/*

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

 * Copyright (C) 2008  Red Hat, Inc

 * Copyright (C) 2009, 2011  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";

/*

 * system_lock_filename is chosen to be the same as the pre v0.3

 * next_repo_filename. This means that once a system has been

 * updated by a v0.3+ copy of razor all pre v0.3 versions of razor

 * will see the system as permenantly locked.

 */

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

static const char system_tmp_filename[] = "system.tmp";

#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;

	struct razor_atomic *atomic;

	int handle;

	char *path, *new_path;

};

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)

{

	int retval;

	struct stat buf;

	struct razor_set *set;

	struct razor_atomic *atomic;

	char *path;

	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;

	}

	path = razor_concat(root, razor_root_path, "/", system_repo_filename,

			    NULL);

	retval = !stat(path, &buf);

	free(path);

	if (retval) {

		fprintf(stderr,

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

		return retval;

	}

	atomic = razor_atomic_open("Create initial package set");

	path = razor_concat(razor_root_path, "/", system_repo_filename, NULL);

	razor_atomic_make_dirs(atomic, root, path);

	set = razor_set_create();

	razor_set_write(set, atomic, path, RAZOR_SECTION_ALL);

	free(path);

	retval = razor_atomic_commit(atomic);

	if (retval)

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

	razor_set_unref(set);

	razor_atomic_destroy(atomic);

	return retval;

}

RAZOR_EXPORT struct razor_root *

razor_root_open(const char *root, struct razor_atomic *atomic)

{

	struct razor_root *image;

	char *lock_path;

	int r;

	assert (root != NULL);

	razor_root_init();

	image = malloc(sizeof *image);

	if (image == NULL) {

		razor_atomic_abort(atomic, "Not enough memory");

		return NULL;

	}

	image->atomic = atomic;

	image->system = razor_set_create_without_root();

	if (image->system == NULL) {

		free(image);

		razor_atomic_abort(atomic, "Not enough memory");

		return NULL;

	}

	lock_path = razor_concat(root, razor_root_path, "/",

				 system_lock_filename, NULL);

	r = razor_set_aquire_lock(image->system, lock_path, 1);

	free(lock_path);

	if (r < 0) {

		razor_atomic_abort(atomic,

				   "Failed to aquire exclusive system lock");

		razor_set_unref(image->system);

		free(image);

		return NULL;

	}

	image->new_path = razor_concat(root, razor_root_path, "/",

				       system_tmp_filename, NULL);

	image->handle = razor_atomic_create_file(atomic, image->new_path,

						 S_IRWXU | S_IRWXG | S_IRWXO);

	if (image->handle < 0) {

		free(image->new_path);

		razor_set_unref(image->system);

		free(image);

		return NULL;

	}

	image->path = razor_concat(root, razor_root_path, "/",

				   system_repo_filename, NULL);

	if (razor_set_bind_sections(image->system, atomic, image->path)) {

		unlink(image->new_path);

		free(image->new_path);

		free(image->path);

		razor_set_unref(image->system);

		free(image);

		return NULL;

	}

	return image;

}

RAZOR_EXPORT struct razor_set *

razor_root_open_read_only(const char *root, struct razor_atomic *atomic)

{

	char *path;

	struct razor_set *set;

	assert (root != NULL);

	razor_root_init();

	set = razor_set_create_without_root();

	if (set == NULL) {

		razor_atomic_abort(atomic, "Not enough memory");

		return NULL;

	}

	path = razor_concat(root, razor_root_path, "/", system_lock_filename,

			    NULL);

	if (razor_set_aquire_lock(set, path, 0) < 0) {

		razor_atomic_abort(atomic, "Failed to aquire non-exclusive "

					   "system lock");

		free(path);

		razor_set_unref(set);

		return NULL;

	}

	free(path);

	path = razor_concat(root, razor_root_path, "/", system_repo_filename,

			    NULL);

	if (razor_set_bind_sections(set, atomic, path)) {

		razor_set_unref(set);

		set = NULL;

	}

	free(path);

	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_unref(root->system);

	razor_atomic_close(root->atomic, root->handle);

	razor_atomic_remove(root->atomic, root->new_path);

	free(root->path);

	free(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_handle(next, root->atomic, root->handle,

				  RAZOR_SECTION_ALL);

	root->next = next;

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

	 * before we start upgrading. */

	razor_atomic_sync(root->atomic, root->handle);

}

RAZOR_EXPORT int

razor_root_commit(struct razor_root *root)

{

	int retval;

	assert (root != NULL);

	razor_atomic_close(root->atomic, root->handle);

	retval = razor_atomic_rename_file(root->atomic, root->new_path,

					  root->path);

	razor_set_unref(root->system);

	free(root->path);

	free(root->new_path);

	free(root);

	return retval;

}