/*-
 *   BSD LICENSE
 *
 *   Copyright (c) Intel Corporation.
 *   All rights reserved.
 *
 *   Redistribution and use in source and binary forms, with or without
 *   modification, are permitted provided that the following conditions
 *   are met:
 *
 *     * Redistributions of source code must retain the above copyright
 *       notice, this list of conditions and the following disclaimer.
 *     * Redistributions in binary form must reproduce the above copyright
 *       notice, this list of conditions and the following disclaimer in
 *       the documentation and/or other materials provided with the
 *       distribution.
 *     * Neither the name of Intel Corporation nor the names of its
 *       contributors may be used to endorse or promote products derived
 *       from this software without specific prior written permission.
 *
 *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 *   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 *   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 *   A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 *   OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 *   SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 *   LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 *   DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 *   THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 *   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#include "spdk/stdinc.h"
#include "spdk/env.h"
#include "spdk/json.h"
#include "spdk/likely.h"
#include "spdk/string.h"
#include "spdk/util.h"

#include <map>

extern "C" {
#include "spdk/trace.h"
#include "spdk/util.h"
}

static struct spdk_trace_histories *g_histories;
static struct spdk_json_write_ctx *g_json;
static bool g_print_tsc = false;

/* This is a bit ugly, but we don't want to include env_dpdk in the app, while spdk_util, which we
 * do need, uses some of the functions implemented there.  We're not actually using the functions
 * that depend on those, so just define them as no-ops to allow the app to link.
 */
extern "C" {
	void *
	spdk_realloc(void *buf, size_t size, size_t align)
	{
		assert(false);

		return NULL;
	}

	void
	spdk_free(void *buf)
	{
		assert(false);
	}
} /* extern "C" */

static void usage(void);

struct entry_key {
	entry_key(uint16_t _lcore, uint64_t _tsc) : lcore(_lcore), tsc(_tsc) {}
	uint16_t lcore;
	uint64_t tsc;
};

class compare_entry_key
{
public:
	bool operator()(const entry_key &first, const entry_key &second) const
	{
		if (first.tsc == second.tsc) {
			return first.lcore < second.lcore;
		} else {
			return first.tsc < second.tsc;
		}
	}
};

typedef std::map<entry_key, spdk_trace_entry *, compare_entry_key> entry_map;

entry_map g_entry_map;

struct object_stats {

	std::map<uint64_t, uint64_t> start;
	std::map<uint64_t, uint64_t> index;
	std::map<uint64_t, uint64_t> size;
	std::map<uint64_t, uint64_t> tpoint_id;
	uint64_t counter;

	object_stats() : start(), index(), size(), tpoint_id(), counter(0) {}
};

struct argument_context {
	struct spdk_trace_entry		*entry;
	struct spdk_trace_entry_buffer	*buffer;
	uint16_t			lcore;
	size_t				offset;

	argument_context(struct spdk_trace_entry *entry,
			 uint16_t lcore) : entry(entry), lcore(lcore)
	{
		buffer = (struct spdk_trace_entry_buffer *)entry;

		/* The first argument resides within the spdk_trace_entry structure, so the initial
		 * offset needs to be adjusted to the start of the spdk_trace_entry.args array
		 */
		offset = offsetof(struct spdk_trace_entry, args) -
			 offsetof(struct spdk_trace_entry_buffer, data);
	}
};

struct object_stats g_stats[SPDK_TRACE_MAX_OBJECT];

static char *g_exe_name;

static uint64_t g_tsc_rate;
static uint64_t g_first_tsc = 0x0;

static float
get_us_from_tsc(uint64_t tsc, uint64_t tsc_rate)
{
	return ((float)tsc) * 1000 * 1000 / tsc_rate;
}

static const char *
format_argname(const char *name)
{
	static char namebuf[16];

	snprintf(namebuf, sizeof(namebuf), "%s: ", name);
	return namebuf;
}

static void
print_ptr(const char *arg_string, uint64_t arg)
{
	printf("%-7.7s0x%-14jx ", format_argname(arg_string), arg);
}

static void
print_uint64(const char *arg_string, uint64_t arg)
{
	/*
	 * Print arg as signed, since -1 is a common value especially
	 *  for FLUSH WRITEBUF when writev() returns -1 due to full
	 *  socket buffer.
	 */
	printf("%-7.7s%-16jd ", format_argname(arg_string), arg);
}

static void
print_string(const char *arg_string, const char *arg)
{
	printf("%-7.7s%-16.16s ", format_argname(arg_string), arg);
}

static void
print_size(uint32_t size)
{
	if (size > 0) {
		printf("size: %6u ", size);
	} else {
		printf("%13s", " ");
	}
}

static void
print_object_id(uint8_t type, uint64_t id)
{
	printf("id:    %c%-15jd ", g_histories->flags.object[type].id_prefix, id);
}

static void
print_float(const char *arg_string, float arg)
{
	printf("%-7s%-16.3f ", format_argname(arg_string), arg);
}

static struct spdk_trace_entry_buffer *
get_next_buffer(struct spdk_trace_entry_buffer *buf, uint16_t lcore)
{
	struct spdk_trace_history *history;

	history = spdk_get_per_lcore_history(g_histories, lcore);

	if (spdk_unlikely((void *)buf == &history->entries[history->num_entries - 1])) {
		return (struct spdk_trace_entry_buffer *)&history->entries[0];
	} else {
		return buf + 1;
	}
}

static bool
build_arg(struct argument_context *argctx, const struct spdk_trace_argument *arg,
	  void *buf, size_t bufsize)
{
	struct spdk_trace_entry *entry = argctx->entry;
	struct spdk_trace_entry_buffer *buffer = argctx->buffer;
	size_t curlen, argoff;

	argoff = 0;
	while (argoff < arg->size) {
		if (argctx->offset == sizeof(buffer->data)) {
			buffer = get_next_buffer(buffer, argctx->lcore);
			if (spdk_unlikely(buffer->tpoint_id != SPDK_TRACE_MAX_TPOINT_ID ||
					  buffer->tsc != entry->tsc)) {
				return false;
			}

			argctx->offset = 0;
			argctx->buffer = buffer;
		}

		curlen = spdk_min(sizeof(buffer->data) - argctx->offset, arg->size - argoff);
		if (argoff < bufsize) {
			memcpy((uint8_t *)buf + argoff, &buffer->data[argctx->offset],
			       spdk_min(curlen, bufsize - argoff));
		}

		argctx->offset += curlen;
		argoff += curlen;
	}

	return true;
}

static void
print_arg(struct argument_context *argctx, const struct spdk_trace_argument *arg)
{
	uint64_t value = 0;
	char strbuf[256];

	switch (arg->type) {
	case SPDK_TRACE_ARG_TYPE_PTR:
		if (build_arg(argctx, arg, &value, sizeof(value))) {
			print_ptr(arg->name, value);
		}
		break;
	case SPDK_TRACE_ARG_TYPE_INT:
		if (build_arg(argctx, arg, &value, sizeof(value))) {
			print_uint64(arg->name, value);
		}
		break;
	case SPDK_TRACE_ARG_TYPE_STR:
		assert((size_t)arg->size <= sizeof(strbuf));
		if (build_arg(argctx, arg, strbuf, sizeof(strbuf))) {
			print_string(arg->name, strbuf);
		}
		break;
	}
}

static void
print_arg_json(struct argument_context *argctx, const struct spdk_trace_argument *arg)
{
	uint64_t value = 0;
	char strbuf[256];

	switch (arg->type) {
	case SPDK_TRACE_ARG_TYPE_PTR:
	case SPDK_TRACE_ARG_TYPE_INT:
		if (build_arg(argctx, arg, &value, sizeof(value))) {
			spdk_json_write_uint64(g_json, value);
		} else {
			spdk_json_write_null(g_json);
		}
		break;
	case SPDK_TRACE_ARG_TYPE_STR:
		assert((size_t)arg->size <= sizeof(strbuf));
		if (build_arg(argctx, arg, strbuf, sizeof(strbuf))) {
			spdk_json_write_string(g_json, strbuf);
		} else {
			spdk_json_write_null(g_json);
		}
		break;
	}
}

static void
print_event(struct spdk_trace_entry *e, uint64_t tsc_rate,
	    uint64_t tsc_offset, uint16_t lcore)
{
	struct spdk_trace_tpoint	*d;
	struct object_stats		*stats;
	float				us;
	size_t				i;

	d = &g_histories->flags.tpoint[e->tpoint_id];
	stats = &g_stats[d->object_type];
	us = get_us_from_tsc(e->tsc - tsc_offset, tsc_rate);

	printf("%2d: %10.3f ", lcore, us);
	if (g_print_tsc) {
		printf("(%9ju) ", e->tsc - tsc_offset);
	}
	if (g_histories->flags.owner[d->owner_type].id_prefix) {
		printf("%c%02d ", g_histories->flags.owner[d->owner_type].id_prefix, e->poller_id);
	} else {
		printf("%4s", " ");
	}

	printf("%-*s ", (int)sizeof(d->name), d->name);
	print_size(e->size);

	if (d->new_object) {
		print_object_id(d->object_type, stats->index[e->object_id]);
	} else if (d->object_type != OBJECT_NONE) {
		if (stats->start.find(e->object_id) != stats->start.end()) {
			us = get_us_from_tsc(e->tsc - stats->start[e->object_id],
					     tsc_rate);
			print_object_id(d->object_type, stats->index[e->object_id]);
			print_float("time", us);
		} else {
			printf("id:    N/A");
		}
	} else if (e->object_id != 0) {
		print_ptr("object", e->object_id);
	}

	struct argument_context argctx(e, lcore);
	for (i = 0; i < d->num_args; ++i) {
		print_arg(&argctx, &d->args[i]);
	}
	printf("\n");
}

static void
print_event_json(struct spdk_trace_entry *e, uint64_t tsc_rate,
		 uint64_t tsc_offset, uint16_t lcore)
{
	struct spdk_trace_tpoint *d;
	struct object_stats *stats;
	size_t i;

	d = &g_histories->flags.tpoint[e->tpoint_id];
	stats = &g_stats[d->object_type];

	spdk_json_write_object_begin(g_json);
	spdk_json_write_named_uint64(g_json, "lcore", lcore);
	spdk_json_write_named_uint64(g_json, "tpoint", e->tpoint_id);
	spdk_json_write_named_uint64(g_json, "tsc", e->tsc);

	if (g_histories->flags.owner[d->owner_type].id_prefix) {
		spdk_json_write_named_string_fmt(g_json, "poller", "%c%02d",
						 g_histories->flags.owner[d->owner_type].id_prefix,
						 e->poller_id);
	}
	if (e->size != 0) {
		spdk_json_write_named_uint32(g_json, "size", e->size);
	}
	if (d->new_object || d->object_type != OBJECT_NONE || e->object_id != 0) {
		char object_type;

		spdk_json_write_named_object_begin(g_json, "object");
		if (d->new_object) {
			object_type =  g_histories->flags.object[d->object_type].id_prefix;
			spdk_json_write_named_string_fmt(g_json, "id", "%c%lu", object_type,
							 stats->index[e->object_id]);
		} else if (d->object_type != OBJECT_NONE) {
			object_type =  g_histories->flags.object[d->object_type].id_prefix;
			if (stats->start.find(e->object_id) != stats->start.end()) {
				spdk_json_write_named_string_fmt(g_json, "id", "%c%lu",
								 object_type,
								 stats->index[e->object_id]);
				spdk_json_write_named_uint64(g_json, "time",
							     e->tsc - stats->start[e->object_id]);
			}
		}
		spdk_json_write_named_uint64(g_json, "value", e->object_id);
		spdk_json_write_object_end(g_json);
	}
	if (d->num_args > 0) {
		struct argument_context argctx(e, lcore);

		spdk_json_write_named_array_begin(g_json, "args");
		for (i = 0; i < d->num_args; ++i) {
			print_arg_json(&argctx, &d->args[i]);
		}
		spdk_json_write_array_end(g_json);
	}

	spdk_json_write_object_end(g_json);
}

static void
process_event(struct spdk_trace_entry *e, uint64_t tsc_rate,
	      uint64_t tsc_offset, uint16_t lcore)
{
	struct spdk_trace_tpoint	*d;
	struct object_stats		*stats;

	d = &g_histories->flags.tpoint[e->tpoint_id];
	stats = &g_stats[d->object_type];

	if (d->new_object) {
		stats->index[e->object_id] = stats->counter++;
		stats->tpoint_id[e->object_id] = e->tpoint_id;
		stats->start[e->object_id] = e->tsc;
		stats->size[e->object_id] = e->size;
	}

	if (g_json == NULL) {
		print_event(e, tsc_rate, tsc_offset, lcore);
	} else {
		print_event_json(e, tsc_rate, tsc_offset, lcore);
	}
}

static int
populate_events(struct spdk_trace_history *history, int num_entries)
{
	int i, num_entries_filled;
	struct spdk_trace_entry *e;
	int first, last, lcore;

	lcore = history->lcore;

	e = history->entries;

	num_entries_filled = num_entries;
	while (e[num_entries_filled - 1].tsc == 0) {
		num_entries_filled--;
	}

	if (num_entries == num_entries_filled) {
		first = last = 0;
		for (i = 1; i < num_entries; i++) {
			if (e[i].tsc < e[first].tsc) {
				first = i;
			}
			if (e[i].tsc > e[last].tsc) {
				last = i;
			}
		}
	} else {
		first = 0;
		last = num_entries_filled - 1;
	}

	/*
	 * We keep track of the highest first TSC out of all reactors.
	 *  We will ignore any events that occured before this TSC on any
	 *  other reactors.  This will ensure we only print data for the
	 *  subset of time where we have data across all reactors.
	 */
	if (e[first].tsc > g_first_tsc) {
		g_first_tsc = e[first].tsc;
	}

	i = first;
	while (1) {
		if (e[i].tpoint_id != SPDK_TRACE_MAX_TPOINT_ID) {
			g_entry_map[entry_key(lcore, e[i].tsc)] = &e[i];
		}
		if (i == last) {
			break;
		}
		i++;
		if (i == num_entries_filled) {
			i = 0;
		}
	}

	return (0);
}

static void
print_tpoint_definitions(void)
{
	struct spdk_trace_tpoint *tpoint;
	size_t i, j;

	/* We only care about these when printing JSON */
	if (!g_json) {
		return;
	}

	spdk_json_write_named_uint64(g_json, "tsc_rate", g_tsc_rate);
	spdk_json_write_named_array_begin(g_json, "tpoints");

	for (i = 0; i < SPDK_COUNTOF(g_histories->flags.tpoint); ++i) {
		tpoint = &g_histories->flags.tpoint[i];
		if (tpoint->tpoint_id == 0) {
			continue;
		}

		spdk_json_write_object_begin(g_json);
		spdk_json_write_named_string(g_json, "name", tpoint->name);
		spdk_json_write_named_uint32(g_json, "id", tpoint->tpoint_id);
		spdk_json_write_named_bool(g_json, "new_object", tpoint->new_object);

		spdk_json_write_named_array_begin(g_json, "args");
		for (j = 0; j < tpoint->num_args; ++j) {
			spdk_json_write_object_begin(g_json);
			spdk_json_write_named_string(g_json, "name", tpoint->args[j].name);
			spdk_json_write_named_uint32(g_json, "type", tpoint->args[j].type);
			spdk_json_write_named_uint32(g_json, "size", tpoint->args[j].size);
			spdk_json_write_object_end(g_json);
		}
		spdk_json_write_array_end(g_json);
		spdk_json_write_object_end(g_json);
	}

	spdk_json_write_array_end(g_json);
}

static int
print_json(void *cb_ctx, const void *data, size_t size)
{
	ssize_t rc;

	while (size > 0) {
		rc = write(STDOUT_FILENO, data, size);
		if (rc < 0) {
			fprintf(stderr, "%s: %s\n", g_exe_name, spdk_strerror(errno));
			abort();
		}

		size -= rc;
	}

	return 0;
}

static void usage(void)
{
	fprintf(stderr, "usage:\n");
	fprintf(stderr, "   %s <option> <lcore#>\n", g_exe_name);
	fprintf(stderr, "                 '-c' to display single lcore history\n");
	fprintf(stderr, "                 '-t' to display TSC offset for each event\n");
	fprintf(stderr, "                 '-s' to specify spdk_trace shm name for a\n");
	fprintf(stderr, "                      currently running process\n");
	fprintf(stderr, "                 '-i' to specify the shared memory ID\n");
	fprintf(stderr, "                 '-p' to specify the trace PID\n");
	fprintf(stderr, "                      (If -s is specified, then one of\n");
	fprintf(stderr, "                       -i or -p must be specified)\n");
	fprintf(stderr, "                 '-f' to specify a tracepoint file name\n");
	fprintf(stderr, "                      (-s and -f are mutually exclusive)\n");
	fprintf(stderr, "                 '-j' to use JSON to format the output\n");
}

int main(int argc, char **argv)
{
	void			*history_ptr;
	struct spdk_trace_history *history;
	int			fd, i, rc;
	int			lcore = SPDK_TRACE_MAX_LCORE;
	uint64_t		tsc_offset;
	const char		*app_name = NULL;
	const char		*file_name = NULL;
	int			op;
	char			shm_name[64];
	int			shm_id = -1, shm_pid = -1;
	uint64_t		trace_histories_size;
	struct stat		_stat;
	bool			json = false;

	g_exe_name = argv[0];
	while ((op = getopt(argc, argv, "c:f:i:jp:s:t")) != -1) {
		switch (op) {
		case 'c':
			lcore = atoi(optarg);
			if (lcore > SPDK_TRACE_MAX_LCORE) {
				fprintf(stderr, "Selected lcore: %d "
					"exceeds maximum %d\n", lcore,
					SPDK_TRACE_MAX_LCORE);
				exit(1);
			}
			break;
		case 'i':
			shm_id = atoi(optarg);
			break;
		case 'p':
			shm_pid = atoi(optarg);
			break;
		case 's':
			app_name = optarg;
			break;
		case 'f':
			file_name = optarg;
			break;
		case 't':
			g_print_tsc = true;
			break;
		case 'j':
			json = true;
			break;
		default:
			usage();
			exit(1);
		}
	}

	if (file_name != NULL && app_name != NULL) {
		fprintf(stderr, "-f and -s are mutually exclusive\n");
		usage();
		exit(1);
	}

	if (file_name == NULL && app_name == NULL) {
		fprintf(stderr, "One of -f and -s must be specified\n");
		usage();
		exit(1);
	}

	if (json) {
		g_json = spdk_json_write_begin(print_json, NULL, 0);
		if (g_json == NULL) {
			fprintf(stderr, "Failed to allocate JSON write context\n");
			exit(1);
		}
	}

	if (file_name) {
		fd = open(file_name, O_RDONLY);
	} else {
		if (shm_id >= 0) {
			snprintf(shm_name, sizeof(shm_name), "/%s_trace.%d", app_name, shm_id);
		} else {
			snprintf(shm_name, sizeof(shm_name), "/%s_trace.pid%d", app_name, shm_pid);
		}
		fd = shm_open(shm_name, O_RDONLY, 0600);
		file_name = shm_name;
	}
	if (fd < 0) {
		fprintf(stderr, "Could not open %s.\n", file_name);
		usage();
		exit(-1);
	}

	rc = fstat(fd, &_stat);
	if (rc < 0) {
		fprintf(stderr, "Could not get size of %s.\n", file_name);
		usage();
		exit(-1);
	}
	if ((size_t)_stat.st_size < sizeof(*g_histories)) {
		fprintf(stderr, "%s is not a valid trace file\n", file_name);
		usage();
		exit(-1);
	}

	/* Map the header of trace file */
	history_ptr = mmap(NULL, sizeof(*g_histories), PROT_READ, MAP_SHARED, fd, 0);
	if (history_ptr == MAP_FAILED) {
		fprintf(stderr, "Could not mmap %s.\n", file_name);
		usage();
		exit(-1);
	}

	g_histories = (struct spdk_trace_histories *)history_ptr;

	g_tsc_rate = g_histories->flags.tsc_rate;
	if (g_tsc_rate == 0) {
		fprintf(stderr, "Invalid tsc_rate %ju\n", g_tsc_rate);
		usage();
		exit(-1);
	}

	if (!g_json) {
		printf("TSC Rate: %ju\n", g_tsc_rate);
	}

	/* Remap the entire trace file */
	trace_histories_size = spdk_get_trace_histories_size(g_histories);
	munmap(history_ptr, sizeof(*g_histories));
	if ((size_t)_stat.st_size < trace_histories_size) {
		fprintf(stderr, "%s is not a valid trace file\n", file_name);
		usage();
		exit(-1);
	}
	history_ptr = mmap(NULL, trace_histories_size, PROT_READ, MAP_SHARED, fd, 0);
	if (history_ptr == MAP_FAILED) {
		fprintf(stderr, "Could not mmap %s.\n", file_name);
		usage();
		exit(-1);
	}

	g_histories = (struct spdk_trace_histories *)history_ptr;

	if (lcore == SPDK_TRACE_MAX_LCORE) {
		for (i = 0; i < SPDK_TRACE_MAX_LCORE; i++) {
			history = spdk_get_per_lcore_history(g_histories, i);
			if (history->num_entries == 0 || history->entries[0].tsc == 0) {
				continue;
			}

			if (!g_json && history->num_entries) {
				printf("Trace Size of lcore (%d): %ju\n", i, history->num_entries);
			}

			populate_events(history, history->num_entries);
		}
	} else {
		history = spdk_get_per_lcore_history(g_histories, lcore);
		if (history->num_entries > 0 && history->entries[0].tsc != 0) {
			if (!g_json && history->num_entries) {
				printf("Trace Size of lcore (%d): %ju\n", lcore, history->num_entries);
			}

			populate_events(history, history->num_entries);
		}
	}

	if (g_json != NULL) {
		spdk_json_write_object_begin(g_json);
		print_tpoint_definitions();
		spdk_json_write_named_array_begin(g_json, "entries");
	}

	tsc_offset = g_first_tsc;
	for (entry_map::iterator it = g_entry_map.begin(); it != g_entry_map.end(); it++) {
		if (it->first.tsc < g_first_tsc) {
			continue;
		}
		process_event(it->second, g_tsc_rate, tsc_offset, it->first.lcore);
	}

	if (g_json != NULL) {
		spdk_json_write_array_end(g_json);
		spdk_json_write_object_end(g_json);
		spdk_json_write_end(g_json);
	}

	munmap(history_ptr, trace_histories_size);
	close(fd);

	return (0);
}