#!/usr/bin/env ruby

require 'rubygems'
require 'pp'
require 'builder'
require 'optimist'
require 'rexml/document'

require_relative 'modules/news'

def create_all_releases_xml news
  releases_xml = REXML::Document.new File.new($opts[:releases])
  builder      = Builder::XmlMarkup.new( :indent => $opts[:noindent] ? 0 : 2 )

  node_to_hash = lambda { |xpath|
    begin
      Hash[ *REXML::XPath.first(releases_xml, xpath).elements.collect { |e| [ e.name, e.text ] }.flatten ]
    rescue
      Hash.new
    end
  }

  builder.instruct! :xml, :version => "1.0", :encoding => "UTF-8"

  xml = builder.tag!('mkvtoolnix-releases') do
    builder.tag!('latest-source',      node_to_hash.call("/mkvtoolnix-releases/latest-source"))
    builder.tag!('latest-windows-pre', node_to_hash.call("/mkvtoolnix-releases/latest-windows-pre"))

    builder.tag! 'latest-windows-binary' do
      builder.tag! 'installer-url', node_to_hash.call("/mkvtoolnix-releases/latest-windows-binary/installer-url")
      builder.tag! 'portable-url',  node_to_hash.call("/mkvtoolnix-releases/latest-windows-binary/portable-url")
    end

    news.each do |release|
      attributes = {
        "version" => release[0],
      }.merge node_to_hash.call("/mkvtoolnix-releases/release[version='#{release[0]}']")

      builder.release attributes do
        builder.changes do
          release[1].each do |entry|
            builder.change(entry[:content], entry.reject { |key| [:version, :content, :date].include? key })
          end
        end
      end
    end
  end

  puts xml
end

def parse_opts
  opts = Optimist::options do
    opt :news,     "News source file",         :type => String, :default => 'NEWS.md'
    opt :releases, "releases.xml source file", :type => String, :default => 'releases.xml'
    opt :noindent, "do not indent the XML"
  end

  Optimist::die :news,     "must be given and exist" if !opts[:news]      || !File.exist?(opts[:news])
  Optimist::die :releases, "must be given and exist" if !opts[:releases]  || !File.exist?(opts[:releases])

  opts
end

def main
  $opts = parse_opts
  create_all_releases_xml parse_news($opts[:news])
end

main