float* constructHistogram (istream& in)
{
    float* histogram = new float[0x100];
    
    uchar c;
    while (c = in.get(), in)
    {
        histogram[c]++;
    }
    
    in.seekg(ios::beg);
    //in.clear();
    cin.clear(istream::eofbit);
    
    return histogram;
}

void usage (char* progname)
{
    cerr << "Usage:\t" << progname << " -e infile outfile\n";
    cerr << "\t" << progname << " -d infile outfile\n\n";
    cerr << "Use the -e option to encode, and -d to decode.\n";
}

int main (int argc, char** argv)
{
    if (argc != 4)
    {
        usage(argv[0]);
        return 1;
    }
    
    ifstream fin(argv[2]);
    ofstream fout(argv[3]);
    
    if (argv[1][1] == 'e')
    {
        float* freqs;
        if (-1 == fin.tellg())
            // this file does not support seeking, so use fallback frequencies
            freqs = fallbackFreqs;
        else
            freqs = constructHistogram(fin);
        
        HuffmanCoder hc(freqs);
        
        if (freqs != fallbackFreqs)
            delete[] freqs;
        
        string text;
        
        deque<bool> huffman_stream = hc.start();
        
        while (fin)
        {
            char buf[1024];
            fin.read(buf, sizeof(buf));
            int buflen = fin.gcount();
            
            cerr << buflen << endl;
            
            string stringbuf(buf, buflen);
            hc.write(huffman_stream, stringbuf);
        }
        
        hc.flush(huffman_stream, fout);
    }
    else if (argv[1][1] == 'd')
    {
        HuffmanDecoder dc(fin);
        fout << dc.decode();
    }
    else
    {
        usage(argv[0]);
        return 1;
    }
}