#
# Copyright (c) 2006-2011 Hal Brodigan (postmodern.mod3 at gmail.com)
#
# This file is part of Ronin Support.
#
# Ronin Support is free software: you can redistribute it and/or modify
# it under the terms of the GNU Lesser General Public License as publishe by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# Ronin Support is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU Lesser General Public License for more details.
#
# You should have received a copy of the GNU Lesser General Public License
# along with Ronin Support.  If not, see <http://www.gnu.org/licenses/>.
#

require 'socket'

module Net
  #
  # Creates a new UDPSocket object connected to a given host and port.
  #
  # @param [String] host
  #   The host to connect to.
  #
  # @param [Integer] port
  #   The port to connect to.
  #
  # @param [String] local_host (nil)
  #   The local host to bind to.
  #
  # @param [Integer] local_port (nil)
  #   The local port to bind to.
  #
  # @yield [socket]
  #   If a block is given, it will be passed the newly created socket.
  #
  # @yieldparam [UDPsocket] socket
  #   The newly created UDPSocket object.
  #
  # @return [UDPSocket]
  #   The newly created UDPSocket object.
  #
  # @example
  #   Net.udp_connect('www.hackety.org',80)
  #   # => UDPSocket
  #
  # @example
  #   Net.udp_connect('www.wired.com',80) do |sock|
  #     puts sock.readlines
  #   end
  #
  def Net.udp_connect(host,port,local_host=nil,local_port=nil)
    host = host.to_s
    local_host = if local_host
                   local_host.to_s
                 end

    sock = UDPSocket.new(host,port,local_host,local_port)

    yield sock if block_given?
    return sock
  end

  #
  # Creates a new UDPSocket object, connected to a given host and port.
  # The given data will then be written to the newly created UDPSocket.
  #
  # @param [String] data
  #   The data to send through the connection.
  #
  # @param [String] host
  #   The host to connect to.
  #
  # @param [Integer] port
  #   The port to connect to.
  #
  # @param [String] local_host (nil)
  #   The local host to bind to.
  #
  # @param [Integer] local_port (nil)
  #   The local port to bind to.
  #
  # @yield [socket]
  #   If a block is given, it will be passed the newly created socket.
  #
  # @yieldparam [UDPsocket] socket
  #   The newly created UDPSocket object.
  #
  # @return [UDPSocket]
  #   The newly created UDPSocket object.
  #
  def Net.udp_connect_and_send(data,host,port,local_host=nil,local_port=nil)
    sock = Net.udp_connect(host,port,local_host,local_port)
    sock.write(data)

    yield sock if block_given?
    return sock
  end

  #
  # Creates a new temporary UDPSocket object, connected to the given host
  # and port.
  #
  # @param [String] host
  #   The host to connect to.
  #
  # @param [Integer] port
  #   The port to connect to.
  #
  # @param [String] local_host (nil)
  #   The local host to bind to.
  #
  # @param [Integer] local_port (nil)
  #   The local port to bind to.
  #
  # @yield [socket]
  #   If a block is given, it will be passed the newly created socket.
  #   After the block has returned, the socket will then be closed.
  #
  # @yieldparam [UDPsocket] socket
  #   The newly created UDPSocket object.
  #
  # @return [nil]
  #
  def Net.udp_session(host,port,local_host=nil,local_port=nil)
    sock = Net.udp_connect(host,port,local_host,local_port)

    yield sock if block_given?

    sock.close
    return nil
  end

  #
  # Reads the banner from the service running on the given host and port.
  #
  # @param [String] host
  #   The host to connect to.
  #
  # @param [Integer] port
  #   The port to connect to.
  #
  # @param [String] local_host (nil)
  #   The local host to bind to.
  #
  # @param [Integer] local_port (nil)
  #   The local port to bind to.
  #
  # @yield [banner]
  #   If a block is given, it will be passed the grabbed banner.
  #
  # @yieldparam [String] banner
  #   The grabbed banner.
  #
  # @return [String]
  #   The grabbed banner.
  #
  def Net.udp_banner(host,port,local_host=nil,local_port=nil)
    banner = nil

    Net.udp_session(host,port,local_host,local_port) do |sock|
      banner = sock.readline
    end

    yield banner if block_given?
    return banner
  end

  #
  # Creates a new UDPServer listening on a given host and port.
  #
  # @param [Integer] port
  #   The local port to listen on.
  #
  # @param [String] host ('0.0.0.0')
  #   The host to bind to.
  #
  # @return [UDPServer]
  #   The new UDP server.
  #
  # @example
  #   Net.udp_server(1337)
  #
  def Net.udp_server(port,host='0.0.0.0')
    host = host.to_s
    server = UDPServer.new(host,port)

    yield server if block_given?
    return server
  end

  #
  # Creates a new temporary UDPServer listening on a given host and port.
  #
  # @param [Integer] port
  #   The local port to bind to.
  #
  # @param [String] host ('0.0.0.0')
  #   The host to bind to.
  #
  # @yield [server]
  #   The block which will be called after the _server_ has been created.
  #   After the block has finished, the _server_ will be closed.
  #
  # @yieldparam [UDPServer] server
  #   The newly created UDP server.
  #
  # @return [nil]
  #
  # @example
  #   Net.udp_server_session(1337) do |server|
  #     data, sender = server.recvfrom(1024)
  #   end
  #
  def Net.udp_server_session(port,host='0.0.0.0',&block)
    server = Net.udp_server(port,host,&block)
    server.close()
    return nil
  end
end