Calculating cycle times with ruby

cycle-times.rb

require 'rubygems'
require 'jira'
require 'date'
require 'time_difference'
require 'pp'

def time_diff(statuses, tstart, tend)
	begin
		TimeDifference.between(statuses[tstart], statuses[tend]).in_days
	rescue Exception => e
		$stderr.puts "failed diffing: #{tstart} - #{tend}"
		$stderr.puts tstart
		$stderr.puts tend
		-1
	end
end

options = {
	:username => "antonio.terreno",
	:password => "",
	:site     => '',
	:context_path => '/',
	:auth_type => :basic
}

client = JIRA::Client.new(options)
project = client.Project.find('DCJ')

proprieties = %w[Key Summary]
states = %w[Backlog Soon Next In\ Progress In\ test Ready\ to\ amaze Withdrawn]

puts (proprieties + states).join("\t")

client.Issue.jql('PROJECT = DCJ ORDER BY KEY DESC', options = {fields: ['key','summary','changelog'], start_at: 1000, max_results: 1000}).each do |issue|
	issue = client.Issue.find(issue.key, {expand:'changelog'})

	statuses = Hash.new
	results = Hash.new

	issue.changelog["histories"].each do |history|
		history["items"].select {|item| item["field"] == 'status'}.each do |item|
			key = item["fromString"] + "->" + item["toString"]
			value = Time.parse(history["created"])
			statuses[key] = value
		end
	end

	$stderr.puts issue.key
	$stderr.puts statuses.keys

	results["Ready to amaze"] = time_diff(statuses,"Ready To Amaze->Amazing","In Test->Ready To Amaze")
	results["In test"] = time_diff(statuses,"In Test->Ready To Amaze" ,"In Progress->In Test")
	results["In Progress"] = time_diff(statuses, "In Progress->In Test" , "Next->In Progress")
	results["Next"] = time_diff(statuses, "Next->In Progress" , "Soon->Next")
	results["Soon"] = time_diff(statuses, "Soon->Next" , "Withdrawn->Soon")
	results["Withdrawn"] = time_diff(statuses, "Withdrawn->Soon" , "Soon->Withdrawn")
	results["Backlog"] = time_diff(statuses, "Soon->Withdrawn" , "Backlog->Soon")

	print "#{issue.key}\t#{issue.summary}\t"
	states.each do |state|
		print "#{results[state]}\t"
	end
	print "\n"
end