/*

  * 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;

 }