#include <osmocom/core/talloc.h>
#include <osmocom/core/linuxlist.h>
#include <osmocom/gsm/tlv.h>

#include "v5x_internal.h"
#include "v5x_protocol.h"
#include "lapv5.h"
#include "v5x_le_ctrl_fsm.h"
#include "v5x_le_port_fsm.h"
#include "v5x_le_pstn_fsm.h"
#include "v5x_le_management.h"
#include "logging.h"

static LLIST_HEAD(v5_instances);

struct v5x_instance *v5x_instance_alloc(void *ctx)
{
	struct v5x_instance *v5i = talloc_zero(ctx, struct v5x_instance);
	if (!v5i)
		return NULL;

	INIT_LLIST_HEAD(&v5i->interfaces);

	llist_add_tail(&v5i->list, &v5_instances);

	return v5i;
}

static void v5x_ts_init(struct v5x_timeslot *v5ts, uint8_t nr, struct v5x_link *v5l, uint16_t l3_addr)
{
	v5ts->nr = nr;
	v5ts->link = v5l;
	v5ts->l3_address = l3_addr;
}

static void v5x_cchan_init(struct v5x_c_channel *v5cc, struct v5x_link *v5l, struct v5x_timeslot *v5ts, bool active)
{
	v5cc->link = v5l;
	v5cc->ts = v5ts;
	v5cc->active = active;
}

static void v5x_link_init(struct v5x_link *v5l, struct v5x_interface *v5if, uint8_t id)
{
	unsigned int i;

	v5l->id = id;
	v5l->interface = v5if;

	for (i = 1; i < ARRAY_SIZE(v5l->ts); i++) {
		v5x_ts_init(&v5l->ts[i], i, v5l, 0 /*l3_addr*/);
	}

	/* primary c-channel must always be present */
	v5x_cchan_init(&v5l->c_channel[0], v5l, &v5l->ts[16], true);
}

struct v5x_interface *v5x_interface_alloc(struct v5x_instance *v5i, enum v5x_dialect dialect,
	int (*ph_data_req_cb)(struct msgb *msg, void *cbdata))
{
	struct v5x_interface *v5if = talloc_zero(v5i, struct v5x_interface);
	//struct v5x_link *v5l;
	struct v5x_c_channel *primary_c_chan;

	v5if->instance = v5i;
	v5if->dialect = dialect;

	/* primary link must alwasy be present */
	v5x_link_init(&v5if->links[0], v5if, 0);
	v5if->primary_link = &v5if->links[0];

	primary_c_chan = &v5if->primary_link->c_channel[0];

	v5if->control.ctrl = v5x_le_ctrl_create(v5if, NULL, 0);
	if (!v5if->control.ctrl)
		return NULL;
	v5if->control.li = lapv5_instance_alloc(1, ph_data_req_cb, v5if, v5x_rcv, v5if,
			&lapd_profile_lapv5dl, "control");
	v5if->control.c_chan = primary_c_chan;

	v5if->pstn.li = lapv5_instance_alloc(1, ph_data_req_cb, v5if, v5x_rcv, v5if,
			&lapd_profile_lapv5dl, "pstn");
	v5if->pstn.c_chan = primary_c_chan;

	if (v5if->dialect == V5X_DIALECT_V52) {
		v5if->lcp.li = lapv5_instance_alloc(1, ph_data_req_cb, v5if, v5x_rcv, v5if,
				&lapd_profile_lapv5dl, "lcp");
		v5if->lcp.c_chan = primary_c_chan;

		v5if->bcc.li = lapv5_instance_alloc(1, ph_data_req_cb, v5if, v5x_rcv, v5if,
				&lapd_profile_lapv5dl, "bcc");
		v5if->bcc.c_chan = primary_c_chan;

		v5if->protection[0].li = lapv5_instance_alloc(1, ph_data_req_cb, v5if, v5x_rcv, v5if,
				&lapd_profile_lapv5dl, "protection0");
		v5if->protection[0].c_chan = primary_c_chan;

		//protection[1] ? 
	}

	INIT_LLIST_HEAD(&v5if->user_ports);

	llist_add_tail(&v5if->list, &v5i->interfaces);

	return v5if;
}

void v5x_interface_free(struct v5x_interface *v5if) {
	struct v5x_user_port *v5up, *v5up2;

	llist_for_each_entry_safe(v5up, v5up2, &v5if->user_ports, list)
		v5x_user_port_destroy(v5up);

	if (v5if->control.ctrl)
		v5x_le_ctrl_destroy(v5if->control.ctrl);

	if (v5if->control.li)
		lapv5_instance_free(v5if->control.li);

	if (v5if->pstn.li)
		lapv5_instance_free(v5if->pstn.li);

	if (v5if->lcp.li)
		lapv5_instance_free(v5if->lcp.li);

	if (v5if->bcc.li)
		lapv5_instance_free(v5if->bcc.li);

	if (v5if->protection[0].li)
		lapv5_instance_free(v5if->protection[0].li);
	if (v5if->protection[1].li)
		lapv5_instance_free(v5if->protection[1].li);

	llist_del(&v5if->list);

	talloc_free(v5if);
}

struct v5x_user_port *v5x_user_port_create(struct v5x_interface *v5if, uint16_t nr, enum v5x_user_type type,
	uint8_t ts1, uint8_t ts2)
{
	struct v5x_user_port *v5up;
	int rc;

	if ((v5up = v5if->links[0].ts[ts1].v5up)) {
		LOGP(DV5, LOGL_ERROR, "Time slot %d is already assigned to another user port\n", ts1);
		return NULL;
	}
	if (type == V5X_USER_TYPE_ISDN) {
		if ((v5up = v5if->links[0].ts[ts2].v5up)) {
			LOGP(DV5, LOGL_ERROR, "Time slot %d is already assigned to another user port\n", ts2);
			return NULL;
		}
	}

	v5up = talloc_zero(v5if, struct v5x_user_port);
	if (!v5up)
		return NULL;

	llist_add_tail(&v5up->list, &v5if->user_ports);

	v5up->inst = v5if;
	v5up->nr = nr;
	v5up->type = type;

	/* assign ports */
	if (v5if->dialect == V5X_DIALECT_V51) {
		OSMO_ASSERT(ts1 >= 1 && ts1 <= 31);
		v5if->links[0].ts[ts1].v5up = v5up;
		v5up->ts_nr[0] = ts1;
		if (type == V5X_USER_TYPE_ISDN) {
			OSMO_ASSERT(ts2 >= 1 && ts2 <= 31);
			v5if->links[0].ts[ts2].v5up = v5up;
			v5up->ts_nr[1] = ts2;
		}
	}

	v5up->ctrl = v5x_le_ctrl_create(NULL, v5up, nr);
	if (!v5up->ctrl) {
		LOGP(DV5, LOGL_ERROR, "Failed to create control protocol\n");
		v5x_user_port_destroy(v5up);
		return NULL;
	}

	switch (type) {
	case V5X_USER_TYPE_ISDN:
		LOGP(DV5, LOGL_NOTICE, "Creating V5 ISDN user port with L3 addr %d\n", nr);
		sprintf(v5up->ifname, "isdn-%d", nr);
		OSMO_ASSERT(nr <= 8175);
		v5up->port_fi = v5x_le_port_isdn_create(v5up, nr);
		if (!v5up->port_fi) {
			LOGP(DV5, LOGL_ERROR, "Failed to create port control\n");
			v5x_user_port_destroy(v5up);
			return NULL;
		}
		break;
	case V5X_USER_TYPE_PSTN:
		LOGP(DV5, LOGL_NOTICE, "Creating V5 PSTN user port with L3 addr %d\n", nr);
		sprintf(v5up->ifname, "pstn-%d", nr);
		OSMO_ASSERT(nr <= 32767);
		v5up->port_fi = v5x_le_port_pstn_create(v5up, nr);
		if (!v5up->port_fi) {
			LOGP(DV5, LOGL_ERROR, "Failed to create port control\n");
			v5x_user_port_destroy(v5up);
			return NULL;
		}
		v5up->pstn.proto = v5x_le_pstn_create(v5up, nr);
		if (!v5up->pstn.proto) {
			LOGP(DV5, LOGL_ERROR, "Failed to create PSTN protocol\n");
			v5x_user_port_destroy(v5up);
			return NULL;
		}
		/* bring port into service */
		v5x_le_pstn_mdu_snd(v5up, MDU_CTRL_port_blocked);
		break;
	}

	rc = ph_socket_init(&v5up->ph_socket, ph_socket_rx_cb, v5up, v5up->ifname, 1);
	if (rc < 0) {
		LOGP(DV5, LOGL_ERROR, "Failed to create PH-socket\n");
		v5x_user_port_destroy(v5up);
		return NULL;
	}

	return v5up;
}

void v5x_user_port_destroy(struct v5x_user_port *v5up)
{
	struct v5x_interface *v5if = v5up->inst;

	LOGP(DV5, LOGL_NOTICE, "Destroying V5 user port with L3 addr %d\n", v5up->nr);

	/* close fitst, because it sends messages */
	ph_socket_exit(&v5up->ph_socket);

	/* unassign ports */
	if (v5up->ts_nr[0])
		v5if->links[v5up->link_nr[0]].ts[v5up->ts_nr[0]].v5up = NULL;
	if (v5up->ts_nr[1])
		v5if->links[v5up->link_nr[1]].ts[v5up->ts_nr[1]].v5up = NULL;

	if (v5up->ctrl)
		v5x_le_ctrl_destroy(v5up->ctrl);

	if (v5up->port_fi)
		osmo_fsm_inst_free(v5up->port_fi);

	if (v5up->pstn.proto)
		v5x_le_pstn_destroy(v5up->pstn.proto);

	llist_del(&v5up->list);

	talloc_free(v5up);
}

struct v5x_user_port *v5x_user_port_find(struct v5x_interface *v5if, uint16_t nr, bool is_isdn)
{
	struct v5x_user_port *v5up;

	llist_for_each_entry(v5up, &v5if->user_ports, list) {
		if (v5up->nr == nr && is_isdn == (v5up->type == V5X_USER_TYPE_ISDN))
			return v5up;
	}
	return NULL;
}