br.com.objectos.tftp.ReadRequestMessage Maven / Gradle / Ivy

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/*
 * Copyright 2016 Objectos, Fábrica de Software LTDA.
 *
 * Licensed under the Apache License, Version 2.0 (the "License"); you may not
 * use this file except in compliance with the License. You may obtain a copy of
 * the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
 * License for the specific language governing permissions and limitations under
 * the License.
 */
package br.com.objectos.tftp;

import java.nio.ByteBuffer;
import java.util.List;

import br.com.objectos.net.ByteBuffers;
import br.com.objectos.udp.Datagram;
import br.com.objectos.udp.DatagramSpec;
import br.com.objectos.udp.DatagramSpec.DatagramBuilder;
import br.com.objectos.udp.Field;
import br.com.objectos.udp.Message;
import br.com.objectos.udp.Packet;

/**
 * @author [email protected] (Marcio Endo)
 */
public class ReadRequestMessage implements Message {

  static final Field OPCODE = OpCode.RRQ.field();
  static final Field FILENAME = TftpString.field("filename");
  static final Field MODE = Mode.field();
  static final Field OPTIONS = Options.field();

  private static final DatagramSpec SPEC = DatagramSpec.builder()
      .add(OPCODE)
      .add(FILENAME)
      .add(MODE)
      .add(OPTIONS)
      .build();

  private final Datagram datagram;

  private ReadRequestMessage(Datagram datagram) {
    this.datagram = datagram;
  }

  static ReadRequestMessage get(String filename) {
    return ReadRequestMessage.builder()
        .put(FILENAME, TftpString.of(filename))
        .put(MODE, Mode.OCTET)
        .build();
  }

  static ReadRequestMessage read(ByteBuffer buffer) {
    System.out.println(ByteBuffers.toHexString(buffer));
    Datagram datagram = SPEC.read(buffer);
    return new ReadRequestMessage(datagram);
  }

  private static DatagramBuilder builder() {
    return SPEC.datagramBuilder(ReadRequestMessage::new);
  }

  @Override
  public Datagram datagram() {
    return datagram;
  }

  public void execute(Server server, Packet packet) {
    String filename = datagram.get(FILENAME).toString();
    byte[] bytes = server.open(filename);
    TftpFile file = new TftpFile(bytes.length);
    OAckMessage oackMessage = options().toSupported(file).toOAckMessage();
    ReadOptions options = oackMessage.toReadOptions();
    List messageList = options.toDataMessage(bytes);
    ReadSession session = ReadSession.of(packet, oackMessage, messageList);
    session.start(server);
  }

  public String filename() {
    return datagram.get(FILENAME).toString();
  }

  public Mode mode() {
    return datagram.get(MODE);
  }

  public TftpString option(OptionType type) {
    return options().get(type);
  }

  @Override
  public String toString() {
    return datagram.toString();
  }

  private Options options() {
    return datagram.get(OPTIONS);
  }

}