/* SPDX-FileCopyrightText: 2023 Blender Authors
 *
 * SPDX-License-Identifier: GPL-2.0-or-later */

#pragma once

/** \file
 * \ingroup bke
 * \brief Volume data-block.
 */

#include <memory>
#include <optional>

#include "BLI_bounds_types.hh"
#include "BLI_math_vector_types.hh"

#include "BKE_volume_grid_fwd.hh"

struct Depsgraph;
struct Main;
struct Object;
struct ReportList;
struct Scene;
struct Volume;
struct VolumeGridVector;

namespace blender::bke::bake {
struct BakeMaterialsList;
}

/* Module */

void BKE_volumes_init();

/* Data-block Management */

void BKE_volume_init_grids(Volume *volume);
void *BKE_volume_add(Main *bmain, const char *name);

bool BKE_volume_is_y_up(const Volume *volume);
bool BKE_volume_is_points_only(const Volume *volume);

/* Depsgraph */

void BKE_volume_eval_geometry(Depsgraph *depsgraph, Volume *volume);
void BKE_volume_data_update(Depsgraph *depsgraph, Scene *scene, Object *object);

void BKE_volume_grids_backup_restore(Volume *volume,
                                     VolumeGridVector *grids,
                                     const char *filepath);

/* Draw Cache */

enum {
  BKE_VOLUME_BATCH_DIRTY_ALL = 0,
};

void BKE_volume_batch_cache_dirty_tag(Volume *volume, int mode);
void BKE_volume_batch_cache_free(Volume *volume);

extern void (*BKE_volume_batch_cache_dirty_tag_cb)(Volume *volume, int mode);
extern void (*BKE_volume_batch_cache_free_cb)(Volume *volume);

/* Grids
 *
 * For volumes referencing a file, the list of grids and metadata must be
 * loaded before it can be accessed. This happens on-demand, only when needed
 * by the user interface, dependency graph or render engine. */

bool BKE_volume_load(const Volume *volume, const Main *bmain);
void BKE_volume_unload(Volume *volume);
bool BKE_volume_is_loaded(const Volume *volume);

int BKE_volume_num_grids(const Volume *volume);
const char *BKE_volume_grids_error_msg(const Volume *volume);
const char *BKE_volume_grids_frame_filepath(const Volume *volume);
const blender::bke::VolumeGridData *BKE_volume_grid_get(const Volume *volume, int grid_index);
blender::bke::VolumeGridData *BKE_volume_grid_get_for_write(Volume *volume, int grid_index);
const blender::bke::VolumeGridData *BKE_volume_grid_active_get_for_read(const Volume *volume);
/* Tries to find a grid with the given name. Make sure that the volume has been loaded. */
const blender::bke::VolumeGridData *BKE_volume_grid_find(const Volume *volume, const char *name);
blender::bke::VolumeGridData *BKE_volume_grid_find_for_write(Volume *volume, const char *name);

/* Tries to set the name of the velocity field. If no such grid exists with the given base name,
 * this will try common post-fixes in order to detect velocity fields split into multiple grids.
 * Return false if neither finding with the base name nor with the post-fixes succeeded. */
bool BKE_volume_set_velocity_grid_by_name(Volume *volume, const char *base_name);

/* Volume Editing
 *
 * These are intended for modifiers to use on evaluated data-blocks.
 *
 * new_for_eval creates a volume data-block with no grids or file path, but
 * preserves other settings such as viewport display options.
 *
 * copy_for_eval creates a volume data-block preserving everything except the
 * file path. Grids are shared with the source data-block, not copied. */

Volume *BKE_volume_new_for_eval(const Volume *volume_src);
Volume *BKE_volume_copy_for_eval(const Volume *volume_src);

void BKE_volume_grid_remove(Volume *volume, const blender::bke::VolumeGridData *grid);

/**
 * Adds a new grid to the volume with the name stored in the grid. The caller is responsible for
 * making sure that the user count already contains the volume as a user.
 */
void BKE_volume_grid_add(Volume *volume, const blender::bke::VolumeGridData &grid);

/**
 * OpenVDB crashes when the determinant of the transform matrix becomes too small.
 */
bool BKE_volume_grid_determinant_valid(double determinant);

/* Simplify */
int BKE_volume_simplify_level(const Depsgraph *depsgraph);
float BKE_volume_simplify_factor(const Depsgraph *depsgraph);

/* File Save */
bool BKE_volume_save(const Volume *volume,
                     const Main *bmain,
                     ReportList *reports,
                     const char *filepath);

std::optional<blender::Bounds<blender::float3>> BKE_volume_min_max(const Volume *volume);

namespace blender::bke {

struct VolumeRuntime {
  /** OpenVDB Grids. */
  VolumeGridVector *grids = nullptr;

  /** Current frame in sequence for evaluated volume. */
  int frame = 0;

  /* Names for scalar grids which would need to be merged to recompose the velocity grid. */
  char velocity_x_grid[64] = "";
  char velocity_y_grid[64] = "";
  char velocity_z_grid[64] = "";

  std::unique_ptr<bake::BakeMaterialsList> bake_materials;
};

}  // namespace blender::bke