#include "BufferBitStream.h"

#include <iostream>

bool BufferBitStream::isFinished() const
{
    return mByteOffset == mBuffer.size() - 1;
}

std::vector<unsigned char> BufferBitStream::peekNextNBytes(unsigned n) const
{
    std::vector<unsigned char> ret (n, 0);
    unsigned count = 0;
    for(unsigned idx=mByteOffset; idx<mByteOffset + n; idx++)
    {
        if (idx == mBuffer.size())
        {
            break;
        }

        ret[count] = mBuffer[idx];
        count ++;
    }
    return ret;
}

std::optional<unsigned char> BufferBitStream::readNextByte()
{
    if (mByteOffset + 1 == mBuffer.size())
    {
        return std::nullopt;
    }
    else
    {
        mByteOffset++;
        mCurrentByte = mBuffer[mByteOffset];
        return mCurrentByte;
    }
}

void BufferBitStream::setBuffer(const std::vector<unsigned char>& data)
{
    mBuffer = data;
}

void BufferBitStream::writeByte(unsigned char data)
{
    if (mChecksumCalculator)
    {
        mChecksumCalculator->addValue(data);
    }
    mBuffer.push_back(data);
}