/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you 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 scatours.smsgateway;

import java.io.ByteArrayInputStream;

import javax.jms.BytesMessage;
import javax.jms.Destination;
import javax.jms.JMSException;
import javax.jms.Message;
import javax.jms.MessageConsumer;
import javax.jms.MessageProducer;
import javax.jms.Session;
import javax.jms.TextMessage;
import javax.xml.namespace.QName;
import javax.xml.stream.XMLStreamException;

import org.apache.axiom.om.OMAbstractFactory;
import org.apache.axiom.om.OMElement;
import org.apache.axiom.om.OMFactory;
import org.apache.axiom.om.OMText;
import org.apache.axiom.om.impl.builder.StAXOMBuilder;

public class SMSGatewayImpl implements SMSGateway {

    private final Session session;
    private final MessageConsumer consumer;
    private final MessageProducer producer;

    public SMSGatewayImpl(Session session) throws JMSException {
      this.session = session;
      Destination requestDest = session.createQueue("SMSRequestQueue");
      consumer = session.createConsumer(requestDest);

      Destination responseDest = session.createQueue("SMSResponseQueue");
      producer = session.createProducer(responseDest);
    }

    public void start() throws JMSException, XMLStreamException {
      while (true) {
        Message message = consumer.receive();
        handleRequest(message);
      }
    }

    private void handleRequest(Message inMessage) throws XMLStreamException, JMSException {
      OMElement xml = parseXMLPayload(inMessage);

      String fromNumber = getStringArg(xml, 0);
      String toNumber = getStringArg(xml, 1);
      String text = getStringArg(xml, 2);

      boolean result = sendSMS(fromNumber, toNumber, text);

      String responseXML = createXMLResponse(result);

      TextMessage outMessage = createResponseMessage(inMessage.getJMSMessageID(), responseXML);
      producer.send(outMessage);
    }

    private OMElement parseXMLPayload(Message inMessage) throws JMSException, XMLStreamException {
      final byte[] msgData;
      if (inMessage instanceof TextMessage) {
          msgData = ((TextMessage) inMessage).getText().getBytes();
      } else if (inMessage instanceof BytesMessage) {
          BytesMessage bytesMessage = (BytesMessage) inMessage;
          msgData = new byte[(int) bytesMessage.getBodyLength()];
          bytesMessage.readBytes(msgData);
      } else {
          throw new JMSException("Unsupported JMS message type of " + inMessage.getClass().getName());
      }
      ByteArrayInputStream in = new ByteArrayInputStream(msgData);
      StAXOMBuilder builder = new StAXOMBuilder(in);
      OMElement doc = builder.getDocumentElement();
      return doc;
    }

    private String getStringArg(OMElement doc, int i) {
      QName argQName = new QName("arg" + i);
      OMElement arg = doc.getFirstChildWithName(argQName);
      if (arg == null) {
        return null;
      }
      return arg.getText();
    }

    public boolean sendSMS(String fromNumber, String toNumber, String text) {
      System.out.println("From: " + fromNumber);
      System.out.println("To: " + toNumber);
      System.out.println(text);
      return true;
    }

    private String createXMLResponse(boolean result) {
      OMFactory omFactory = OMAbstractFactory.getOMFactory();
      OMElement response = omFactory.createOMElement("sendSMS", "http://smsgateway.scatours/", "ns2");
      OMElement returnValue = omFactory.createOMElement("return", null);
      OMText returnV = omFactory.createOMText(Boolean.toString(result));
      returnValue.addChild(returnV);
      response.addChild(returnValue);
      return response.toString();
    }

    private TextMessage createResponseMessage(String correlationID, String responseXML) throws JMSException {
      TextMessage outMessage = session.createTextMessage("sendSMS");
      outMessage.setText(responseXML);
      outMessage.setJMSCorrelationID(correlationID);
      return outMessage;
    }
  }