/*

  * Copyright (C) 2011-2012  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"

 #if HAVE_WINDOWS_KTM

 #include <stdlib.h>

 #include <windows.h>

 #include <stdio.h>

 #include <limits.h>

 #include <errno.h>

 #include <unistd.h>

 #include <fcntl.h>

 #include <sys/stat.h>

 #include <string.h>

 #include <assert.h>

 #include <wchar.h>

 #include <ktmw32.h>

 #include "razor.h"

 #include "razor-internal.h"

 #define RAZOR_ASCII_ISALPHA(c)	\

 			((c) >= 'A' && (c) <= 'Z' || (c) >= 'a' && (c) <= 'z')

 static int

 razor_valid_root_name2(const wchar_t *name)

 {

 	if (razor_allow_all_root_names())

 		return !wcschr(name, '/');

 	return RAZOR_ASCII_ISALPHA(name[0]) && name[1] == ':' &&

 	       name[2] == '\0';

 }

 struct razor_wstr {

 	wchar_t *str;

 	int len, allocated;

 };

 static struct razor_wstr *

 razor_wstr_create(const char *init, int len)

 {

 	int n;

 	struct razor_wstr *wstr;

 	wstr = malloc(sizeof(struct razor_wstr));

 	n = MultiByteToWideChar(CP_UTF8, 0, init, len, NULL, 0);

 	if (len >= 0 && init[len])

 		wstr->len = n++;

 	else

 		wstr->len = n - 1;

 	wstr->allocated = n * 2;

 	wstr->str = malloc(wstr->allocated * sizeof(wchar_t));

 	if (!wstr->str) {

 		free(wstr);

 		return NULL;

 	}

 	(void)MultiByteToWideChar(CP_UTF8, 0, init, len, wstr->str, n);

 	if (len >= 0 && init[len])

 		wstr->str[wstr->len] = 0;

 	return wstr;

 }

 static int

 razor_wstr_append(struct razor_wstr *wstr, const char *s, int len)

 {

 	int n, allocated;

 	wchar_t *str;

 	n = MultiByteToWideChar(CP_UTF8, 0, s, len, NULL, 0);

 	if (len < 0 || !s[len])

 		n--;

 	if (wstr->allocated <= wstr->len + n) {

 		allocated = (wstr->len + n + 1) * 2;

 		str = realloc(wstr->str, allocated * sizeof(wchar_t));

 		if (!str)

 			return -1;

 		wstr->allocated = allocated;

 		wstr->str = str;

 	}

 	(void)MultiByteToWideChar(CP_UTF8, 0, s, len, wstr->str + wstr->len, n);

 	wstr->len += n;

 	wstr->str[wstr->len] = 0;

 	return 0;

 }

 static void

 razor_wstr_destroy(struct razor_wstr *wstr)

 {

 	free(wstr->str);

 	free(wstr);

 }

 RAZOR_EXPORT struct razor_atomic *

 razor_atomic_open(const char *description)

 {

 	wchar_t *buf;

 	struct razor_atomic *atomic;

 	atomic = zalloc(sizeof *atomic);

 	buf = razor_utf8_to_utf16(description, -1);

 	atomic->transaction = CreateTransaction(NULL, 0,

 						TRANSACTION_DO_NOT_PROMOTE,

 						0, 0, 0, buf);

 	free(buf);

 	return atomic;

 }

 void

 razor_atomic_set_error_str(struct razor_atomic *atomic, const wchar_t *path,

 			   const char *str)

 {

 	assert(!atomic->error_str);

 	free(atomic->error_path);

 	if (path)

 		atomic->error_path = razor_utf16_to_utf8(path, -1);

 	else

 		atomic->error_path = NULL;

 	atomic->error_str = strdup(str);

 }

 static void

 razor_atomic_set_error(struct razor_atomic *atomic, const wchar_t *path,

 		       DWORD error)

 {

 	wchar_t *buf;

 	assert(!atomic->error_str);

 	free(atomic->error_path);

 	if (path)

 		atomic->error_path = razor_utf16_to_utf8(path, -1);

 	else

 		atomic->error_path = NULL;

 	FormatMessageW(FORMAT_MESSAGE_ALLOCATE_BUFFER|

 		       FORMAT_MESSAGE_FROM_SYSTEM|FORMAT_MESSAGE_IGNORE_INSERTS,

 		       NULL, error, MAKELANGID(LANG_NEUTRAL,SUBLANG_DEFAULT),

 		       (LPWSTR)&buf, 0, NULL);

 	atomic->error_str = razor_utf16_to_utf8(buf, -1);

 	LocalFree(buf);

 }

 RAZOR_EXPORT int

 razor_atomic_commit(struct razor_atomic *atomic)

 {

 	int retval;

 	if (razor_atomic_in_error_state(atomic))

 		return -1;

 	retval = !CommitTransaction(atomic->transaction);

 	if (retval) {

 		razor_atomic_set_error(atomic, NULL, GetLastError());

 		RollbackTransaction(atomic->transaction);

 	}

 	CloseHandle(atomic->transaction);

 	atomic->transaction = INVALID_HANDLE_VALUE;

 	return retval;

 }

 RAZOR_EXPORT void

 razor_atomic_destroy(struct razor_atomic *atomic)

 {

 	int i;

 	for(i = 0; i < atomic->n_files; i++) {

 		if (atomic->files[i].h != INVALID_HANDLE_VALUE) {

 			CloseHandle(atomic->files[i].h);

 			free(atomic->files[i].path);

 		}

 	}

 	free(atomic->files);

 	if (atomic->transaction != INVALID_HANDLE_VALUE) {

 		RollbackTransaction(atomic->transaction);

 		CloseHandle(atomic->transaction);

 	}

 	free(atomic->error_path);

 	free(atomic->error_str);

 	free(atomic->error_msg);

 	free(atomic);

 }

 RAZOR_EXPORT int

 razor_atomic_make_dirs(struct razor_atomic *atomic, const char *root,

 		       const char *path)

 {

 	struct razor_wstr *buffer;

 	const char *slash, *next;

 	WIN32_FILE_ATTRIBUTE_DATA fa;

 	DWORD err;

 	int r, creating = 0;

 	if (razor_atomic_in_error_state(atomic))

 		return -1;

 	buffer = razor_wstr_create(root, -1);

 	slash = path;

 	for (; *slash != '\0'; slash = next) {

 		next = strpbrk(slash + 1, "/\\");

 		if (next == NULL)

 			break;

 		razor_wstr_append(buffer, slash, next - slash);

 		if (!creating) {

 			if (razor_valid_root_name2(buffer->str))

 				continue;

 			r = GetFileAttributesTransactedW(buffer->str,

 							 GetFileExInfoStandard,

 							 &fa,

 							 atomic->transaction);

 			if (!r) {

 				err = GetLastError();

 				if (err == ERROR_FILE_NOT_FOUND) {

 					creating = 1;

 				} else {

 					razor_atomic_set_error(atomic,

 							       buffer->str,

 							       err);

 					razor_wstr_destroy(buffer);

 					return -1;

 				}

 			} else if (!(fa.dwFileAttributes&

 				     FILE_ATTRIBUTE_DIRECTORY)) {

 				razor_atomic_set_error_str(atomic, buffer->str,

 							   "Not a directory");

 				razor_wstr_destroy(buffer);

 				return -1;

 			}

 		}

 		if (creating) {

 			if (!CreateDirectoryTransactedW(NULL, buffer->str, NULL,

 							atomic->transaction)) {

 				razor_atomic_set_error(atomic, buffer->str,

 						       GetLastError());

 				razor_wstr_destroy(buffer);

 				return -1;

 			}

 			/* FIXME: What to do about permissions for dirs we

 			 * have to create but are not in the cpio archive? */

 		}

 	}

 	razor_wstr_destroy(buffer);

 	return 0;

 }

 RAZOR_EXPORT int

 razor_atomic_remove(struct razor_atomic *atomic, const char *path)

 {

 	wchar_t *buf;

 	DWORD err;

 	if (razor_atomic_in_error_state(atomic))

 		return -1;

 	buf = razor_utf8_to_utf16(path, -1);

 	if (DeleteFileTransactedW(buf, atomic->transaction)) {

 		free(buf);

 		return 0;

 	}

 	err = GetLastError();

 	if (err == ERROR_FILE_NOT_FOUND || err == ERROR_PATH_NOT_FOUND) {

 		free(buf);

 		return 0;

 	}

 	if (SetFileAttributesTransactedW(buf, FILE_ATTRIBUTE_NORMAL,

 					 atomic->transaction)) {

 		if (DeleteFileTransactedW(buf, atomic->transaction)) {

 			free(buf);

 			return 0;

 		}

 		err = GetLastError();

 	}

 	if (RemoveDirectoryTransactedW(buf, atomic->transaction) ||

 	    GetLastError() == ERROR_DIR_NOT_EMPTY) {

 		free(buf);

 		return 0;

 	}

 	/*

 	 * It would be tempting to use:

 	 * 	MoveFileEx(path, NULL, MOVEFILE_DELAY_UNTIL_REBOOT)

 	 * but unless we can guarantee that the system will be rebooted

 	 * before we (or some other application) write another file with the

 	 * same path, this is likely to cause more problems than it solves.

 	 */

 	razor_atomic_set_error(atomic, buf, err);

 	free(buf);

 	return -1;

 }

 RAZOR_EXPORT int

 razor_atomic_rename_file(struct razor_atomic *atomic, const char *oldpath,

 			 const char *newpath)

 {

 	wchar_t *oldbuf, *newbuf;

 	const DWORD flags = MOVEFILE_COPY_ALLOWED | MOVEFILE_REPLACE_EXISTING;

 	if (razor_atomic_in_error_state(atomic))

 		return -1;

 	newbuf = razor_utf8_to_utf16(newpath, -1);

 	oldbuf = razor_utf8_to_utf16(oldpath, -1);

 	/*

 	 * Passing MOVEFILE_REPLACE_EXISTING to MoveFileTransaction() will

 	 * cover every case we care about _except_ replacing an empty

 	 * directory with a file. Calling RemoveDirectoryTransacted() will deal

 	 * with this case while having no effect in all other cases.

 	 */

 	(void)RemoveDirectoryTransactedW(newbuf, atomic->transaction);

 	if (!MoveFileTransactedW(oldbuf, newbuf, NULL, NULL, flags,

 			         atomic->transaction))

 		razor_atomic_set_error(atomic, newbuf, GetLastError());

 	free(newbuf);

 	free(oldbuf);

 	return !!atomic->error_str;

 }

 RAZOR_EXPORT int

 razor_atomic_create_dir(struct razor_atomic *atomic, const char *dirname,

 			mode_t mode)

 {

 	wchar_t *buf;

 	DWORD err;

 	WIN32_FILE_ATTRIBUTE_DATA fa;

 	if (razor_atomic_in_error_state(atomic))

 		return -1;

 	buf = razor_utf8_to_utf16(dirname, -1);

 	if (!CreateDirectoryTransactedW(NULL, buf, NULL, atomic->transaction)) {

 		err = GetLastError();

 		if (err != ERROR_FILE_EXISTS && err != ERROR_ALREADY_EXISTS) {

 abort:

 			razor_atomic_set_error(atomic, buf, err);

 			free(buf);

 			return -1;

 		}

 		if (!GetFileAttributesTransactedW(buf, GetFileExInfoStandard,

 						  &fa, atomic->transaction))

 			goto abort;

 		if (!(fa.dwFileAttributes&FILE_ATTRIBUTE_DIRECTORY)) {

 			if (razor_atomic_remove(atomic, dirname)) {

 				free(buf);

 				return -1;

 			}

 			if (!CreateDirectoryTransactedW(NULL, buf, NULL,

 							atomic->transaction)) {

 				err = GetLastError();

 				goto abort;

 			}

 		}

 	}

 	free(buf);

 	return 0;

 }

 RAZOR_EXPORT int

 razor_atomic_create_symlink(struct razor_atomic *atomic, const char *target,

 			    const char *path)

 {

 	if (razor_atomic_in_error_state(atomic))

 		return -1;

 	/*

 	 * This isn't true, but symbolic links under Windows 7

 	 * need to know whether the target is a directory or not

 	 * and we don't always know that at the time when the

 	 * link is created, so it's a convienent lie for now.

 	 */

 	razor_atomic_set_error_str(atomic, NULL, "Symbolic links not supported "

 						 "on this platform");

 	return -1;

 }

 RAZOR_EXPORT int

 razor_atomic_create_file(struct razor_atomic *atomic, const char *filename,

 			 mode_t mode)

 {

 	DWORD attribs;

 	struct razor_atomic_file *files;

 	int i = atomic->n_files;

 	if (razor_atomic_in_error_state(atomic))

 		return -1;

 	files = realloc(atomic->files,

 			(atomic->n_files+1) * sizeof(struct razor_atomic_file));

 	if (!files) {

 		razor_atomic_set_error_str(atomic, NULL, "Not enough memory");

 		return -1;

 	}

 	atomic->n_files++;

 	atomic->files = files;

 	files[i].path = razor_utf8_to_utf16(filename, -1);

 	/*

 	 * Passing CREATE_ALWAYS to CreateFileTransacted() will cover

 	 * every case we care about _except_ replacing an empty directory

 	 * with a file. Calling RemoveDirectoryTransacted() will deal

 	 * with this case while having no effect in all other cases.

 	 */

 	(void)RemoveDirectoryTransactedW(files[i].path, atomic->transaction);

 	if (mode & S_IWUSR)

 		attribs = FILE_ATTRIBUTE_NORMAL;

 	else

 		attribs = FILE_ATTRIBUTE_READONLY;

 	files[i].h = CreateFileTransactedW(files[i].path, GENERIC_WRITE,

 					   0, NULL, CREATE_ALWAYS, attribs,

 					   NULL, atomic->transaction, NULL,

 					   NULL);

 	if (files[i].h == INVALID_HANDLE_VALUE) {

 		razor_atomic_set_error(atomic, files[i].path, GetLastError());

 		free(files[i].path);

 		atomic->n_files--;

 		return -1;

 	}

 	return i;

 }

 RAZOR_EXPORT int

 razor_atomic_write(struct razor_atomic *atomic, int handle, const void *data,

 		   size_t size)

 {

 	DWORD written;

 	if (razor_atomic_in_error_state(atomic))

 		return -1;

 	assert(handle < atomic->n_files);

 	assert(atomic->files[handle].h != INVALID_HANDLE_VALUE);

 	while(size) {

 		if (!WriteFile(atomic->files[handle].h, data, size, &written,

 			       NULL)) {

 			razor_atomic_set_error(atomic,

 					       atomic->files[handle].path,

 					       GetLastError());

 			(void)CloseHandle(atomic->files[handle].h);

 			free(atomic->files[handle].path);

 			atomic->files[handle].path = NULL;

 			atomic->files[handle].h = INVALID_HANDLE_VALUE;

 			return -1;

 		}

 		data += written;

 		size -= written;

 	}

 	return 0;

 }

 RAZOR_EXPORT int

 razor_atomic_sync(struct razor_atomic *atomic, int handle)

 {

 	HANDLE h;

 	if (razor_atomic_in_error_state(atomic))

 		return -1;

 	assert(handle < atomic->n_files);

 	assert(atomic->files[handle].h != INVALID_HANDLE_VALUE);

 	if (!CloseHandle(atomic->files[handle].h)) {

 		razor_atomic_set_error(atomic, atomic->files[handle].path,

 				       GetLastError());

 		free(atomic->files[handle].path);

 		atomic->files[handle].path = NULL;

 		atomic->files[handle].h = INVALID_HANDLE_VALUE;

 		return -1;

 	}

 	h = CreateFileTransactedW(atomic->files[handle].path, GENERIC_WRITE, 0,

 				  NULL, OPEN_EXISTING, 0, NULL,

 				  atomic->transaction, NULL, NULL);

 	atomic->files[handle].h = h;

 	if (atomic->files[handle].h == INVALID_HANDLE_VALUE) {

 		razor_atomic_set_error(atomic, atomic->files[handle].path,

 				       GetLastError());

 		free(atomic->files[handle].path);

 		atomic->files[handle].path = NULL;

 		return -1;

 	}

 	return !!atomic->error_str;

 }

 RAZOR_EXPORT int

 razor_atomic_close(struct razor_atomic *atomic, int handle)

 {

 	if (razor_atomic_in_error_state(atomic))

 		return -1;

 	assert(handle < atomic->n_files);

 	assert(atomic->files[handle].h != INVALID_HANDLE_VALUE);

 	if (!CloseHandle(atomic->files[handle].h))

 		razor_atomic_set_error(atomic, atomic->files[handle].path,

 				       GetLastError());

 	free(atomic->files[handle].path);

 	atomic->files[handle].path = NULL;

 	atomic->files[handle].h = INVALID_HANDLE_VALUE;

 	while(atomic->n_files > 0 &&

 	      atomic->files[atomic->n_files-1].h == INVALID_HANDLE_VALUE)

 		atomic->n_files--;

 	return !!atomic->error_str;

 }

 #endif		/* HAVE_WINDOWS_KTM */