/* SPDX-License-Identifier: BSD-2-Clause */
/*
 * main.c — daedalus-v4l2 userspace daemon entry point.
 *
 * Phase 8.3 mode of operation: CLI tool.
 *   daedalus_v4l2_daemon parse <file>
 *
 * Phase 8.4+ adds the daemon mode that opens the chardev
 * /dev/daedalus-v4l2 and services REQ_DECODE etc.
 */
#include "ffmpeg_loader.h"
#include "parser.h"
#include "chardev_client.h"
#include "log.h"

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <signal.h>
#include <unistd.h>
#include <errno.h>

#include <libavutil/log.h>

static volatile sig_atomic_t g_terminate = 0;

static void on_signal(int sig)
{
	(void) sig;
	g_terminate = 1;
}

static int install_signal_handlers(void)
{
	struct sigaction sa = { 0 };
	sa.sa_handler = on_signal;
	sigemptyset(&sa.sa_mask);
	if (sigaction(SIGINT,  &sa, NULL) < 0 ||
	    sigaction(SIGTERM, &sa, NULL) < 0) {
		log_err("sigaction: %s", strerror(errno));
		return -1;
	}
	return 0;
}

static int cmd_parse(struct ffmpeg_loader *fm, int argc, char **argv)
{
	if (argc < 1) {
		fprintf(stderr, "usage: parse <path-to-media-file>\n");
		return 2;
	}
	int rc = daedalus_parse_file(fm, argv[0]);
	return rc < 0 ? 1 : 0;
}

static int cmd_daemon(struct ffmpeg_loader *fm, int argc, char **argv)
{
	struct chardev_client cli;
	int rc;

	(void) argc;
	(void) argv;

	rc = chardev_client_open(&cli, fm, &g_terminate);
	if (rc < 0) {
		log_err("chardev_client_open: %d", rc);
		return 1;
	}
	rc = chardev_client_run(&cli);
	chardev_client_close(&cli);
	return rc < 0 ? 1 : 0;
}

static void usage(const char *progname)
{
	fprintf(stderr,
		"usage: %s <command> [args]\n\n"
		"commands:\n"
		"  parse <file>     Phase 8.3: demux+enumerate frames\n"
		"  daemon           Phase 8.4: open /dev/daedalus-v4l2 and\n"
		"                   service REQ_DECODE from the kernel\n"
		"\n"
		"options:\n"
		"  -v, --verbose    enable debug logging\n"
		"  -h, --help       this message\n",
		progname);
}

int main(int argc, char **argv)
{
	int verbose = 0;
	int i;

	for (i = 1; i < argc; i++) {
		if (strcmp(argv[i], "-v") == 0 ||
		    strcmp(argv[i], "--verbose") == 0)
			verbose = 1;
		else if (strcmp(argv[i], "-h") == 0 ||
			 strcmp(argv[i], "--help") == 0) {
			usage(argv[0]);
			return 0;
		} else {
			break;	/* first non-option = command */
		}
	}
	if (i >= argc) {
		usage(argv[0]);
		return 2;
	}

	log_init(verbose ? LOG_DEBUG : LOG_INFO);
	if (install_signal_handlers() < 0)
		return 1;

	struct ffmpeg_loader fm;
	if (ffmpeg_loader_init(&fm) < 0) {
		log_err("ffmpeg_loader_init failed");
		return 1;
	}
	/* Mute FFmpeg's own chattiness unless the user asked. */
	fm.av_log_set_level(verbose ? AV_LOG_INFO : AV_LOG_WARNING);

	int rc;
	const char *cmd = argv[i++];
	if (strcmp(cmd, "parse") == 0) {
		rc = cmd_parse(&fm, argc - i, argv + i);
	} else if (strcmp(cmd, "daemon") == 0) {
		rc = cmd_daemon(&fm, argc - i, argv + i);
	} else {
		fprintf(stderr, "unknown command: %s\n", cmd);
		usage(argv[0]);
		rc = 2;
	}

	ffmpeg_loader_cleanup(&fm);
	log_cleanup();
	return rc;
}