// -*-c++-*- osgWidget - Code by: Jeremy Moles (cubicool) 2007-2008
// $Id: Util.cpp 59 2008-05-15 20:55:31Z cubicool $

#include <osg/io_utils>

#include <osgGA/TrackballManipulator>
#include <osgGA/StateSetManipulator>
#include <osgDB/FileUtils>
#include <osgDB/WriteFile>
#include <osgViewer/ViewerEventHandlers>
#include <osgWidget/Util>
#include <osgWidget/ViewerEventHandlers>
#include <osgWidget/WindowManager>

namespace osgWidget {

std::string getFilePath(const std::string& filename) {
    osgDB::FilePathList path;

    char* fp = getenv("OSGWIDGET_FILE_PATH");
    
    osgDB::convertStringPathIntoFilePathList(fp ? fp : ".", path);

    return osgDB::findFileInPath(filename, path);
}

std::string generateRandomName(const std::string& base) {
    static unsigned int count = 0;
    
    std::stringstream ss;

    ss << base << "_" << count;
    
    count++;

    return ss.str();
}

osg::Matrix createInvertedYOrthoProjectionMatrix(matrix_type width, matrix_type height) {
    osg::Matrix m = osg::Matrix::ortho2D(0.0f, width, 0.0f, height);
    osg::Matrix s = osg::Matrix::scale(1.0f, -1.0f, 1.0f);
    osg::Matrix t = osg::Matrix::translate(0.0f, -height, 0.0f);

    return t * s * m;
}

osg::Camera* createOrthoCamera(matrix_type width, matrix_type height) {
    osg::Camera* camera = new osg::Camera();

    camera->getOrCreateStateSet()->setMode(
        GL_LIGHTING,
        osg::StateAttribute::PROTECTED | osg::StateAttribute::OFF
    );

    camera->setProjectionMatrix(osg::Matrix::ortho2D(0.0, width, 0.0f, height));
    camera->setReferenceFrame(osg::Transform::ABSOLUTE_RF);
    camera->setViewMatrix(osg::Matrix::identity());
    camera->setClearMask(GL_DEPTH_BUFFER_BIT);
    camera->setRenderOrder(osg::Camera::POST_RENDER);
    
    return camera;
}

osg::Camera* createInvertedYOrthoCamera(matrix_type width, matrix_type height) {
    osg::Camera* camera = createOrthoCamera(width, height);

    camera->setProjectionMatrix(createInvertedYOrthoProjectionMatrix(width, height));
    
    return camera;
}

osg::Group* _createExampleCommon(osgViewer::View* view, WindowManager* wm, osg::Node* node) {
    if(!wm) return 0;

    view->setUpViewInWindow(
        0,
        0,
        static_cast<int>(wm->getWidth()),
        static_cast<int>(wm->getHeight())
    );

    osg::Group*  group  = new osg::Group();
    osg::Camera* camera = wm->createParentOrthoCamera();

    group->addChild(camera);

    if(node) group->addChild(node);

    view->addEventHandler(new osgWidget::MouseHandler(wm));
    view->addEventHandler(new osgWidget::KeyboardHandler(wm));
    view->addEventHandler(new osgWidget::ResizeHandler(wm, camera));
    view->addEventHandler(new osgViewer::StatsHandler());
    view->addEventHandler(new osgViewer::WindowSizeHandler());
    view->addEventHandler(new osgGA::StateSetManipulator(
        view->getCamera()->getOrCreateStateSet()
    ));

    wm->resizeAllWindows();
    
    return group;
}

int createExample(osgViewer::Viewer& viewer, WindowManager* wm, osg::Node* node) {
    osg::Group* group = _createExampleCommon(&viewer, wm, node);

    viewer.setSceneData(group);

    return viewer.run();
}

// TODO: This function is totally broken; I don't really have any idea of how to do this.
// Incredibly frustrating stuff.
int createCompositeExample(
    osgViewer::CompositeViewer& viewer,
    osgViewer::View*            view,
    WindowManager*              wm,
    osg::Node*                  node
) {
    osg::Group*           group   = _createExampleCommon(view, wm, node);
    osg::MatrixTransform* watcher = new osg::MatrixTransform();

    watcher->addChild(wm);

    // Setup the main 2D view.
    viewer.addView(view);

    view->setSceneData(group);

    // The view that "watches" the main view.
    osgViewer::View* viewWatcher = new osgViewer::View();

    viewer.addView(viewWatcher);

    int w = static_cast<int>(wm->getWidth());
    int h = static_cast<int>(wm->getHeight());
    
    viewWatcher->setUpViewInWindow(0, 0, w, h);

    // Setup our parent MatrixTransform so things look right in perspective.
    watcher->setMatrix(
        osg::Matrix::scale(1.0f, -1.0f, 1000.0f) *
        osg::Matrix::rotate(osg::DegreesToRadians(90.0f), osg::Vec3d(1.0f, 0.0f, 0.0f))
    );

    watcher->getOrCreateStateSet()->setAttributeAndModes(
        new osg::Scissor(0, 0, w, h),
        osg::StateAttribute::OVERRIDE
    );

    osgGA::TrackballManipulator* tb = new osgGA::TrackballManipulator();

    warn() << watcher->getMatrix() << std::endl;

    /*
    const osg::BoundingSphere& bs = watcher->getBound();

    tb->setHomePosition(
        bs.center() + osg::Vec3(0.0f, -3.5f * bs.radius(), 0.0f),
        bs.center(),
        osg::Vec3(0.0f, 1.0f, 0.0f)
    );
    */

    viewWatcher->setSceneData(watcher);
    viewWatcher->setCameraManipulator(tb);

    return viewer.run();
}

bool writeWindowManagerNode(WindowManager* wm) {
    osgDB::writeNodeFile(*wm->getParent(0), "osgWidget.osg");

    return true;
}

}