#!/usr/bin/env ruby

require "async/io"
require "async/io/stream"

class Network
  def initialize(**opts)
    @endpoint = if opts[:tls]
      ctx = nil

      if opts[:cert]
        ctx = OpenSSL::SSL::SSLContext.new

        ctx.client_cert_cb = Proc.new do
          pem = File.open opts[:cert] do |file|
            file.read
          end

          [
            OpenSSL::X509::Certificate.new(pem),
            OpenSSL::PKey::RSA.new(pem)
          ]
        end

        ctx.setup
        ctx.freeze
      end

      Async::IO::SSLEndpoint.ssl opts[:host], opts[:port], ssl_context: ctx
    else
      Async::IO::Endpoint.tcp opts[:host], opts[:port]
    end

    @callbacks = { }
    @nick = opts[:nick]
    @ident = opts[:ident]
    @realname = opts[:realname]

    yield self if block_given?
  end

  def on(event, &block)
    @callbacks[event.to_sym] = block
  end

  def build(*pieces)
    pieces[0..-2].join(" ") + " :" + pieces.last
  end

  def destroy(line)
    msg = {
      src: { }, cmd: nil,
      params: [ ], words: [ ]
    }

    line = line.chomp

    if line[0] == ?: then
      src, line = line.split " ", 2
      from, host = src[1..].split ?@

      if not host then
        msg[:src][:host] = from
      else
        nick, ident = from.split ?!
        msg[:src][:nick] = nick
        msg[:src][:ident] = ident
        msg[:src][:host] = host
      end
    end

    msg[:cmd], line = line.split " ", 2

    until line.empty? do
      if line[0] == ?: then
        msg[:params] += [line[1..]]
        msg[:words] = line[1..].split " "
        line = ""
      else
        param, line = line.split " ", 2
        line = "" if line.nil?
        msg[:params] += [param]
      end
    end

    msg
  end

  def type(*pieces)
    @stream.puts build(*pieces) + "\r"
  end

  def run
    Async do |task|
      @endpoint.connect do |peer|
        @stream = Async::IO::Stream.new peer

        type "NICK", @nick
        type "USER", @ident, ?*, ?*, @realname

        while line = @stream.gets
          if line
            msg = destroy line

            res = if @callbacks.key? msg[:cmd].downcase.to_sym
              @callbacks[msg[:cmd].downcase.to_sym].call msg
            end

            if respond_to? msg[:cmd].downcase and res
              send(msg[:cmd], msg)
            elsif respond_to? "code_" + msg[:cmd] and res
              send("code_" + msg[:cmd], msg)
            elsif not res
              puts "unhandled line: " + msg.inspect
            end
          end
        end
      end
    end
  end
end

settings = {
  host: "chat.freenode.net",
  port: 6697,
  nick: "niamh-dev",
  ident: "niamh",
  realname: "./niamh",
  tls: true,
  cert: "tmp/sparkle.pem"
}

bot = Network.new(**settings) do |net|
  net.on :notice do |msg|
    if msg[:src].key? :nick
      puts ?- + msg[:src][:nick] + ?/ + msg[:params].first + "- " + msg[:params].last
    else
      puts ?- + msg[:src][:host] + ?/ + msg[:params].first + "- " + msg[:params].last
    end

    true
  end

  net.on :privmsg do |msg|
    if msg[:src].key? :nick
      puts ?< + msg[:src][:nick] + ?/ + msg[:params].first + "> " + msg[:params].last
    else
      puts ?< + msg[:src][:host] + ?/ + msg[:params].first + "> " + msg[:params].last
    end

    true
  end
end

Async do
  bot.run
end