#include <JSystem/JKernel/JKRFile.h>
#include <JSystem/JSupport/JSUStream.h>
#include "types.h"

JSUFileInputStream::JSUFileInputStream(JKRFile* file)
{
	mObject = file;
	mLength = 0;
}

int JSUFileInputStream::readData(void* buffer, long byteCount)
{
	int readBytes = 0;
	if (((JKRFile*)mObject)->isAvailable()) {
		if ((u32)(mLength + byteCount) > ((JKRFile*)mObject)->getFileSize()) {
			byteCount = ((JKRFile*)mObject)->getFileSize() - mLength;
		}
		if (byteCount > 0) {
			readBytes = ((JKRFile*)mObject)->readData(buffer, byteCount, mLength);
			if (readBytes < 0) {
				return 0;
			} else {
				mLength += readBytes;
			}
		}
	}
	return readBytes;
}

int JSUFileInputStream::seekPos(long offset, JSUStreamSeekFrom mode)
{
	u32 originalLength = mLength;
	switch (mode) {
	case SEEK_SET:
		mLength = offset;
		break;
	case SEEK_END:
		mLength = ((JKRFile*)mObject)->getFileSize() - offset;
		break;
	case SEEK_CUR:
		mLength += offset;
		break;
	default:
		break;
	}
	if (0 > mLength) {
		mLength = 0;
	}
	if (mLength > ((JKRFile*)mObject)->getFileSize()) {
		mLength = ((JKRFile*)mObject)->getFileSize();
	}
	return mLength - originalLength;
}