class Eye::Checker::Socket < Eye::Checker::Defer

  # check :socket, :every => 5.seconds, :times => 1,
  #  :addr => "unix:/var/run/daemon.sock", :timeout => 3.seconds,
  #
  # Available parameters:
  # :addr          the socket addr to open. The format is tcp://<host>:<port> or unix:<path>
  # :timeout       generic timeout for reading data from socket
  # :open_timeout  override generic timeout for the connection
  # :read_timeout  override generic timeout for data read/write
  # :send_data     after connection send this data
  # :expect_data   after sending :send_data expect this response. Can be a string, Regexp or a Proc
  # :protocol      way of pack,unpack messages (default = socket default), example: :protocol => :em_object

  param :addr,          String, true
  param :timeout,       [Integer, Float]
  param :open_timeout,  [Integer, Float]
  param :read_timeout,  [Integer, Float]
  param :send_data
  param :expect_data,   [String, Regexp, Proc]
  param :protocol,      [Symbol], nil, nil, [:default, :em_object, :raw]

  def initialize(*args)
    super
    @open_timeout = (open_timeout || 1).to_f
    @read_timeout = (read_timeout || timeout || 5).to_f

    if addr =~ %r[\Atcp://(.*?):(.*?)\z]
      @socket_family = :tcp
      @socket_addr = Regexp.last_match(1)
      @socket_port = Regexp.last_match(2).to_i
    elsif addr =~ %r[\Aunix:(.*)\z]
      @socket_family = :unix
      @socket_path = Regexp.last_match(1)
    end
  end

  def get_value
    sock = begin
      Timeout.timeout(@open_timeout) { open_socket }
    rescue Timeout::Error
      return { exception: "OpenTimeout<#{@open_timeout}>" }
    end

    return { result: :listen } unless send_data

    begin
      Timeout.timeout(@read_timeout) do
        _write_data(sock, send_data)
        result = _read_data(sock)

        { result: result }
      end
    rescue Timeout::Error
      return { result: @buffer } if protocol == :raw
      { exception: "ReadTimeout<#{@read_timeout}>" }
    end

  rescue Exception => e
    { exception: "Error<#{e.message}>" }

  ensure
    sock.close if sock
  end

  def good?(value)
    return false unless value[:result]

    return true unless expect_data

    if expect_data.is_a?(Proc)
      match = begin
        !!expect_data[value[:result]]
      rescue Object => ex
        mes = "proc match failed with '#{ex.message}'"
        error(mes)
        value[:notice] = mes
        return false
      end

      unless match
        warn "proc #{expect_data} not matched (#{value[:result].to_s[0..30]}) answer"
        value[:notice] = 'missing proc validation'
      end

      return match
    end

    return true if expect_data.is_a?(Regexp) && expect_data.match(value[:result])
    return true if value[:result].to_s == expect_data.to_s

    warn "#{expect_data} not matched (#{value[:result].to_s[0..30]}) answer"
    value[:notice] = "missing '#{expect_data}'"

    false
  end

  def human_value(value)
    if !value.is_a?(Hash)
      '-'
    elsif value[:exception]
      value[:exception]
    elsif value[:result] == :listen
      'listen'
    else
      res = "#{value[:result].to_s.size}b"
      res += "<#{value[:notice]}>" if value[:notice]
      res
    end
  end

private

  def open_socket
    if @socket_family == :tcp
      TCPSocket.open(@socket_addr, @socket_port)
    elsif @socket_family == :unix
      UNIXSocket.open(@socket_path)
    else
      raise "Unknown socket addr #{addr}"
    end
  end

  def _write_data(socket, data)
    case protocol
      when :em_object
        data = Marshal.dump(data)
        socket.write([data.bytesize, data].pack('Na*'))
      else
        socket.write(data.to_s)
    end
  end

  def _read_data(socket)
    case protocol
      when :em_object
        content = ''
        msg_size = socket.recv(4).unpack('N')[0] rescue 0
        content << socket.recv(msg_size - content.length) while content.length < msg_size
        if content.present?
          Marshal.load(content) rescue 'corrupted_marshal'
        end
      when :raw
        @buffer = ''
        loop { @buffer << socket.recv(1) }
      else
        socket.readline.chop
    end
  end

end