#!/usr/bin/ruby

#
# sectotime.rb v1.0 - 2006/11
#
# this script converts a time string in seconds into a string with the
# representation of the same time in days, hours and minutes.
#
# Copyright (C) 2006 by Pedro Venda < pjvenda (at) pjvenda org >
#
# Distributed under the terms of the GNU Public License Agreement (GPLv2)
# http://www.fsf.org/licensing/licenses/gpl.html or
# http://www.fsf.org/licensing/licenses/gpl.txt
#
# Usage
# =====
#
# this script receives its input from stdin and outputs it into stdout
# example: $ echo "10000" | ./sectotime.rb
#           2h 46m 40s
#          $
# alternatively, the time input can be given as a command line argument
# example: $ ./sectotime.rb 10000
#           2h 46m 40s
# finally it can be included as a class 'SecToTime' to instantiate objects
# or it can just provide some static methods.
#
# Changelog
# =========
#
# v1.0 - 2006/11/20
# - initial (ruby) version, ported from a equivalent written in python
#

class SecToTime
	# class version
	@@VERSION="1.0"

	# time constants
	@@MINUTE_SECONDS=60
	@@HOUR_SECONDS=@@MINUTE_SECONDS*60
	@@DAY_SECONDS=@@HOUR_SECONDS*24

	# class variables:
	# given total_seconds
	# discrete time calculation
	@seconds
	@time

	# enable read/write access to seconds attribute
	attr_accessor :seconds
	# enable read access to time attribute
	attr_reader :time

	# constructur - optional argument
	def initialize(total_seconds=0)
		@seconds=total_seconds
		update_time
	end
	
	# updates @time hash according to @seconds
	def update_time
		@time=SecToTime.seconds_to_time(@seconds)
	end

	# changes internal @seconds variable and updates
	# @time hash
	def seconds=(sec)
		@seconds=sec
		update_time
	end

	# printout
	def to_s
		SecToTime.seconds_str(@time)
	end

	#
	# convert a number of seconds into corresponding days, hours, minutes and seconds
	# this is to be used directly as a static method
	#
	def self.seconds_to_time(total_seconds)
		remain=total_seconds.to_i
		days=remain/@@DAY_SECONDS
		remain-=days*@@DAY_SECONDS
		hours=remain/@@HOUR_SECONDS
		remain-=hours*@@HOUR_SECONDS
		minutes=remain/@@MINUTE_SECONDS
		remain-=minutes*@@MINUTE_SECONDS
		seconds=remain
		
		# returns a hash with the following elements;
		# days, hours, minutes and seconds
		{:days => days,:hours => hours,:minutes => minutes,:seconds => seconds}
	end

	#
	# convert and print some amount of time in seconds.
	# this is to be used directly as a static method
	#
	def self.seconds_str(seconds)
		if seconds.is_a?(Hash)
			# seconds is already a hash
			time=seconds
		else 
			# convert total_seconds in hash with discrete elements
			time=seconds_to_time(seconds)
		end

		# build a string
		ret=""
		noblock=false
		if time[:days]>0
			ret+=time[:days].to_s+"d "
			noblock=true
		end
		if time[:hours]>0 || noblock
			ret+=time[:hours].to_s.rjust(2)+"h "
			noblock=true
		end
		if time[:minutes]>0 || noblock
			ret+=time[:minutes].to_s.rjust(2)+"m "
			noblock=true
		end
		if time[:seconds]>0 || noblock
			ret+=time[:seconds].to_s.rjust(2)+"s"
			noblock=true
		end
		ret
	end
end

#
# stand alone usage:
#
# total_seconds can be given as argument or from stdin
if __FILE__ == $0
	if ARGV.length == 0
		puts SecToTime.seconds_str(gets.to_i)
	else
		puts SecToTime.seconds_str(ARGV[0].to_i)
	end
end