/* SPDX-License-Identifier: BSD-3-Clause */
/* Copyright (c) 2026 Open-IOV contributors */
/* main.c - rmtop: ncurses real-time read-only GPU dashboard.
 *
 * Interactive mode needs a terminal; --once renders the same panels as plain
 * table/json/csv text for scripting and harness capture. All sampling is
 * read-only (RM control queries and /proc/sysfs reads); no write path exists.
 */
#include <curses.h>
#include <getopt.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include <unistd.h>

#include "rmtop.h"

static void usage(void)
{
	printf("rmtop %s - read-only NVIDIA GPU dashboard (Open-IOV)\n\n",
	       RMTOP_VERSION);
	printf("usage: rmtop [-g N|BDF] [--interval=MS] [--once] "
	       "[--format=...]\n\n"
	       "  -g N|BDF       select GPU (default: first)\n"
	       "  --interval=MS  refresh interval in ms (default 500)\n"
	       "  --once         render one snapshot as plain text and exit\n"
	       "  --format=FMT   table|json|csv (with --once)\n"
	       "  --help, --version\n\n"
	       "keys: q quit  r refresh  s interval  p pause  h help\n"
	       "      g/G next/previous GPU\n\n"
	       "Live engine utilization, power and thermals are marked n/a in\n"
	       "this read-only minimal build; see docs/17-RM-HARNESS.md.\n");
}

static int parse_common(struct rm_ctx *ctx, int *interval_ms, int *once,
			int argc, char **argv)
{
	static const struct option long_opts[] = {
		{ "device-spec", required_argument, NULL, 'g' },
		{ "interval", required_argument, NULL, 'i' },
		{ "once", no_argument, NULL, 'o' },
		{ "format", required_argument, NULL, 'f' },
		{ "device", required_argument, NULL, 1000 },
		{ "help", no_argument, NULL, 'h' },
		{ "version", no_argument, NULL, 1001 },
		{ NULL, 0, NULL, 0 },
	};
	int opt;

	optind = 1;
	opterr = 0;
	while ((opt = getopt_long(argc, argv, "g:i:of:h", long_opts,
				  NULL)) != -1) {
		if (opt == 'g' || opt == 'f') {
			if (rm_apply_common_opt(ctx, opt == 'g' ? 'd' : 'f',
						optarg) < 0)
				return -1;
			continue;
		}
		if (opt == 'i') {
			*interval_ms = atoi(optarg);
			if (*interval_ms < 100)
				*interval_ms = 100;
			continue;
		}
		if (opt == 'o') {
			*once = 1;
			continue;
		}
		if (opt == 'h') {
			usage();
			exit(0);
		}
		if (opt == 1000) {
			ctx->dev_path = optarg;
			continue;
		}
		if (opt == 1001) {
			printf("rmtop %s (read-only; Open-IOV)\n",
			       RMTOP_VERSION);
			exit(0);
		}
		return -1;
	}
	return 0;
}

static void draw_bar(WINDOW *win, int y, int x, int width, double ratio,
		     const char *label)
{
	int filled = (int)(ratio * width);
	int i;

	if (filled < 0)
		filled = 0;
	if (filled > width)
		filled = width;
	mvwprintw(win, y, x, "%-10s [", label);
	for (i = 0; i < width; i++) {
		if (i < filled)
			waddch(win, ACS_CKBOARD);
		else
			waddch(win, '-');
	}
	wprintw(win, "] %5.1f%%", ratio * 100.0);
}

void rmtop_render_curses(const struct rmtop_state *st, int interval_ms,
			 int paused)
{
	char when[32];
	struct tm tm;
	struct timespec ts;
	int row = 1;

	clock_gettime(CLOCK_REALTIME, &ts);
	localtime_r(&ts.tv_sec, &tm);
	strftime(when, sizeof(when), "%H:%M:%S", &tm);

	erase();
	attron(A_REVERSE);
	mvprintw(0, 0, " rmtop %s | GPU %d: %.40s | %.50s | %s%s ",
		 RMTOP_VERSION, st->gpu_minor,
		 st->model[0] ? st->model : "-",
		 st->driver[0] ? st->driver : "driver unknown", when,
		 paused ? " | PAUSED" : "");
	clrtoeol();
	attroff(A_REVERSE);

	mvprintw(row++, 1, "Bus %-14s UUID %-40s",
		 st->bdf[0] ? st->bdf : "-",
		 st->uuid[0] ? st->uuid : "-");
	mvprintw(row++, 1, "RM client: %s%s",
		 st->have_rm ? "ok" : "unavailable",
		 st->have_rm && st->rm_name[0] ? "  " : "");
	if (st->have_rm && st->rm_name[0])
		printw("%s", st->rm_name);
	mvprintw(row++, 1, "Arch: %s (0x%x/0x%x rev %u)",
		 st->have_rm ? rm_arch_str(st->mc_arch) : "-",
		 st->mc_arch, st->mc_impl, st->mc_rev);
	mvprintw(row++, 1, "VRAM: %u MiB total, %u MiB free, %u MiB used",
		 st->vram_total_kib / 1024, st->heap_free_kib / 1024,
		 (st->vram_total_kib - st->heap_free_kib) / 1024);
	mvprintw(row++, 1, "BAR1: %u MiB size, %u MiB available",
		 st->bar1_size_kib / 1024, st->bar1_avail_kib / 1024);
	row++;
	mvprintw(row++, 1, "Engines (%u)%s:", st->engine_count,
		 st->engine_names_ok ? "" : " [FIFO names unavailable]");
	if (st->engine_count > 0) {
		unsigned int i;

		move(row, 3);
		for (i = 0; i < st->engine_count; i++) {
			const char *name = st->engine_names_ok ?
				st->engine_names[i] : "-";

			printw("%s ", name);
			if ((i + 1) % 8 == 0 && i + 1 < st->engine_count)
				mvprintw(++row, 3, " ");
		}
		row++;
	}
	row++;
	if (st->have_timer) {
		time_t secs = (time_t)(st->timer_nsec / 1000000000ULL);

		gmtime_r(&secs, &tm);
		strftime(when, sizeof(when), "%Y-%m-%dT%H:%M:%S", &tm);
		mvprintw(row++, 1, "GPU timer: %llu ns (%sZ)",
			 (unsigned long long)st->timer_nsec, when);
	}
	row++;
	{
		double total = st->vram_total_kib ? st->vram_total_kib : 1.0;

		draw_bar(stdscr, row++, 1, 40,
			 (double)(st->vram_total_kib - st->heap_free_kib) /
			 total, "VRAM");
	}
	draw_bar(stdscr, row++, 1, 40,
		 st->bar1_size_kib ?
		 (double)(st->bar1_size_kib - st->bar1_avail_kib) /
		 st->bar1_size_kib : 0.0, "BAR1");
	row++;
	attron(A_DIM);
	mvprintw(row++, 1, "Live util/power/thermal: n/a in this read-only "
		 "minimal build (see docs/17-RM-HARNESS.md)");
	attroff(A_DIM);

	attron(A_REVERSE);
	mvprintw(LINES - 1, 0, " q quit | r refresh | s %dms interval | "
		 "p pause | g/G GPU | h help ", interval_ms);
	clrtoeol();
	attroff(A_REVERSE);
	refresh();
}

static void help_screen(void)
{
	erase();
	mvprintw(0, 1, "rmtop help");
	mvprintw(2, 1, "This dashboard samples read-only RM controls and "
		 "/proc/sysfs.");
	mvprintw(3, 1, "It never allocates, maps, resets or claims the GPU.");
	mvprintw(5, 1, "q / F10   quit");
	mvprintw(6, 1, "r         refresh now");
	mvprintw(7, 1, "s         cycle sample interval (250/500/1000/2000 ms)");
	mvprintw(8, 1, "p         pause/resume sampling");
	mvprintw(9, 1, "g / G     next / previous GPU");
	mvprintw(10, 1, "h         this help");
	mvprintw(12, 1, "Press any key to return.");
	refresh();
	timeout(-1);
	getch();
	timeout(0);
}

int main(int argc, char **argv)
{
	struct rm_ctx ctx;
	struct rmtop_state st;
	int interval_ms = 500;
	int once = 0;
	int paused = 0;
	int rc;

	ctx.gpu_minor = -1;
	ctx.dev_path = NULL;
	ctx.format = RM_FMT_TABLE;
	ctx.have_rm = 0;
	ctx.rm.fd = -1;

	if (parse_common(&ctx, &interval_ms, &once, argc, argv) < 0) {
		usage();
		return 2;
	}

	if (once) {
		rmtop_collect(&ctx, &st);
		rmtop_render_plain(&st, ctx.format);
		if (ctx.have_rm)
			rm_client_close(&ctx.rm);
		return 0;
	}

	initscr();
	cbreak();
	noecho();
	keypad(stdscr, TRUE);
	curs_set(0);
	if (has_colors()) {
		start_color();
		use_default_colors();
		init_pair(1, COLOR_GREEN, -1);
		init_pair(2, COLOR_YELLOW, -1);
		init_pair(3, COLOR_RED, -1);
	}

	rc = 0;
	while (1) {
		int ch;

		if (!paused) {
			rmtop_collect(&ctx, &st);
			rmtop_render_curses(&st, interval_ms, paused);
			timeout(interval_ms);
		} else {
			timeout(-1);
		}
		ch = getch();
		switch (ch) {
		case 'q':
		case 'Q':
		case KEY_F(10):
			goto done;
		case 'r':
			break;
		case 's':
			if (interval_ms == 250)
				interval_ms = 500;
			else if (interval_ms == 500)
				interval_ms = 1000;
			else if (interval_ms == 1000)
				interval_ms = 2000;
			else
				interval_ms = 250;
			break;
		case 'p':
			paused = !paused;
			break;
		case 'g':
		case 'G': {
			struct rm_gpu_desc gpus[RM_MAX_GPUS];
			int n = rm_scan_gpus(gpus, RM_MAX_GPUS);
			int i;

			for (i = 0; i < n; i++) {
				if (gpus[i].minor == ctx.gpu_minor) {
					int next = (ch == 'g') ?
						(i + 1) % n : (i + n - 1) % n;

					rm_client_close(&ctx.rm);
					ctx.have_rm = 0;
					ctx.gpu_minor = gpus[next].minor;
					break;
				}
			}
			break;
		}
		case 'h':
			help_screen();
			break;
		case KEY_RESIZE:
			break;
		default:
			break;
		}
	}
done:
	endwin();
	if (ctx.have_rm)
		rm_client_close(&ctx.rm);
	return rc;
}