#include <Core/Core.h>
#include <Web/Web.h>
using namespace Upp;

#define SPEED_LIMIT 1024 // 1 kB/s

inline double PreciseTime(){
	// returns time with milisecond resolution - there should be something more
	// clever than this, but I was too lazy to search...
	return GetSysTime().Get()+(GetTickCount()%1000)/1000.0;
}

bool Throttler(int written,int length){
	static double start=PreciseTime();
	if(length==0) start=PreciseTime(); // the download goes in chunks, we will count 
	                                   // average speed in each chunk separately (it's easier)
	double elapsed=max(PreciseTime()-start,1e-8); //we don't want to divide by zero!
	double speed=written/elapsed;
	while(speed>SPEED_LIMIT){
		Sleep(10);                   // this loop effectively pauses the download until
		elapsed=PreciseTime()-start; // the average speed doesn't fall back under
		speed=written/elapsed;       // given threshold
	}
	Cout()<<"Time: "<<elapsed<<", "           // This callback is originally meant
	        "Downloaded: "<<written<<         // to be used for reporting the progress
	        " => "<<(speed/1024)<<"kB/s.\n";  // so we do it here too...
	return false; // we always return false, true would cause aborting the download
}

CONSOLE_APP_MAIN{
	HttpClient c("http://www.ultimatepp.org/index.html_0.png");
	String result=c.ExecuteRedirect(5,3,callback(Throttler));
	SaveFile(GetHomeDirFile("upp.png"),result);
}