/* $Id$ */
/* 
 * Copyright (C) 2008-2009 Teluu Inc. (http://www.teluu.com)
 * Copyright (C) 2003-2008 Benny Prijono <benny@prijono.org>
 *
 * 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 2 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, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA 
 */
#ifndef __PJSIP_SIP_UA_LAYER_H__
#define __PJSIP_SIP_UA_LAYER_H__

/**
 * @file sip_ua_layer.h
 * @brief SIP User Agent Layer Module
 */
#include <pjsip/sip_types.h>


PJ_BEGIN_DECL

/**
 * @defgroup PJSIP_UA Base User Agent Layer/Common Dialog Layer
 * @brief Dialog management.
 *
 * This module provides basic dialog management, which is used by higher
 * layer dialog usages such as INVITE sessions and SIP Event Subscription
 * framework (RFC 3265). Application should link  with <b>pjsip-core</b> 
 * library to use this base UA layer. The base UA layer module is initialized
 * with #pjsip_ua_init_module().
 */

/**
 * @defgroup PJSUA_UA SIP User Agent Module
 * @ingroup PJSIP_UA
 * @brief Provides dialog management.
 * @{
 *
 * Application MUST initialize the user agent layer module by calling
 * #pjsip_ua_init_module() before using any of the dialog API, and link
 * the application with with <b>pjsip-core</b> library.
 */

/** User agent initialization parameter. */
typedef struct pjsip_ua_init_param
{
    /** Callback to be called when the UA layer detects that outgoing
     *  dialog has forked.
     */
    pjsip_dialog* (*on_dlg_forked)(pjsip_dialog *first_set, pjsip_rx_data *res);
} pjsip_ua_init_param;

/**
 * Initialize user agent layer and register it to the specified endpoint.
 *
 * @param endpt		The endpoint where the user agent will be
 *			registered.
 * @param prm		UA initialization parameter.
 *
 * @return		PJ_SUCCESS on success.
 */
PJ_DECL(pj_status_t) pjsip_ua_init_module(pjsip_endpoint *endpt,
					  const pjsip_ua_init_param *prm);

/**
 * Get the instance of the user agent.
 *
 * @return		The user agent module instance.
 */
PJ_DECL(pjsip_user_agent*) pjsip_ua_instance(void);


/**
 * Retrieve the current number of dialog-set currently registered
 * in the hash table. Note that dialog-set is different than dialog
 * when the request forks. In this case, all dialogs created from
 * the original request will belong to the same dialog set. When
 * no forking occurs, the number of dialog sets will be equal to
 * the number of dialogs.
 *
 * @return	    Number of dialog sets.
 */
PJ_DECL(pj_uint32_t) pjsip_ua_get_dlg_set_count(void);


/**
 * Find a dialog with the specified Call-ID and tags properties. This
 * function may optionally lock the matching dialog instance before
 * returning it back to the caller.
 *
 * @param call_id	The call ID to be matched.
 * @param local_tag	The local tag to be matched.
 * @param remote_tag	The remote tag to be matched.
 * @param lock_dialog	If non-zero, instruct the function to lock the 
 *			matching dialog with #pjsip_dlg_inc_lock(). 
 *			Application is responsible to release the dialog's
 *			lock after it has finished manipulating the dialog,
 *			by calling #pjsip_dlg_dec_lock().
 *
 * @return		The matching dialog instance, or NULL if no matching
 *			dialog is found.
 */
PJ_DECL(pjsip_dialog*) pjsip_ua_find_dialog(const pj_str_t *call_id,
					    const pj_str_t *local_tag,
					    const pj_str_t *remote_tag,
					    pj_bool_t lock_dialog);

/**
 * Destroy the user agent layer.
 *
 * @return		PJ_SUCCESS on success.
 */
PJ_DECL(pj_status_t) pjsip_ua_destroy(void);

/**
 * Dump user agent contents (e.g. all dialogs).
 *
 * @param detail	If non-zero, list of dialogs will be printed.
 */
PJ_DECL(void) pjsip_ua_dump(pj_bool_t detail);

/**
 * Get the endpoint instance of a user agent module.
 *
 * @param ua		The user agent instance.
 *
 * @return		The endpoint instance where the user agent is
 *			registered.
 */
PJ_DECL(pjsip_endpoint*) pjsip_ua_get_endpt(pjsip_user_agent *ua);


/**
 * @}
 */


/*
 * Internal (called by sip_dialog.c).
 */

PJ_DECL(pj_status_t) pjsip_ua_register_dlg( pjsip_user_agent *ua,
					    pjsip_dialog *dlg );
PJ_DECL(pj_status_t) pjsip_ua_unregister_dlg(pjsip_user_agent *ua,
					     pjsip_dialog *dlg );


PJ_END_DECL


#endif	/* __PJSIP_SIP_UA_LAYER_H__ */