class RubyLsp::Listeners::DocumentLink

def extract_document_link(node)
  comment = @lines_to_comments[node.location.start_line - 1]
  return unless comment
  match = comment.location.slice.match(%r{source://.*#\d+$})
  return unless match
  uri =  begin
    URI(
      match[0], #: as !nil
    )
  rescue URI::Error
    nil
  end #: as URI::Source?
  return unless uri
  gem_version = resolve_version(uri)
  return if gem_version.nil?
  path = uri.path
  return unless path
  gem_name = uri.gem_name
  return unless gem_name
  file_path = self.class.gem_paths.dig(gem_name, gem_version, CGI.unescape(path))
  return if file_path.nil?
  @response_builder << Interface::DocumentLink.new(
    range: range_from_location(comment.location),
    target: "file://#{file_path}##{uri.line_number}",
    tooltip: "Jump to #{file_path}##{uri.line_number}",
  )
end

def gem_paths
  @gem_paths ||= begin
    lookup = {}
    Gem::Specification.stubs.each do |stub|
      spec = stub.to_spec
      lookup[spec.name] = {}
      lookup[spec.name][spec.version.to_s] = {}
      Dir.glob("**/*.rb", base: "#{spec.full_gem_path.delete_prefix("//?/")}/").each do |path|
        lookup[spec.name][spec.version.to_s][path] = "#{spec.full_gem_path}/#{path}"
      end
    end
    Gem::Specification.default_stubs.each do |stub|
      spec = stub.to_spec
      lookup[spec.name] = {}
      lookup[spec.name][spec.version.to_s] = {}
      prefix_matchers = Regexp.union(spec.require_paths.map do |rp|
                                       Regexp.new("^#{rp}/")
                                     end)
      prefix_matcher = Regexp.union(prefix_matchers, //)
      spec.files.each do |file|
        path = file.sub(prefix_matcher, "")
        lookup[spec.name][spec.version.to_s][path] = "#{RbConfig::CONFIG["rubylibdir"]}/#{path}"
      end
    end
    lookup
  end #: Hash[String, Hash[String, Hash[String, String]]]?
end

def initialize(response_builder, uri, comments, dispatcher)
  # Match the version based on the version in the RBI file name. Notice that the `@` symbol is sanitized to `%40`
  # in the URI
  @response_builder = response_builder
  path = uri.to_standardized_path
  version_match = path ? /(?<=%40)[\d.]+(?=\.rbi$)/.match(path) : nil
  @gem_version = version_match && version_match[0] #: String?
  @lines_to_comments = comments.to_h do |comment|
    [comment.location.end_line, comment]
  end #: Hash[Integer, Prism::Comment]
  dispatcher.register(
    self,
    :on_def_node_enter,
    :on_class_node_enter,
    :on_module_node_enter,
    :on_constant_write_node_enter,
    :on_constant_path_write_node_enter,
  )
end

def on_class_node_enter(node)
  extract_document_link(node)
end

def on_constant_path_write_node_enter(node)
  extract_document_link(node)
end

def on_constant_write_node_enter(node)
  extract_document_link(node)
end

def on_def_node_enter(node)
  extract_document_link(node)
end

def on_module_node_enter(node)
  extract_document_link(node)
end

def resolve_version(uri)
  version = uri.gem_version
  return version unless version.nil? || version.empty?
  return @gem_version unless @gem_version.nil? || @gem_version.empty?
  gem_name = uri.gem_name
  return unless gem_name
  GEM_TO_VERSION_MAP[gem_name]
end