#!/usr/bin/ruby

require 'ftools';

requiredExtension = ''
if $*.length > 0
	if $*[0] == '--help'
		puts ''
		puts 'Renames all files in the current directory to the form date.extension. If more than one file has the same time stamp, index strings "_(2)", "_(3)", and so forth, are appended before the extension.'
		puts ''
		puts 'Synopsis:'
		puts '	timestamp2filename [extension]'
		puts ''
		puts 'Arguments:'
		puts '	extension - only rename files with the given extension'
		puts '' 
	else
		requiredExtension = '.' + $*[0]
	end
end

def twoDigitString(n) 
	s = n.to_s
	if s.length == 1
		s = '0' + s
	end
	return s
end

files = Dir::entries('.')
files::each { |name|
	if name != '.' && name != '..'
		if !File::directory? name
			extension = ''
			if name =~ /\.[^.]*$/
				extension = $~[0]
			else 
				extension == ''
			end
			if requiredExtension == '' || extension == requiredExtension
				time = File::mtime name
				newName = time.year.to_s() + '_' + twoDigitString(time.month) + '_' + twoDigitString(time.day) + '_'
				newName += twoDigitString(time.hour) + ':' + twoDigitString(time.min)
				indexString = ''
				index = 1
				while FileTest::exist?( newName + indexString + extension )
					index += 1
					indexString = '_(' + index.to_s() + ')'
				end
				newName = newName + indexString + extension
				indexString = ''
				index = 1
				File::move name, newName, true
			end
		end
	end
}