class Gem::Commands::SpecificationCommand

def arguments # :nodoc:
  <<-ARGS
MFILE       name of gem to show the gemspec for
ELD         name of gemspec field to show
  ARGS
end

def defaults_str # :nodoc:
  "--local --version '#{Gem::Requirement.default}' --yaml"
end

def description # :nodoc:
  <<-EOF
e specification command allows you to extract the specification from
gem for examination.
e specification can be output in YAML, ruby or Marshal formats.
ecific fields in the specification can be extracted in YAML format:
$ gem spec rake summary
--- Ruby based make-like utility.
...
  EOF
end

def execute
  specs = []
  gem = options[:args].shift
  unless gem
    raise Gem::CommandLineError,
          "Please specify a gem name or file on the command line"
  end
  case v = options[:version]
  when String
    req = Gem::Requirement.create v
  when Gem::Requirement
    req = v
  else
    raise Gem::CommandLineError, "Unsupported version type: '#{v}'"
  end
  if !req.none? and options[:all]
    alert_error "Specify --all or -v, not both"
    terminate_interaction 1
  end
  if options[:all]
    dep = Gem::Dependency.new gem
  else
    dep = Gem::Dependency.new gem, req
  end
  field = get_one_optional_argument
  raise Gem::CommandLineError, "--ruby and FIELD are mutually exclusive" if
    field and options[:format] == :ruby
  if local?
    if File.exist? gem
      specs << Gem::Package.new(gem).spec rescue nil
    end
    if specs.empty?
      specs.push(*dep.matching_specs)
    end
  end
  if remote?
    dep.prerelease = options[:prerelease]
    found, _ = Gem::SpecFetcher.fetcher.spec_for_dependency dep
    specs.push(*found.map {|spec,| spec })
  end
  if specs.empty?
    alert_error "No gem matching '#{dep}' found"
    terminate_interaction 1
  end
  platform = get_platform_from_requirements(options)
  if platform
    specs = specs.select{|s| s.platform.to_s == platform }
  end
  unless options[:all]
    specs = [specs.max_by {|s| s.version }]
  end
  specs.each do |s|
    s = s.send field if field
    say case options[:format]
        when :ruby then s.to_ruby
        when :marshal then Marshal.dump s
        else s.to_yaml
        end
    say "\n"
  end
end

def initialize
  Gem.load_yaml
  super 'specification', 'Display gem specification (in yaml)',
        :domain => :local, :version => Gem::Requirement.default,
        :format => :yaml
  add_version_option('examine')
  add_platform_option
  add_prerelease_option
  add_option('--all', 'Output specifications for all versions of',
             'the gem') do |value, options|
    options[:all] = true
  end
  add_option('--ruby', 'Output ruby format') do |value, options|
    options[:format] = :ruby
  end
  add_option('--yaml', 'Output YAML format') do |value, options|
    options[:format] = :yaml
  end
  add_option('--marshal', 'Output Marshal format') do |value, options|
    options[:format] = :marshal
  end
  add_local_remote_options
end

def usage # :nodoc:
  "#{program_name} [GEMFILE] [FIELD]"
end