import java.util.LinkedList;
import java.util.List;

import org.orbeon.oxf.pipeline.api.PipelineContext;
import org.orbeon.oxf.processor.SimpleProcessor;
import org.orbeon.oxf.processor.ProcessorInputOutputInfo;

import org.xml.sax.ContentHandler;
import org.xml.sax.SAXException;
import org.xml.sax.helpers.AttributesImpl;

import org.dom4j.Document;
import org.dom4j.Node;

public class ComputeOutput extends SimpleProcessor {

    class set {
        public String name;
        
        public int number1;
        public int number2;
		
        public double result;
    }

    public ComputeOutput() {
        addInputInfo(new ProcessorInputOutputInfo("number"));
        addOutputInfo(new ProcessorInputOutputInfo(OUTPUT_DATA));
    }

    public void generateResult(PipelineContext context, ContentHandler contentHandler) throws SAXException {
        Document dataDoc = readInputAsDOM4J(context, " input");
        List<Node> nodes = dataDoc.selectNodes("//data/set");

        List<set> data = new LinkedList<set>();

        for (Node n: nodes) {
            set currentSet = new set();
            currentSet.name = new String(n.valueOf("@name"));

            Node n1 = dataDoc.selectSingleNode("//data/set[@name=" + currentSet.name + "]/number1");
            Node n2 = dataDoc.selectSingleNode("//data/set[@name=" + currentSet.name + "]/number2");

            currentSet.number1 = new Integer(n1.getText()).intValue();
            currentSet.number2 = new Integer(n2.getText()).intValue();

            if (currentSet.name.equals("Add")) {
                currentSet.result = currentSet.number1 + currentSet.number2;
            }

            if (currentSet.name.equals("Substract")) {
                currentSet.result = currentSet.number1 - currentSet.number2;
            }

            if (currentSet.name.equals("Multiply")) {
                currentSet.result = currentSet.number1 * currentSet.number2;
            }

            if (currentSet.name.equals("Divide")) {
                currentSet.result = currentSet.number1 / currentSet.number2;
            }

            data.add(currentSet);
        }

        contentHandler.startDocument();
        contentHandler.startElement("", "number", "number", new AttributesImpl());

        for (set s: data) {
            String content = String.valueOf(s.result);
            contentHandler.characters(content.toCharArray(), 0, content.length());
        }

        contentHandler.endElement("", "number", "number");
        contentHandler.endDocument();
    }
}