#pragma once
/**
 * @file brep_drawing.h
 * @brief Engineering drawing: 2D projection views + section + DXF export
 *
 * Orthographic projection views from B-Rep models with hidden-line
 * removal via mesh ray-casting. Supports section (cross-section) views
 * and AutoCAD R12 DXF format export.
 *
 * @ingroup brep
 */
#include "vde/brep/brep.h"
#include "vde/core/point.h"
#include <vector>
#include <string>

namespace vde::brep {

/// 2D line segment for drawing output
struct DrawSegment {
    double x1, y1, x2, y2;
    bool hidden = false;  ///< true = dashed hidden line
};

/// Projection view of a B-Rep body
struct ProjectionView {
    std::string name;                      ///< "front", "top", "right", "iso"
    std::vector<DrawSegment> segments;     ///< visible lines
    std::vector<DrawSegment> hidden_lines; ///< dashed hidden lines
    double scale = 1.0;
    core::Point3D view_direction;          ///< camera direction

    [[nodiscard]] size_t total_segments() const {
        return segments.size() + hidden_lines.size();
    }
};

/// Generate orthographic projection views
/// @param body B-Rep model to project
/// @return Vector of projection views (front, top, right, iso)
[[nodiscard]] std::vector<ProjectionView> generate_views(const BrepModel& body);

/// Generate a section view (cross-section)
/// @param body Body to slice
/// @param point Point on section plane
/// @param normal Section plane normal
/// @return Section view with cut edges and hatch lines
[[nodiscard]] ProjectionView section_view(const BrepModel& body,
    const core::Point3D& point, const core::Vector3D& normal);

/// Offset (stepped) section view — multiple parallel cutting planes
/// Each offset defines a cutting plane at a different position along the normal
/// direction. Results are merged with step lines at plane boundaries.
/// @param body Body to slice
/// @param normal Section direction (all planes share this normal)
/// @param offsets Vector of plane positions (distance along normal from origin)
/// @return Combined section view
[[nodiscard]] ProjectionView offset_section_view(const BrepModel& body,
    const core::Vector3D& normal, const std::vector<double>& offsets);

/// Export views to DXF format (R12 compatible)
/// @param filepath Output file path (.dxf)
/// @param views Vector of views to export
/// @return true on success
bool export_dxf(const std::string& filepath,
                const std::vector<ProjectionView>& views);

}  // namespace vde::brep