/*
* Copyright 2020 sysmocom - s.f.m.c. GmbH <info@sysmocom.de>
* Author: Pau Espin Pedrol <pespin@sysmocom.de>
*
* SPDX-License-Identifier: 0BSD
*
    Permission to use, copy, modify, and/or distribute this software for any purpose with or without fee is hereby granted.
    THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL
    IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT,
    INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN
    AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
    PERFORMANCE OF THIS SOFTWARE.
*/
#ifdef __cplusplus
extern "C" {
#endif

#define _GNU_SOURCE
#include <pthread.h>


#include <debug.h>

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <errno.h>
#include <assert.h>
#include <sys/socket.h>
#include <sys/un.h>
#include <inttypes.h>
#include <sys/mman.h>
#include <sys/stat.h> /* For mode constants */
#include <fcntl.h> /* For O_* constants */
#include <getopt.h>

#include <osmocom/core/application.h>
#include <osmocom/core/talloc.h>
#include <osmocom/core/select.h>
#include <osmocom/core/socket.h>
#include <osmocom/core/logging.h>
#include <osmocom/core/utils.h>
#include <osmocom/core/msgb.h>
#include <osmocom/core/select.h>
#include <osmocom/core/timer.h>

#include "shm.h"
#include "ipc_shm.h"
#include "ipc_chan.h"
#include "ipc_sock.h"

#define DEFAULT_SHM_NAME "/osmo-trx-ipc-driver-shm2"

static void *tall_ctx;
struct ipc_sock_state *global_ipc_sock_state;

/* 8 channels are plenty */
struct ipc_sock_state *global_ctrl_socks[8];
struct ipc_shm_io *ios_tx_to_device[8];
struct ipc_shm_io *ios_rx_from_device[8];

void *shm;
void *global_dev;

static struct ipc_shm_region *decoded_region;

/* Debug Areas of the code */
//enum { DMAIN,
//};
static const struct log_info_cat default_categories[] = {
	[DMAIN] = {
		.name = "DMAIN",
        		.color = NULL,
		.description = "Main generic category",
		 .loglevel = LOGL_DEBUG,.enabled = 1,
	},
    [DDEV] = {
		.name = "DDEV",
		.description = "Device/Driver specific code",
		.color = NULL,
		.enabled = 1, .loglevel = LOGL_DEBUG,
	},
};

const struct log_info log_infox = {
	.cat = default_categories,
	.num_cat = ARRAY_SIZE(default_categories),
};
#ifdef __cplusplus
}
#endif

#include "uhdwrap.h"

volatile int ipc_exit_requested = 0;

static int ipc_shm_setup(const char *shm_name, size_t shm_len)
{
	int fd;
	int rc;

	LOGP(DMAIN, LOGL_NOTICE, "Opening shm path %s\n", shm_name);
	if ((fd = shm_open(shm_name, O_CREAT | O_RDWR | O_TRUNC, S_IRUSR | S_IWUSR)) < 0) {
		LOGP(DMAIN, LOGL_ERROR, "shm_open %d: %s\n", errno, strerror(errno));
		rc = -errno;
		goto err_shm_open;
	}

	LOGP(DMAIN, LOGL_NOTICE, "Truncating %d to size %zu\n", fd, shm_len);
	if (ftruncate(fd, shm_len) < 0) {
		LOGP(DMAIN, LOGL_ERROR, "ftruncate %d: %s\n", errno, strerror(errno));
		rc = -errno;
		goto err_mmap;
	}

	LOGP(DMAIN, LOGL_NOTICE, "mmaping shared memory fd %d\n", fd);
	if ((shm = mmap(NULL, shm_len, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0)) == MAP_FAILED) {
		LOGP(DMAIN, LOGL_ERROR, "mmap %d: %s\n", errno, strerror(errno));
		rc = -errno;
		goto err_mmap;
	}

	LOGP(DMAIN, LOGL_NOTICE, "mmap'ed shared memory at addr %p\n", shm);
	/* After a call to mmap(2) the file descriptor may be closed without affecting the memory mapping. */
	close(fd);
	return 0;
err_mmap:
	shm_unlink(shm_name);
	close(fd);
err_shm_open:
	return rc;
}

struct msgb *ipc_msgb_alloc(uint8_t msg_type)
{
	struct msgb *msg;
	struct ipc_sk_if *ipc_prim;

	msg = msgb_alloc(sizeof(struct ipc_sk_if) + 1000, "ipc_sock_tx");
	if (!msg)
		return NULL;
	msgb_put(msg, sizeof(struct ipc_sk_if) + 1000);
	ipc_prim = (struct ipc_sk_if *)msg->data;
	ipc_prim->msg_type = msg_type;

	return msg;
}

static int ipc_tx_greeting_cnf(uint8_t req_version)
{
	struct msgb *msg;
	struct ipc_sk_if *ipc_prim;

	msg = ipc_msgb_alloc(IPC_IF_MSG_GREETING_CNF);
	if (!msg)
		return -ENOMEM;
	ipc_prim = (struct ipc_sk_if *)msg->data;
	ipc_prim->u.greeting_cnf.req_version = req_version;

	return ipc_sock_send(msg);
}

static int ipc_tx_info_cnf()
{
	struct msgb *msg;
	struct ipc_sk_if *ipc_prim;

	msg = ipc_msgb_alloc(IPC_IF_MSG_INFO_CNF);
	if (!msg)
		return -ENOMEM;
	ipc_prim = (struct ipc_sk_if *)msg->data;

	uhdwrap_fill_info_cnf(ipc_prim);

	return ipc_sock_send(msg);
}

static int ipc_tx_open_cnf(int rc, uint32_t num_chans, int32_t timingoffset)
{
	struct msgb *msg;
	struct ipc_sk_if *ipc_prim;
	struct ipc_sk_if_open_cnf_chan *chan_info;
	unsigned int i;

	msg = ipc_msgb_alloc(IPC_IF_MSG_OPEN_CNF);
	if (!msg)
		return -ENOMEM;
	ipc_prim = (struct ipc_sk_if *)msg->data;
	ipc_prim->u.open_cnf.return_code = rc;
	ipc_prim->u.open_cnf.path_delay = timingoffset; // 6.18462e-5 * 1625e3 / 6;
	OSMO_STRLCPY_ARRAY(ipc_prim->u.open_cnf.shm_name, DEFAULT_SHM_NAME);

	chan_info = ipc_prim->u.open_cnf.chan_info;
	for (i = 0; i < num_chans; i++) {
		snprintf(chan_info->chan_ipc_sk_path, sizeof(chan_info->chan_ipc_sk_path), "%s_%d", IPC_SOCK_PATH_PREFIX, i);
		/* FIXME: dynamc chan limit, currently 8 */
		if (i < 8)
			ipc_sock_init(chan_info->chan_ipc_sk_path, &global_ctrl_socks[i], ipc_chan_sock_accept, i);
		chan_info++;
	}

	return ipc_sock_send(msg);
}

int ipc_rx_greeting_req(struct ipc_sk_if_greeting *greeting_req)
{
	if (greeting_req->req_version == IPC_SOCK_API_VERSION)
		ipc_tx_greeting_cnf(IPC_SOCK_API_VERSION);
	else
		ipc_tx_greeting_cnf(0);
	return 0;
}

int ipc_rx_info_req(struct ipc_sk_if_info_req *info_req)
{
	ipc_tx_info_cnf();
	return 0;
}

int ipc_rx_open_req(struct ipc_sk_if_open_req *open_req)
{
	/* calculate size needed */
	unsigned int len;

	global_dev = uhdwrap_open(open_req);

	/* b210 packet size is 2040, but our tx size is 2500, so just do *2 */
	int shmbuflen = uhdwrap_get_bufsizerx(global_dev) * 2;

	len = ipc_shm_encode_region(NULL, open_req->num_chans, 4, shmbuflen);
	/* Here we verify num_chans, rx_path, tx_path, clockref, etc. */
	int rc = ipc_shm_setup(DEFAULT_SHM_NAME, len);
	len = ipc_shm_encode_region((struct ipc_shm_raw_region *)shm, open_req->num_chans, 4, shmbuflen);
//	LOGP(DMAIN, LOGL_NOTICE, "%s\n", osmo_hexdump((const unsigned char *)shm, 80));

	/* set up our own copy of the decoded area, we have to do it here,
	 *  since the uhd wrapper does not allow starting single channels
	* additionally go for the producer init for both, so only we are responsible for the init, instead
     * of splitting it with the client and causing potential races if one side uses it too early */
	decoded_region = ipc_shm_decode_region(0, (struct ipc_shm_raw_region *)shm);
	for (unsigned int i = 0; i < open_req->num_chans; i++) {
		//		ios_tx_to_device[i] = ipc_shm_init_consumer(decoded_region->channels[i]->dl_stream);
		ios_tx_to_device[i] = ipc_shm_init_producer(decoded_region->channels[i]->dl_stream);
		ios_rx_from_device[i] = ipc_shm_init_producer(decoded_region->channels[i]->ul_stream);
	}

	ipc_tx_open_cnf(-rc, open_req->num_chans, uhdwrap_get_timingoffset(global_dev));
	return 0;
}

volatile int ul_running = 0;
volatile int dl_running = 0;

void *uplink_thread(void *x_void_ptr)
{
	uint32_t chann = decoded_region->num_chans;
	ul_running = 1;
	pthread_setname_np(pthread_self(), "uplink rx");

	while (!ipc_exit_requested) {
		int32_t read = uhdwrap_read(global_dev, chann);
		if (read < 0)
			return 0;
	}
	return 0;
}

void *downlink_thread(void *x_void_ptr)
{
	int chann = decoded_region->num_chans;
	dl_running = 1;
	pthread_setname_np(pthread_self(), "downlink tx");

	while (!ipc_exit_requested) {
		bool underrun;
		uhdwrap_write(global_dev, chann, &underrun);
	}
	return 0;
}

int ipc_rx_chan_start_req(struct ipc_sk_chan_if_op_void *req, uint8_t chan_nr)
{
	struct msgb *msg;
	struct ipc_sk_chan_if *ipc_prim;
	int rc = 0;

	rc = uhdwrap_start(global_dev, chan_nr);

	/* no per-chan start/stop */
	if(!dl_running || !ul_running) {

		/* chan != first chan start will "fail", which is fine, usrp can't start/stop chans independently */
		if(rc) {
			LOGP(DMAIN, LOGL_INFO, "starting rx/tx threads.. req for chan:%d\n", chan_nr);
			pthread_t rx, tx;
			pthread_create(&rx, NULL, uplink_thread, 0);
			pthread_create(&tx, NULL, downlink_thread, 0);
		}
	} else
		LOGP(DMAIN, LOGL_INFO, "starting rx/tx threads request ignored.. req for chan:%d\n", chan_nr);

	msg = ipc_msgb_alloc(IPC_IF_MSG_START_CNF);
	if (!msg)
		return -ENOMEM;
	ipc_prim = (struct ipc_sk_chan_if *)msg->data;
	ipc_prim->u.start_cnf.return_code = rc ? 0 : -1;

	return ipc_chan_sock_send(msg, chan_nr);
}
int ipc_rx_chan_stop_req(struct ipc_sk_chan_if_op_void *req, uint8_t chan_nr)
{
	struct msgb *msg;
	struct ipc_sk_chan_if *ipc_prim;
	int rc;

	/* no per-chan start/stop */
	rc = uhdwrap_stop(global_dev, chan_nr);

	msg = ipc_msgb_alloc(IPC_IF_MSG_STOP_CNF);
	if (!msg)
		return -ENOMEM;
	ipc_prim = (struct ipc_sk_chan_if *)msg->data;
	ipc_prim->u.stop_cnf.return_code = rc ? 0 : -1;

	return ipc_chan_sock_send(msg, chan_nr);
}
int ipc_rx_chan_setgain_req(struct ipc_sk_chan_if_gain *req, uint8_t chan_nr)
{
	struct msgb *msg;
	struct ipc_sk_chan_if *ipc_prim;
	double rv;

	rv = uhdwrap_set_gain(global_dev, req->gain, chan_nr, req->is_tx);

	msg = ipc_msgb_alloc(IPC_IF_MSG_SETGAIN_CNF);
	if (!msg)
		return -ENOMEM;
	ipc_prim = (struct ipc_sk_chan_if *)msg->data;
	ipc_prim->u.set_gain_cnf.is_tx = req->is_tx;
	ipc_prim->u.set_gain_cnf.gain = rv;

	return ipc_chan_sock_send(msg, chan_nr);
}

int ipc_rx_chan_setfreq_req(struct ipc_sk_chan_if_freq_req *req, uint8_t chan_nr)
{
	struct msgb *msg;
	struct ipc_sk_chan_if *ipc_prim;
	bool rv;

	rv = uhdwrap_set_freq(global_dev, req->freq, chan_nr, req->is_tx);

	msg = ipc_msgb_alloc(IPC_IF_MSG_SETFREQ_CNF);
	if (!msg)
		return -ENOMEM;
	ipc_prim = (struct ipc_sk_chan_if *)msg->data;
	ipc_prim->u.set_freq_cnf.return_code = rv ? 0 : 1;

	return ipc_chan_sock_send(msg, chan_nr);
}

int ipc_rx_chan_settxatten_req(struct ipc_sk_chan_if_tx_attenuation *req, uint8_t chan_nr)
{
	struct msgb *msg;
	struct ipc_sk_chan_if *ipc_prim;
	double rv;

	rv = uhdwrap_set_txatt(global_dev, req->attenuation, chan_nr);

	msg = ipc_msgb_alloc(IPC_IF_MSG_SETTXATTN_CNF);
	if (!msg)
		return -ENOMEM;
	ipc_prim = (struct ipc_sk_chan_if *)msg->data;
	ipc_prim->u.txatten_cnf.attenuation = rv;

	return ipc_chan_sock_send(msg, chan_nr);
}

int ipc_sock_init(const char *path, struct ipc_sock_state **global_state_var,
		  int (*sock_callback_fn)(struct osmo_fd *fd, unsigned int what), int n)
{
	struct ipc_sock_state *state;
	struct osmo_fd *bfd;
	int rc;

	state = talloc_zero(NULL, struct ipc_sock_state);
	if (!state)
		return -ENOMEM;
	*global_state_var = state;

	INIT_LLIST_HEAD(&state->upqueue);
	state->conn_bfd.fd = -1;

	bfd = &state->listen_bfd;

	bfd->fd = osmo_sock_unix_init(SOCK_SEQPACKET, 0, path, OSMO_SOCK_F_BIND);
	if (bfd->fd < 0) {
		LOGP(DMAIN, LOGL_ERROR, "Could not create %s unix socket: %s\n", path, strerror(errno));
		talloc_free(state);
		return -1;
	}

	bfd->when = BSC_FD_READ;
	bfd->cb = sock_callback_fn;
	bfd->data = state;
	bfd->priv_nr = n;

	rc = osmo_fd_register(bfd);
	if (rc < 0) {
		LOGP(DMAIN, LOGL_ERROR, "Could not register listen fd: %d\n", rc);
		close(bfd->fd);
		talloc_free(state);
		return rc;
	}

	//osmo_signal_register_handler(SS_GLOBAL, IPC_if_signal_cb, NULL);

	LOGP(DMAIN, LOGL_INFO, "Started listening on IPC socket: %s\n", path);

	return 0;
}

static void print_help(void)
{
	printf(	"ipc-driver-test Usage:\n"
		" -h  --help		This message\n"
		" -n  --sock-num NR	Master socket suffix number NR\n"
	      );
}

static int msocknum = 0;

static void handle_options(int argc, char **argv)
{
	while (1) {
		int option_index = 0, c;
		const struct option long_options[] = {
			{ "help", 0, 0, 'h' },
			{ "sock-num", 1, 0, 'n' },
			{0,0,0,0}
		};

		c = getopt_long(argc, argv, "hn:",
				long_options, &option_index);
		if (c == -1)
			break;

		switch (c) {
		case 'h':
			print_help();
			exit(0);
			break;
		case 'n':
			msocknum = atoi(optarg);
			break;
		default:
			exit(2);
			break;
		}
	}

	if (argc > optind) {
		fprintf(stderr, "Unsupported positional arguments on command line\n");
		exit(2);
	}
}

#if defined(IPCMAGIC) && defined(__cplusplus)
extern "C" int osmo_ctx_init(const char *id);

extern "C" int magicmain(int argc, char **argv)
{
	osmo_ctx_init("main");
	osmo_select_init();

#else
int main(int argc, char **argv)
{
#endif
	char ipc_msock_path[sizeof(IPC_SOCK_PATH_PREFIX)+3];
	tall_ctx = talloc_named_const(NULL, 0, "OsmoTRX");
	msgb_talloc_ctx_init(tall_ctx, 0);
	osmo_init_logging2(tall_ctx, &log_infox);
	log_enable_multithread();

	handle_options(argc, argv);
	snprintf(ipc_msock_path,sizeof(ipc_msock_path), "%s%d", IPC_SOCK_PATH_PREFIX, msocknum);

	LOGP(DMAIN, LOGL_INFO, "Starting %s\n", argv[0]);
	ipc_sock_init(ipc_msock_path, &global_ipc_sock_state, ipc_sock_accept, 0);
	while (!ipc_exit_requested)
		osmo_select_main(0);

	if (global_dev)
		for (unsigned int i = 0; i < decoded_region->num_chans; i++)
			uhdwrap_stop(global_dev, i);

	//ipc_sock_close()
	return 0;
}