h"

using std::cout;
using std::endl;
using std::wcerr;
using std::wstring;
using std::wstringstream;

using namespace irr;
using namespace irr::core;
using namespace irr::scene;
using namespace irr::video;
using namespace irr::gui;

/* //////////////////////////////////////////////////////////////////////////
   PRIVATE METHODS
   /////////////////////////////////////////////////////////////////////// */

void Engine::setupScene()
{
    // Setup Light
    m_SceneLight = m_Scene->addLightSceneNode();
    m_SceneLight->setID(SIID_LIGHT);
    m_SceneLight->setLightType(ELT_DIRECTIONAL);
    m_SceneLight->getLightData().AmbientColor = SColorf(0.2f, 0.2f, 0.2f);
    m_SceneLight->getLightData().DiffuseColor = SColorf(0.8f, 0.8f, 0.8f);
    m_Scene->setAmbientLight(SColorf(0.2f, 0.2f, 0.2f));

    // Setup Camera
    // (so z-forward characters face camera partially (formerly vector3df(0, 0, -10), vector3df())
    m_CamPos = vector3df(4.5, 3, 9);
    m_CamTarget = vector3df(0, 3, 0);
    ICameraSceneNode* camera = m_Scene->addCameraSceneNode(nullptr, m_CamPos, m_CamTarget); // this will be overridden by View m_Yaw and m_Pitch--see "calculate m_Yaw" further down
    camera->setAspectRatio(static_cast<f32>(m_Driver->getScreenSize().Width) / static_cast<f32>(m_Driver->getScreenSize().Height));
}

IGUIEnvironment* Engine::getGUIEnvironment() const
{
    return m_Device->getGUIEnvironment();
}

void Engine::drawAxisLines()
{
    SMaterial* lineX = new SMaterial();
    lineX->Lighting = false;
    lineX->EmissiveColor = SColor(255, 255, 0, 0);
    lineX->Thickness = 1.0f;

    SMaterial* lineY = new SMaterial(*lineX);
    lineY->EmissiveColor = SColor(255, 0, 255, 0);

    SMaterial* lineZ = new SMaterial(*lineX);
    lineZ->EmissiveColor = SColor(255, 0, 0, 255);

    m_Driver->setTransform(ETS_WORLD, matrix4());

    m_Driver->setMaterial(*lineX);
    m_Driver->draw3DLine(vector3df(), vector3df(5, 0, 0), SColor(255, 255, 0, 0));
    position2d<s32> textPos = m_Scene->getSceneCollisionManager()->getScreenCoordinatesFrom3DPosition(vector3df(5.2f, 0, 0));
    dimension2d<u32> textSize;
    if (m_AxisFont != nullptr) {
        textSize = m_AxisFont->getDimension(L"X+");
        m_AxisFont->draw(L"X+", rect<s32>(textPos, textSize), SColor(255, 255, 0, 0), true, true);
    }
    m_Driver->setMaterial(*lineY);
    m_Driver->draw3DLine(vector3df(), vector3df(0, 5, 0), SColor(255, 0, 255, 0));
    textPos = m_Scene->getSceneCollisionManager()->getScreenCoordinatesFrom3DPosition(vector3df(0, 5.2f, 0));
    if (m_AxisFont != nullptr) {
        textSize = m_AxisFont->getDimension(L"Y+");
        m_AxisFont->draw(L"Y+", rect<s32>(textPos, textSize), SColor(255, 0, 255, 0), true, true);
    }
    m_Driver->setMaterial(*lineZ);
    m_Driver->draw3DLine(vector3df(), vector3df(0, 0, 5), SColor(255, 0, 0, 255));
    textPos = m_Scene->getSceneCollisionManager()->getScreenCoordinatesFrom3DPosition(vector3df(0, 0, 5.2f));
    if (m_AxisFont != nullptr) {
        textSize = m_AxisFont->getDimension(L"Z+");
        m_AxisFont->draw(L"Z+", rect<s32>(textPos, textSize), SColor(255, 0, 0, 255), true, true);
    }
    delete lineX;
    delete lineY;
    delete lineZ;
}

void Engine::drawBackground()
{
    dimension2d<u32> screenSize = m_Driver->getScreenSize();
    m_Driver->draw2DRectangle(rect<s32>(0, 0, static_cast<s32>(screenSize.Width), static_cast<s32>(screenSize.Height)),
        SColor(255, 128, 128, 255),
        SColor(255, 128, 128, 255),
        SColor(255, 224, 224, 255),
        SColor(255, 224, 224, 255));
}

void Engine::checkResize()
{
    if ((m_WindowSize.Width != m_Driver->getScreenSize().Width) || (m_WindowSize.Height != m_Driver->getScreenSize().Height)) {
        m_WindowSize.Width = m_Driver->getScreenSize().Width;
        m_WindowSize.Height = m_Driver->getScreenSize().Height;

        // Send custom event
        IEventReceiver* eventReceiver = m_Device->getEventReceiver();

        SEvent event;
        event.EventType = EET_USER_EVENT;
        event.UserEvent.UserData1 = UEI_WINDOWSIZECHANGED;
        eventReceiver->OnEvent(event);
        //m_UserInterface->
    }
}

s32 Engine::getNumberOfVertices()
{
    IMesh* mesh = m_LoadedMesh->getMesh()->getMesh(0, 255, -1, -1);

    int vertices = 0;
    for (irr::u32 bufferIndex = 0; bufferIndex < mesh->getMeshBufferCount(); bufferIndex++)
        vertices += mesh->getMeshBuffer(bufferIndex)->getVertexCount();

    cout << vertices << endl;

    return vertices;
}

/* //////////////////////////////////////////////////////////////////////////
   PUBLIC METHODS
   /////////////////////////////////////////////////////////////////////// */

Engine::Engine()
{
    // For monitoring single press: see
    // <http://irrlicht.sourceforge.net/forum/viewtopic.php?p=210744>
    for (u32 i = 0; i < KEY_KEY_CODES_COUNT; ++i)
        KeyIsDown[i] = false;
    for (u32 i = 0; i < KEY_KEY_CODES_COUNT; ++i)
        keyState[i] = 0;
    LMouseState = 0;
    RMouseState = 0;

    this->worldFPS = 60;
    this->prevFPS = 30;
    this->textureExtensions.push_back(L"png");
    this->textureExtensions.push_back(L"jpg");
    this->textureExtensions.push_back(L"bmp");
#if WIN32
    m_Device = createDevice(EDT_DIRECT3D9, dimension2d<u32>(1024, 768), 32, false, false, false, nullptr);
#else
    m_Device = createDevice(EDT_OPENGL, dimension2d<u32>(1024, 768), 32, false, false, false, nullptr);
#endif
    m_Device->setResizable(true);

    m_EventHandler = new EventHandler(m_Device);
    m_Device->setEventReceiver(m_EventHandler);

    m_Driver = m_Device->getVideoDriver();
    m_Scene = m_Device->getSceneManager();

    wstringstream windowTitle;
    windowTitle << L"b3view (Blitz3D/Irrlicht Viewer) [" << m_Driver->getName() << L"]";
    m_Device->setWindowCaption(windowTitle.str().c_str());

    setupScene();

    // Setup User Interface
    m_UserInterface = new UserInterface(this);
    m_EventHandler->addEventReceiver(ERT_USERINTERFACE, m_UserInterface);

    // Setup 3D View
    m_View = new View(this);
    m_EventHandler->addEventReceiver(ERT_3DVIEW, m_View);

    // Load font for displaying Axis names
    m_AxisFontFace = new CGUITTFace();
    // NOTE: m_FontPath is modified y UserInterface constructor above if font was missing
    if (m_AxisFontFace->load(m_FontPath.c_str())) {
        m_AxisFont = new CGUITTFont(m_UserInterface->getGUIEnvironment());
        m_AxisFont->attach(m_AxisFontFace, 14);
        m_AxisFont->AntiAlias = false;
    } else {
        delete m_AxisFontFace;
        m_AxisFontFace = nullptr;
    }
    // Set Engine enabled
    m_RunEngine = true;
    m_LoadedMesh = nullptr;

    // Store actual window size
    m_WindowSize.Width = m_Driver->getScreenSize().Width;
    m_WindowSize.Height = m_Driver->getScreenSize().Height;

    // (do not calculate m_Yaw and m_Pitch here--see View constructor)

    this->playAnimation();
}

Engine::~Engine()
{
    m_Device->drop();
    delete m_AxisFont;
    delete m_AxisFontFace;
}

void Engine::loadMesh(const wstring& fileName)
{
    this->m_PreviousPath = fileName; // even if bad, set this
        // to allow F5 to reload

    if (m_LoadedMesh != nullptr)
        m_LoadedMesh->remove();

    irr::scene::IAnimatedMesh* mesh = m_Scene->getMesh(fileName.c_str());
    if (mesh != nullptr) {
        m_LoadedMesh = m_Scene->addAnimatedMeshSceneNode(mesh);
        Utility::dumpMeshInfoToConsole(m_LoadedMesh);
        if (Utility::toLower(Utility::extensionOf(fileName)) == L"3ds") {
            m_View->setZUp(true);
        } else {
            m_View->setZUp(false);
        }
        if (m_LoadedMesh != nullptr) {
            ICameraSceneNode* camera = this->m_Scene->getActiveCamera();
            aabbox3d<f32> box = m_LoadedMesh->getTransformedBoundingBox();
            //vector3d<float> extents = box.getExtent();
            if (m_View->zUp()) {
                float oldDist = m_CamPos.getDistanceFrom(m_CamTarget);
                float newDist = oldDist;
                if (Utility::equalsApprox(oldDist, 0.0f)) {
                    vector3d<float> center = box.getCenter();
                    vector3df edges[8];
                    box.getEdges(edges);
                    /*
                                              /3--------/7
                                             /  |      / |
                                            /   |     /  |
                                            1---------5  |
                                            |   2- - -| -6
                                            |  /      |  /
                                            |/        | /
                                            0---------4/
                    */
                    newDist = 0;
                    for (int i = 0; i < 8; i++) {
                        float tryDist = center.getDistanceFrom(edges[i]);
                        if (tryDist > newDist)
                            newDist = tryDist;
                    }
                    newDist *= 2; // so camera doesn't touch model
                    if (!Utility::equalsApprox<float>(newDist, oldDist)) {
                        float scale = newDist / oldDist; // already checked 0
                        vector3df oldCamPos = camera->getPosition();
                        m_CamPos = oldCamPos;
                        m_CamPos.X = m_CamPos.X * scale;
                        m_CamPos.Y = m_CamPos.Y * scale;
                        m_CamPos.Z = m_CamPos.Z * scale;
                        oldCamPos = m_CamPos;
                        m_View->setCameraDistance(m_CamPos.getDistanceFrom(m_CamTarget));
                        camera->setPosition(m_CamPos);
                    }
                }
            }
            m_LoadedMesh->setMaterialType(video::EMT_TRANSPARENT_ALPHA_CHANNEL_REF);
            // EMT_TRANSPARENT_ALPHA_CHANNEL: constant transparency
        }
    }
}

void Engine::reloadMesh()
{
    if (this->m_PreviousPath.length() > 0) {
        loadMesh(this->m_PreviousPath);
    }
}

void Engine::reloadTexture()
{
    if (this->m_PrevTexturePath.length() > 0) {
        if (wcslen(this->m_UserInterface->texturePathEditBox->getText()) == 0)
            loadTexture(this->m_UserInterface->texturePathEditBox->getText());
        else
            loadTexture(this->m_PrevTexturePath);
    }
}

bool Engine::loadTexture(const wstring& fileName)
{
    ITexture* texture = this->m_Driver->getTexture(fileName.c_str());
    bool ret = false;
    if (texture != nullptr) {
        m_LoadedMesh->setMaterialTexture(0, texture);
        ret = true;
    }
    this->m_PrevTexturePath = fileName;
    this->m_UserInterface->texturePathEditBox->setText(this->m_PrevTexturePath.c_str());
    return ret;
}

void Engine::setMeshDisplayMode(bool wireframe, bool lighting, bool textureInterpolation)
{
    if (m_LoadedMesh != nullptr) {
        for (u32 materialIndex = 0; materialIndex < m_LoadedMesh->getMaterialCount(); materialIndex++) {
            // Set Wireframe display
            m_LoadedMesh->getMaterial(materialIndex).Wireframe = wireframe;

            // Set Lighting
            if (!lighting) {
                m_LoadedMesh->getMaterial(materialIndex).Lighting = false;
                m_LoadedMesh->getMaterial(materialIndex).EmissiveColor = SColor(255, 255, 255, 255);
            } else {
                m_LoadedMesh->getMaterial(materialIndex).Lighting = true;
                m_LoadedMesh->getMaterial(materialIndex).EmissiveColor = SColor(255, 0, 0, 0);
            }
            // m_LoadedMesh->setMaterialType(video::EMT_TRANSPARENT_ALPHA_CHANNEL); //already done on load
            // m_LoadedMesh->setMaterialFlag(video::E_ALPHA_SOURCE, true);  // requires EMT_ONETEXTURE
            if (textureInterpolation) {
                m_LoadedMesh->setMaterialFlag(video::EMF_BILINEAR_FILTER, true);
                m_LoadedMesh->setMaterialFlag(video::EMF_TRILINEAR_FILTER, true);
            } else {
                m_LoadedMesh->setMaterialFlag(video::EMF_BILINEAR_FILTER, false);
                m_LoadedMesh->setMaterialFlag(video::EMF_TRILINEAR_FILTER, false);
                //m_LoadedMesh->setMaterialFlag(video::E_ALPHA_SOURCE, true);

                // below doesn't work for some reason:
                // video::SMaterial mat = m_LoadedMesh->getMaterial(materialIndex);
                // mat.UseMipMaps = false;
                // mat.setFlag(video::EMF_BILINEAR_FILTER, false);
                // mat.setFlag(video::EMF_TRILINEAR_FILTER, false);

                // below would require patching Irrlicht:
                // GLint filteringMipMaps = GL_NEAREST_MIPMAP_NEAREST
                // // above is used by glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, filteringMipMaps);
            }
        }
    } else
        debug() << "WARNING in setMeshDisplayMode: No mesh is loaded " << endl;
}

bool Engine::isAnimating()
{
    return this->isPlaying;
}

void Engine::playAnimation()
{
    if (this->animationFPS() < 1) {
        this->setAnimationFPS(5);
    }
    if (!this->isAnimating()) {
        if (this->m_LoadedMesh != nullptr) {
            if (this->prevFPS < 1)
                this->prevFPS = 5;
            this->m_LoadedMesh->setAnimationSpeed(this->prevFPS);
        }
    }
    this->isPlaying = true;
}

void Engine::pauseAnimation()
{
    if (this->isAnimating()) {
        this->prevFPS = animationFPS();
        if (this->m_LoadedMesh != nullptr) {
            this->prevFPS = this->m_LoadedMesh->getAnimationSpeed();
            this->m_LoadedMesh->setAnimationSpeed(0);
        }
    }
    this->isPlaying = false;
}

void Engine::toggleAnimation()
{
    if (this->isAnimating()) {
        this->pauseAnimation();
        debug() << "paused " << this->animationFPS() << "fps" << endl;
    } else {
        this->playAnimation();
        debug() << "unpaused " << this->animationFPS() << "fps" << endl;
    }
}

void Engine::setAnimationFPS(u32 animationFPS)
{
    if (this->m_LoadedMesh != nullptr) {
        this->m_LoadedMesh->setAnimationSpeed(animationFPS);
    }
}

void Engine::setZUp(bool zUp)
{
    if (this->m_View != nullptr) {
        this->m_View->setZUp(zUp);
    }
}

u32 Engine::animationFPS()
{
    u32 ret = 0;
    if (this->m_LoadedMesh != nullptr) {
        ret = this->m_LoadedMesh->getAnimationSpeed();
    }
    return ret;
}

void Engine::run()
{
    u32 timePerFrame = 1000.0f;
    if (this->worldFPS > 0) {
        timePerFrame = static_cast<u32>(1000.0f / this->worldFPS);
    }
    ITimer* timer = m_Device->getTimer();

    // Run the Device with fps frames/sec
    while (m_Device->run() && m_RunEngine) {
        u32 startTime = timer->getRealTime();

        checkResize();
        if (this->m_LoadedMesh != nullptr) {
            if (isPlaying) {
                this->m_LoadedMesh->setLoopMode(true);
                this->m_UserInterface->playbackSetFrameEditBox->setText(Utility::toWstring(this->m_LoadedMesh->getFrameNr()).c_str());
            } else {
                this->m_LoadedMesh->setLoopMode(false);
            }
        }
        m_Driver->beginScene();
        drawBackground(); // Draw Background
        drawAxisLines(); // Draw XYZ Axis
        m_Scene->drawAll(); // Draw Scenegraph

        m_UserInterface->getGUIEnvironment()->drawAll();
        m_UserInterface->drawStatusLine();

        m_Driver->endScene();

        u32 sleepTime = timePerFrame - (timer->getRealTime() - startTime);
        if (sleepTime > 0 && sleepTime < timePerFrame)
            m_Device->sleep(sleepTime, false);
    }
}