/*
Copyright (c) 2013 Daniele Bartolini, Michele Rossi
Copyright (c) 2012 Daniele Bartolini, Simone Boscaratto

Permission is hereby granted, free of charge, to any person
obtaining a copy of this software and associated documentation
files (the "Software"), to deal in the Software without
restriction, including without limitation the rights to use,
copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the
Software is furnished to do so, subject to the following
conditions:

The above copyright notice and this permission notice shall be
included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
OTHER DEALINGS IN THE SOFTWARE.
*/

#include "OsFile.h"
#include "Assert.h"
#include "OS.h"
#include "tchar.h"

namespace crown
{

OsFile::OsFile(const char* path, FileOpenMode mode) :
	m_eof(false)
{
	m_file_handle = CreateFile(path,
							   mode == FOM_READ ? GENERIC_READ : GENERIC_WRITE,
							   0,
							   NULL,
							   OPEN_ALWAYS,
        					   FILE_ATTRIBUTE_NORMAL,
        					   NULL);

	CE_ASSERT(m_file_handle != INVALID_HANDLE_VALUE, "Unable to open file: %s", path);

	m_mode = mode;
}

OsFile::~OsFile()
{
	close();
}

void OsFile::close()
{
	if (is_open())
	{
		CloseHandle(m_file_handle);
		m_file_handle = NULL;
	}
}

bool OsFile::is_open() const
{
	return m_file_handle != NULL;
}

size_t OsFile::size() const
{
	DWORD size;

	size = GetFileSize(m_file_handle, NULL);

	return size;
}

FileOpenMode OsFile::mode()
{
	return m_mode;
}

size_t OsFile::read(void* data, size_t size)
{
	DWORD bytes_read;
	
	BOOL result = ReadFile(m_file_handle, data, size, &bytes_read, NULL);

	CE_ASSERT(result == TRUE, "Unable to read from file");

	if (result && bytes_read == 0)
	{
		m_eof = true;
	}

	return bytes_read;
}

size_t OsFile::write(const void* data, size_t size)
{
	DWORD bytes_written;

	bool write = WriteFile(m_file_handle, data, size, &bytes_written, NULL);
	
	CE_ASSERT(size == bytes_written, "Cannot read from file\n");		

	return size;
}

void OsFile::seek(size_t position)
{
	DWORD seek_result = SetFilePointer(m_file_handle, position, NULL, FILE_BEGIN);

	CE_ASSERT(seek_result != INVALID_SET_FILE_POINTER, "Failed to seek");
}

void OsFile::seek_to_end()
{
	DWORD seek_result = SetFilePointer(m_file_handle, 0, NULL, FILE_END);

	CE_ASSERT(seek_result != INVALID_SET_FILE_POINTER, "Failed to seek to end");
}

void OsFile::skip(size_t bytes)
{
	DWORD seek_result = SetFilePointer(m_file_handle, bytes, NULL, FILE_CURRENT);

	CE_ASSERT(seek_result != INVALID_SET_FILE_POINTER, "Failed to skip");
}

size_t OsFile::position() const
{
	DWORD position = SetFilePointer(m_file_handle, 0, NULL, FILE_CURRENT);
	
	CE_ASSERT(position != INVALID_SET_FILE_POINTER, "Failed to get position");

	return position;
}

bool OsFile::eof() const
{
	return m_eof;
}

} // namespace crown