/*

 *

 *  BlueZ - Bluetooth protocol stack for Linux

 *

 *  Copyright (C) 2018-2019  Intel Corporation. All rights reserved.

 *

 *

 *  This library is free software; you can redistribute it and/or

 *  modify it under the terms of the GNU Lesser General Public

 *  License as published by the Free Software Foundation; either

 *  version 2.1 of the License, or (at your option) any later version.

 *

 *  This library 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

 *  Lesser General Public License for more details.

 *

 */

#ifdef HAVE_CONFIG_H

#include <config.h>

#endif

#include <errno.h>

#include <string.h>

#include <sys/time.h>

#include <ell/ell.h>

#include "monitor/bt.h"

#include "src/shared/hci.h"

#include "lib/bluetooth.h"

#include "lib/mgmt.h"

#include "mesh/mesh-mgmt.h"

#include "mesh/mesh-io.h"

#include "mesh/mesh-io-api.h"

#include "mesh/mesh-io-generic.h"

struct mesh_io_private {

	uint16_t index;

	struct bt_hci *hci;

	struct l_timeout *tx_timeout;

	struct l_queue *rx_regs;

	struct l_queue *tx_pkts;

	uint8_t filters[4];

	bool sending;

	struct tx_pkt *tx;

	uint16_t interval;

};

struct pvt_rx_reg {

	uint8_t filter_id;

	mesh_io_recv_func_t cb;

	void *user_data;

};

struct process_data {

	struct mesh_io_private		*pvt;

	const uint8_t			*data;

	uint8_t				len;

	struct mesh_io_recv_info	info;

};

struct tx_pkt {

	struct mesh_io_send_info	info;

	bool				delete;

	uint8_t				len;

	uint8_t				pkt[30];

};

struct tx_pattern {

	const uint8_t			*data;

	uint8_t				len;

};

static uint32_t get_instant(void)

{

	struct timeval tm;

	uint32_t instant;

	gettimeofday(&tm, NULL);

	instant = tm.tv_sec * 1000;

	instant += tm.tv_usec / 1000;

	return instant;

}

static uint32_t instant_remaining_ms(uint32_t instant)

{

	instant -= get_instant();

	return instant;

}

static void process_rx_callbacks(void *v_rx, void *v_reg)

{

	struct pvt_rx_reg *rx_reg = v_rx;

	struct process_data *rx = v_reg;

	uint8_t ad_type;

	ad_type = rx->pvt->filters[rx_reg->filter_id - 1];

	if (rx->data[0] == ad_type && rx_reg->cb)

		rx_reg->cb(rx_reg->user_data, &rx->info, rx->data, rx->len);

}

static void process_rx(struct mesh_io_private *pvt, int8_t rssi,

					uint32_t instant,

					const uint8_t *data, uint8_t len)

{

	struct process_data rx = {

		.pvt = pvt,

		.data = data,

		.len = len,

		.info.instant = instant,

		.info.chan = 7,

		.info.rssi = rssi,

	};

	l_queue_foreach(pvt->rx_regs, process_rx_callbacks, &rx);

}

static void event_adv_report(struct mesh_io *io, const void *buf, uint8_t size)

{

	const struct bt_hci_evt_le_adv_report *evt = buf;

	const uint8_t *adv;

	uint32_t instant;

	uint8_t adv_len;

	uint16_t len = 0;

	int8_t rssi;

	if (evt->event_type != 0x03)

		return;

	instant = get_instant();

	adv = evt->data;

	adv_len = evt->data_len;

	/* rssi is just beyond last byte of data */

	rssi = (int8_t) adv[adv_len];

	while (len < adv_len - 1) {

		uint8_t field_len = adv[0];

		/* Check for the end of advertising data */

		if (field_len == 0)

			break;

		len += field_len + 1;

		/* Do not continue data parsing if got incorrect length */

		if (len > adv_len)

			break;

		/* TODO: Create an Instant to use */

		process_rx(io->pvt, rssi, instant, adv + 1, adv[0]);

		adv += field_len + 1;

	}

}

static void event_callback(const void *buf, uint8_t size, void *user_data)

{

	uint8_t event = l_get_u8(buf);

	struct mesh_io *io = user_data;

	switch (event) {

	case BT_HCI_EVT_LE_ADV_REPORT:

		event_adv_report(io, buf + 1, size - 1);

		break;

	default:

		l_info("Other Meta Evt - %d", event);

	}

}

static void local_commands_callback(const void *data, uint8_t size,

							void *user_data)

{

	const struct bt_hci_rsp_read_local_commands *rsp = data;

	if (rsp->status)

		l_error("Failed to read local commands");

}

static void local_features_callback(const void *data, uint8_t size,

							void *user_data)

{

	const struct bt_hci_rsp_read_local_features *rsp = data;

	if (rsp->status)

		l_error("Failed to read local features");

}

static void hci_generic_callback(const void *data, uint8_t size,

								void *user_data)

{

	uint8_t status = l_get_u8(data);

	if (status)

		l_error("Failed to initialize HCI");

}

static void configure_hci(struct mesh_io_private *io)

{

	struct bt_hci_cmd_le_set_scan_parameters cmd;

	struct bt_hci_cmd_set_event_mask cmd_sem;

	struct bt_hci_cmd_le_set_event_mask cmd_slem;

	/* Set scan parameters */

	cmd.type = 0x00; /* Passive Scanning. No scanning PDUs shall be sent */

	cmd.interval = 0x0030; /* Scan Interval = N * 0.625ms */

	cmd.window = 0x0030; /* Scan Window = N * 0.625ms */

	cmd.own_addr_type = 0x00; /* Public Device Address */

	/* Accept all advertising packets except directed advertising packets

	 * not addressed to this device (default).

	 */

	cmd.filter_policy = 0x00;

	/* Set event mask

	 *

	 * Mask: 0x2000800002008890

	 *   Disconnection Complete

	 *   Encryption Change

	 *   Read Remote Version Information Complete

	 *   Hardware Error

	 *   Data Buffer Overflow

	 *   Encryption Key Refresh Complete

	 *   LE Meta

	 */

	cmd_sem.mask[0] = 0x90;

	cmd_sem.mask[1] = 0x88;

	cmd_sem.mask[2] = 0x00;

	cmd_sem.mask[3] = 0x02;

	cmd_sem.mask[4] = 0x00;

	cmd_sem.mask[5] = 0x80;

	cmd_sem.mask[6] = 0x00;

	cmd_sem.mask[7] = 0x20;

	/* Set LE event mask

	 *

	 * Mask: 0x000000000000087f

	 *   LE Connection Complete

	 *   LE Advertising Report

	 *   LE Connection Update Complete

	 *   LE Read Remote Used Features Complete

	 *   LE Long Term Key Request

	 *   LE Remote Connection Parameter Request

	 *   LE Data Length Change

	 *   LE PHY Update Complete

	 */

	cmd_slem.mask[0] = 0x7f;

	cmd_slem.mask[1] = 0x08;

	cmd_slem.mask[2] = 0x00;

	cmd_slem.mask[3] = 0x00;

	cmd_slem.mask[4] = 0x00;

	cmd_slem.mask[5] = 0x00;

	cmd_slem.mask[6] = 0x00;

	cmd_slem.mask[7] = 0x00;

	/* TODO: Move to suitable place. Set suitable masks */

	/* Reset Command */

	bt_hci_send(io->hci, BT_HCI_CMD_RESET, NULL, 0, hci_generic_callback,

								NULL, NULL);

	/* Read local supported commands */

	bt_hci_send(io->hci, BT_HCI_CMD_READ_LOCAL_COMMANDS, NULL, 0,

					local_commands_callback, NULL, NULL);

	/* Read local supported features */

	bt_hci_send(io->hci, BT_HCI_CMD_READ_LOCAL_FEATURES, NULL, 0,

					local_features_callback, NULL, NULL);

	/* Set event mask */

	bt_hci_send(io->hci, BT_HCI_CMD_SET_EVENT_MASK, &cmd_sem,

			sizeof(cmd_sem), hci_generic_callback, NULL, NULL);

	/* Set LE event mask */

	bt_hci_send(io->hci, BT_HCI_CMD_LE_SET_EVENT_MASK, &cmd_slem,

			sizeof(cmd_slem), hci_generic_callback, NULL, NULL);

	/* Scan Params */

	bt_hci_send(io->hci, BT_HCI_CMD_LE_SET_SCAN_PARAMETERS, &cmd,

				sizeof(cmd), hci_generic_callback, NULL, NULL);

}

static bool hci_init(struct mesh_io *io)

{

	io->pvt->hci = bt_hci_new_user_channel(io->pvt->index);

	if (!io->pvt->hci) {

		l_error("Failed to start mesh io (hci %u): %s", io->pvt->index,

							strerror(errno));

		return false;

	}

	configure_hci(io->pvt);

	bt_hci_register(io->pvt->hci, BT_HCI_EVT_LE_META_EVENT,

						event_callback, io, NULL);

	l_debug("Started mesh on hci %u", io->pvt->index);

	return true;

}

static void read_info(int index, void *user_data)

{

	struct mesh_io *io = user_data;

	if (io->pvt->index != MGMT_INDEX_NONE &&

					index != io->pvt->index) {

		l_debug("Ignore index %d", index);

		return;

	}

	io->pvt->index = index;

	hci_init(io);

}

static bool dev_init(struct mesh_io *io, void *opts)

{

	if (!io || io->pvt)

		return false;

	io->pvt = l_new(struct mesh_io_private, 1);

	io->pvt->index = *(int *)opts;

	io->pvt->rx_regs = l_queue_new();

	io->pvt->tx_pkts = l_queue_new();

	if (io->pvt->index == MGMT_INDEX_NONE)

		return mesh_mgmt_list(read_info, io);

	else

		return hci_init(io);

}

static bool dev_destroy(struct mesh_io *io)

{

	struct mesh_io_private *pvt = io->pvt;

	if (!pvt)

		return true;

	bt_hci_unref(pvt->hci);

	l_timeout_remove(pvt->tx_timeout);

	l_queue_destroy(pvt->rx_regs, l_free);

	l_queue_destroy(pvt->tx_pkts, l_free);

	l_free(pvt);

	io->pvt = NULL;

	return true;

}

static bool dev_caps(struct mesh_io *io, struct mesh_io_caps *caps)

{

	struct mesh_io_private *pvt = io->pvt;

	if (!pvt || !caps)

		return false;

	caps->max_num_filters = sizeof(pvt->filters);

	caps->window_accuracy = 50;

	return true;

}

static void send_cancel_done(const void *buf, uint8_t size,

							void *user_data)

{

	struct mesh_io_private *pvt = user_data;

	struct bt_hci_cmd_le_set_random_address cmd;

	if (!pvt)

		return;

	pvt->sending = false;

	/* At end of any burst of ADVs, change random address */

	l_getrandom(cmd.addr, 6);

	cmd.addr[5] |= 0xc0;

	bt_hci_send(pvt->hci, BT_HCI_CMD_LE_SET_RANDOM_ADDRESS,

				&cmd, sizeof(cmd), NULL, NULL, NULL);

}

static void send_cancel(struct mesh_io_private *pvt)

{

	struct bt_hci_cmd_le_set_adv_enable cmd;

	if (!pvt)

		return;

	if (!pvt->sending) {

		send_cancel_done(NULL, 0, pvt);

		return;

	}

	cmd.enable = 0x00;	/* Disable advertising */

	bt_hci_send(pvt->hci, BT_HCI_CMD_LE_SET_ADV_ENABLE,

				&cmd, sizeof(cmd),

				send_cancel_done, pvt, NULL);

}

static void set_send_adv_enable(const void *buf, uint8_t size,

							void *user_data)

{

	struct mesh_io_private *pvt = user_data;

	struct bt_hci_cmd_le_set_adv_enable cmd;

	if (!pvt)

		return;

	pvt->sending = true;

	cmd.enable = 0x01;	/* Enable advertising */

	bt_hci_send(pvt->hci, BT_HCI_CMD_LE_SET_ADV_ENABLE,

				&cmd, sizeof(cmd), NULL, NULL, NULL);

}

static void set_send_adv_data(const void *buf, uint8_t size,

							void *user_data)

{

	struct mesh_io_private *pvt = user_data;

	struct tx_pkt *tx;

	struct bt_hci_cmd_le_set_adv_data cmd;

	if (!pvt || !pvt->tx)

		return;

	tx = pvt->tx;

	if (tx->len >= sizeof(cmd.data))

		goto done;

	memset(&cmd, 0, sizeof(cmd));

	cmd.len = tx->len + 1;

	cmd.data[0] = tx->len;

	memcpy(cmd.data + 1, tx->pkt, tx->len);

	bt_hci_send(pvt->hci, BT_HCI_CMD_LE_SET_ADV_DATA,

					&cmd, sizeof(cmd),

					set_send_adv_enable, pvt, NULL);

done:

	if (tx->delete)

		l_free(tx);

	pvt->tx = NULL;

}

static void set_send_adv_params(const void *buf, uint8_t size,

							void *user_data)

{

	struct mesh_io_private *pvt = user_data;

	struct bt_hci_cmd_le_set_adv_parameters cmd;

	uint16_t hci_interval;

	if (!pvt)

		return;

	hci_interval = (pvt->interval * 16) / 10;

	cmd.min_interval = L_CPU_TO_LE16(hci_interval);

	cmd.max_interval = L_CPU_TO_LE16(hci_interval);

	cmd.type = 0x03; /* ADV_NONCONN_IND */

	cmd.own_addr_type = 0x01; /* ADDR_TYPE_RANDOM */

	cmd.direct_addr_type = 0x00;

	memset(cmd.direct_addr, 0, 6);

	cmd.channel_map = 0x07;

	cmd.filter_policy = 0x03;

	bt_hci_send(pvt->hci, BT_HCI_CMD_LE_SET_ADV_PARAMETERS,

				&cmd, sizeof(cmd),

				set_send_adv_data, pvt, NULL);

}

static void send_pkt(struct mesh_io_private *pvt, struct tx_pkt *tx,

							uint16_t interval)

{

	struct bt_hci_cmd_le_set_adv_enable cmd;

	pvt->tx = tx;

	pvt->interval = interval;

	if (!pvt->sending) {

		set_send_adv_params(NULL, 0, pvt);

		return;

	}

	cmd.enable = 0x00;	/* Disable advertising */

	bt_hci_send(pvt->hci, BT_HCI_CMD_LE_SET_ADV_ENABLE,

				&cmd, sizeof(cmd),

				set_send_adv_params, pvt, NULL);

}

static void tx_timeout(struct l_timeout *timeout, void *user_data)

{

	struct mesh_io_private *pvt = user_data;

	struct tx_pkt *tx;

	uint16_t ms;

	uint8_t count;

	if (!pvt)

		return;

	tx = l_queue_pop_head(pvt->tx_pkts);

	if (!tx) {

		l_timeout_remove(timeout);

		pvt->tx_timeout = NULL;

		send_cancel(pvt);

		return;

	}

	if (tx->info.type == MESH_IO_TIMING_TYPE_GENERAL) {

		ms = tx->info.u.gen.interval;

		count = tx->info.u.gen.cnt;

		if (count != MESH_IO_TX_COUNT_UNLIMITED)

			tx->info.u.gen.cnt--;

	} else {

		ms = 25;

		count = 1;

	}

	tx->delete = !!(count == 1);

	send_pkt(pvt, tx, ms);

	if (count == 1) {

		/* send_pkt will delete when done */

		tx = l_queue_peek_head(pvt->tx_pkts);

		if (tx && tx->info.type == MESH_IO_TIMING_TYPE_POLL_RSP) {

			ms = instant_remaining_ms(tx->info.u.poll_rsp.instant +

						tx->info.u.poll_rsp.delay);

		}

	} else

		l_queue_push_tail(pvt->tx_pkts, tx);

	if (timeout) {

		pvt->tx_timeout = timeout;

		l_timeout_modify_ms(timeout, ms);

	} else

		pvt->tx_timeout = l_timeout_create_ms(ms, tx_timeout,

								pvt, NULL);

}

static void tx_worker(void *user_data)

{

	struct mesh_io_private *pvt = user_data;

	struct tx_pkt *tx;

	uint32_t delay;

	tx = l_queue_peek_head(pvt->tx_pkts);

	if (!tx)

		return;

	switch (tx->info.type) {

	case MESH_IO_TIMING_TYPE_GENERAL:

		if (tx->info.u.gen.min_delay == tx->info.u.gen.max_delay)

			delay = tx->info.u.gen.min_delay;

		else {

			l_getrandom(&delay, sizeof(delay));

			delay %= tx->info.u.gen.max_delay -

						tx->info.u.gen.min_delay;

			delay += tx->info.u.gen.min_delay;

		}

		break;

	case MESH_IO_TIMING_TYPE_POLL:

		if (tx->info.u.poll.min_delay == tx->info.u.poll.max_delay)

			delay = tx->info.u.poll.min_delay;

		else {

			l_getrandom(&delay, sizeof(delay));

			delay %= tx->info.u.poll.max_delay -

						tx->info.u.poll.min_delay;

			delay += tx->info.u.poll.min_delay;

		}

		break;

	case MESH_IO_TIMING_TYPE_POLL_RSP:

		/* Delay until Instant + Delay */

		delay = instant_remaining_ms(tx->info.u.poll_rsp.instant +

						tx->info.u.poll_rsp.delay);

		if (delay > 255)

			delay = 0;

		break;

	default:

		return;

	}

	if (!delay)

		tx_timeout(pvt->tx_timeout, pvt);

	else if (pvt->tx_timeout)

		l_timeout_modify_ms(pvt->tx_timeout, delay);

	else

		pvt->tx_timeout = l_timeout_create_ms(delay, tx_timeout,

								pvt, NULL);

}

static bool send_tx(struct mesh_io *io, struct mesh_io_send_info *info,

					const uint8_t *data, uint16_t len)

{

	struct mesh_io_private *pvt = io->pvt;

	struct tx_pkt *tx;

	bool sending = false;

	if (!info || !data || !len || len > sizeof(tx->pkt))

		return false;

	tx = l_new(struct tx_pkt, 1);

	if (!tx)

		return false;

	memcpy(&tx->info, info, sizeof(tx->info));

	memcpy(&tx->pkt, data, len);

	tx->len = len;

	if (info->type == MESH_IO_TIMING_TYPE_POLL_RSP)

		l_queue_push_head(pvt->tx_pkts, tx);

	else {

		sending = !l_queue_isempty(pvt->tx_pkts);

		l_queue_push_tail(pvt->tx_pkts, tx);

	}

	if (!sending) {

		l_timeout_remove(pvt->tx_timeout);

		pvt->tx_timeout = NULL;

		l_idle_oneshot(tx_worker, pvt, NULL);

	}

	return true;

}

static bool find_by_ad_type(const void *a, const void *b)

{

	const struct tx_pkt *tx = a;

	uint8_t ad_type = L_PTR_TO_UINT(b);

	return !ad_type || ad_type == tx->pkt[0];

}

static bool find_by_pattern(const void *a, const void *b)

{

	const struct tx_pkt *tx = a;

	const struct tx_pattern *pattern = b;

	if (tx->len < pattern->len)

		return false;

	return (!memcmp(tx->pkt, pattern->data, pattern->len));

}

static bool tx_cancel(struct mesh_io *io, const uint8_t *data, uint8_t len)

{

	struct mesh_io_private *pvt = io->pvt;

	struct tx_pkt *tx;

	if (!data)

		return false;

	if (len == 1) {

		do {

			tx = l_queue_remove_if(pvt->tx_pkts, find_by_ad_type,

							L_UINT_TO_PTR(data[0]));

			l_free(tx);

			if (tx == pvt->tx)

				pvt->tx = NULL;

		} while (tx);

	} else {

		struct tx_pattern pattern = {

			.data = data,

			.len = len

		};

		do {

			tx = l_queue_remove_if(pvt->tx_pkts, find_by_pattern,

								&pattern);

			l_free(tx);

			if (tx == pvt->tx)

				pvt->tx = NULL;

		} while (tx);

	}

	if (l_queue_isempty(pvt->tx_pkts)) {

		send_cancel(pvt);

		l_timeout_remove(pvt->tx_timeout);

		pvt->tx_timeout = NULL;

	}

	return true;

}

static bool find_by_filter_id(const void *a, const void *b)

{

	const struct pvt_rx_reg *rx_reg = a;

	uint8_t filter_id = L_PTR_TO_UINT(b);

	return rx_reg->filter_id == filter_id;

}

static void set_recv_scan_enable(const void *buf, uint8_t size,

							void *user_data)

{

	struct mesh_io_private *pvt = user_data;

	struct bt_hci_cmd_le_set_scan_enable cmd;

	cmd.enable = 0x01;	/* Enable scanning */

	cmd.filter_dup = 0x00;	/* Report duplicates */

	bt_hci_send(pvt->hci, BT_HCI_CMD_LE_SET_SCAN_ENABLE,

			&cmd, sizeof(cmd), NULL, NULL, NULL);

}

static bool recv_register(struct mesh_io *io, uint8_t filter_id,

				mesh_io_recv_func_t cb, void *user_data)

{

	struct bt_hci_cmd_le_set_scan_parameters cmd;

	struct mesh_io_private *pvt = io->pvt;

	struct pvt_rx_reg *rx_reg;

	bool already_scanning;

	l_info("%s %d", __func__, filter_id);

	if (!cb || !filter_id || filter_id > sizeof(pvt->filters))

		return false;

	rx_reg = l_queue_remove_if(pvt->rx_regs, find_by_filter_id,

						L_UINT_TO_PTR(filter_id));

	if (!rx_reg) {

		rx_reg = l_new(struct pvt_rx_reg, 1);

		if (!rx_reg)

			return false;

	}

	rx_reg->filter_id = filter_id;

	rx_reg->cb = cb;

	rx_reg->user_data = user_data;

	already_scanning = !l_queue_isempty(pvt->rx_regs);

	l_queue_push_head(pvt->rx_regs, rx_reg);

	if (!already_scanning) {

		cmd.type = 0x00;			/* Passive scanning */

		cmd.interval = L_CPU_TO_LE16(0x0010);	/* 10 ms */

		cmd.window = L_CPU_TO_LE16(0x0010);	/* 10 ms */

		cmd.own_addr_type = 0x01;		/* ADDR_TYPE_RANDOM */

		cmd.filter_policy = 0x00;		/* Accept all */

		bt_hci_send(pvt->hci, BT_HCI_CMD_LE_SET_SCAN_PARAMETERS,

				&cmd, sizeof(cmd),

				set_recv_scan_enable, pvt, NULL);

	}

	return true;

}

static bool recv_deregister(struct mesh_io *io, uint8_t filter_id)

{

	struct bt_hci_cmd_le_set_scan_enable cmd;

	struct mesh_io_private *pvt = io->pvt;

	struct pvt_rx_reg *rx_reg;

	rx_reg = l_queue_remove_if(pvt->rx_regs, find_by_filter_id,

						L_UINT_TO_PTR(filter_id));

	if (rx_reg)

		l_free(rx_reg);

	if (l_queue_isempty(pvt->rx_regs)) {

		cmd.enable = 0x00;	/* Disable scanning */

		cmd.filter_dup = 0x00;	/* Report duplicates */

		bt_hci_send(pvt->hci, BT_HCI_CMD_LE_SET_SCAN_ENABLE,

				&cmd, sizeof(cmd), NULL, NULL, NULL);

	}

	return true;

}

static bool filter_set(struct mesh_io *io,

		uint8_t filter_id, const uint8_t *data, uint8_t len,

		mesh_io_status_func_t callback, void *user_data)

{

	struct mesh_io_private *pvt = io->pvt;

	l_info("%s id: %d, --> %2.2x", __func__, filter_id, data[0]);

	if (!data || !len || !filter_id || filter_id > sizeof(pvt->filters))

		return false;

	pvt->filters[filter_id - 1] = data[0];

	/* TODO: Delayed Call to successful status */

	return true;

}

const struct mesh_io_api mesh_io_generic = {

	.init = dev_init,

	.destroy = dev_destroy,

	.caps = dev_caps,

	.send = send_tx,

	.reg = recv_register,

	.dereg = recv_deregister,

	.set = filter_set,

	.cancel = tx_cancel,

};