#include "GLSelectionRectangle.hpp"
#include "Camera.hpp"
#include "3DScene.hpp"
#include "GLCanvas3D.hpp"
#include "GUI_App.hpp"
#include "Plater.hpp"
#include <igl/project.h>

#include <GL/glew.h>

namespace Slic3r {
namespace GUI {

    void GLSelectionRectangle::start_dragging(const Vec2d& mouse_position, EState state)
    {
        if (is_dragging() || (state == Off))
            return;

        m_state = state;
        m_start_corner = mouse_position;
        m_end_corner = mouse_position;
    }

    void GLSelectionRectangle::dragging(const Vec2d& mouse_position)
    {
        if (!is_dragging())
            return;

        m_end_corner = mouse_position;
    }

    std::vector<unsigned int> GLSelectionRectangle::stop_dragging(const GLCanvas3D& canvas, const std::vector<Vec3d>& points)
    {
        std::vector<unsigned int> out;

        if (!is_dragging())
            return out;

        m_state = Off;

        const Camera& camera = wxGetApp().plater()->get_camera();
        Matrix4d modelview = camera.get_view_matrix().matrix();
        Matrix4d projection= camera.get_projection_matrix().matrix();
        Vec4i viewport(camera.get_viewport().data());

        // Convert our std::vector to Eigen dynamic matrix.
        Eigen::Matrix<double, Eigen::Dynamic, 3, Eigen::DontAlign> pts(points.size(), 3);
        for (size_t i=0; i<points.size(); ++i)
            pts.block<1, 3>(i, 0) = points[i];

        // Get the projections.
        Eigen::Matrix<double, Eigen::Dynamic, 3, Eigen::DontAlign> projections;
        igl::project(pts, modelview, projection, viewport, projections);

        // bounding box created from the rectangle corners - will take care of order of the corners
        BoundingBox rectangle(Points{ Point(m_start_corner.cast<coord_t>()), Point(m_end_corner.cast<coord_t>()) });

        // Iterate over all points and determine whether they're in the rectangle.
        for (int i = 0; i<projections.rows(); ++i)
            if (rectangle.contains(Point(projections(i, 0), canvas.get_canvas_size().get_height() - projections(i, 1))))
                out.push_back(i);

        return out;
    }

    void GLSelectionRectangle::stop_dragging()
    {
        if (is_dragging())
            m_state = Off;
    }

    void GLSelectionRectangle::render(const GLCanvas3D& canvas)
    {
        if (!is_dragging())
            return;

        const Size cnv_size = canvas.get_canvas_size();
        const float cnv_width = (float)cnv_size.get_width();
        const float cnv_height = (float)cnv_size.get_height();
        if (cnv_width == 0.0f || cnv_height == 0.0f)
            return;

        const float cnv_inv_width = 1.0f / cnv_width;
        const float cnv_inv_height = 1.0f / cnv_height;
        const float left = 2.0f * (get_left() * cnv_inv_width - 0.5f);
        const float right = 2.0f * (get_right() * cnv_inv_width - 0.5f);
        const float top = -2.0f * (get_top() * cnv_inv_height - 0.5f);
        const float bottom = -2.0f * (get_bottom() * cnv_inv_height - 0.5f);
        
        glsafe(::glLineWidth(1.5f));

        glsafe(::glDisable(GL_DEPTH_TEST));

        glsafe(::glPushAttrib(GL_ENABLE_BIT));
        glsafe(::glLineStipple(4, 0xAAAA));
        glsafe(::glEnable(GL_LINE_STIPPLE));

        GLShaderProgram* shader = wxGetApp().get_shader("flat_attr");
        if (shader != nullptr) {
            shader->start_using();

            if (!m_rectangle.is_initialized() || !m_old_start_corner.isApprox(m_start_corner) || !m_old_end_corner.isApprox(m_end_corner)) {
                m_old_start_corner = m_start_corner;
                m_old_end_corner = m_end_corner;
                m_rectangle.reset();

                GLModel::Geometry init_data;
                init_data.format = { GLModel::Geometry::EPrimitiveType::LineLoop, GLModel::Geometry::EVertexLayout::P2 };
                init_data.reserve_vertices(4);
                init_data.reserve_indices(4);

                // vertices
                init_data.add_vertex(Vec2f(left, bottom));
                init_data.add_vertex(Vec2f(right, bottom));
                init_data.add_vertex(Vec2f(right, top));
                init_data.add_vertex(Vec2f(left, top));

                // indices
                init_data.add_index(0);
                init_data.add_index(1);
                init_data.add_index(2);
                init_data.add_index(3);

                m_rectangle.init_from(std::move(init_data));
            }

            shader->set_uniform("view_model_matrix", Transform3d::Identity());
            shader->set_uniform("projection_matrix", Transform3d::Identity());

            m_rectangle.set_color({0.0f, 1.0f, 0.38f, 1.0f});
            m_rectangle.render();
            shader->stop_using();
        }

        glsafe(::glPopAttrib());
    }

} // namespace GUI
} // namespace Slic3r