require 'rubygems/command'

##
# Installs RubyGems itself.  This command is ordinarily only available from a
# RubyGems checkout or tarball.

class Gem::Commands::SetupCommand < Gem::Command
  HISTORY_HEADER = /^===\s*[\d.]+\s*\/\s*\d{4}-\d{2}-\d{2}\s*$/
  VERSION_MATCHER = /^===\s*([\d.]+)\s*\/\s*\d{4}-\d{2}-\d{2}\s*$/

  def initialize
    require 'tmpdir'

    super 'setup', 'Install RubyGems',
          :format_executable => true, :document => %w[ri],
          :site_or_vendor => 'sitelibdir',
          :destdir => '', :prefix => '', :previous_version => ''

    add_option '--previous-version=VERSION',
               'Previous version of rubygems',
               'Used for changelog processing' do |version, options|
      options[:previous_version] = version
    end

    add_option '--prefix=PREFIX',
               'Prefix path for installing RubyGems',
               'Will not affect gem repository location' do |prefix, options|
      options[:prefix] = File.expand_path prefix
    end

    add_option '--destdir=DESTDIR',
               'Root directory to install RubyGems into',
               'Mainly used for packaging RubyGems' do |destdir, options|
      options[:destdir] = File.expand_path destdir
    end

    add_option '--[no-]vendor',
               'Install into vendorlibdir not sitelibdir' do |vendor, options|
      options[:site_or_vendor] = vendor ? 'vendorlibdir' : 'sitelibdir'
    end

    add_option '--[no-]format-executable',
               'Makes `gem` match ruby',
               'If ruby is ruby18, gem will be gem18' do |value, options|
      options[:format_executable] = value
    end

    add_option '--[no-]document [TYPES]', Array,
               'Generate documentation for RubyGems.',
               'List the documentation types you wish to',
               'generate.  For example: rdoc,ri' do |value, options|
      options[:document] = case value
                           when nil   then %w[rdoc ri]
                           when false then []
                           else            value
                           end
    end

    add_option '--[no-]rdoc',
               'Generate RDoc documentation for RubyGems' do |value, options|
      if value then
        options[:document] << 'rdoc'
      else
        options[:document].delete 'rdoc'
      end

      options[:document].uniq!
    end

    add_option '--[no-]ri',
               'Generate RI documentation for RubyGems' do |value, options|
      if value then
        options[:document] << 'ri'
      else
        options[:document].delete 'ri'
      end

      options[:document].uniq!
    end

    @verbose = nil
  end

  def check_ruby_version
    required_version = Gem::Requirement.new '>= 1.8.7'

    unless required_version.satisfied_by? Gem.ruby_version then
      alert_error "Expected Ruby version #{required_version}, is #{Gem.ruby_version}"
      terminate_interaction 1
    end
  end

  def defaults_str # :nodoc:
    "--format-executable --document ri"
  end

  def description # :nodoc:
    <<-EOF
Installs RubyGems itself.

RubyGems installs RDoc for itself in GEM_HOME.  By default this is:
  #{Gem.dir}

If you prefer a different directory, set the GEM_HOME environment variable.

RubyGems will install the gem command with a name matching ruby's
prefix and suffix.  If ruby was installed as `ruby18`, gem will be
installed as `gem18`.

By default, this RubyGems will install gem as:
  #{Gem.default_exec_format % 'gem'}
    EOF
  end

  def execute
    @verbose = Gem.configuration.really_verbose

    install_destdir = options[:destdir]

    unless install_destdir.empty? then
      ENV['GEM_HOME'] ||= File.join(install_destdir,
                                    Gem.default_dir.gsub(/^[a-zA-Z]:/, ''))
    end

    check_ruby_version

    require 'fileutils'
    if Gem.configuration.really_verbose then
      extend FileUtils::Verbose
    else
      extend FileUtils
    end

    lib_dir, bin_dir = make_destination_dirs install_destdir

    install_lib lib_dir

    install_executables bin_dir

    remove_old_bin_files bin_dir

    remove_old_lib_files lib_dir

    say "RubyGems #{Gem::VERSION} installed"

    uninstall_old_gemcutter

    documentation_success = install_rdoc

    say
    if @verbose then
      say "-" * 78
      say
    end

    if options[:previous_version].empty?
      options[:previous_version] = Gem::VERSION.sub(/[0-9]+$/, '0')
    end

    options[:previous_version] = Gem::Version.new(options[:previous_version])

    show_release_notes

    say
    say "-" * 78
    say

    say "RubyGems installed the following executables:"
    say @bin_file_names.map { |name| "\t#{name}\n" }
    say

    unless @bin_file_names.grep(/#{File::SEPARATOR}gem$/) then
      say "If `gem` was installed by a previous RubyGems installation, you may need"
      say "to remove it by hand."
      say
    end

    if documentation_success
      if options[:document].include? 'rdoc' then
        say "Rdoc documentation was installed. You may now invoke:"
        say "  gem server"
        say "and then peruse beautifully formatted documentation for your gems"
        say "with your web browser."
        say "If you do not wish to install this documentation in the future, use the"
        say "--no-document flag, or set it as the default in your ~/.gemrc file. See"
        say "'gem help env' for details."
        say
      end

      if options[:document].include? 'ri' then
        say "Ruby Interactive (ri) documentation was installed. ri is kind of like man "
        say "pages for ruby libraries. You may access it like this:"
        say "  ri Classname"
        say "  ri Classname.class_method"
        say "  ri Classname#instance_method"
        say "If you do not wish to install this documentation in the future, use the"
        say "--no-document flag, or set it as the default in your ~/.gemrc file. See"
        say "'gem help env' for details."
        say
      end
    end
  end

  def install_executables(bin_dir)
    say "Installing gem executable" if @verbose

    @bin_file_names = []

    Dir.chdir 'bin' do
      bin_files = Dir['*']

      bin_files.delete 'update_rubygems'

      bin_files.each do |bin_file|
        bin_file_formatted = if options[:format_executable] then
                               Gem.default_exec_format % bin_file
                             else
                               bin_file
                             end

        dest_file = File.join bin_dir, bin_file_formatted
        bin_tmp_file = File.join Dir.tmpdir, "#{bin_file}.#{$$}"

        begin
          bin = File.readlines bin_file
          bin[0] = "#!#{Gem.ruby}\n"

          File.open bin_tmp_file, 'w' do |fp|
            fp.puts bin.join
          end

          install bin_tmp_file, dest_file, :mode => 0755
          @bin_file_names << dest_file
        ensure
          rm bin_tmp_file
        end

        next unless Gem.win_platform?

        begin
          bin_cmd_file = File.join Dir.tmpdir, "#{bin_file}.bat"

          File.open bin_cmd_file, 'w' do |file|
            file.puts <<-TEXT
@ECHO OFF
IF NOT "%~f0" == "~f0" GOTO :WinNT
@"#{File.basename(Gem.ruby).chomp('"')}" "#{dest_file}" %1 %2 %3 %4 %5 %6 %7 %8 %9
GOTO :EOF
:WinNT
@"#{File.basename(Gem.ruby).chomp('"')}" "%~dpn0" %*
TEXT
          end

          install bin_cmd_file, "#{dest_file}.bat", :mode => 0755
        ensure
          rm bin_cmd_file
        end
      end
    end
  end

  def install_file file, dest_dir
    dest_file = File.join dest_dir, file
    dest_dir = File.dirname dest_file
    mkdir_p dest_dir unless File.directory? dest_dir

    install file, dest_file, :mode => 0644
  end

  def install_lib(lib_dir)
    say "Installing RubyGems" if @verbose

    lib_files = rb_files_in 'lib'
    pem_files = pem_files_in 'lib'

    Dir.chdir 'lib' do
      lib_files.each do |lib_file|
        install_file lib_file, lib_dir
      end

      pem_files.each do |pem_file|
        install_file pem_file, lib_dir
      end
    end
  end

  def install_rdoc
    gem_doc_dir = File.join Gem.dir, 'doc'
    rubygems_name = "rubygems-#{Gem::VERSION}"
    rubygems_doc_dir = File.join gem_doc_dir, rubygems_name

    begin
      Gem.ensure_gem_subdirectories Gem.dir
    rescue SystemCallError
      # ignore
    end

    if File.writable? gem_doc_dir and
       (not File.exist? rubygems_doc_dir or
        File.writable? rubygems_doc_dir) then
      say "Removing old RubyGems RDoc and ri" if @verbose
      Dir[File.join(Gem.dir, 'doc', 'rubygems-[0-9]*')].each do |dir|
        rm_rf dir
      end

      require 'rubygems/rdoc'

      fake_spec = Gem::Specification.new 'rubygems', Gem::VERSION
      def fake_spec.full_gem_path
        File.expand_path '../../../..', __FILE__
      end

      generate_ri   = options[:document].include? 'ri'
      generate_rdoc = options[:document].include? 'rdoc'

      rdoc = Gem::RDoc.new fake_spec, generate_rdoc, generate_ri
      rdoc.generate

      return true
    elsif @verbose then
      say "Skipping RDoc generation, #{gem_doc_dir} not writable"
      say "Set the GEM_HOME environment variable if you want RDoc generated"
    end

    return false
  end

  def make_destination_dirs(install_destdir)
    lib_dir, bin_dir = Gem.default_rubygems_dirs

    unless lib_dir
      lib_dir, bin_dir = generate_default_dirs(install_destdir)
    end

    mkdir_p lib_dir
    mkdir_p bin_dir

    return lib_dir, bin_dir
  end

  def generate_default_dirs(install_destdir)
    prefix = options[:prefix]
    site_or_vendor = options[:site_or_vendor]

    if prefix.empty? then
      lib_dir = RbConfig::CONFIG[site_or_vendor]
      bin_dir = RbConfig::CONFIG['bindir']
    else
      # Apple installed RubyGems into libdir, and RubyGems <= 1.1.0 gets
      # confused about installation location, so switch back to
      # sitelibdir/vendorlibdir.
      if defined?(APPLE_GEM_HOME) and
        # just in case Apple and RubyGems don't get this patched up proper.
        (prefix == RbConfig::CONFIG['libdir'] or
         # this one is important
         prefix == File.join(RbConfig::CONFIG['libdir'], 'ruby')) then
         lib_dir = RbConfig::CONFIG[site_or_vendor]
         bin_dir = RbConfig::CONFIG['bindir']
      else
        lib_dir = File.join prefix, 'lib'
        bin_dir = File.join prefix, 'bin'
      end
    end

    unless install_destdir.empty? then
      lib_dir = File.join install_destdir, lib_dir.gsub(/^[a-zA-Z]:/, '')
      bin_dir = File.join install_destdir, bin_dir.gsub(/^[a-zA-Z]:/, '')
    end

    [lib_dir, bin_dir]
  end

  def pem_files_in dir
    Dir.chdir dir do
      Dir[File.join('**', '*pem')]
    end
  end

  def rb_files_in dir
    Dir.chdir dir do
      Dir[File.join('**', '*rb')]
    end
  end

  def remove_old_bin_files(bin_dir)
    old_bin_files = {
      'gem_mirror' => 'gem mirror',
      'gem_server' => 'gem server',
      'gemlock' => 'gem lock',
      'gemri' => 'ri',
      'gemwhich' => 'gem which',
      'index_gem_repository.rb' => 'gem generate_index',
    }

    old_bin_files.each do |old_bin_file, new_name|
      old_bin_path = File.join bin_dir, old_bin_file
      next unless File.exist? old_bin_path

      deprecation_message = "`#{old_bin_file}` has been deprecated.  Use `#{new_name}` instead."

      File.open old_bin_path, 'w' do |fp|
        fp.write <<-EOF
#!#{Gem.ruby}

abort "#{deprecation_message}"
    EOF
      end

      next unless Gem.win_platform?

      File.open "#{old_bin_path}.bat", 'w' do |fp|
        fp.puts %{@ECHO.#{deprecation_message}}
      end
    end
  end

  def remove_old_lib_files lib_dir
    rubygems_dir = File.join lib_dir, 'rubygems'
    lib_files = rb_files_in 'lib/rubygems'

    old_lib_files = rb_files_in rubygems_dir

    to_remove = old_lib_files - lib_files

    to_remove.delete_if do |file|
      file.start_with? 'defaults'
    end

    Dir.chdir rubygems_dir do
      to_remove.each do |file|
        FileUtils.rm_f file

        warn "unable to remove old file #{file} please remove it by hand" if
          File.exist? file
      end
    end
  end

  def show_release_notes
    release_notes = File.join Dir.pwd, 'History.txt'

    release_notes =
      if File.exist? release_notes then
        history = File.read release_notes

        history.force_encoding Encoding::UTF_8 if
          Object.const_defined? :Encoding

        history = history.sub(/^# coding:.*?^=/m, '')

        text = history.split(HISTORY_HEADER)
        text.shift # correct an off-by-one generated by split
        version_lines = history.scan(HISTORY_HEADER)
        versions = history.scan(VERSION_MATCHER).flatten.map do |x|
          Gem::Version.new(x)
        end

        history_string = ""

        until versions.length == 0 or
              versions.shift < options[:previous_version] do
          history_string += version_lines.shift + text.shift
        end

        history_string
      else
        "Oh-no! Unable to find release notes!"
      end

    say release_notes
  end

  def uninstall_old_gemcutter
    require 'rubygems/uninstaller'

    ui = Gem::Uninstaller.new('gemcutter', :all => true, :ignore => true,
                              :version => '< 0.4')
    ui.uninstall
  rescue Gem::InstallError
  end

end