#pragma once
#include "vde/spatial/bvh.h"
#include <functional>
#include <vector>

namespace vde::spatial {

/**
 * @brief Incremental BVH that supports insert/remove without full rebuild
 *
 * Wraps the standard BVH with a dirty flag. Triangles can be inserted,
 * removed, or updated incrementally. The tree is lazily rebuilt on the
 * next query when dirty. Suitable for moderately dynamic scenes where
 * queries are less frequent than modifications.
 *
 * @ingroup spatial
 */
class IncrementalBVH {
public:
    /// @brief Build from initial set of triangles
    void build(const std::vector<core::Triangle3D>& triangles);

    /// @brief Insert a new triangle (marks dirty, no immediate rebuild)
    void insert(const core::Triangle3D& tri);

    /// @brief Remove a triangle by index (marks dirty)
    void remove(size_t index);

    /// @brief Update a triangle's geometry in-place (marks dirty)
    void update(size_t index, const core::Triangle3D& tri);

    /**
     * @brief Ray query (rebuilds if dirty, then delegates to BVH)
     *
     * @param ray Query ray
     * @return All hit results (t, triangle, hit point)
     */
    std::vector<BVH::HitResult> ray_query(const Ray3Dd& ray) const;

    /// @brief Number of triangles
    [[nodiscard]] size_t size() const { return triangles_.size(); }

private:
    std::vector<core::Triangle3D> triangles_;
    std::vector<core::AABB3D> bboxes_;
    BVH bvh_;
    bool dirty_ = true;

    void rebuild_if_dirty();
};

} // namespace vde::spatial