class Gem::Indexer

def build_indices
  specs = map_gems_to_specs gem_file_list
  Gem::Specification._resort! specs
  build_marshal_gemspecs specs
  build_modern_indices specs if @build_modern
  compress_indices
end

def build_marshal_gemspecs specs
  count = specs.count
  progress = ui.progress_reporter count,
                                  "Generating Marshal quick index gemspecs for #{count} gems",
                                  "Complete"
  files = []
  Gem.time 'Generated Marshal quick index gemspecs' do
    specs.each do |spec|
      next if spec.default_gem?
      spec_file_name = "#{spec.original_name}.gemspec.rz"
      marshal_name = File.join @quick_marshal_dir, spec_file_name
      marshal_zipped = Gem.deflate Marshal.dump(spec)
      open marshal_name, 'wb' do |io| io.write marshal_zipped end
      files << marshal_name
      progress.updated spec.original_name
    end
    progress.done
  end
  @files << @quick_marshal_dir
  files
end

def build_modern_index(index, file, name)
  say "Generating #{name} index"
  Gem.time "Generated #{name} index" do
    open(file, 'wb') do |io|
      specs = index.map do |*spec|
        # We have to splat here because latest_specs is an array, while the
        # others are hashes.
        spec = spec.flatten.last
        platform = spec.original_platform
        # win32-api-1.0.4-x86-mswin32-60
        unless String === platform then
          alert_warning "Skipping invalid platform in gem: #{spec.full_name}"
          next
        end
        platform = Gem::Platform::RUBY if platform.nil? or platform.empty?
        [spec.name, spec.version, platform]
      end
      specs = compact_specs(specs)
      Marshal.dump(specs, io)
    end
  end
end

def build_modern_indices specs
  prerelease, released = specs.partition { |s|
    s.version.prerelease?
  }
  latest_specs =
    Gem::Specification._latest_specs specs
  build_modern_index(released.sort, @specs_index, 'specs')
  build_modern_index(latest_specs.sort, @latest_specs_index, 'latest specs')
  build_modern_index(prerelease.sort, @prerelease_specs_index,
                     'prerelease specs')
  @files += [@specs_index,
             "#{@specs_index}.gz",
             @latest_specs_index,
             "#{@latest_specs_index}.gz",
             @prerelease_specs_index,
             "#{@prerelease_specs_index}.gz"]
end

def compact_specs(specs)
  names = {}
  versions = {}
  platforms = {}
  specs.map do |(name, version, platform)|
    names[name] = name unless names.include? name
    versions[version] = version unless versions.include? version
    platforms[platform] = platform unless platforms.include? platform
    [names[name], versions[version], platforms[platform]]
  end
end

def compress(filename, extension)
  data = Gem.read_binary filename
  zipped = Gem.deflate data
  open "#{filename}.#{extension}", 'wb' do |io|
    io.write zipped
  end
end

def compress_indices
  say "Compressing indices"
  Gem.time 'Compressed indices' do
    if @build_modern then
      gzip @specs_index
      gzip @latest_specs_index
      gzip @prerelease_specs_index
    end
  end
end

def gem_file_list
  Dir[File.join(@dest_directory, "gems", '*.gem')]
end

def generate_index
  make_temp_directories
  build_indices
  install_indices
rescue SignalException
ensure
  FileUtils.rm_rf @directory
end

def gzip(filename)
  Zlib::GzipWriter.open "#{filename}.gz" do |io|
    io.write Gem.read_binary(filename)
  end
end

def initialize(directory, options = {})
  require 'fileutils'
  require 'tmpdir'
  require 'zlib'
  unless defined?(Builder::XChar) then
    raise "Gem::Indexer requires that the XML Builder library be installed:" +
          "\n\tgem install builder"
  end
  options = { :build_modern => true }.merge options
  @build_modern = options[:build_modern]
  @dest_directory = directory
  @directory = File.join(Dir.tmpdir, "gem_generate_index_#{$$}")
  marshal_name = "Marshal.#{Gem.marshal_version}"
  @master_index = File.join @directory, 'yaml'
  @marshal_index = File.join @directory, marshal_name
  @quick_dir = File.join @directory, 'quick'
  @quick_marshal_dir = File.join @quick_dir, marshal_name
  @quick_marshal_dir_base = File.join "quick", marshal_name # FIX: UGH
  @quick_index = File.join @quick_dir, 'index'
  @latest_index = File.join @quick_dir, 'latest_index'
  @specs_index = File.join @directory, "specs.#{Gem.marshal_version}"
  @latest_specs_index =
    File.join(@directory, "latest_specs.#{Gem.marshal_version}")
  @prerelease_specs_index =
    File.join(@directory, "prerelease_specs.#{Gem.marshal_version}")
  @dest_specs_index =
    File.join(@dest_directory, "specs.#{Gem.marshal_version}")
  @dest_latest_specs_index =
    File.join(@dest_directory, "latest_specs.#{Gem.marshal_version}")
  @dest_prerelease_specs_index =
    File.join(@dest_directory, "prerelease_specs.#{Gem.marshal_version}")
  @files = []
end

def install_indices
  verbose = Gem.configuration.really_verbose
  say "Moving index into production dir #{@dest_directory}" if verbose
  files = @files
  files.delete @quick_marshal_dir if files.include? @quick_dir
  if files.include? @quick_marshal_dir and not files.include? @quick_dir then
    files.delete @quick_marshal_dir
    dst_name = File.join(@dest_directory, @quick_marshal_dir_base)
    FileUtils.mkdir_p File.dirname(dst_name), :verbose => verbose
    FileUtils.rm_rf dst_name, :verbose => verbose
    FileUtils.mv(@quick_marshal_dir, dst_name,
                 :verbose => verbose, :force => true)
  end
  files = files.map do |path|
    path.sub(/^#{Regexp.escape @directory}\/?/, '') # HACK?
  end
  files.each do |file|
    src_name = File.join @directory, file
    dst_name = File.join @dest_directory, file
    FileUtils.rm_rf dst_name, :verbose => verbose
    FileUtils.mv(src_name, @dest_directory,
                 :verbose => verbose, :force => true)
  end
end

def make_temp_directories
  FileUtils.rm_rf @directory
  FileUtils.mkdir_p @directory, :mode => 0700
  FileUtils.mkdir_p @quick_marshal_dir
end

def map_gems_to_specs gems
  gems.map { |gemfile|
    if File.size(gemfile) == 0 then
      alert_warning "Skipping zero-length gem: #{gemfile}"
      next
    end
    begin
      spec = Gem::Package.new(gemfile).spec
      spec.loaded_from = gemfile
      spec.abbreviate
      spec.sanitize
      spec
    rescue SignalException
      alert_error "Received signal, exiting"
      raise
    rescue Exception => e
      msg = ["Unable to process #{gemfile}",
             "#{e.message} (#{e.class})",
             "\t#{e.backtrace.join "\n\t"}"].join("\n")
      alert_error msg
    end
  }.compact
end

def paranoid(path, extension)
  data = Gem.read_binary path
  compressed_data = Gem.read_binary "#{path}.#{extension}"
  unless data == Gem.inflate(compressed_data) then
    raise "Compressed file #{compressed_path} does not match uncompressed file #{path}"
  end
end

def update_index
  make_temp_directories
  specs_mtime = File.stat(@dest_specs_index).mtime
  newest_mtime = Time.at 0
  updated_gems = gem_file_list.select do |gem|
    gem_mtime = File.stat(gem).mtime
    newest_mtime = gem_mtime if gem_mtime > newest_mtime
    gem_mtime >= specs_mtime
  end
  if updated_gems.empty? then
    say 'No new gems'
    terminate_interaction 0
  end
  specs = map_gems_to_specs updated_gems
  prerelease, released = specs.partition { |s| s.version.prerelease? }
  files = build_marshal_gemspecs specs
  Gem.time 'Updated indexes' do
    update_specs_index released, @dest_specs_index, @specs_index
    update_specs_index released, @dest_latest_specs_index, @latest_specs_index
    update_specs_index(prerelease,
                       @dest_prerelease_specs_index,
                       @prerelease_specs_index)
  end
  compress_indices
  verbose = Gem.configuration.really_verbose
  say "Updating production dir #{@dest_directory}" if verbose
  files << @specs_index
  files << "#{@specs_index}.gz"
  files << @latest_specs_index
  files << "#{@latest_specs_index}.gz"
  files << @prerelease_specs_index
  files << "#{@prerelease_specs_index}.gz"
  files = files.map do |path|
    path.sub(/^#{Regexp.escape @directory}\/?/, '') # HACK?
  end
  files.each do |file|
    src_name = File.join @directory, file
    dst_name = File.join @dest_directory, file # REFACTOR: duped above
    FileUtils.mv src_name, dst_name, :verbose => verbose,
                 :force => true
    File.utime newest_mtime, newest_mtime, dst_name
  end
end

def update_specs_index(index, source, dest)
  specs_index = Marshal.load Gem.read_binary(source)
  index.each do |spec|
    platform = spec.original_platform
    platform = Gem::Platform::RUBY if platform.nil? or platform.empty?
    specs_index << [spec.name, spec.version, platform]
  end
  specs_index = compact_specs specs_index.uniq.sort
  open dest, 'wb' do |io|
    Marshal.dump specs_index, io
  end
end