//
//  progressbar.hpp
//
//  Created by Joshua Moerman on 11/5/11.
//  Copyright 2011 Vadovas. All rights reserved.
//

/*
 A simple progressbar for the terminal (relies on \r).
 Wrap your for loop in an extra scope with a progressbar, like this:
 
 {	// extra scope
	Progressbar p(std::cout);
	for(i = 0; i < 1000; ++i){
		...
		p.show(i, 999);
	}
 }	// end extra scope (destructor of Progressbar will be used).
 
 You can give extra information to show in the constructor:
 Progressbar p(stream, "prefix", "Start message", " End message");
 this will look like:
 
	Start message
	prefix [===============>               ]
	End message
 
 You may leave these things empty ("").
 
 NOTE: the width of the bar (incl. prefix) is fixed ATM.
 NOTE: pass the maximum-value to the function show, not the bound of the for-loop (this way the function also works nicely for floating types)
 */

#ifndef PROGRESSBAR_HPP
#define PROGRESSBAR_HPP

#include <iostream>

struct progressbar {
	progressbar(std::ostream & out, std::string prefix = "", std::string begin = "", std::string end = "")
	: out(out)
	, begin(begin)
	, prefix(prefix)
	, end(end)
	{
		if (begin != "") {
			out << begin << std::endl;
		}
		
		show(0, 1, ' ');
	}
	
	~progressbar(){
		show(1, 1, '=');
		
		if (end != "") {
			out << "\n" << end << std::endl;
		} else {
			out << std::endl;
		}
	}
	
	template <typename T>
	void show(T const & progress, T const & max, char delim = '>'){
		out << "\r";
		
		size_t width = 80;	// default terminal size :D
		width -= prefix.size();
		width -= 3;	// [, > and ]
		
		if (prefix != "") {
			width -= 1;
			out << prefix << ' ';
		}
		
		double ratio = (double) progress / (double) max;
		size_t length = width * ratio;
		
		std::string fill(length, '=');
		std::string empty(width - length, ' ');
		out << '[' << fill << delim << empty << ']';
	}
	
private:
	std::ostream & out;
	std::string begin;
	std::string prefix;
	std::string end;
};

#endif	// PROGRESSBAR_HPP