/*

 * Copyright (C) 2008  Kristian Høgsberg <krh@redhat.com>

 * Copyright (C) 2008  Red Hat, Inc

 *

 * This program is free software; you can redistribute it and/or modify

 * it under the terms of the GNU General Public License as published by

 * the Free Software Foundation; either version 2 of the License, or

 * (at your option) any later version.

 *

 * This program is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

 * GNU General Public License for more details.

 *

 * You should have received a copy of the GNU General Public License along

 * with this program; if not, write to the Free Software Foundation, Inc.,

 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.

 */

#include <stdlib.h>

#include <stdint.h>

#include <stdio.h>

#include <string.h>

#include <sys/stat.h>

#include <dirent.h>

#include <unistd.h>

#include <fcntl.h>

#include <limits.h>

#include <assert.h>

#include "razor.h"

#include "razor-internal.h"

static const char system_repo_filename[] = "system.rzdb";

static const char system_repo_details_filename[] = "system-details.rzdb";

static const char system_repo_files_filename[] = "system-files.rzdb";

static const char next_repo_filename[] = "system-next.rzdb";

static const char razor_root_path[] = "/var/lib/razor";

struct razor_root {

	struct razor_set *system;

	struct razor_set *next;

	int fd;

	char root[PATH_MAX];

	char path[PATH_MAX];

	char new_path[PATH_MAX];

};

RAZOR_EXPORT int

razor_root_create(const char *root)

{

	struct stat buf;

	struct razor_set *set;

	char path[PATH_MAX], details_path[PATH_MAX], files_path[PATH_MAX];

	assert (root != NULL);

	if (root[0] == '\0') {

		/* root is file system root */

	} else if (stat(root, &buf) < 0) {

		if (mkdir(root, 0777) < 0) {

			fprintf(stderr,

				"could not create install root \"%s\"\n",

				root);

			return -1;

		}

		fprintf(stderr, "created install root \"%s\"\n", root);

	} else if (!S_ISDIR(buf.st_mode)) {

		fprintf(stderr,

			"install root \"%s\" exists, but is not a directory\n",

			root);

		return -1;

	}

	snprintf(path, sizeof path, "%s/%s",

		 razor_root_path, system_repo_filename);

	if (razor_create_dir(root, path) < 0) {

		fprintf(stderr, "could not create %s%s\n",

			root, razor_root_path);

		return -1;

	}

	set = razor_set_create();

	snprintf(path, sizeof path, "%s%s/%s",

		 root, razor_root_path, system_repo_filename);

	snprintf(details_path, sizeof details_path, "%s%s/%s",

		 root, razor_root_path, system_repo_details_filename);

	snprintf(files_path, sizeof files_path, "%s%s/%s",

		 root, razor_root_path, system_repo_files_filename);

	if (stat(path, &buf) == 0) {

		fprintf(stderr,

			"a razor install root is already initialized\n");

		return -1;

	}

	if (razor_set_write(set, path, RAZOR_REPO_FILE_MAIN) < 0 ||

	    razor_set_write(set, details_path, RAZOR_REPO_FILE_DETAILS) < 0 ||

	    razor_set_write(set, files_path, RAZOR_REPO_FILE_FILES) < 0 ) {

		fprintf(stderr, "could not write initial package set\n");

		return -1;

	}

	razor_set_destroy(set);

	return 0;

}

RAZOR_EXPORT struct razor_root *

razor_root_open(const char *root)

{

	struct razor_root *image;

	char details_path[PATH_MAX], files_path[PATH_MAX];

	assert (root != NULL);

	image = malloc(sizeof *image);

	if (image == NULL)

		return NULL;

	/* Create the new next repo file up front to ensure exclusive

	 * access. */

	snprintf(image->new_path, sizeof image->new_path,

		 "%s%s/%s", root, razor_root_path, next_repo_filename);

	image->fd = open(image->new_path,

			 O_CREAT | O_WRONLY | O_TRUNC | O_EXCL, 0666);

	if (image->fd < 0) {

		fprintf(stderr, "failed to get lock file, "

			"maybe previous operation crashed?\n");

		/* FIXME: Use fcntl advisory locking on the system

		 * package set file to figure out whether previous

		 * operation crashed or is still in progress. */

		free(image);

		return NULL;

	}

	snprintf(image->path, sizeof image->path,

		 "%s%s/%s", root, razor_root_path, system_repo_filename);

	snprintf(details_path, sizeof details_path,

		 "%s%s/%s", root, razor_root_path, system_repo_details_filename);

	snprintf(files_path, sizeof files_path,

		 "%s%s/%s", root, razor_root_path, system_repo_files_filename);

	/* FIXME: We store the root path to make the hack in

	 * razor_root_update() work.  Need to get rid of this. */

	strcpy(image->root, root);

	image->system = razor_set_open(image->path);

	if (image->system == NULL ||

	    razor_set_open_details(image->system, details_path) ||

	    razor_set_open_files(image->system, files_path)) {

		unlink(image->new_path);

		close(image->fd);

		free(image);

		return NULL;

	}

	return image;

}

RAZOR_EXPORT struct razor_set *

razor_root_open_read_only(const char *root)

{

	char path[PATH_MAX], details_path[PATH_MAX], files_path[PATH_MAX];

	struct razor_set *set;

	assert (root != NULL);

	snprintf(path, sizeof path, "%s%s/%s",

		 root, razor_root_path, system_repo_filename);

	snprintf(details_path, sizeof details_path,

		 "%s%s/%s", root, razor_root_path, system_repo_details_filename);

	snprintf(files_path, sizeof files_path,

		 "%s%s/%s", root, razor_root_path, system_repo_files_filename);

	set = razor_set_open(path);

	if (set == NULL)

		return NULL;

	if (razor_set_open_details(set, details_path) ||

	    razor_set_open_files(set, files_path)) {

		razor_set_destroy(set);

		return NULL;

	}

	return set;

}

RAZOR_EXPORT struct razor_set *

razor_root_get_system_set(struct razor_root *root)

{

	assert (root != NULL);

	return root->system;

}

RAZOR_EXPORT int

razor_root_close(struct razor_root *root)

{

	assert (root != NULL);

	razor_set_destroy(root->system);

	unlink(root->new_path);

	close(root->fd);

	free(root);

	return 0;

}

RAZOR_EXPORT void

razor_root_update(struct razor_root *root, struct razor_set *next)

{

	char path[PATH_MAX];

	assert (root != NULL);

	assert (next != NULL);

	razor_set_write_to_fd(next, root->fd, RAZOR_REPO_FILE_MAIN);

	root->next = next;

	/* FIXME: This is a pretty bad hack that just overwrites the

	 * system details and files rzdb files before the transaction

	 * succeeds.  We need to fix this by merging the separate

	 * details and files rzdb files back into the main rzdb

	 * file. */

	snprintf(path, sizeof path,

		 "%s%s/%s", root->root, razor_root_path, system_repo_details_filename);

	razor_set_write(next, path, RAZOR_REPO_FILE_DETAILS);

	snprintf(path, sizeof path,

		 "%s%s/%s", root->root, razor_root_path, system_repo_files_filename);

	razor_set_write(next, path, RAZOR_REPO_FILE_FILES);

	/* Sync the new repo file so the new package set is on disk

	 * before we start upgrading. */

	fsync(root->fd);

	printf("wrote %s\n", root->new_path);

}

RAZOR_EXPORT int

razor_root_commit(struct razor_root *root)

{

	assert (root != NULL);

	/* Make it so. */

	rename(root->new_path, root->path);

	printf("renamed %s to %s\n", root->new_path, root->path);

	razor_set_destroy(root->system);

	close(root->fd);

	free(root);

	return 0;

}