/*
 * Copyright (C) 2020-2024 Soleta Networks <info@soleta.eu>
 *
 * This program is free software: you can redistribute it and/or modify it under
 * the terms of the GNU Affero General Public License as published by the
 * Free Software Foundation; either version 3 of the License, or
 * (at your option) any later version.
 */

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <time.h>
#include <syslog.h>
#include <sys/stat.h>
#include <errno.h>
#include "boot.h"
#include "utils.h"

#define OGRELIVE_TEMPLATE					\
"# Autogenerated by ogserver on %s - do not edit this file!\n"	\
"set ogserver=%s\n"						\
"set ogrepo=%s\n"						\
"set ogreliveversion=%s\n"					\
"set ogrelivedir=ogrelive/$ogreliveversion\n"			\
"set username=%s\n"						\
"set passwd=%s\n"						\
"\n"								\
"set timeout=0\n"						\
"set timeout_style=hidden\n"					\
"\n"								\
"echo \"checking for vmlinuz in cache...\"\n"			\
"set root=''\n"							\
"search --file --set root /boot/$ogreliveversion/vmlinuz\n"	\
"if [ \"$root\" == \"\" ]; then\n"				\
"    echo \"no vmlinuz found in cache, booting from network\"\n" \
"    set default=1;\n"						\
"else\n"							\
"    echo \"vmlinuz found, booting from cache\"\n"		\
"    set default=0;\n"						\
"fi\n"								\
"\n"								\
"menuentry \"ogReLive HTTP boot\" {\n"				\
"    insmod http\n"						\
"    insmod net\n"						\
"    net_bootp\n"						\
"    linux (http,$ogrepo)/$ogrelivedir/vmlinuz ro boot=live quiet splash oglivedir=$ogrelivedir ip=$ogserver ogrepo=$ogrepo username=$username passwd=$passwd fetch=http://$ogrepo/$ogrelivedir/filesystem.squashfs\n" \
"    initrd (http,$ogrepo)/$ogrelivedir/initrd.img\n"		\
"    boot\n"							\
"}\n"

/* Same as OG_TFTP_BOOT_UEFI. */
#define OG_BOOT_GRUB_DIR	"/opt/opengnsys/tftpboot/grub"

static void ogrelive_grub2_file_path(char *grub2_filename,
				     size_t grub2_filename_size,
				     const char *mac)
{
        snprintf(grub2_filename, grub2_filename_size,
		 OG_BOOT_GRUB_DIR"/01-%c%c:%c%c:%c%c:%c%c:%c%c:%c%c",
		 mac[0], mac[1], mac[2], mac[3], mac[4], mac[5],
		 mac[6], mac[7], mac[8], mac[9], mac[10], mac[11]);
        str_tolower(grub2_filename);
}

int ogrelive_generate_grub2_file(const struct og_boot_cfg *cfg, const char *mac)
{
	char grub2_tmp_filename[] = "/tmp/grub_template_XXXXXX";
	char grub2_filename[FILENAME_MAX] = {};
	time_t now = time(NULL);
	char *date;
	FILE *fp;
	int fd;

	date = asctime(localtime(&now));
	date[strlen(date) - 1] = '\0';

	fd = mkstemp(grub2_tmp_filename);
	if (fd < 0) {
		syslog(LOG_ERR, "Cannot open %s to %s (%s:%u)\n",
		       grub2_tmp_filename, grub2_filename, __FILE__, __LINE__);
		return -1;
	}

	fp = fdopen(fd, "w+");
	if (!fp) {
		close(fd);
		syslog(LOG_ERR, "Cannot open %s to %s (%s:%u)\n",
		       grub2_tmp_filename, grub2_filename, __FILE__, __LINE__);
		return -1;
	}

	fprintf(fp, OGRELIVE_TEMPLATE, date,
		cfg->ogserver, cfg->ogrepo, cfg->ogrelivedir, cfg->username, cfg->passwd);

	fclose(fp);

	if (unlink(grub2_filename) < 0) {
		if (errno != ENOENT) {
			syslog(LOG_ERR, "Failed to delete %s (%s:%u)\n",
			       grub2_filename, __FILE__, __LINE__);
			return -1;
		}
	}

	ogrelive_grub2_file_path(grub2_filename, sizeof(grub2_filename), mac);

	if (rename(grub2_tmp_filename, grub2_filename) < 0) {
		unlink(grub2_tmp_filename);
		syslog(LOG_ERR, "Failed to rename %s to %s (%s:%u)\n",
		       grub2_tmp_filename, grub2_filename, __FILE__, __LINE__);
		return -1;
	}

	chmod(grub2_filename, 0644);

	return 0;
}