// Slow64.cpp : Defines the entry point for the console application.
//

#include <vector>
#include <string>
#include <iostream>
#include <algorithm>
#include <fstream>
#include <iterator>
#include <time.h>

using namespace std;

void Base64Encode(const vector<unsigned char>& input,vector<unsigned char>& output)
{
	static const unsigned char BASE64_CODE[65]="ABCDEFGHIJKLMNOPQRSTUVWXYZ"
		"abcdefghijklmnopqrstuvwxyz""0123456789+/";
	static const unsigned char BASE64_PADDING='=';
	static int LINE_COUNT=76;
	unsigned int input_index,output_index;
	unsigned int size=input.size();
	static const string CRLF="\r\n";
	output.resize(size/3*4+(size%3?4:0)+size/3*4/LINE_COUNT*CRLF.size());
	for(input_index=0,output_index=0;input_index<size;input_index+=3)
	{
		output[output_index++]=BASE64_CODE[input[input_index]/4];
		output[output_index++]=BASE64_CODE[input[input_index]%4*16
			+input[input_index+1]/16];
		output[output_index++]=BASE64_CODE[input[input_index+1]%16*4
			+input[input_index+2]/64];
		output[output_index++]=BASE64_CODE[input[input_index+2]%64];
		if(output_index%(LINE_COUNT+CRLF.size())==LINE_COUNT)
		{
			output[output_index++]=CRLF[0];
			output[output_index++]=CRLF[1];
		}
	}
	switch(input.size()%3)
	{
	case 0:
		break;
	case 1:
		output[output_index++]=BASE64_CODE[input[input_index]/4];
		output[output_index++]=BASE64_CODE[input[input_index]%4*16];
		output[output_index++]=BASE64_PADDING;
		output[output_index++]=BASE64_PADDING;
		break;
	case 2:
		output[output_index++]=BASE64_CODE[input[input_index]/4];
		output[output_index++]=BASE64_CODE[input[input_index]%4*16+input[input_index+1]/16];
		output[output_index++]=BASE64_CODE[input[input_index+1]%16*4];
		output[output_index++]=BASE64_PADDING;
		break;
	}
}

int main(int argc, char* argv[])
{
	if(argc>=2)
	{
		ifstream ifs(argv[1],ios::binary);
		vector<unsigned char> vc;
		cerr<<"reading in data ..."<<endl;
		copy(istreambuf_iterator<char>(ifs),istreambuf_iterator<char>(),
			back_inserter(vc));
		vector<unsigned char> output;
		cerr<<"start encoding data ..."<<endl;
		time_t start=time(NULL);
		for(int i=0;i<100;++i)
		{
			Base64Encode(vc,output);
			output.resize(0);
		}
		cerr<<"end encoding data, takes "<<time(NULL)-start<<" seconds"<<endl;
	}
	else
	{
		cerr<<"USAGE: Slow64 <filename>"<<endl;
	}
	return 0;
}