/* ScummVM - Graphic Adventure Engine
 *
 * ScummVM is the legal property of its developers, whose names
 * are too numerous to list here. Please refer to the COPYRIGHT
 * file distributed with this source distribution.
 *
 * 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.
 *
 */

#if !defined(DISABLE_STDIO_FILESTREAM)

// Disable symbol overrides so that we can use FILE, fopen etc.
#define FORBIDDEN_SYMBOL_ALLOW_ALL

#include "backends/fs/stdiostream.h"

StdioStream::StdioStream(void *handle) : _handle(handle) {
	assert(handle);
}

StdioStream::~StdioStream() {
	fclose((FILE *)_handle);
}

bool StdioStream::err() const {
	return ferror((FILE *)_handle) != 0;
}

void StdioStream::clearErr() {
	clearerr((FILE *)_handle);
}

bool StdioStream::eos() const {
	return feof((FILE *)_handle) != 0;
}

int32 StdioStream::pos() const {
	return ftell((FILE *)_handle);
}

int32 StdioStream::size() const {
	int32 oldPos = ftell((FILE *)_handle);
	fseek((FILE *)_handle, 0, SEEK_END);
	int32 length = ftell((FILE *)_handle);
	fseek((FILE *)_handle, oldPos, SEEK_SET);

	return length;
}

bool StdioStream::seek(int32 offs, int whence) {
	return fseek((FILE *)_handle, offs, whence) == 0;
}

uint32 StdioStream::read(void *ptr, uint32 len) {
	return fread((byte *)ptr, 1, len, (FILE *)_handle);
}

uint32 StdioStream::write(const void *ptr, uint32 len) {
	return fwrite(ptr, 1, len, (FILE *)_handle);
}

bool StdioStream::flush() {
	return fflush((FILE *)_handle) == 0;
}

StdioStream *StdioStream::makeFromPath(const Common::String &path, bool writeMode) {
#if defined(__VMS)
	// OpenVMS: a file CREATED by a bare fopen(path, "wb") is not the
	// byte-addressable stream file the rest of this code base assumes, which is
	// why saved games did not survive a run.  RMS needs to be told explicitly:
	//
	//   ctx=stm / rfm=stmlf / rat=none
	//       Create a Stream_LF file with no record attributes.  Without this the
	//       RTL creates rfm=var,rat=cr, i.e. a RECORD file: every fwrite() call
	//       becomes a record and the RTL re-inserts record terminators on the way
	//       back out, so the byte offsets that saveload.cpp seeks to no longer
	//       mean anything.  This is the same attribute set RUNSETUP.COM has to
	//       plant on KYRA.DAT by hand (SET FILE/ATTRIBUTES=(RFM:STMLF,RAT:NONE))
	//       for that file to be readable at all - creation needs it just as much
	//       as reading does.
	//   fop=sup
	//       Supersede: overwrite the existing file in place.  VMS otherwise
	//       creates a NEW VERSION (LOL-CD.000;2, ;3, ...) on every save.  Reads
	//       silently pick the highest version, so re-saving appears to work until
	//       the version limit is hit, after which the save simply fails.
	//   mbc=32
	//       Multiblock count; saves are written in many small fwrite()s.
	//
	// Only the CREATE path gets these.  Reads deliberately keep the plain
	// fopen(): the game data files are whatever format they were shipped/
	// transferred as, and forcing attributes on an existing file fails the open.
	FILE *handle = writeMode
		? fopen(path.c_str(), "wb", "ctx=stm", "rfm=stmlf", "rat=none", "fop=sup", "mbc=32")
		: fopen(path.c_str(), "rb");
#else
	FILE *handle = fopen(path.c_str(), writeMode ? "wb" : "rb");
#endif

#ifdef __amigaos4__
	//
	// Work around for possibility that someone uses AmigaOS "newlib" build
	// with SmartFileSystem (blocksize 512 bytes), leading to buffer size
	// being only 512 bytes. "Clib2" sets the buffer size to 8KB, resulting
	// smooth movie playback. This forces the buffer to be enough also when
	// using "newlib" compile on SFS.
	//
	if (handle && !writeMode) {
		setvbuf(handle, NULL, _IOFBF, 8192);
	}
#endif

#if defined(__WII__)
	// disable newlib's buffering, the device libraries handle caching
	if (handle)
		setvbuf(handle, NULL, _IONBF, 0);
#endif

	if (handle)
		return new StdioStream(handle);
	return 0;
}

#endif