class Gem::Commands::OpenCommand

def arguments # :nodoc:
  "GEMNAME     name of gem to open in editor"
end

def defaults_str # :nodoc:
  "-e #{get_env_editor}"
end

def description # :nodoc:
  <<-EOF
      The open command opens gem in editor and changes current path
      to gem's source directory. Editor can be specified with -e option,
      otherwise rubygems will look for editor in $EDITOR, $VISUAL and
      $GEM_EDITOR variables.
  EOF
end

def execute
  @version = options[:version] || Gem::Requirement.default
  @editor  = options[:editor] || get_env_editor
  found = open_gem(get_one_gem_name)
  terminate_interaction 1 unless found
end

def get_env_editor
  ENV['GEM_EDITOR'] ||
    ENV['VISUAL'] ||
    ENV['EDITOR'] ||
    'vi'
end

def initialize
  super 'open', 'Open gem sources in editor'
  add_option('-e', '--editor EDITOR', String,
             "Opens gem sources in EDITOR") do |editor, options|
    options[:editor] = editor || get_env_editor
  end
  add_option('-v', '--version VERSION', String,
             "Opens specific gem version") do |version|
    options[:version]  = version
  end
end

def open_editor path
  Dir.chdir(path) do
    system(*@editor.split(/\s+/) + [path])
  end
end

def open_gem name
  spec = spec_for name
  return false unless spec
  open_editor(spec.full_gem_path)
end

def spec_for name
  spec = Gem::Specification.find_all_by_name(name, @version).last
  return spec if spec
  say "Unable to find gem '#{name}'"
end

def usage # :nodoc:
  "#{program_name} GEMNAME [-e EDITOR]"
end