#!/usr/bin/ruby -w

# Path to custom-installed Ruby Gems
require '/home/imsop/gem-paths.rb'

require 'date'
require 'cgi'
require 'iconv'
require 'icalendar'
require 'net/http'
require 'net/https'
require 'rexml/document'

# Adapted from http://blog.patrick-morgan.net/2007/02/ruby-https-with-http-basic-auth.html
def get_intervals_response(path, auth_token)
	http = Net::HTTP.new('api.myintervals.com',443)
	req = Net::HTTP::Get.new(path)
	http.use_ssl = true
	req.basic_auth auth_token, 'X'
	
	req['Accept'] = 'text/xml'
	response = http.request(req)
	
	return response.body
end

## MAIN ##
begin
	cgi = CGI.new
	
	# Find out the user's "person ID" 
	me_xml = get_intervals_response('/me/', cgi['token']);
	me_rexml = REXML::Document.new me_xml
	person_id = me_rexml.elements['//id'].text
	
	# Do we want information on closed tasks?
	if cgi['tasks'] == 'all' then
		excludeclosed = 'f';
	else
		excludeclosed = 't';
	end
	
	# Find tasks assigned to that user
	task_xml = get_intervals_response("/task/?assigneeid=#{person_id}&excludeclosed=#{excludeclosed}&limit=100", cgi['token']);
	task_rexml = REXML::Document.new task_xml
	
	# Re-encode broken chars, eliminating anything that's not in ISO 8859-15
	# (this is extremely hacky, but just using UTF-8//IGNORE left characters that choked Lightning)
	def fix_encoding(s)
		s = Iconv.conv('ISO-8859-15//IGNORE', 'UTF-8', s)
		Iconv.conv('UTF-8', 'ISO-8859-15', s)
	end

	# Create the calendar
	cal = Icalendar::Calendar.new
	task_rexml.elements.each('//item') { 
		|xml_node|
		if cgi['due_events'] == 'all' || cgi['due_events'] == 'smart' then
			if xml_node.elements['datedue'].text != nil && xml_node.elements['status'].text != 'Closed' then
				
				event_due_date = Date.parse xml_node.elements['datedue'].text;
				# "smart" events mode over-rides overdue events with today's date  
				if cgi['due_events'] == 'smart' && event_due_date < Date.today then
					event_due_date = Date.today;
				end
				
				cal.event do
					dtstart		event_due_date
					dtend		dtstart + 1
					summary		"##{xml_node.elements['localid'].text}: #{xml_node.elements['title'].text}"
					# Strip HTML tags from summary, and hope the result is sane...
					if xml_node.elements['summary'].text != nil then
						description	fix_encoding( xml_node.elements['summary'].text.gsub(%r{</?[^>]+?>}, '') )
					end
				end
			end
		end
		
		if cgi['tasks'] == 'all' || (cgi['tasks'] == 'open' && xml_node.elements['status'].text != 'Closed') then
			cal.todo do
				sequence	xml_node.elements['localid'].text
				summary		"##{xml_node.elements['localid'].text}: #{xml_node.elements['title'].text}"
				dtstart		Date.parse xml_node.elements['dateopen'].text
				
				if xml_node.elements['datedue'].text != nil then
					due		Date.parse xml_node.elements['datedue'].text
				end
				if xml_node.elements['status'].text == 'Closed' then
					completed	Date.parse xml_node.elements['dateclosed'].text
					percent		100
					status		"COMPLETED"
					# Lightning appears to require this in order to display the closed tasks correctly
					custom_property('PERCENT-COMPLETE', '100')
				end
				# Strip HTML tags from summary, and hope the result is sane...
				if xml_node.elements['summary'].text != nil then
					description	fix_encoding( xml_node.elements['summary'].text.gsub(%r{</?[^>]+?>}, '') )
				end
			end
		end
	}
	
	cgi.out ( cgi['send_plain'] == 'true' ? 'text/plain' : 'text/calendar' ) { cal.to_ical }
	
	
rescue Exception => err
	cgi.out ( 'text/plain' ) { "Exception: #{err}" }
end