#ifndef _E1_INPUT_H
#define _E1_INPUT_H

#include <stdlib.h>
#include <netinet/in.h>

#include <osmocom/core/linuxlist.h>
#include <osmocom/core/timer.h>
#include <osmocom/core/msgb.h>
#include <osmocom/core/select.h>
#include <osmocom/abis/subchan_demux.h>
#include <osmocom/abis/lapd.h>

#define NUM_E1_TS   32
#define E1INP_USE_DEFAULT (-1)

enum e1inp_sign_type {
	E1INP_SIGN_NONE,
	E1INP_SIGN_OML,
	E1INP_SIGN_RSL,
};
const char *e1inp_signtype_name(enum e1inp_sign_type tp);

enum e1inp_ctr {
	E1I_CTR_HDLC_ABORT,
	E1I_CTR_HDLC_BADFCS,
	E1I_CTR_HDLC_OVERR,
	E1I_CTR_ALARM,
	E1I_CTR_REMOVED,
};

struct e1inp_ts;
struct vty;

struct e1inp_sign_link {
	/* list of signalling links */
	struct llist_head list;

	/* to which timeslot do we belong? */
	struct e1inp_ts *ts;

	enum e1inp_sign_type type;

	/* trx for msg->trx of received msgs */	
	struct gsm_bts_trx *trx;

	/* msgb queue of to-be-transmitted msgs */
	struct llist_head tx_list;

	/* SAPI and TEI on the E1 TS */
	uint8_t sapi;
	uint8_t tei;

	union {
		struct {
			uint8_t channel;
		} misdn;
	} driver;
};

enum e1inp_ts_type {
	E1INP_TS_TYPE_NONE,
	E1INP_TS_TYPE_SIGN,
	E1INP_TS_TYPE_TRAU,
};
const char *e1inp_tstype_name(enum e1inp_ts_type tp);

/* A timeslot in the E1 interface */
struct e1inp_ts {
	enum e1inp_ts_type type;
	int num;

	/* to which line do we belong ? */
	struct e1inp_line *line;

	/* LAPD instance, if any */
	struct lapd_instance *lapd;

	union {
		struct {
			/* list of all signalling links on this TS */
			struct llist_head sign_links;
			/* delay for the queue */
			int delay;
			/* timer when to dequeue next frame */
			struct osmo_timer_list tx_timer;
		} sign;
		struct {
			/* subchannel demuxer for frames from E1 */
			struct subch_demux demux;
			/* subchannel muxer for frames to E1 */
			struct subch_mux mux;
		} trau;
	};
	union {
		struct {
			/* mISDN driver has one fd for each ts */
			struct osmo_fd fd;
		} misdn;
		struct {
			/* ip.access driver has one fd for each ts */
			struct osmo_fd fd;
		} ipaccess;
		struct {
			/* DAHDI driver has one fd for each ts */
			struct osmo_fd fd;
		} dahdi;
		struct {
			struct osmo_fd fd;
		} rs232;
	} driver;

	struct msgb *pending_msg;
};

struct gsm_e1_subslot {
	/* Number of E1 link */
	uint8_t e1_nr;
	/* Number of E1 TS inside E1 link */
	uint8_t e1_ts;
	/* Sub-slot within the E1 TS, 0xff if full TS */
	uint8_t e1_ts_ss;
};

enum e1inp_line_role {
	E1INP_LINE_R_NONE,
	E1INP_LINE_R_BSC,
	E1INP_LINE_R_BTS,
	E1INP_LINE_R_MAX
};

struct e1inp_driver {
	struct llist_head list;
	const char *name;
	int (*want_write)(struct e1inp_ts *ts);
	int (*line_update)(struct e1inp_line *line);
	void (*close)(struct e1inp_sign_link *link);
	void (*vty_show)(struct vty *vty, struct e1inp_line *line);
	int default_delay;
	int has_keepalive;
};

struct e1inp_line_ops {
	union {
		struct {
			enum e1inp_line_role role;	/* BSC or BTS mode. */
			const char *addr;		/* IP address .*/
			void *dev;			/* device parameters. */
		} ipa;
		struct {
			const char *port;		/* e.g. /dev/ttyUSB0 */
			unsigned int delay;
		} rs232;
	} cfg;

	struct e1inp_sign_link *	(*sign_link_up)(void *unit_info, struct e1inp_line *line, enum e1inp_sign_type type);
	void	(*sign_link_down)(struct e1inp_line *line);
	int	(*sign_link)(struct msgb *msg);
};

struct e1inp_line {
	struct llist_head list;
	int refcnt;

	unsigned int num;
	const char *name;
	unsigned int port_nr;
	struct rate_ctr_group *rate_ctr;

	/* keepalive configuration */
	int keepalive_num_probes; /* 0: disable, num, or E1INP_USE_DEFAULT */
	int keepalive_idle_timeout; /* secs, or E1INP_USE_DEFAULT */
	int keepalive_probe_interval; /* secs or E1INP_USE_DEFAULT */

	/* array of timestlots */
	struct e1inp_ts ts[NUM_E1_TS];
	unsigned int num_ts;

	const struct e1inp_line_ops *ops;

	struct e1inp_driver *driver;
	void *driver_data;
};

/* SS_L_INPUT signals */
enum e1inp_signal_input {
	S_L_INP_NONE,
	S_L_INP_TEI_UP,
	S_L_INP_TEI_DN,
	S_L_INP_TEI_UNKNOWN,
	S_L_INP_LINE_INIT,
	S_L_INP_LINE_ALARM,
	S_L_INP_LINE_NOALARM,
};

/* register a driver with the E1 core */
int e1inp_driver_register(struct e1inp_driver *drv);

/* fine a previously registered driver */
struct e1inp_driver *e1inp_driver_find(const char *name);

/* register a line with the E1 core */
int e1inp_line_register(struct e1inp_line *line);

/* get a line by its ID */
struct e1inp_line *e1inp_line_find(uint8_t e1_nr);

/* create a line in the E1 input core */
struct e1inp_line *e1inp_line_create(uint8_t e1_nr, const char *driver_name);

/* clone one existing E1 input line */
struct e1inp_line *e1inp_line_clone(void *ctx, struct e1inp_line *line);

/* increment refcount use of E1 input line */
void e1inp_line_get(struct e1inp_line *line);

/* decrement refcount use of E1 input line, release if unused */
void e1inp_line_put(struct e1inp_line *line);

/* bind operations to one E1 input line */
void e1inp_line_bind_ops(struct e1inp_line *line, const struct e1inp_line_ops *ops);

/* find a sign_link for given TEI and SAPI in a TS */
struct e1inp_sign_link *
e1inp_lookup_sign_link(struct e1inp_ts *ts, uint8_t tei,
			uint8_t sapi);

/* create a new signalling link in a E1 timeslot */
struct e1inp_sign_link *
e1inp_sign_link_create(struct e1inp_ts *ts, enum e1inp_sign_type type,
			struct gsm_bts_trx *trx, uint8_t tei,
			uint8_t sapi);

/* configure and initialize one signalling e1inp_ts */
int e1inp_ts_config_sign(struct e1inp_ts *ts, struct e1inp_line *line);

/* configure and initialize one timeslot dedicated to TRAU frames. */
int e1inp_ts_config_trau(struct e1inp_ts *ts, struct e1inp_line *line,
                         int (*trau_rcv_cb)(struct subch_demux *dmx, int ch,
					uint8_t *data, int len, void *_priv));

/* Call from the Stack: configuration of this TS has changed */
int e1inp_update_ts(struct e1inp_ts *ts);

/* Receive a packet from the E1 driver */
int e1inp_rx_ts(struct e1inp_ts *ts, struct msgb *msg,
		uint8_t tei, uint8_t sapi);
int e1inp_rx_ts_lapd(struct e1inp_ts *e1i_ts, struct msgb *msg);

/* called by driver if it wants to transmit on a given TS */
struct msgb *e1inp_tx_ts(struct e1inp_ts *e1i_ts,
			 struct e1inp_sign_link **sign_link);

/* called by driver in case some kind of link state event */
int e1inp_event(struct e1inp_ts *ts, int evt, uint8_t tei, uint8_t sapi);

/* L2->L3 */
void e1inp_dlsap_up(struct osmo_dlsap_prim *odp, uint8_t tei, uint8_t sapi,
        void *rx_cbdata);

/* Write LAPD frames to the fd. */
int e1_set_pcap_fd(int fd);

/* called by TRAU muxer to obtain the destination mux entity */
struct subch_mux *e1inp_get_mux(uint8_t e1_nr, uint8_t ts_nr);

/* on an IPA BTS, the BTS needs to establish the RSL connection much
 * later than the OML connection. */
int e1inp_ipa_bts_rsl_connect(struct e1inp_line *line,
			      const char *rem_addr, uint16_t rem_port);

void e1inp_sign_link_destroy(struct e1inp_sign_link *link);
int e1inp_line_update(struct e1inp_line *line);

int e1inp_vty_init(void);

struct gsm_network;
int ipaccess_setup(struct gsm_network *gsmnet);

extern struct llist_head e1inp_driver_list;
extern struct llist_head e1inp_line_list;

/* XXX */
struct input_signal_data {
	int link_type;
	uint8_t tei;
	uint8_t sapi;
	struct gsm_bts_trx *trx;
	struct e1inp_line *line;
};

int abis_sendmsg(struct msgb *msg);
int abis_rsl_sendmsg(struct msgb *msg);

#endif /* _E1_INPUT_H */