/*
 * Copyright (C) 2007, Gilles Casse <gcasse@oralux.org>
 * Copyright (C) 2015-2016 Reece H. Dunn
 *
 * 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/>.
 */

// Helps to add espeak commands in a first-in first-out queue
// and run them asynchronously.

#ifndef ESPEAK_NG_FIFO_H
#define ESPEAK_NG_FIFO_H

#include "espeak_ng.h"
#include "espeak_command.h"

#ifdef __cplusplus
extern "C"
{
#endif

// Initialize the fifo component.
// First function to be called.
void fifo_init(void);

// Add an espeak command.
//
// Note: this function fails if too many commands are already buffered.
// In such a case, the calling function could wait and then add again its command.
espeak_ng_STATUS fifo_add_command(t_espeak_command *c);

// Add two espeak commands in a single transaction.
//
// Note: this function fails if too many commands are already buffered.
// In such a case, the calling function could wait and then add again these commands.
espeak_ng_STATUS fifo_add_commands(t_espeak_command *c1, t_espeak_command *c2);

// The current running command must be stopped and the awaiting commands are cleared.
espeak_ng_STATUS fifo_stop(void);

// Is there a running command?
// Returns 1 if yes; 0 otherwise.
int fifo_is_busy(void);

// Terminate the fifo component.
// Last function to be called.
void fifo_terminate(void);

// Indicates if the running command is still enabled.
//
// Note: this function is mainly called by the SynthCallback (speak_lib.cpp)
// It indicates if the actual wave sample can still be played. It is helpful for
// stopping speech as soon as a cancel command is applied.
//
// Returns 1 if yes, or 0 otherwise.
int fifo_is_command_enabled(void);

#ifdef __cplusplus
}
#endif

#endif
