portage_gems.rb

#!/usr/bin/env ruby
require 'rubygems'
require 'rubygems/gem_runner'
require 'rubygems/exceptions'
require 'readline'

module Gem
  class StreamUI
    def say( statement = '' )
      @@buffer ||= []
      @@buffer << statement
    end

    def self.flush
      return @@buffer
    end
  end
end

module PortageGateway
  class Runner
    def initialize( provided_file = nil )
      @provided = provided_file
      check_provided_file
      run
      register_in_package_provided
    end

    protected

    def check_provided_file
      @provided ||= '/etc/portage/profile/package.provided'
      unless File.writable? @provided
        puts "Error: #{@provided} is not writable. Exiting."
        exit 1
      end
    end

    def find_portage_packages
      @found ||= {}
      @notFound ||= {}

      @packages.each do |name,package|
        found = %x(eix -C dev-ruby -e #{name}).split("\n")[0]
        if found =~ /#{name}/
          package[ 'portage' ] = "dev-ruby/#{name}"
          @found[ name ] = package

        else
          @notFound[ name ] = package
        end
      end
    end

    def register_in_package_provided
      file = File.new( @provided, 'a' )
      @found.each do |name,package|
        file.puts "#{package[ 'portage' ]}-#{package[ 'version' ]}"
      end
      file.close

      puts "Done."
    end
  end



  class Populater < Runner
    protected

    def run
      get_local_gems
      intersect_packages
      find_portage_packages
      report_and_ask_to_continue
    end

    def get_local_gems
      Gem::GemRunner.new.run %w( list )
      @packages ||= {}
      @locals = Gem::StreamUI::flush#[0].split( "\n" )
      @locals.delete_if { |line| line !~ /^\S+ \(.*\)/ }
      @locals = @locals.first.split( "\n" )
      @locals.each do |line|
        line =~ /^(\S+) \((.*)\)$/
        name, versions_string = $1, $2
        versions = versions_string.gsub( / +/, '' ).split( ',' )
        @packages[ name ] = { 'version' => versions.last }
      end
    end

    def intersect_packages
      provided = File.read( @provided ).gsub( / +/, '' ).split( "\n" )
      @packages.delete_if { |name,package| provided.include?( "dev-ruby/#{name}-#{package[ 'version' ]}" ) }
    end

    def report_and_ask_to_continue
      puts "Those packages will be added to package.provided : "
      @found.each { |name,package| puts "- #{name}-#{package[ 'version' ] }" }

      puts
      puts "Not found in portage : "
      @notFound.each { |name,package| puts "- #{name}" }

      puts
      puts "Continue? (y/N)"
      answer = Readline.readline( '> ' )

      if answer != 'y'
        exit
      end
    end
  end



  class Updater < Runner
    protected
    def run
      find_outdated
      parse_packages
      find_portage_packages
      report_and_ask_to_continue
      do_the_update
    end

    def find_outdated
      Gem::GemRunner.new.run %w( outdated )
      @outdated = Gem::StreamUI::flush
    end

    def parse_packages
      @packages ||= {}

      @outdated.each do |package|
        if package =~ /^(\S+) \(\S+ < (\S+)\)/
          @packages[ $1 ] = { 'version' => $2 }
        else
          puts "don't understand : #{package}. Sorry."
        end
      end
    end


    def report_and_ask_to_continue
      puts "#{@outdated.length} package to update"

      puts "Found in portage : "
      @found.each { |name,package| puts "- #{name}" }

      puts
      puts "Not found in portage : "
      @notFound.each { |name,package| puts "- #{name}" }

      puts
      puts "Continue? (y/N)"
      answer = Readline.readline( '> ' )

      if answer != 'y'
        exit
      end
    end

    def do_the_update
      Gem::GemRunner.new.run %w( update )
      Gem::StreamUI::flush.each do |line|
        puts line
      end
    end

  end
end

mode = ARGV[0]
unless %w( update populate ).include?( mode )
  app = File.basename($0)
  puts "usage: #{app} [update|populate]"
  puts
  puts "  #{app} let portage knows about gem managed packages."
  puts "    populate:   scan locally installed gems and put them in package.provided if they are not yet."
  puts "    update:     run gem update and add new installed packages in package.provided if the same package name exists in dev-ruby"
  exit 1
end

case mode
when 'update'
  PortageGateway::Updater.new
when 'populate'
  PortageGateway::Populater.new
end