#include "munga.h"
#pragma hdrstop

#include "filestrm.h"

//#############################################################################
//###########################    FileStream    ################################
//#############################################################################

//~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
//
FileStream::FileStream(const char* file_name, Logical writable) : MemoryStream(NULL, 0)
{
	Open(file_name, writable);
}

//~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
//
void FileStream::Open(const char* file_name, Logical writable)
{
	readOnly = !writable;
	fileHandle = -1;
	currentPosition = streamStart = NULL;
	streamSize = 0;
	if (file_name)
	{
		Check_Pointer(file_name);
		fileHandle = OpenImplementation(file_name, readOnly);
	}

	if (fileHandle != -1)
	{
		if (readOnly)
		{
			streamSize = SeekImplementation(fileHandle, 0, True);
			SeekImplementation(fileHandle, 0);
		}
		else
			streamSize = 0xFFFFFFFFU;
	}
}

//~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
//
void FileStream::Close()
{
	Check(this);

	if (fileHandle != -1)
	{
		if (!readOnly)
			FlushImplementation(fileHandle);
		CloseImplementation(fileHandle);
	}
	fileHandle = -1;
}

//~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
//
void FileStream::SetPointer(size_t index)
{
	Check(this);
	Verify(fileHandle != -1);

	currentPosition = (char*)SeekImplementation(fileHandle, index);
}

//~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
//
MemoryStream& FileStream::AdvancePointer(size_t index)
{
	Check(this);
	Verify(fileHandle != -1);

	currentPosition = (char*)SeekImplementation(fileHandle, (size_t)currentPosition + index);
	return *this;
}

//~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
//
MemoryStream& FileStream::RewindPointer(size_t index)
{
	Check(this);
	Verify(fileHandle != -1);

	currentPosition = (char*)SeekImplementation(fileHandle, (size_t)currentPosition + index);
	return *this;
}

//~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
//
MemoryStream& FileStream::ReadBytes(void *ptr, size_t number_of_bytes)
{
	Check(this);
	Verify(fileHandle != -1);
	Verify(readOnly);
	size_t read = ReadImplementation(fileHandle, ptr, number_of_bytes);
	Verify(read == number_of_bytes);
	currentPosition += read;
	return *this;
}

//~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
//
MemoryStream& FileStream::WriteBytes(const void *ptr, size_t number_of_bytes)
{
	Check(this);
	Verify(fileHandle != -1);
	Verify(!readOnly);
	size_t written = WriteImplementation(fileHandle, ptr, number_of_bytes);
	Verify(written == number_of_bytes);
	currentPosition += written;
	return *this;
}

//~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
//
Logical FileStream::TestInstance() const
{
	return true;
}