class SemanticLogger::Appender::Syslog

def default_formatter
  if protocol == :syslog
    # Format is text output without the time
    SemanticLogger::Formatters::Default.new(time_format: :notime)
  else
    SemanticLogger::Formatters::Syslog.new(facility: facility, level_map: level_map, max_size: max_size)
  end
end

def flush
  @remote_syslog.flush if @remote_syslog.respond_to?(:flush)
end

def initialize(url: "syslog://localhost",
               facility: ::Syslog::LOG_USER,
               max_size: 1024,
               level_map: SemanticLogger::Formatters::Syslog::LevelMap.new,
               options: ::Syslog::LOG_PID | ::Syslog::LOG_CONS,
               tcp_client: {},
               **args,
               &block)
  @options            = options
  @facility           = facility
  @max_size           = max_size
  @level_map          = level_map
  @url                = url
  uri                 = URI(@url)
  @server             = uri.host || "localhost"
  @protocol           = (uri.scheme || :syslog).to_sym
  @port               = uri.port || 514
  @server             = "localhost" if @protocol == :syslog
  @tcp_client_options = tcp_client
  raise "Unknown protocol #{@protocol}!" unless %i[syslog tcp udp].include?(@protocol)
  # The syslog_protocol gem is required when logging over TCP or UDP.
  if %i[tcp udp].include?(@protocol)
    begin
      require "syslog_protocol"
    rescue LoadError
      raise LoadError,
            "Missing gem: syslog_protocol. This gem is required when logging over TCP or UDP. To fix this error: gem install syslog_protocol"
    end
    # The net_tcp_client gem is required when logging over TCP.
    if protocol == :tcp
      begin
        require "net/tcp_client"
      rescue LoadError
        raise LoadError,
              "Missing gem: net_tcp_client. This gem is required when logging over TCP. To fix this error: gem install net_tcp_client"
      end
    end
  end
  super(**args, &block)
  reopen
end

def log(log)
  case @protocol
  when :syslog
    # Since the Ruby Syslog API supports sprintf format strings, double up all existing '%'
    message = formatter.call(log, self).gsub "%", "%%"
    ::Syslog.log @level_map[log.level], message
  when :tcp
    @remote_syslog.retry_on_connection_failure { @remote_syslog.write("#{formatter.call(log, self)}\r\n") }
  when :udp
    @remote_syslog.send(formatter.call(log, self), 0, @server, @port)
  else
    raise "Unsupported protocol: #{protocol}"
  end
  true
end

def reopen
  case @protocol
  when :syslog
    method = ::Syslog.opened? ? :reopen : :open
    ::Syslog.send(method, application, options, facility)
  when :tcp
    @tcp_client_options[:server] = "#{@server}:#{@port}"
    @remote_syslog               = Net::TCPClient.new(**@tcp_client_options)
    # Use the local logger for @remote_syslog so errors with the remote logger can be recorded locally.
    @remote_syslog.logger = logger
  when :udp
    @remote_syslog = UDPSocket.new
  else
    raise "Unsupported protocol: #{@protocol}"
  end
end