class Net::IRC::Message
  include Net::IRC

  class InvalidMessage < Net::IRC::IRCException; end

  attr_reader :prefix, :command, :params

  # Parse string and return new Message.
  # If the string is invalid message, this method raises Net::IRC::Message::InvalidMessage.
  def self.parse(str)
    _, prefix, command, *rest = *PATTERN::MESSAGE_PATTERN.match(str)
    raise InvalidMessage, "Invalid message: #{str.dump}" unless _

    case
    when rest[0] && !rest[0].empty?
      middle, trailer, = *rest
    when rest[2] && !rest[2].empty?
      middle, trailer, = *rest[2, 2]
    when rest[1]
      params  = []
      trailer = rest[1]
    when rest[3]
      params  = []
      trailer = rest[3]
    else
      params  = []
    end

    params ||= middle.split(/ /)[1..-1]
    params << trailer if trailer

    new(prefix, command, params)
  end

  def initialize(prefix, command, params)
    @prefix  = Prefix.new(prefix.to_s)
    @command = command
    @params  = params
  end

  # Same as @params[n].
  def [](n)
    @params[n]
  end

  # Iterate params.
  def each(&block)
    @params.each(&block)
  end

  # Stringfy message to raw IRC message.
  def to_s
    str = ""

    str << ":#{@prefix} " unless @prefix.empty?
    str << @command

    if @params
      f = false
      @params.each do |param|
        f = !f && (param.empty? || param[0] == ?: || param.include?(" "))
        str << " "
        str << ":" if f
        str << param
      end
    end

    str << "\x0D\x0A"

    str
  end
  alias to_str to_s

  # Same as params.
  def to_a
    @params.dup
  end

  # If the message is CTCP, return true.
  def ctcp?
    #message = @params[1]
    #message[0] == ?\01 && message[-1] == ?\01
    /\x01(?>[^\x00\x01\r\n]*)\x01/ === @params[1]
  end

  def ctcps
    messages = []
    @params[1].gsub!(/\x01(?>[^\x00\x01\r\n]*)\x01/) do
      messages << ctcp_decode($&)
      ""
    end
    messages
  end

  def inspect
    "#<%s:0x%x prefix:%s command:%s params:%s>" % [
      self.class,
      self.object_id,
      @prefix,
      @command,
      @params.inspect
    ]
  end

  autoload :ModeParser, "net/irc/message/modeparser"
  autoload :ServerConfig, "net/irc/message/serverconfig"
  #autoload :ISupportModeParser, "net/irc/message/isupportmodeparser"
end # Message