/*
 * Copyright (C) 2008  Kristian Høgsberg <krh@redhat.com>
 * Copyright (C) 2008  Red Hat, Inc
 * Copyright (C) 2009, 2011, 2012, 2014, 2016, 2018  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 <errno.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

#ifndef FALSE
#define FALSE 0
#endif

#ifndef TRUE
#define TRUE (!FALSE)
#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";
#ifdef MSWIN_API
#define RAZOR_DATABASE_URI	NULL
#else
/*
 * The non-MSWIN default is a relative-ref and thus affected by the root
 */
#define RAZOR_DATABASE_URI	"var/lib/razor"
#endif
static char *razor_database_uri = RAZOR_DATABASE_URI;
static int razor_database_uri_alloced = FALSE;
static int razor_database_uri_default = TRUE;

struct razor_root {
	struct razor_set *system;
	char *uri;
};

static void
razor_root_init(void)
{
#ifdef MSWIN_API
	/*
	 * The MSWIN default is an absolute-URI and thus unaffected by the root
	 */
	char database_path[MAX_PATH];
	if (!razor_database_uri) {
		SHGetFolderPath(NULL,
			CSIDL_COMMON_APPDATA | CSIDL_FLAG_DONT_VERIFY, NULL, 0,
			database_path);
		strcat(database_path, "\\Razor");
		razor_database_uri = razor_path_to_uri(database_path);
		razor_database_uri_alloced = TRUE;
	}
#endif
}

RAZOR_EXPORT const char *razor_get_database_uri(void)
{
	razor_root_init();
	return razor_database_uri;
}

RAZOR_EXPORT void
razor_set_database_uri(const char *database_uri)
{
	if (razor_database_uri_alloced)
		free(razor_database_uri);

	if (database_uri) {
		razor_database_uri = strdup(database_uri);
		razor_database_uri_alloced = TRUE;
		razor_database_uri_default = FALSE;
	} else {
		razor_database_uri = RAZOR_DATABASE_URI;
		razor_database_uri_alloced = FALSE;
		razor_database_uri_default = TRUE;
	}
}

char *razor_resolve_database_file(const char *root_uri, const char *filename,
				  struct razor_error **error)
{
	char *s, *uri;

	razor_root_init();

	s = razor_concat(razor_database_uri, "/", filename, NULL);

	uri = razor_resolve_uri_root(root_uri, s, -1, error);

	free(s);

	return uri;
}

RAZOR_EXPORT int
razor_root_create(const char *root_uri, struct razor_error **error)
{
	int retval, is_within_root, is_directory;
	struct razor_set *set;
	struct razor_atomic *atomic;
	struct razor_error *tmp_err = NULL;
	char *uri;

	uri = razor_resolve_database_file(root_uri, system_repo_filename,
					  error);

	if (!uri)
		return -1;

	if (razor_uri_is_directory(uri, NULL) >= 0) {
		razor_set_error(error, RAZOR_GENERAL_ERROR,
				RAZOR_GENERAL_ERROR_DATABASE_EXISTS, NULL,
				"A razor install root is already initialized");
		free(uri);
		return -1;
	}

	is_within_root = root_uri && strchr(root_uri, '/') &&
			 str_has_prefix(uri, root_uri);

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

	if (is_within_root) {
		is_directory = razor_uri_is_directory(root_uri, NULL);

		if (!is_directory) {
			razor_set_error(error, RAZOR_POSIX_ERROR, ENOTDIR,
					root_uri, "Not a directory");
			return -1;
		} else if (is_directory < 0 &&
			   razor_uri_mkdir(root_uri, 0777, &tmp_err) < 0) {
			razor_set_error(error,
					razor_error_get_domain(tmp_err),
					razor_error_get_code(tmp_err),
					root_uri,
					"Could not create install root");
			return -1;
		}

		razor_atomic_make_dirs(atomic, root_uri,
				       uri + strlen(root_uri));
	} else
		razor_atomic_make_dirs(atomic, "", uri);

	set = razor_set_create();
	razor_set_write(set, atomic, uri, RAZOR_SECTION_ALL);
	free(uri);
	retval = razor_atomic_commit(atomic);
	if (retval)
		razor_propagate_error(error,
				      razor_atomic_get_error(atomic),
				      "Could not write initial package set");
	razor_set_unref(set);
	razor_atomic_destroy(atomic);

	return retval;
}

RAZOR_EXPORT struct razor_root *
razor_root_open(const char *root_uri, struct razor_error **error)
{
	struct razor_root *image;
	char *lock_uri;
	int r;

	lock_uri = razor_resolve_database_file(root_uri, system_lock_filename,
					       error);

	if (!lock_uri)
		return NULL;

	image = malloc(sizeof *image);
	if (image == NULL) {
		free(lock_uri);
		razor_set_error(error, RAZOR_POSIX_ERROR, ENOMEM, NULL,
				"Not enough memory");
		return NULL;
	}

	image->system = razor_set_create_without_root();
	if (image->system == NULL) {
		free(image);
		free(lock_uri);
		razor_set_error(error, RAZOR_POSIX_ERROR, ENOMEM, NULL,
				"Not enough memory");
		return NULL;
	}

	r = razor_set_acquire_lock(image->system, lock_uri, 1, error);

	free(lock_uri);

	if (r < 0) {
		if (error && razor_database_uri_default)
			razor_error_set_object(*error, root_uri);
		razor_set_unref(image->system);
		free(image);
		return NULL;
	}

	image->uri = razor_resolve_database_file(root_uri, system_repo_filename,
						 error);

	if (!image->uri) {
		razor_set_unref(image->system);
		free(image);
		return NULL;
	}

	if (razor_set_bind_sections(image->system, image->uri,
				    RAZOR_SET_PRIVATE, error)) {
		free(image->uri);
		razor_set_unref(image->system);
		free(image);
		return NULL;
	}

	return image;
}

RAZOR_EXPORT struct razor_set *
razor_root_open_read_only(const char *root_uri, struct razor_error **error)
{
	int r;
	char *uri;
	struct razor_set *set;

	uri = razor_resolve_database_file(root_uri, system_lock_filename,
					  error);

	if (!uri)
		return NULL;

	set = razor_set_create_without_root();
	if (set == NULL) {
		free(uri);
		razor_set_error(error, RAZOR_POSIX_ERROR, ENOMEM, NULL,
				"Not enough memory");
		return NULL;
	}

	r = razor_set_acquire_lock(set, uri, 0, error);

	free(uri);

	if (r < 0) {
		if (error && razor_database_uri_default)
			razor_error_set_object(*error, root_uri);
		razor_set_unref(set);
		return NULL;
	}

	uri = razor_resolve_database_file(root_uri, system_repo_filename,
					  error);

	if (!uri || razor_set_bind_sections(set, uri, 0, error)) {
		razor_set_unref(set);
		set = NULL;
	}

	free(uri);

	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);
	free(root->uri);
	free(root);

	return 0;
}

RAZOR_EXPORT int
razor_root_update(struct razor_root *root, struct razor_set *next,
		  struct razor_atomic *atomic)
{
	int handle, retval;

	assert (root != NULL);
	assert (next != NULL);

	handle = razor_atomic_create_file(atomic, root->uri,
					  S_IRWXU | S_IRWXG | S_IRWXO);
	if (handle < 0)
		return handle;

	razor_set_write_to_handle(next, atomic, handle, RAZOR_SECTION_ALL);

	retval = razor_atomic_close(atomic, handle);

	if (!retval) {
		razor_set_unref(root->system);
		root->system = razor_set_ref(next);
	}

	return retval;
}