#--
#
# Author:: Francis Cianfrocca (gmail: blackhedd)
# Homepage::  http://rubyeventmachine.com
# Date:: 8 Apr 2006
#
# See EventMachine and EventMachine::Connection for documentation and
# usage examples.
#
#----------------------------------------------------------------------------
#
# Copyright (C) 2006-07 by Francis Cianfrocca. All Rights Reserved.
# Gmail: blackhedd
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of either: 1) the GNU General Public License
# as published by the Free Software Foundation; either version 2 of the
# License, or (at your option) any later version; or 2) Ruby's License.
#
# See the file COPYING for complete licensing information.
#
#---------------------------------------------------------------------------
#
#

# This module provides "glue" for the Java version of the EventMachine reactor core.
# For C++ EventMachines, the analogous functionality is found in ext/rubymain.cpp,
# which is a garden-variety Ruby-extension glue module.

require 'java'
require 'rubyeventmachine'
require 'socket'
require 'openssl'

java_import java.io.FileDescriptor
java_import java.nio.channels.SocketChannel
java_import java.lang.reflect.Field

module JavaFields
  def set_field(key, value)
    field = getClass.getDeclaredField(key)
    field.setAccessible(true)
    if field.getType.toString == 'int'
      field.setInt(self, value)
    else
      field.set(self, value)
    end
  end

  def get_field(key)
    field = getClass.getDeclaredField(key)
    field.setAccessible(true)
    field.get(self)
  end
end

FileDescriptor.send :include, JavaFields
SocketChannel.send :include, JavaFields

module EventMachine
  # TODO: These event numbers are defined in way too many places.
  # DRY them up.
  # @private
  TimerFired = 100
  # @private
  ConnectionData = 101
  # @private
  ConnectionUnbound = 102
  # @private
  ConnectionAccepted = 103
  # @private
  ConnectionCompleted = 104
  # @private
  LoopbreakSignalled = 105
  # @private
  ConnectionNotifyReadable = 106
  # @private
  ConnectionNotifyWritable = 107
  # @private
  SslHandshakeCompleted = 108
  # @private
  SslVerify = 109

  # Exceptions that are defined in rubymain.cpp
  class ConnectionError < RuntimeError; end
  class ConnectionNotBound < RuntimeError; end
  class UnknownTimerFired < RuntimeError; end
  class Unsupported < RuntimeError; end

  def self.initialize_event_machine
    @em = com.rubyeventmachine.EmReactor.new do |sig, event, buf, data|
      s = String.from_java_bytes(buf.array[buf.position...buf.limit]) if buf
      EventMachine::event_callback sig, event.int_value, s || data
      nil
    end
  end
  def self.release_machine
    @em = nil
  end
  def self.add_oneshot_timer interval
    @em.installOneshotTimer interval
  end
  def self.run_machine
    @em.run
  end
  def self.stop
    @em.stop
  end
  def self.start_tcp_server server, port
    @em.startTcpServer server, port
  end
  def self.stop_tcp_server sig
    @em.stopTcpServer sig
  end
  def self.start_unix_server filename
    # TEMPORARILY unsupported until someone figures out how to do it.
    raise "unsupported on this platform"
  end
  def self.send_data sig, data, length
    @em.sendData sig, data.to_java_bytes
  end
  def self.send_datagram sig, data, length, address, port
    @em.sendDatagram sig, data.to_java_bytes, length, address, port
  end
  def self.connect_server server, port
    bind_connect_server nil, nil, server, port
  end
  def self.bind_connect_server bind_addr, bind_port, server, port
    @em.connectTcpServer bind_addr, bind_port.to_i, server, port
  end
  def self.close_connection sig, after_writing
    @em.closeConnection sig, after_writing
  end
  def self.set_comm_inactivity_timeout sig, interval
    @em.setCommInactivityTimeout sig, interval
  end
  def self.get_comm_inactivity_timeout sig
  end
  def self.set_pending_connect_timeout sig, val
  end
  def self.set_heartbeat_interval val
  end
  def self.start_tls sig
    @em.startTls sig
  end
  def self.ssl?
    true
  end
  def self.ssl_verify_peer conn, der_data
    data = OpenSSL::X509::Certificate.new(der_data).to_pem
    @em.acceptSslPeer conn.signature if conn.ssl_verify_peer data
  end
  def self.get_peer_cert sig
    der_data = @em.getPeerCert sig
    OpenSSL::X509::Certificate.new(String.from_java_bytes(der_data)).to_pem
  end
  def self.signal_loopbreak
    @em.signalLoopbreak
  end
  def self.set_timer_quantum q
    @em.setTimerQuantum q
  end
  def self.epoll
    # Epoll is a no-op for Java.
    # The latest Java versions run epoll when possible in NIO.
  end
  def self.epoll= val
  end
  def self.kqueue
  end
  def self.kqueue= val
  end
  def self.epoll?
    false
  end
  def self.kqueue?
    false
  end
  def self.set_rlimit_nofile n_descriptors
    # Currently a no-op for Java.
  end
  def self.open_udp_socket server, port
    @em.openUdpSocket server, port
  end
  def self.invoke_popen cmd
    # TEMPORARILY unsupported until someone figures out how to do it.
    raise "unsupported on this platform"
  end
  def self.read_keyboard
    # TEMPORARILY unsupported until someone figures out how to do it.
    raise "temporarily unsupported on this platform"
  end
  def self.set_max_timer_count num
    # harmless no-op in Java. There's no built-in timer limit.
    @max_timer_count = num
  end
  def self.get_max_timer_count
    # harmless no-op in Java. There's no built-in timer limit.
    @max_timer_count || 100_000
  end
  def self.library_type
    :java
  end
  def self.get_peername sig
    if peer = @em.getPeerName(sig)
      Socket.pack_sockaddr_in(*peer)
    end
  end
  def self.get_sockname sig
    if sockName = @em.getSockName(sig)
      Socket.pack_sockaddr_in(*sockName)
    end
  end
  # @private
  def self.attach_fd fileno, watch_mode
    # 3Aug09: We could pass in the actual SocketChannel, but then it would be modified (set as non-blocking), and
    # we would need some logic to make sure detach_fd below didn't clobber it. For now, we just always make a new
    # SocketChannel for the underlying file descriptor
    # if fileno.java_kind_of? SocketChannel
    #   ch = fileno
    #   ch.configureBlocking(false)
    #   fileno = nil
    # elsif fileno.java_kind_of? java.nio.channels.Channel

    if fileno.java_kind_of? java.nio.channels.Channel
      field = fileno.getClass.getDeclaredField('fdVal')
      field.setAccessible(true)
      fileno = field.get(fileno)
    else
      raise ArgumentError, 'attach_fd requires Java Channel or POSIX fileno' unless fileno.is_a? Fixnum
    end

    if fileno == 0
      raise "can't open STDIN as selectable in Java =("
    elsif fileno.is_a? Fixnum
      # 8Aug09: The following code is specific to the sun jvm's SocketChannelImpl. Is there a cross-platform
      # way of implementing this? If so, also remember to update EventableSocketChannel#close and #cleanup
      fd = FileDescriptor.new
      fd.set_field 'fd', fileno

      ch = SocketChannel.open
      ch.configureBlocking(false)
      ch.kill
      ch.set_field 'fd', fd
      ch.set_field 'fdVal', fileno
      ch.set_field 'state', ch.get_field('ST_CONNECTED')
    end

    @em.attachChannel(ch,watch_mode)
  end
  def self.detach_fd sig
    if ch = @em.detachChannel(sig)
      ch.get_field 'fdVal'
    end
  end

  def self.set_notify_readable sig, mode
    @em.setNotifyReadable(sig, mode)
  end
  def self.set_notify_writable sig, mode
    @em.setNotifyWritable(sig, mode)
  end

  def self.is_notify_readable sig
    @em.isNotifyReadable(sig)
  end
  def self.is_notify_writable sig
    @em.isNotifyWritable(sig)
  end
  def self.get_connection_count
    @em.getConnectionCount
  end

  def self.pause_connection(sig)
    @em.pauseConnection(sig)
  end
  def self.resume_connection(sig)
    @em.resumeConnection(sig)
  end
  def self.connection_paused?(sig)
    @em.isConnectionPaused(sig)
  end
  def self._get_outbound_data_size(sig)
    @em.getOutboundDataSize(sig)
  end

  def self.set_tls_parms(sig, privkeyfile, certchainfile, verify_peer, use_tls, cipher_list)
    keystore = KeyStoreBuilder.create privkeyfile, certchainfile unless (privkeyfile.empty? or certchainfile.empty?)
    @em.setTlsParms(sig, keystore, (!!verify_peer))
  end
  def self.send_file_data(sig, filename)
  end

  class Connection
    def associate_callback_target sig
      # No-op for the time being
    end
    def get_outbound_data_size
      EM._get_outbound_data_size @signature
    end
  end
end

module KeyStoreBuilder
  require 'bouncy-castle-java'
  java_import java.io.FileReader
  java_import java.io.FileInputStream
  java_import java.security.cert.Certificate
  java_import java.security.cert.CertificateFactory
  java_import java.security.KeyStore
  java_import java.security.Security
  java_import org.bouncycastle.openssl.PEMReader
  java_import org.bouncycastle.jce.provider.BouncyCastleProvider
  @name = 'em_java_tls_key' # TODO - find a correct value, or whether it even really matters.
  @initialized = false

  def self.init
    unless @initialized
      Security.add_provider BouncyCastleProvider.new
      @initialized = true
    end
  end

  def self.create(privkeyfile, certchainfile)
    self.init

    key_reader = FileReader.new privkeyfile
    key_pair = PEMReader.new(key_reader).read_object

    cert_stream = FileInputStream.new certchainfile
    certs = CertificateFactory.get_instance('X.509', 'BC').generate_certificates cert_stream

    store = KeyStore.get_instance 'PKCS12', 'BC'
    store.load nil, nil
    store.set_key_entry @name, key_pair.get_private, nil, certs.to_array(Certificate[certs.size].new)

    store
  end
end