class Gem::Source

def <=>(other)
  case other
  when Gem::Source::Installed,
       Gem::Source::Local,
       Gem::Source::Lock,
       Gem::Source::SpecificFile,
       Gem::Source::Git,
       Gem::Source::Vendor then
    -1
  when Gem::Source then
    if !@uri
      return 0 unless other.uri
      return 1
    end
    return -1 if !other.uri
    # Returning 1 here ensures that when sorting a list of sources, the
    # original ordering of sources supplied by the user is preserved.
    return 1 unless @uri.to_s == other.uri.to_s
    0
  else
    nil
  end
end

def ==(other) # :nodoc:
  self.class === other and @uri == other.uri
end

def cache_dir(uri)
  # Correct for windows paths
  escaped_path = uri.path.sub(/^\/([a-z]):\//i, '/\\1-/')
  escaped_path.tap(&Gem::UNTAINT)
  File.join Gem.spec_cache_dir, "#{uri.host}%#{uri.port}", File.dirname(escaped_path)
end

def dependency_resolver_set # :nodoc:
  return Gem::Resolver::IndexSet.new self if 'file' == uri.scheme
  fetch_uri = if uri.host == "rubygems.org"
                index_uri = uri.dup
                index_uri.host = "index.rubygems.org"
                index_uri
              else
                uri
              end
  bundler_api_uri = enforce_trailing_slash(fetch_uri)
  begin
    fetcher = Gem::RemoteFetcher.fetcher
    response = fetcher.fetch_path bundler_api_uri, nil, true
  rescue Gem::RemoteFetcher::FetchError
    Gem::Resolver::IndexSet.new self
  else
    Gem::Resolver::APISet.new response.uri + "./info/"
  end
end

def download(spec, dir=Dir.pwd)
  fetcher = Gem::RemoteFetcher.fetcher
  fetcher.download spec, uri.to_s, dir
end

def enforce_trailing_slash(uri)
  uri.merge(uri.path.gsub(/\/+$/, '') + '/')
end

def fetch_spec(name_tuple)
  fetcher = Gem::RemoteFetcher.fetcher
  spec_file_name = name_tuple.spec_name
  source_uri = enforce_trailing_slash(uri) + "#{Gem::MARSHAL_SPEC_DIR}#{spec_file_name}"
  cache_dir = cache_dir source_uri
  local_spec = File.join cache_dir, spec_file_name
  if File.exist? local_spec
    spec = Gem.read_binary local_spec
    spec = Marshal.load(spec) rescue nil
    return spec if spec
  end
  source_uri.path << '.rz'
  spec = fetcher.fetch_path source_uri
  spec = Gem::Util.inflate spec
  if update_cache?
    require "fileutils"
    FileUtils.mkdir_p cache_dir
    File.open local_spec, 'wb' do |io|
      io.write spec
    end
  end
  # TODO: Investigate setting Gem::Specification#loaded_from to a URI
  Marshal.load spec
end

def hash # :nodoc:
  @uri.hash
end

def initialize(uri)
  begin
    unless uri.kind_of? URI
      uri = URI.parse(uri.to_s)
    end
  rescue URI::InvalidURIError
    raise if Gem::Source == self.class
  end
  @uri = uri
end

def load_specs(type)
  file       = FILES[type]
  fetcher    = Gem::RemoteFetcher.fetcher
  file_name  = "#{file}.#{Gem.marshal_version}"
  spec_path  = enforce_trailing_slash(uri) + "#{file_name}.gz"
  cache_dir  = cache_dir spec_path
  local_file = File.join(cache_dir, file_name)
  retried    = false
  if update_cache?
    require "fileutils"
    FileUtils.mkdir_p cache_dir
  end
  spec_dump = fetcher.cache_update_path spec_path, local_file, update_cache?
  begin
    Gem::NameTuple.from_list Marshal.load(spec_dump)
  rescue ArgumentError
    if update_cache? && !retried
      FileUtils.rm local_file
      retried = true
      retry
    else
      raise Gem::Exception.new("Invalid spec cache file in #{local_file}")
    end
  end
end

def pretty_print(q) # :nodoc:
  q.group 2, '[Remote:', ']' do
    q.breakable
    q.text @uri.to_s
    if api = uri
      q.breakable
      q.text 'API URI: '
      q.text api.to_s
    end
  end
end

def typo_squatting?(host, distance_threshold=4)
  return if @uri.host.nil?
  levenshtein_distance(@uri.host, host).between? 1, distance_threshold
end

def update_cache?
  @update_cache ||=
    begin
      File.stat(Gem.user_home).uid == Process.uid
    rescue Errno::ENOENT
      false
    end
end