/*

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

 * Copyright (C) 2008  Red Hat, Inc

 * Copyright (C) 2009  J. Ali Harlow <ali@juiblex.co.uk>

 *

 * 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 "config.h"

#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>

#ifdef MSWIN_API

#include <shlobj.h>

#endif

#include "razor.h"

#include "razor-internal.h"

#ifndef O_BINARY

#define O_BINARY	0

#endif

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

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

#ifdef MSWIN_API

#define RAZOR_ROOT_PATH	NULL

#else

#define RAZOR_ROOT_PATH	"/var/lib/razor"

#endif

static const char *razor_root_path = RAZOR_ROOT_PATH;

struct razor_root {

	struct razor_set *system;

	struct razor_set *next;

	int fd;

	char path[PATH_MAX];

	char new_path[PATH_MAX];

};

static void

razor_root_init(void)

{

#ifdef MSWIN_API

	static char root_path[MAX_PATH];

	if (!razor_root_path) {

		SHGetFolderPath(NULL,

			CSIDL_COMMON_APPDATA | CSIDL_FLAG_DONT_VERIFY, NULL, 0,

			root_path);

		strcat(root_path, "\\Razor");

		razor_root_path = root_path;

	}

#endif

}

RAZOR_EXPORT int

razor_root_create(const char *root)

{

	struct stat buf;

	struct razor_set *set;

	char path[PATH_MAX];

	assert (root != NULL);

	razor_root_init();

	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);

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

		fprintf(stderr,

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

		return -1;

	}

	if (razor_set_write(set, path, RAZOR_SECTION_ALL) < 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;

	assert (root != NULL);

	razor_root_init();

	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 | O_BINARY,

			 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);

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

	if (image->system == NULL) {

		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];

	assert (root != NULL);

	razor_root_init();

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

		 root, razor_root_path, system_repo_filename);

	return razor_set_open(path);

}

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);

	close(root->fd);

	unlink(root->new_path);

	free(root);

	return 0;

}

RAZOR_EXPORT void

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

{

	assert (root != NULL);

	assert (next != NULL);

	razor_root_init();

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

	root->next = next;

	/* 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)

{

	int retval;

	assert (root != NULL);

	/* Make it so. */

	close(root->fd);

#ifdef MSWIN_API

	/* Rename is not atomic under MS-Windows */

	remove(root->path);

#endif

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

	if (retval)

		perror(root->path);

	else

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

	razor_set_destroy(root->system);

	free(root);

	return retval;

}