/***

  Oak Video Editor - Non-Linear Video Editor
  Copyright (C) 2026 Oak Team

  This program is free software: you can redistribute it and/or modify
  it under the terms of the GNU General Public License as published by
  the Free Software Foundation, either version 3 of the License, or
  (at your option) any later version.

  This program is distributed in the hope that it will be useful,
  but WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  GNU General Public License for more details.

  You should have received a copy of the GNU General Public License
  along with this program.  If not, see <http://www.gnu.org/licenses/>.

***/

#ifndef OAK_EDITOR_CURRENT_H
#define OAK_EDITOR_CURRENT_H

#include "common/error.h"

#ifdef __cplusplus
extern "C" {
#endif

typedef struct OakCommonCurrent OakCommonCurrent;

/**
 * @brief Destructor callback for objects handed to Current slots.
 *
 * Called when the slot is overwritten or cleared. May be NULL if the
 * caller keeps ownership of the object.
 */
typedef void (*OakCommonDestroyFn)(void *obj);

/**
 * @brief Return a handle to the process-wide Current singleton.
 *
 * The returned handle is borrowed: it is valid for the lifetime of the
 * process and must not be freed with oakcommon_current_free() more
 * than out of symmetry (free is a no-op for the singleton).
 */
OakCommonCurrent *oakcommon_current_instance(void);

/**
 * @brief Release a Current handle.
 *
 * No-op: the underlying object is a singleton. Safe to call with NULL.
 */
void oakcommon_current_free(OakCommonCurrent *self);

/**
 * @brief Store a pointer in a Current slot, taking over destruction.
 *
 * Passing NULL for obj clears the slot (destroy is ignored). If a
 * previous object with a destroy callback was stored, it is destroyed.
 *
 * @param self Handle from oakcommon_current_instance().
 * @param obj Opaque pointer to the external object (e.g. a
 * VideoParams), or NULL to clear.
 * @param destroy Optional destructor invoked when the slot is replaced.
 * @return OAKCOMMON_OK on success, OAKCOMMON_E_INVALID if self is NULL.
 */
int oakcommon_current_set_video_params(OakCommonCurrent *self, void *obj,
				       OakCommonDestroyFn destroy);
int oakcommon_current_set_audio_params(OakCommonCurrent *self, void *obj,
				       OakCommonDestroyFn destroy);
int oakcommon_current_set_plugin_host(OakCommonCurrent *self, void *obj,
				      OakCommonDestroyFn destroy);
int oakcommon_current_set_plugin_cache(OakCommonCurrent *self, void *obj,
				       OakCommonDestroyFn destroy);

/**
 * @brief Fetch the raw pointer currently stored in a slot.
 *
 * The returned pointer is borrowed and remains valid until the slot is
 * overwritten or cleared. *out is set to NULL when the slot is empty.
 *
 * @param self Handle from oakcommon_current_instance().
 * @param out Receives the stored pointer.
 * @return OAKCOMMON_OK on success, OAKCOMMON_E_INVALID if self or out
 * is NULL.
 */
int oakcommon_current_get_video_params(OakCommonCurrent *self, void **out);
int oakcommon_current_get_audio_params(OakCommonCurrent *self, void **out);
int oakcommon_current_get_plugin_host(OakCommonCurrent *self, void **out);
int oakcommon_current_get_plugin_cache(OakCommonCurrent *self, void **out);

/**
 * @brief Query whether the session is interactive.
 *
 * @param self Handle from oakcommon_current_instance().
 * @param out Receives 1 for interactive, 0 otherwise.
 * @return OAKCOMMON_OK on success, OAKCOMMON_E_INVALID if self or out
 * is NULL.
 */
int oakcommon_current_is_interactive(OakCommonCurrent *self, int *out);

#ifdef __cplusplus
}
#endif

#endif // OAK_EDITOR_CURRENT_H