/*
 * Copyright (c) 2017 Ian Sutton <ian@ce.gl>
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * 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.
 */

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

#define LINE_SIZE 4096

struct config {
	char *obj_path;
	char *tool_path;
	char *src_path;
	FILE *conf;
	FILE *term;
} *gcfg;

struct sigaction sigact;
static void sigh(int);
static void sigc(void);

static void __dead
usage(void)
{
	fprintf(stderr, "usage: puffcrash [-c config] [serial console log]\n");
	exit(1);
}

void
sigh(int sig)
{
	if (sig == SIGINT) sigc();
}

void
sigc(void)
{
	if (gcfg->obj_path) free(gcfg->obj_path);
	if (gcfg->tool_path) free(gcfg->tool_path);
	if (gcfg->src_path) free(gcfg->src_path);

	if (gcfg->conf) fclose(gcfg->conf);
	if (gcfg->term && gcfg->term != stdin) fclose(gcfg->term);

	exit(1);
}

int
parse_config(char *config_path, struct config *cfg)
{
	char *line, *i;
	int check = 0;

	cfg->conf = fopen(config_path, "r");

	if(!(line = calloc(1, 256)) || !cfg->conf)
	    return 1;

	while ((fgets(line, 256, cfg->conf))) {
	    if (strstr(line, "obj_path")) {
		i = strstr(line, "=") + 2;
		strlcpy(cfg->obj_path, i, PATH_MAX);
		check |= (1 << 0);
	    } else if (strstr(line, "tool_path")) {
		i = strstr(line, "=") + 2;
		strlcpy(cfg->tool_path, i, PATH_MAX);
		check |= (1 << 1);
	    } else if (strstr(line, "src_path")) {
		i = strstr(line, "=") + 2;
		strlcpy(cfg->src_path, i, PATH_MAX);
		check |= (1 << 2);
	    }
	}

	free(line);

	if (check == 0x7)
	    return 0;
	else
	    return 1;
}

void
watch_serial(void)
{
	char *line;

	if (!(line = calloc(1, LINE_SIZE))) {
	    printf("could not allocate memory\n");
	    sigc();
	}

	while ((fgets(line, LINE_SIZE, gcfg->term))) {
	    printf("%s", line);
	}
}

int
main(int argc, char *argv[])
{
	struct config cfg;
	int ch;
	char term_path[PATH_MAX], config_path[PATH_MAX];

	bzero(&cfg, sizeof(struct config));
	strlcpy(config_path, "/etc/puffcrash.conf", PATH_MAX);

	atexit(sigc);
	sigact.sa_handler = sigh;
	sigemptyset(&sigact.sa_mask);
	sigact.sa_flags = 0;
	sigaction(SIGINT, &sigact, (struct sigaction *) NULL);

	while ((ch = getopt(argc, argv, "c:")) != -1) {
	    switch (ch) {
	    case 'c':
		strlcpy(config_path, optarg, PATH_MAX);
		break;
	    default:
		usage();
		break;
	    }
	}

	argv += optind;
	argc -= optind;

	cfg.obj_path  = calloc(1, PATH_MAX);
	cfg.tool_path = calloc(1, PATH_MAX);
	cfg.src_path  = calloc(1, PATH_MAX);

	gcfg = &cfg;

	if (parse_config(config_path, &cfg)) {
	    printf("failed to parse config file %s.\n", config_path);
	    sigc();
	}

	if (argc) {
	    strlcpy(term_path, argv[0], PATH_MAX);
	    cfg.term = fopen(term_path, "r");
	} else
	    cfg.term = stdin;

	if (!cfg.term) {
	    printf("failed to open serial console output logfile \"%s\"\n", argv[0]);
	    sigc();
	}

	watch_serial();

	return 0;
}