class Gem::Commands::UpdateCommand

# File lib/rubygems/commands/update_command.rb, line 19
def initialize
  super 'update', 'Update installed gems to the latest version',
    :document => %w[rdoc ri],
    :force    => false

  add_install_update_options

  OptionParser.accept Gem::Version do |value|
    Gem::Version.new value

    value
  end

  add_option('--system [VERSION]', Gem::Version,
             'Update the RubyGems system software') do |value, options|
    value = true unless value

    options[:system] = value
  end

  add_local_remote_options
  add_platform_option
  add_prerelease_option "as update targets"

  @updated   = []
  @installer = nil
end

# File lib/rubygems/commands/update_command.rb, line 84
def execute
  hig = {}

  if options[:system] then
    update_rubygems
    return
  end

  say "Updating installed gems"

  hig = highest_installed_gems

  gems_to_update = which_to_update hig, options[:args].uniq

  updated = update_gems gems_to_update

  if updated.empty? then
    say "Nothing to update"
  else
    say "Gems updated: #{updated.map { |spec| spec.name }.join ' '}"
  end
end

# File lib/rubygems/commands/update_command.rb, line 165
def rubygems_target_version
  version = options[:system]
  update_latest = version == true

  if update_latest then
    version     = Gem::Version.new     Gem::VERSION
    requirement = Gem::Requirement.new ">= #{Gem::VERSION}"
  else
    version     = Gem::Version.new     version
    requirement = Gem::Requirement.new version
  end

  rubygems_update         = Gem::Specification.new
  rubygems_update.name    = 'rubygems-update'
  rubygems_update.version = version

  hig = {
    'rubygems-update' => rubygems_update
  }

  gems_to_update = which_to_update hig, options[:args], :system
  _, up_ver   = gems_to_update.first

  target = if update_latest then
             up_ver
           else
             version
           end

  return target, requirement
end

# File lib/rubygems/commands/update_command.rb, line 197
def update_gem name, version = Gem::Requirement.default
  return if @updated.any? { |spec| spec.name == name }

  @installer ||= Gem::DependencyInstaller.new options

  success = false

  say "Updating #{name}"
  begin
    @installer.install name, Gem::Requirement.new(version)
    success = true
  rescue Gem::InstallError => e
    alert_error "Error installing #{name}:\n\t#{e.message}"
    success = false
  end

  @installer.installed_gems.each do |spec|
    @updated << spec
  end
end

# File lib/rubygems/commands/update_command.rb, line 218
def update_gems gems_to_update
  gems_to_update.uniq.sort.each do |(name, version)|
    update_gem name, version
  end

  @updated
end

# File lib/rubygems/commands/update_command.rb, line 229
def update_rubygems
  check_update_arguments

  version, requirement = rubygems_target_version

  check_latest_rubygems version

  update_gem 'rubygems-update', version

  installed_gems = Gem::Specification.find_all_by_name 'rubygems-update', requirement
  version        = installed_gems.last.version

  install_rubygems version
end

# File lib/rubygems/commands/update_command.rb, line 257
def which_to_update highest_installed_gems, gem_names, system = false
  result = []

  highest_installed_gems.each do |l_name, l_spec|
    next if not gem_names.empty? and
            gem_names.all? { |name| /#{name}/ !~ l_spec.name }

    highest_remote_ver = highest_remote_version l_spec

    if system or (l_spec.version < highest_remote_ver) then
      result << [l_spec.name, [l_spec.version, highest_remote_ver].max]
    end
  end

  result
end