#!/bin/env ruby
#-*- coding: utf-8 -*-
require("rexml/document");

def compare_entry_by_property_value(e1,e2,property)
  p1 = REXML::XPath.first(e1,"apps:property[@name='#{property}']");
  p2 = REXML::XPath.first(e2,"apps:property[@name='#{property}']");
  return p1.attribute("value").value <=> p2.attribute("value").value if (p1 && p2);
  return -1 if (p1);
  return +1 if (p2);
  return 0;
end

def compare_entry_by_property_exists(e1,e2,property)
  p1 = REXML::XPath.first(e1,"apps:property[@name='#{property}']");
  p2 = REXML::XPath.first(e1,"apps:property[@name='#{property}']");
  return -1 if (p1 && !p2);
  return +1 if (!p1 && p2);
  return 0;
end


def compare_entry(e1,e2)
  c = compare_entry_by_property_value(e1,e2,"label");
  return  c if (c!=0);

  c = compare_entry_by_property_exists(e1,e2,"shouldTrash");
  return -c if (c!=0);
  c = compare_entry_by_property_exists(e1,e2,"shouldArchive");
  return -c if (c!=0);
  c = compare_entry_by_property_exists(e1,e2,"shouldMarkAsRead");
  return -c if (c!=0);
  c = compare_entry_by_property_exists(e1,e2,"shouldStar");
  return  c if (c!=0);

  c = compare_entry_by_property_value(e1,e2,"from");
  return c if (c!=0);

  return 0;
end

doc = REXML::Document.new(File.open(ARGV[0]));
entries = REXML::XPath.match(doc,"/feed/entry");

entries.sort! { |e1,e2| compare_entry(e1,e2); }

puts("<?xml version='1.0' encoding='UTF-8'?><feed xmlns='http://www.w3.org/2005/Atom' xmlns:apps='http://schemas.google.com/apps/2006'>");
entries.each { |entry| puts(entry); }
puts("</feed>");