#pragma once

/* (C) 2021 by Harald Welte <laforge@gnumonks.org>
 *
 * All Rights Reserved
 *
 * SPDX-License-Identifier: GPL-2.0+
 *
 * 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.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 */


#include <stdint.h>
#include <osmocom/core/utils.h>
#include <osmocom/gsm/lapd_core.h>

struct osmo_fsm_inst;

enum v5x_dialect {
	V5X_DIALECT_V51		= 1,
	V5X_DIALECT_V52		= 2,
};

/* forward-declarations */
struct v5x_interface;
struct v5x_instance;
struct v5x_link;

/* A C-channel is a 64k timeslot used for signalling */
struct v5x_c_channel {
	struct v5x_link *link;			/* back-pointer */
	struct v5x_timeslot *ts;		/* E1 link timeslot. NULL = C-channel doesn't exist */
	bool active;				/* false == standby */
};

/* one physical E1 timeslot used on an E1 interface part of a V5.2 interface */
struct v5x_timeslot {
	uint8_t nr;
	struct v5x_link *link;			/* back-pointer */
	uint16_t l3_address;
};

/* one physical E1 interface used within a V5.2 interface */
struct v5x_link {
	uint8_t id;
	struct v5x_interface *interface;	/* back-pointer */
	struct v5x_timeslot ts[32];		/* 32 E1 slots; 0 not available */
	struct v5x_c_channel c_channel[3];	/* 64k signaling possible on TS16, TS15 and TS31 */
	struct osmo_fsm_inst *l1_link_fi;	/* Layer 1 Link FSM instance */
};

/* one V5.x interface between AN (Access Network) and LE (Local Exchange) */
struct v5x_interface {
	struct llist_head list;			/* instance.interfaces */
	struct v5x_instance *instance;		/* back-pointer */
	enum v5x_dialect dialect;
	struct v5x_link *primary_link;		/* one of the links below */
	struct v5x_link *secondary_link;	/* one of the links below */
	/* 1..16 links in one interface */
	struct v5x_link links[16];

	struct osmo_fsm_inst *fi;		/* Interface FSM instance */
	struct {
		struct lapd_datalink dl;	/* Control data link */
		struct v5x_c_channel *c_chan;	/* pointer to active C-channel */
	} control;
	struct {
		struct lapd_datalink dl;	/* Link control data link */
		struct v5x_c_channel *c_chan;	/* pointer to active C-channel */
		struct osmo_fsm_inst *fi;	/* Link Control FSM instance */
	} lcp;
	struct {
		struct lapd_datalink dl;	/* PSTN data link */
		struct v5x_c_channel *c_chan;	/* pointer to active C-channel */
	} pstn;
	struct {
		struct lapd_datalink dl;	/* BCC data link */
		struct v5x_c_channel *c_chan;	/* pointer to active C-channel */
	} bcc;
	struct {
		struct lapd_datalink dl;	/* Protection data link 1 + 2 */
		struct v5x_c_channel *c_chan;	/* pointer to active C-channel */
	} protection[2];
};

/* one user-facing port (subscriber line) */
struct v5x_user_port {
	struct llist_head list; 		/* part of v5x_instance.ports */
	struct v5x_instance *inst; 		/* back-pointer to instance we're part of */

	uint16_t nr; 				/* port-number in decoded form (0..32767) */
	bool is_isdn;				/* is this port an ISDN port? */

	struct {
		struct osmo_fsm_inst *ctrl_fi;	/* control protocol FSM instance */
		struct osmo_fsm_inst *fi;	/* port state FSM instance */
	} isdn;
	struct {
	} pstn;
};

struct v5x_instance {
	struct llist_head list;			/* part of global list of instances */
	struct llist_head interfaces;		/* v5x_interface.list */
	struct llist_head user_ports;		/* list of v5x_user_port */
	struct osmo_fsm_inst *ctrl_fi;		/* common control FSM */
};

struct v5x_instance *v5x_instance_alloc(void *ctx);
struct v5x_interface *v5x_interface_alloc(struct v5x_instance *v5i, enum v5x_dialect dialect);