#pragma once

#include "CesiumGeometry/AxisAlignedBox.h"
#include "CesiumGeometry/Library.h"
#include "CesiumGeometry/OctreeTileID.h"

#include <glm/vec3.hpp>

#include <optional>

namespace CesiumGeometry {

/**
 * @brief Defines how an {@link AxisAlignedBox} is divided into octree
 * tiles.
 */
class CESIUMGEOMETRY_API OctreeTilingScheme {
public:
  /**
   * @brief Constructs a new instance.
   *
   * @param box The overall box that is tiled, expressed in projected
   * coordinates.
   * @param rootTilesX The number of tiles at the root of the quadtree in the X
   * direction.
   * @param rootTilesY The nubmer of tiles at the root of the quadtree in the Y
   * direction.
   * @param rootTilesZ The number of tiles at the root of the quadtree in the Z
   * direction.
   */
  OctreeTilingScheme(
      const AxisAlignedBox& box,
      uint32_t rootTilesX,
      uint32_t rootTilesY,
      uint32_t rootTilesZ) noexcept;

  /**
   * @brief Return the overall box that is tiled.
   */
  const AxisAlignedBox& getBox() const noexcept { return this->_box; }

  /**
   * @brief Returns the number of root tiles, in x-direction.
   */
  uint32_t getRootTilesX() const noexcept { return this->_rootTilesX; }

  /**
   * @brief Returns the number of root tiles, in y-direction.
   */
  uint32_t getRootTilesY() const noexcept { return this->_rootTilesY; }

  /**
   * @brief Returns the number of root tiles, in z-direction.
   */
  uint32_t getRootTilesZ() const noexcept { return this->_rootTilesZ; }

  /**
   * @brief Returns the number of tiles, in x-direction, at the given level.
   */
  uint32_t getNumberOfXTilesAtLevel(uint32_t level) const noexcept;

  /**
   * @brief Returns the number of tiles, in y-direction, at the given level.
   */
  uint32_t getNumberOfYTilesAtLevel(uint32_t level) const noexcept;

  /**
   * @brief Returns the number of tiles, in z-direction, at the given level.
   */
  uint32_t getNumberOfZTilesAtLevel(uint32_t level) const noexcept;

  /**
   * @brief Computes the {@link CesiumGeometry::OctreeTileID} for a given
   * position and level.
   *
   * If the projected position is within the {@link getBox} of this tiling
   * scheme, then this will compute the octree tile ID for the tile that
   * contains the given position at the given level. Otherwise, `nullopt` is
   * returned.
   *
   * @param position The position in projected coordinates.
   * @param level The level
   * @return The tile ID, or `nullopt`.
   */
  std::optional<CesiumGeometry::OctreeTileID>
  positionToTile(const glm::dvec3& position, uint32_t level) const noexcept;

  /**
   * @brief Returns the {@link AxisAlignedBox} that is
   * covered by the specified tile.
   *
   * The volume that is covered by the tile that is identified with
   * the given {@link CesiumGeometry::OctreeTileID} will be computed,
   * based on the {@link getBox} of this tiling scheme.
   *
   * @param tileID The tile ID
   * @return The box
   */
  AxisAlignedBox
  tileToBox(const CesiumGeometry::OctreeTileID& tileID) const noexcept;

private:
  AxisAlignedBox _box;
  uint32_t _rootTilesX;
  uint32_t _rootTilesY;
  uint32_t _rootTilesZ;
};

} // namespace CesiumGeometry