#!/usr/bin/env ruby

# Get latest version of tools

require 'yaml'
require 'uri'
require 'net/http'
require 'rubygems/version'

# Compare versions including libjpeg ones (9b <=> 9)
class Version
  include Comparable

  attr_reader :string, :parsed
  alias_method :to_s, :string

  def initialize(string)
    @string = string
    @parsed = begin
      Gem::Version.new(string)
    rescue ArgumentError
      nil
    end
  end

  def <=>(other)
    if parsed && other.parsed
      parsed <=> other.parsed
    else
      string <=> other.string
    end
  end
end

bare = ARGV.delete('--bare')

unless [1, 2].include?(ARGV.length)
  abort 'expected project name and optional current version'
end

def version(string)
  Version.new(string)
end

def get(url)
  uri = URI(url)

  http = Net::HTTP.new(uri.host, uri.port)
  http.use_ssl = (uri.scheme == 'https')

  request = Net::HTTP::Get.new(uri.request_uri)
  http.request(request).body
end

name = ARGV[0].downcase
config = YAML.load(DATA)[name]
abort "Livecheck for #{name} was not defined" unless config

url = config['url']
version_regex = Regexp.new(config['regexp'])
current_version = ARGV[1] && version(ARGV[1])

data = get(url)
versions = data.scan(version_regex).uniq.map{ |match| version(match[0]) }
abort "No versions found for #{name} in data:\n#{data}" if versions.empty?

latest_version = versions.max
case
when bare
  print latest_version
when current_version
  if latest_version != current_version
    sign = latest_version > current_version ? '>' : '<'
    puts "#{name} #{latest_version} #{sign} #{current_version}"
  end
else
  puts "#{name} #{latest_version}"
end

__END__
advancecomp:
  url: https://github.com/amadvance/advancecomp/releases.atom
  regexp: /amadvance/advancecomp/releases/tag/v(\d+(?:\.\d+)*)
gifsicle:
  url: https://www.lcdf.org/gifsicle/
  regexp: gifsicle-(\d+(?:\.\d+)*)\.tar\.gz
jhead:
  url: http://www.sentex.net/~mwandel/jhead/
  regexp: jhead-(\d+(?:\.\d+)*)
jpegoptim:
  url: https://www.kokkonen.net/tjko/src/
  regexp: jpegoptim-(\d+(?:\.\d+)*)
jpegarchive:
  url: https://github.com/danielgtaylor/jpeg-archive/releases.atom
  regexp: <title>JPEG-Archive (\d+(?:\.\d+)*)</title>
libjpeg:
  url: http://www.ijg.org/files/
  regexp: jpegsrc.v(.*?).tar.gz
libmozjpeg:
  url: https://github.com/mozilla/mozjpeg/releases.atom
  regexp: <title>mozjpeg v(\d+(?:\.\d+)*)</title>
libpng:
  url: https://sourceforge.net/projects/libpng/rss?path=/libpng16
  regexp: /libpng\d*/(\d+(?:\.\d+)*)/
libz:
  url: https://sourceforge.net/projects/libpng/rss?path=/zlib
  regexp: /zlib/(\d+(?:\.\d+)*)/
optipng:
  url: https://sourceforge.net/projects/optipng/rss
  regexp: /OptiPNG/optipng-(\d+(?:\.\d+)*)/
pngcrush:
  url: https://sourceforge.net/projects/pmt/rss?path=/pngcrush
  regexp: /pngcrush/(\d+(?:\.\d+)*)/
pngquant:
  url: https://github.com/pornel/pngquant/releases.atom
  regexp: /pornel/pngquant/releases/tag/(\d+(?:\.\d+)*)