/*
 * $Id: fio.c,v 1.23 2006/06/30 04:18:47 bacon Exp $
 *
   Copyright 2006-2008 Chung, Hyung-Hwan.

   Licensed under the Apache License, Version 2.0 (the "License");
   you may not use this file except in compliance with the License.
   You may obtain a copy of the License at

       http://www.apache.org/licenses/LICENSE-2.0

   Unless required by applicable law or agreed to in writing, software
   distributed under the License is distributed on an "AS IS" BASIS,
   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   See the License for the specific language governing permissions and
   limitations under the License.
 */

#include <qse/cmn/fio.h>
#include <qse/cmn/str.h>
#include "mem.h"

#ifdef _WIN32
#	include <windows.h>
#	include <psapi.h>
#	include <tchar.h>
#else
#	include "syscall.h"
#	include <sys/types.h>
#	include <fcntl.h>
#	include <limits.h>
#endif

QSE_IMPLEMENT_STD_FUNCTIONS (fio)

static qse_ssize_t fio_input (int cmd, void* arg, void* buf, qse_size_t size);
static qse_ssize_t fio_output (int cmd, void* arg, void* buf, qse_size_t size);

qse_fio_t* qse_fio_open (
	qse_mmgr_t* mmgr, qse_size_t ext,
	const qse_char_t* path, int flags, int mode)
{
	qse_fio_t* fio;

	if (mmgr == QSE_NULL)
	{
		mmgr = QSE_MMGR_GETDFL();

		QSE_ASSERTX (mmgr != QSE_NULL,
			"Set the memory manager with QSE_MMGR_SETDFL()");

		if (mmgr == QSE_NULL) return QSE_NULL;
	}

	fio = QSE_MMGR_ALLOC (mmgr, QSE_SIZEOF(qse_fio_t) + ext);
	if (fio == QSE_NULL) return QSE_NULL;

	if (qse_fio_init (fio, mmgr, path, flags, mode) == QSE_NULL)
	{
		QSE_MMGR_FREE (mmgr, fio);
		return QSE_NULL;
	}

	return fio;
}

void qse_fio_close (qse_fio_t* fio)
{
	qse_fio_fini (fio);
	QSE_MMGR_FREE (fio->mmgr, fio);
}

qse_fio_t* qse_fio_init (
	qse_fio_t* fio, qse_mmgr_t* mmgr,
	const qse_char_t* path, int flags, int mode)
{
	qse_fio_hnd_t handle;

	QSE_MEMSET (fio, 0, QSE_SIZEOF(*fio));
	fio->mmgr = mmgr;

#ifdef _WIN32
	if (flags & QSE_FIO_HANDLE)
	{
		handle = *(qse_fio_hnd_t*)path;
	}
	else
	{
		DWORD desired_access = 0;
		DWORD share_mode = FILE_SHARE_READ | FILE_SHARE_WRITE;
		DWORD creation_disposition = 0;
		DWORD flag_and_attr = FILE_ATTRIBUTE_NORMAL;

		if (flags & QSE_FIO_APPEND)
		{
			/* this is not officially documented for CreateFile.
			 * ZwCreateFile (kernel) seems to document it */
			desired_access |= FILE_APPEND_DATA;
		}
		else if (flags & QSE_FIO_WRITE)
		{
			/* In WIN32, FILE_APPEND_DATA and GENERIC_WRITE can't
			 * be used together */
			desired_access |= GENERIC_WRITE;
		}
		if (flags & QSE_FIO_READ) desired_access |= GENERIC_READ;

		if (flags & QSE_FIO_CREATE)
		{
			creation_disposition =
				(flags & QSE_FIO_EXCLUSIVE)? CREATE_NEW:
				(flags & QSE_FIO_TRUNCATE)? CREATE_ALWAYS: OPEN_ALWAYS;
		}
		else if (flags & QSE_FIO_TRUNCATE)
		{
			creation_disposition = TRUNCATE_EXISTING;
		}
		else creation_disposition = OPEN_EXISTING;

		if (flags & QSE_FIO_NOSHRD)
			share_mode &= ~FILE_SHARE_READ;
		if (flags & QSE_FIO_NOSHWR)
			share_mode &= ~FILE_SHARE_WRITE;

		if (!(mode & QSE_FIO_WUSR)) 
			flag_and_attr = FILE_ATTRIBUTE_READONLY;
		if (flags & QSE_FIO_SYNC) 
			flag_and_attr |= FILE_FLAG_WRITE_THROUGH;

		/* these two are just hints to OS */
		if (flags & QSE_FIO_RANDOM) 
			flag_and_attr |= FILE_FLAG_RANDOM_ACCESS;
		if (flags & QSE_FIO_SEQUENTIAL) 
			flag_and_attr |= FILE_FLAG_SEQUENTIAL_SCAN;

		handle = CreateFile (path,
			desired_access, share_mode, QSE_NULL,
			creation_disposition, flag_and_attr, 0);
	}

	if (handle == INVALID_HANDLE_VALUE) return QSE_NULL;

	{
		DWORD file_type = GetFileType(handle);
		if (file_type == FILE_TYPE_UNKNOWN)
		{
			CloseHandle (handle);
			return QSE_NULL;
		}
	}

	/* TODO: support more features on WIN32 - TEMPORARY, DELETE_ON_CLOSE */
#else

	if (flags & QSE_FIO_HANDLE)
	{
		handle = *(qse_fio_hnd_t*)path;
	}
	else
	{
		int desired_access = 0;

	#ifdef QSE_CHAR_IS_MCHAR
		const qse_mchar_t* path_mb = path;
	#else
		qse_mchar_t path_mb[PATH_MAX + 1];
		if (qse_wcstombs_strict (path,
			path_mb, QSE_COUNTOF(path_mb)) == -1) return QSE_NULL;
	#endif
		/*
		 * rwa -> RDWR   | APPEND
		 * ra  -> RDWR   | APPEND
		 * wa  -> WRONLY | APPEND
		 * a   -> WRONLY | APPEND
		 */
		if (flags & QSE_FIO_APPEND)
		{
			if ((flags & QSE_FIO_READ)) desired_access |= O_RDWR;
			else desired_access |= O_WRONLY;
			desired_access |= O_APPEND;
		}
		else
		{
			if ((flags & QSE_FIO_READ) &&
			    (flags & QSE_FIO_WRITE)) desired_access |= O_RDWR;
			else if (flags & QSE_FIO_READ) desired_access |= O_RDONLY;
			else if (flags & QSE_FIO_WRITE) desired_access |= O_WRONLY;
		}

		if (flags & QSE_FIO_CREATE) desired_access |= O_CREAT;
		if (flags & QSE_FIO_TRUNCATE) desired_access |= O_TRUNC;
		if (flags & QSE_FIO_EXCLUSIVE) desired_access |= O_EXCL;
		if (flags & QSE_FIO_SYNC) desired_access |= O_SYNC;

	#if defined(O_LARGEFILE)
		desired_access |= O_LARGEFILE;
	#endif

		handle = QSE_OPEN (path_mb, desired_access, mode);
	}

	if (handle == -1) return QSE_NULL;

#endif

	if (flags & QSE_FIO_TEXT)
	{
		qse_tio_t* tio;

		tio = qse_tio_open (fio->mmgr, 0);
		if (tio == QSE_NULL) QSE_ERR_THROW (tio);

		if (qse_tio_attachin (tio, fio_input, fio) == -1 ||
		    qse_tio_attachout (tio, fio_output, fio) == -1)
		{
			qse_tio_close (tio);
			QSE_ERR_THROW (tio);
		}

		QSE_ERR_CATCH (tio) 
		{
		#ifdef _WIN32
			CloseHandle (handle);
		#else
			QSE_CLOSE (handle);
		#endif
			return QSE_NULL;
		}

		fio->tio = tio;
	}

	fio->handle = handle;

	return fio;
}

void qse_fio_fini (qse_fio_t* fio)
{
	if (fio->tio != QSE_NULL) qse_tio_close (fio->tio);
#ifdef _WIN32
	CloseHandle (fio->handle);
#else
	QSE_CLOSE (fio->handle);
#endif
}

qse_fio_hnd_t qse_fio_gethandle (qse_fio_t* fio)
{
	return fio->handle;
}

void qse_fio_sethandle (qse_fio_t* fio, qse_fio_hnd_t handle)
{
	fio->handle = handle;
}

qse_fio_off_t qse_fio_seek (
	qse_fio_t* fio, qse_fio_off_t offset, qse_fio_ori_t origin)
{
#ifdef _WIN32
	static int seek_map[] =
	{
		FILE_BEGIN,
		FILE_CURRENT,
		FILE_END
	};
	LARGE_INTEGER x, y;

	QSE_ASSERT (AES_SIZEOF(offset) <= AES_SIZEOF(x.QuadPart));

	x.QuadPart = offset;
	if (SetFilePointerEx (fio->handle, x, &y, seek_map[origin]) == FALSE)
	{
		return (qse_fio_off_t)-1;
	}

	return (qse_fio_off_t)y.QuadPart;

	/*
	x.QuadPart = offset;
	x.LowPart = SetFilePointer (
		fio->handle, x.LowPart, &x.HighPart, seek_map[origin]);
	if (x.LowPart == INVALID_SET_FILE_POINTER && GetLastError() != NO_ERROR)
	{
		return (qse_fio_off_t)-1;
	}

	return (qse_fio_off_t)x.QuadPart;
	*/

#else
	static int seek_map[] =
	{
		SEEK_SET,
		SEEK_CUR,
		SEEK_END
	};

#if defined(QSE_LLSEEK)
	loff_t tmp;

	if (QSE_LLSEEK (fio->handle,
		(unsigned long)(offset>>32),
		(unsigned long)(offset&0xFFFFFFFFlu),
		&tmp,
		seek_map[origin]) == -1)
	{
		return (qse_fio_off_t)-1;
	}

	return (qse_fio_off_t)tmp;

#elif defined(QSE_LSEEK64)
	return QSE_LSEEK64 (fio->handle, offset, seek_map[origin]);
#else
	return QSE_LSEEK (fio->handle, offset, seek_map[origin]);
#endif

#endif
}

int qse_fio_truncate (qse_fio_t* fio, qse_fio_off_t size)
{
#ifdef _WIN32
	LARGE_INTEGER x;
	x.QuadPart = size;

	if (SetFilePointerEx(fio->handle,x,NULL,FILE_BEGIN) == FALSE ||
	    SetEndOfFile(fio->handle) == FALSE) return -1;

	return 0;
#else
	return QSE_FTRUNCATE (fio->handle, size);
#endif
}

static qse_ssize_t fio_read (qse_fio_t* fio, void* buf, qse_size_t size)
{
#ifdef _WIN32
	DWORD count;
	if (size > QSE_TYPE_MAX(DWORD)) size = QSE_TYPE_MAX(DWORD);
	if (ReadFile(fio->handle, buf, size, &count, QSE_NULL) == FALSE) return -1;
	return (qse_ssize_t)count;
#else
	if (size > QSE_TYPE_MAX(size_t)) size = QSE_TYPE_MAX(size_t);
	return QSE_READ (fio->handle, buf, size);
#endif
}

qse_ssize_t qse_fio_read (qse_fio_t* fio, void* buf, qse_size_t size)
{
	if (fio->tio == QSE_NULL) 
		return fio_read (fio, buf, size);
	else
		return qse_tio_read (fio->tio, buf, size);
}

static qse_ssize_t fio_write (qse_fio_t* fio, const void* data, qse_size_t size)
{
#ifdef _WIN32
	DWORD count;
	if (size > QSE_TYPE_MAX(DWORD)) size = QSE_TYPE_MAX(DWORD);
	if (WriteFile(fio->handle, data, size, &count, QSE_NULL) == FALSE) return -1;
	return (qse_ssize_t)count;
#else
	if (size > QSE_TYPE_MAX(size_t)) size = QSE_TYPE_MAX(size_t);
	return QSE_WRITE (fio->handle, data, size);
#endif
}

qse_ssize_t qse_fio_write (qse_fio_t* fio, const void* data, qse_size_t size)
{
	if (fio->tio == QSE_NULL)
		return fio_write (fio, data, size);
	else
		return qse_tio_write (fio->tio, data, size);
}

qse_ssize_t qse_fio_flush (qse_fio_t* fio)
{
        if (fio->tio == QSE_NULL) return 0;
        return qse_tio_flush (fio->tio);
}


#ifdef _WIN32

static int get_devname_from_handle (
	HANDLE handle, qse_char_t* buf, qse_size_t len) 
{
	BOOL bSuccess = FALSE;
	HANDLE map = NULL;
	void* mem = NULL;
	DWORD olen;

	/* create a file mapping object */
	map = CreateFileMapping (
		handle, 
		NULL, 
		PAGE_READONLY,
		0, 
		1,
		NULL
	);
	if (map == NULL) return -1;

	/* create a file mapping to get the file name. */
	mem = MapViewOfFile (map, FILE_MAP_READ, 0, 0, 1);
	if (mem == NULL)
	{
		CloseHandle (map);
		return -1;
	}

	olen = GetMappedFileName (GetCurrentProcess(), mem, buf, len); 
	if (olen == 0)
	{
		UnmapViewOfFile (mem);
		CloseHandle (map);
		return -1;
	}

	UnmapViewOfFile (mem);
	CloseHandle (map);
	return 0;
}

static int get_volname_from_handle (
	HANDLE handle, qse_char_t* buf, qse_size_t len) 
{

	if (get_devname_from_handle (handle, buf, len) == -1) return -1;

	if (_tcsnicmp(QSE_T("\\Device\\LanmanRedirector\\"), buf, 25) == 0)
	{
		buf[0] = QSE_T('\\');
		_tcscpy (&buf[1], &buf[24]);
	}
	else
	{
		DWORD n;
		qse_char_t drives[128];

		n = GetLogicalDriveStrings (QSE_COUNTOF(drives), drives);

		if (n == 0 /* error */ || 
		    n > QSE_COUNTOF(drives) /* buffer small */) 
		{
			return -1;	
		}

		while (n > 0)
		{
			qse_char_t drv[3];
			qse_char_t path[MAX_PATH];

			drv[0] = drives[--n];
			drv[1] = QSE_T(':');
			drv[2] = QSE_T('\0');
			if (QueryDosDevice (drv, path, QSE_COUNTOF(path)))
			{
				qse_size_t pl = _tcslen(path);
				qse_size_t bl = _tcslen(buf);
				if (bl > pl && buf[pl] == QSE_T('\\') &&
				    _tcsnicmp(path, buf, pl) == 0)
				{
					buf[0] = drv[0];
					buf[1] = QSE_T(':');
					_tcscpy (&buf[2], &buf[pl]);
					break;
				}
			}
		}
	}
	
	/* if the match is not found, the device name is returned
	 * without translation */
	return 0;
}
#endif

int qse_fio_chmod (qse_fio_t* fio, int mode)
{
#ifdef _WIN32
	int flags = FILE_ATTRIBUTE_NORMAL;
	qse_char_t name[MAX_PATH];

	/* it is a best effort implementation. if the file size is 0,
	 * it can't even get the file name from the handle and thus fails. */

	if (get_volname_from_handle (
		fio->handle, name, QSE_COUNTOF(name)) == -1) return -1;

	if (!(mode & QSE_FIO_WUSR)) flags = FILE_ATTRIBUTE_READONLY;
	return (SetFileAttributes (name, flags) == FALSE)? -1: 0;
#else
	return QSE_FCHMOD (fio->handle, mode);
#endif
}

int qse_fio_sync (qse_fio_t* fio)
{
#ifdef _WIN32
	return (FlushFileBuffers (fio->handle) == FALSE)? -1: 0;
#else
	return QSE_FSYNC (fio->handle);
#endif
}

int qse_fio_lock (qse_fio_t* fio, qse_fio_lck_t* lck, int flags)
{
	/* TODO: qse_fio_lock 
	 * struct flock fl;
	 * fl.l_type = F_RDLCK, F_WRLCK;
	 * QSE_FCNTL (fio->handle, F_SETLK, &fl);
	 */
	return -1;
}

int qse_fio_unlock (qse_fio_t* fio, qse_fio_lck_t* lck, int flags)
{
	/* TODO: qse_fio_unlock 
	 * struct flock fl;
	 * fl.l_type = F_UNLCK;
	 * QSE_FCNTL (fio->handle, F_SETLK, &fl);
	 */
	return -1;
}

static qse_ssize_t fio_input (int cmd, void* arg, void* buf, qse_size_t size)
{
        qse_fio_t* fio = (qse_fio_t*)arg;
        QSE_ASSERT (fio != QSE_NULL);
        if (cmd == QSE_TIO_IO_DATA) 
	{
		return fio_read (fio, buf, size);
	}

	/* take no actions for OPEN and CLOSE as they are handled
	 * by fio */
        return 0;
}

static qse_ssize_t fio_output (int cmd, void* arg, void* buf, qse_size_t size)
{
        qse_fio_t* fio = (qse_fio_t*)arg;
        QSE_ASSERT (fio != QSE_NULL);
        if (cmd == QSE_TIO_IO_DATA) 
	{
		return fio_write (fio, buf, size);
	}

	/* take no actions for OPEN and CLOSE as they are handled
	 * by fio */
        return 0;
}