chat

chat.cr

require "socket"
module Chat
  def self.init(url : String, port : Int32 = 80)
    tcp = TCPSocket.new
    tcp.reuse_address = true
    tcp.reuse_port = true
    tcp.connect url, port
    tcp << "GET /connect HTTP/1.1\r\nHost: #{url}\r\nUser-Agent: curl/1.0\r\nConnection: Keep-Alive\r\nAccept: */*\r\nContent-Length: 0\r\n\r\n"

    me = tcp.local_address.address
    me_port = tcp.local_address.port

    body = nil
    addresses = [] of String
    while res = tcp.gets
      puts res
      if addresses.size >= 1
        tcp.close
        puts tcp.closed?
        break
      end
      if md = res.match /Peer-Address: (.*)$/
        addresses << md[1]
      end
      # if md = res.match /My-Address: (.*)$/
      #   addresses << md[1]
      # end
    end

    if data = addresses[0]?
      peer, peer_port = data.split /:(\d*$)/, remove_empty: true
      #if new_data = addresses[1]?
        #me, me_port = data.split(/:(\d*$)/, remove_empty: true)
      Connection.new(me, me_port.to_i32, peer, peer_port.to_i32)

    else
      raise "whoops"
    end
  end
  class Connection
    def initialize(@my_address : String, @my_port : Int32, @peer_address : String, @peer_port : Int32)
      spawn do
        retry(20, backoff: 0.5) do
          connect
        end
      end

      retry(20, backoff: 0.5) do
        listen
      end
    end

    def listen
        server = TCPSocket.new#(@my_address, @my_port)
        server.reuse_address = true
        server.reuse_port = true
        server.flush_on_newline = true
        STDOUT.puts "listening on #{@my_address}:#{@my_port}"
        server.bind @my_address, @my_port
        server.listen
        puts "listening"
        loop do
         while conn = server.accept
            conn.puts "Hello from #{@my_address}"
            spawn do
              STDOUT.puts conn.gets
            end
          end
        end
    end

    def connect
      socket = TCPSocket.new
      socket.reuse_address = true
      socket.reuse_port = true

      puts "Connection to #{@peer_address}:#{@peer_port}"

      socket.connect @peer_address, @peer_port, connect_timeout: 4
      puts "connection established"
      while line = STDIN.gets
        puts "from me: #{line}"
        break if line == "exit"
        socket.puts line
      end
    end

    def retry(limit, *, backoff=nil)
      attempts = 1
      loop do
        begin
          break if yield
          rescue error
            raise error if attempts == limit
            sleep backoff*attempts if backoff
          attempts += 1
        end
      end
    end
  end
end

if url = ARGV[0]?
  puts "Connecting to rendevous @ #{url}"
  Chat.init(url)
else
  puts "need a url"
end